(Circulation. 2001;103:3019.)
© 2001 American Heart Association, Inc.
ACC/AHA Practice Guidelines |
ACC/AHA Guidelines for Percutaneous Coronary Intervention (Revision of the 1993 PTCA Guidelines)—Executive Summary
A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the 1993 Guidelines for Percutaneous Transluminal Coronary Angioplasty) Endorsed by the Society for Cardiac Angiography and Interventions
Committee Members
Task Force Members
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I. Introduction |
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 Top I. Introduction II. General Considerations and...III. OutcomesIV. Institutional and Operator...V. IndicationsVI. Management of Patients...VII. Special ConsiderationsVIII. Future Directions |
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The American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines was formed to gather information and make recommendations about appropriate use of technology for the diagnosis and treatment of patients with cardiovascular disease. Percutaneous coronary interventions (PCI) are an important group of technologies in this regard. Although initially limited to PTCA, and termed percutaneous transluminal coronary angioplasty (PTCA), PCI now includes other new techniques capable of relieving coronary narrowing. Accordingly, in this document, rotational atherectomy, directional atherectomy, extraction atherectomy, laser angioplasty, implantation of intracoronary stents and other catheter devices for treating coronary atherosclerosis are considered components of PCI. In this context PTCA will be used to refer to those studies using primarily PTCA while PCI will refer to the broader group of percutaneous techniques. These new technologies have impacted the effectiveness and safety profile initially established for PTCA. Moreover, important advances have occurred in the use of adjunctive medical therapies such as glycoprotein (GP) IIb/IIIa receptor blockers. In addition, since publication of the previous Guidelines in 1993, greater experience in the performance of PCI in patients with acute coronary syndromes and in community hospital settings has been gained. In view of these developments, further review and revision of the guidelines is warranted. This document reflects the opinion of the third ACC/AHA committee charged with revising the guidelines for PTCA to include the broader group of technologies now termed PCI.
Several issues relevant to the Committee’s process and the interpretation of the Guidelines have been noted previously and are worthy of restatement. First, PCI is a technique that has been continually refined and modified; hence continued, periodic Guideline revision is anticipated. Second, these guidelines are to be viewed as broad recommendations to aid in the appropriate application of PCI. Under unique circumstances, exceptions may exist. These Guidelines are intended to complement, not replace, sound medical judgment and knowledge. They are intended for operators who possess the cognitive and technical skills for performing PCI and assume that facilities and resources required to properly perform PCI are available. As in the past, the indications are categorized as Class I, II, or III based on a multifactorial assessment of risk as well as expected efficacy viewed in the context of current knowledge and the relative strength of this knowledge. Initially, this document describes the background information that forms the foundation for specific indications. Topics fundamental to coronary intervention are reviewed followed by separate discussions relating to unique technical and operational issues. Formal recommendations for the use of angioplasty are included in Section V. Indications are organized according to clinical presentation. This format is designed to enhance the usefulness of this document for the assessment and care of patients with coronary artery disease (CAD).
This document employs the ACC/AHA style classification as Class I, II, or III. These classes summarize the indications for PCI as follows:
Class I: Conditions for which there is evidence for and/or general agreement that the procedure or treatment is useful and effective.
Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment.
Class IIa: Weight of evidence/opinion is in favor of usefulness/efficacy.
Class IIb: Usefulness/efficacy is less well established by evidence/opinion.
Class III: Conditions for which there is evidence and/or general agreement that the procedure/treatment is not useful/effective, and in some cases may be harmful.
The weight of evidence in support of the recommendation for each listed indication is presented as follows:
Level of Evidence A: Data derived from multiple ran domized clinical trials.
Level of Evidence B: Data derived from a single ran domized trial or nonrandomized studies.
Level of Evidence C: Consensus opinion of experts.
The ACC/AHA Task Force on Practice Guidelines makes every effort to avoid any actual or potential conflicts of interest that might arise as a result of an outside relationship or personal interest of a member of the writing panel. Specifically, all members of the writing panel are asked to provide disclosure statements of all such relationships that might be perceived as real or potential conflicts of interest. These statements are reviewed by the parent task force, reported orally to all members of the writing panel at the first meeting, and updated as changes occur.
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II. General Considerations and Background |
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TopI. IntroductionII. General Considerations and...III. OutcomesIV. Institutional and Operator...V. IndicationsVI. Management of Patients...VII. Special ConsiderationsVIII. Future Directions |
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More than 500,000 PCI procedures are performed yearly in the U.S., and it has been estimated that more than 1,000,000 procedures are performed annually worldwide. New coronary devices have expanded the clinical and anatomical indications for revascularization initially limited by balloon catheter angioplasty. For example, stents reduce both the acute risk of major complications and late-term restenosis. The success of new coronary devices in meeting these goals is in part represented by the less frequent use of PTCA alone (<30%) and the high (>70%) penetration of coronary stenting in the current practice of interventional cardiology. Atherectomy devices and stenting, associated with improved acute angiographic and clinical outcomes compared to PTCA, in specific subsets, continue to be applied to a wider patient domain that includes multivessel disease and complex coronary anatomy. However, strong evidence (level A data from multiple randomized clinical trials) is only available for stenting in selected patients undergoing single-vessel PCI. These Guidelines will focus on the Food and Drug Administration (FDA) approved balloon-related and nonballoon coronary revascularization devices.
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III. Outcomes |
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TopI. IntroductionII. General Considerations and...III. OutcomesIV. Institutional and Operator...V. IndicationsVI. Management of Patients...VII. Special ConsiderationsVIII. Future Directions |
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The outcomes of coronary interventional procedures are measured in terms of success and complications and are related to the mechanisms of the employed devices, as well as the clinical and anatomic patient-related factors. With increased operator experience, new technology, and adjunctive pharmacotherapy, the overall success and complication rates of angioplasty have improved.
A. Definitions of PCI Success
The success of a PCI procedure may be defined by angiographic,
procedural, and clinical criteria.
1. Angiographic Success
A successful PCI produces substantial enlargement of the
lumen at the target site. The consensus definition prior to the
widespread use of stents was the achievement of a minimum stenosis
diameter reduction to <50% in the presence of grade 3 TIMI flow
(assessed by angiography). However, with the advent of advanced adjunct
technology, including coronary stents, a minimum stenosis diameter
reduction to <20% has been the clinical benchmark of an optimal
angiographic result.
2. Procedural Success
A successful PCI should achieve angiographic success without
in-hospital major clinical complications (e.g., death, myocardial
infarction [MI], emergency coronary artery bypass surgery
[CABG]) during hospitalization. Although the occurrence of emergency
artery coronary bypass surgery and death are easily identified end
points, the definition of procedure-related MI has been debated. The
development of Q-waves in addition to a threshold value of CK elevation
has been commonly used. However, the significance of enzyme elevations
in the absence of Q-waves remains a subject of investigation and
debate. Several reports have identified non–Q-wave MIs with CK-MB
elevations 3 to 5 times the upper limit of normal as having clinical
significance. Thus a significant increase in CK-MB without Q-waves is
considered by most to qualify as an associated complication of PCI.
If serial determinations are performed after PCI, an abnormally high value (CK-MB >1 times normal) can be expected in 10 to 15% of PTCA procedures, 15 to 20% of stent procedures, 25 to 35% of atherectomy procedures, and >25% for any device used in saphenous vein grafts (SVGs) or long lesions with a high atherosclerotic burden, even in the absence of other signs and symptoms of MI. There is no accepted consensus on what level of CK-MB index (with or without clinical or electrocardiographic [ECG] findings) is indicative of a clinically important MI following the interventional procedure. Cardiac troponin T and I have now been introduced as measurements of myocardial necrosis and have been proven to be more sensitive and specific than CK-MB. However, prognostic criteria after PCI based on troponin T and I have not yet been developed. The Writing Committee recommends that CK-MB determination be performed on all patients who have signs or symptoms suggestive of MI following the procedure or in patients in whom there is angiographic evidence of abrupt vessel closure, important side branch occlusion, or new and persistent slow coronary flow. In patients in whom a clinically driven CK-MB determination is made, a CK-MB of >3 times the upper limit of normal would constitute a clinically significant MI.
3. Clinical Success
In the short term, a clinically successful PCI includes anatomic
and procedural success with relief of signs and/or symptoms of
myocardial ischemia after the patient recovers from the procedure.
The long-term clinical success requires that the short-term clinical
success remains durable and that the patient has persistent relief of
signs and symptoms of myocardial ischemia for more than 6 months
after the procedure. Restenosis is the principal cause
of lack of long-term clinical success when a short-term clinical
success has been achieved.
B. Definitions of Procedural Complications
As outlined in the 1998 coronary interventional document,
procedural complications are divided into six basic categories: death,
MI, emergency CABG, stroke, vascular access site complications, and
contrast agent nephropathy. Key data elements and definitions to
measure the clinical management and outcomes of patients undergoing
diagnostic catheterization and/or PCI have been defined in the Clinical
Data Standards document and the ACC-National Cardiovascular Data
RegistryTM Catheterization Laboratory Module version 2.0. These
rigorous definitions for key adverse events are endorsed by this
Writing Committee for inclusion in the present PCI Guidelines (Table 1
).
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C. Acute Outcome
Improvements in balloon technology coupled with the increased use
of nonballoon devices, particularly stents (which are effective in
treating abrupt vessel closure) and GP IIb/IIIa platelet receptor
antagonists have favorably influenced acute procedural outcome. This
combined balloon/device/pharmacologic approach to coronary intervention
in elective procedures has resulted in angiographic success rates of 96
to 99%, with Q-wave MI rates of 1 to 3%, emergency coronary bypass
surgery rates of 0.2 to 3%, and unadjusted in-hospital mortality rates
of 0.5 to 1.4%.
D. Long-Term Outcome and Restenosis
Although improvements in technology, including stents and new
pharmacologic therapy, have resulted in an improved acute outcome of
the procedure, the impact of these changes on long-term (5 to 10 years)
outcome may be less dramatic where factors such as advanced age,
reduced left ventricular (LV) function, and complex multivessel disease
in patients currently undergoing PCI may have a more important
influence. In addition, available data on long-term outcome are mostly
limited to patients undergoing PTCA. Ten-year follow-up of the initial
cohort of patients treated with PTCA revealed an 89.5% survival rate
(95% in patients with single-vessel disease, 81% in patients with
multivessel disease). In patients within the 1985–1986 NHLBI PTCA
Registry, 5-year survival was 92.9% for patients with single-vessel
disease, 88.5% for those with 2-vessel disease, and 86.5% for those
with 3-vessel disease. In patients with multivessel disease undergoing
PTCA in BARI, 5-year survival was 86.3% and infarct-free
survival was 78.7%. Specifically, 5-year survival was 84.7% in
patients with 3-vessel disease and 87.6% in patients with 2-vessel
disease.
In addition to the presence of multivessel disease, other clinical factors adversely impact late mortality. In randomized patients with treated diabetes in BARI, the 5-year survival was 65.5%, and the cardiac mortality was 20.6% in comparison to 5.8% cardiac mortality in patients without treated diabetes, although among eligible but not randomized diabetic patients, the 5-year cardiac mortality was 7.5%. In the 1985–1986 NHLBI PTCA Registry, 4-year survival was significantly lower in women (89.2%) in comparison to men (93.4%). In addition, although LV dysfunction was not associated with an increase in in-hospital mortality or nonfatal MI in patients undergoing PTCA in the same registry, it was an independent predictor of a higher long-term mortality.
A major determinant of event-free survival following coronary
intervention is the incidence of restenosis which had,
until the development of stents, remained fairly constant, despite
multiple pharmacologic and mechanical approaches to limit this process
(Table 2). Depending on the definition,
(i.e., whether clinical or angiographic restenosis or
target lesion revascularization is measured), the incidence of
restenosis following coronary intervention had been 30
to 40%, and higher in certain clinical and angiographic subsets.
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Although multiple clinical factors (diabetes, unstable angina,
acute MI, prior restenosis), angiographic factors
(proximal left anterior descending artery, small vessel diameters,
total occlusion, long lesion length, SVG), and procedural factors
(higher post-procedure percent diameter stenosis, smaller minimal lumen
diameter, and smaller acute gain), have been associated with an
increased incidence of restenosis, the ability to
integrate these factors and predict the risk of
restenosis in individual patients following the
procedure remains difficult. The most promising potential approaches to
favorably impact the restenosis process relate to: 1)
the ability to decrease elastic recoil and remodeling using
intracoronary stents, and 2) to the ability to reduce intimal
hyperplasia using catheter-based ionizing radiation. More than 6,300
patients have been studied in 12 randomized clinical trials to assess
the efficacy of PTCA vs. stents to reduce restenosis
(Table 3).
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In addition, randomized studies in patients with in-stent restenosis have shown that both intracoronary gamma and beta radiation significantly reduced the rate of subsequent angiographic and clinical restenosis by 30 to 50%.
E. Predictors of Success/Complications
1. Anatomic Factors
The risk of PTCA in the pre-stent era relative to anatomic
subsets has been identified in previous NHLBI PTCA Registry data and by
the ACC/AHA Task Force. The lesion classification based on severity of
characteristics proposed in the past has been principally altered using
the present PCI techniques, which capitalize on the ability of stents
to manage initial and subsequent complications of coronary
interventions. As a result the Committee has revised the previous
ACC/AHA lesion classification system to reflect low, moderate, and high
risk (Table 4) in accordance with the PCI
Clinical Data Standards from the ACC-National Cardiovascular Data
RegistryTM.
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2. Clinical Factors
Coexistent clinical conditions can increase the complication rates
for any given anatomic risk factor. The clinical risk factors
associated with in-hospital adverse events have been further evaluated
with additional experience during the PCI era and summarized based on
odds ratio >2.0 or results of multivariate analysis (Table 5).
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3. Risk of Death
In the majority of patients undergoing elective PCI, death
as a result of PCI is directly related to the occurrence of coronary
artery occlusion and is most frequently associated with
pro-nounced LV failure. The clinical and angiographic variables
associated with increased mortality include advanced age, female
gender, diabetes, prior MI, multivessel disease, left main or
equivalent coronary disease, a large area of myocardium at risk,
pre-existing impairment of LV or renal function, and collateral vessels
supplying significant areas of myocardium that originate distal to the
segment to be dilated (Table 5
).
4. Women
In comparison to men, women undergoing PCI are older and have a
higher incidence of hypertension, diabetes mellitus,
hypercholesterolemia, and comorbid disease. Early reports of patients
undergoing PTCA revealed a lower procedural success rate in women;
however, more recent studies have noted similar angiographic outcome
and incidence of MI and emergency coronary bypass surgery in women and
men. Although reports have been inconsistent, in several large-scale
registries, in-hospital mortality is significantly higher in women and
an independent effect of gender on acute mortality following PCI
persists after adjustments for the baseline higher-risk profile in
women.
5. The Elderly Patient
Age >75 years is one of the major clinical variables associated
with increased risk of complications. In the elderly population, the
morphologic and clinical variables are compounded by advanced years
with the very elderly having the highest-risk of adverse outcomes. In
the stent era, procedural success rates and short-term outcomes are
comparable to those for nonoctogenarians. Thus, with rare exception
(primary PCI for cardiogenic shock for patients >75 years), a separate
category has not been created in these Guidelines for the elderly.
However, their higher incidence of comorbidities should be taken into
account when considering the need for PCI.
6. Diabetes Mellitus
In the TIMI-IIB study of MI, patients with diabetes mellitus had
significantly higher 6-week (11.6% vs. 4.7%), 1-year (18.0% vs.
6.7%), and 3-year (21.6% vs. 9.6%) mortality rates compared to
nondiabetic patients. The BARI trial, in which stents and abciximab
were not used, showed that survival was better for patients with
treated diabetes undergoing CABG with an arterial conduit than for
those undergoing angioplasty. Stenting decreases the need for target
revascularization procedures in diabetic patients compared with PTCA.
The efficacy of stenting with GP IIb/IIIa inhibitors was assessed in
the diabetic population compared to those without diabetes in a
substudy of the EPISTENT trial. Irrespective of revascularization
strategy abciximab significantly reduced 6-month death and MI rates in
patients with diabetes for all strategies. Likewise, 6-month
target-vessel revascularization was reduced in the stent/abciximab
group approach.
7. Coronary Angioplasty After Coronary Artery Bypass Surgery
Although speculated to be at higher risk, patients having PCI of
native vessels after prior coronary bypass surgery have, in recent
years, nearly equivalent interventional outcomes and complication rates
compared to patients having similar interventions without prior
surgery. For PCI of SVG, studies indicate that the rate of successful
angioplasty exceeds 90%, death <1.2%, Q-wave MI <2.5%. The
incidence of non–Q-wave MI may be higher than that associated with
native coronary arteries.
Use of GP IIb/IIIa blockers has not been shown to improve results of angioplasty in vein grafts. The native vessels should be treated with PCI if feasible. Patients with older and/or severely diseased SVGs may benefit from elective repeat coronary artery bypass graft surgery rather than PCI.
8. Specific Technical Considerations
Certain outcomes of PCI may be specifically related to the
technology utilized for coronary recanalization. Antecedent unstable
angina appears to be a clinical predictor of slow flow and
periprocedural infarction following ablative technologies and
direct platelet activation has been demonstrated to occur with both
directional and rotational atherectomy.
Coronary perforation may occur more commonly following the use of ablative technologies including rotational, directional or extraction atherectomy, and excimer laser coronary angioplasty. Coronary perforation complicates PCI more frequently in the elderly and in women. While 20% of perforations may be secondary to the coronary guidewire, most are related to the specific technology used.
9. Issues of Hemodynamic Support in High-Risk
Angioplasty
Elective high-risk PCI can be performed safely without
intra-aortic balloon pump (IABP) or cardiopulmonary support (CPS) in
most circumstances. Emergency high-risk PCI such as direct PCI for
acute MI can usually be performed without IABP or CPS. CPS for
high-risk PCI should be reserved only for patients at the extreme end
of the spectrum of hemodynamic compromise, such as those patients with
extremely depressed LV function and patients in cardiogenic shock.
However, it should be noted that in patients with borderline
hemodynamics, ongoing ischemia, or cardiogenic shock, insertion of
an intra-aortic balloon just prior to coronary instrumentation has been
associated with improved outcomes. Furthermore, it is reasonable to
obtain vascular access in the contralateral femoral artery prior to the
procedure in patients in whom the risk of hemodynamic compromise is
high, thereby facilitating intra-aortic balloon insertion, if
necessary.
In patients having a higher-risk profile, consideration of alternative therapies, particularly CABG, formalized surgical standby, or periprocedural hemodynamic support should be addressed before proceeding with PCI.
F. Comparison With Bypass Surgery
The major advantage of PCI is its relative ease of use, avoiding
general anesthesia, thoracotomy, extracorporeal circulation, CNS
complications, and prolonged convalescence. Repeat PCI can be performed
more easily than repeat bypass surgery, and revascularization can be
achieved more quickly in emergency situations. The disadvantages of PCI
are early restenosis and the inability to relieve many
totally occluded arteries and/or those vessels with extensive
atherosclerotic disease.
Coronary artery bypass surgery has the advantages of greater durability (graft patency rates exceeding 90% at 10 years with arterial conduits) and more complete revascularization irrespective of the morphology of the obstructing atherosclerotic lesion. Generally speaking, the greater the extent of coronary atherosclerosis and its diffuseness, the more compelling the choice of CABG, particularly if LV function is depressed. Patients with lesser extent of disease and localized lesions are good candidates for endovascular approaches.
Percutaneous transluminal coronary angioplasty and CABG have been compared in many nonrandomized and randomized studies. The most accurate comparisons of outcomes are best made from prospective randomized trials of patients suitable for either treatment. Although results of these trials provide useful information for selection of therapy in several patient subgroups, prior studies of PTCA may not reflect outcome of current PCI practice, which includes frequent use of stents and antiplatelet drugs. Similarly, many previous studies of CABG may not reflect outcome of current surgical practice in which arterial conduits are used whenever practicable. Beating heart bypass operations are also employed for selected patients with single-vessel disease with reduced morbidity. In addition, patients are selected for PCI (with or without stenting) because of certain lesion characteristics, and these anatomical criteria are not required for CABG.
Despite these limitations, some generalizations can be made from comparative trials of PTCA and CABG. First, for most patients with single-vessel disease, late survival is similar with either revascularization strategy, and this might be expected given the generally good prognosis of most patients with single-vessel disease managed medically.
In the ARTS trial, the first trial to compare stenting with surgery, there was no significant difference in mortality between PCI and surgical groups at one year. The main difference compared to previous PTCA and CABG trials was an approximate 50% reduction in the need for repeat revascularization in a group randomized to PCI with stent placement.
Direct comparison of initial strategies of PCI or CABG in patients with multivessel coronary disease is possible only by randomized trials because of selection criteria of patients for PCI. There have been five large (>300 patients) randomized trials of PTCA versus CABG and two smaller studies. These trials demonstrate that in appropriately selected patients with multivessel coronary disease, an initial strategy of standard PTCA yields similar overall outcomes (e.g., death, MI) compared to initial revascularization with coronary artery bypass.
An important exception to the conclusion of the relative safety of PCI in multivessel disease is the subgroup of patients with treated diabetes mellitus. Among treated diabetic patients in BARI assigned to PTCA, 5-year survival was 65.5% compared to 80.6% for patients having CABG (p = 0.003); the improved outcome with CABG was due to reduced cardiac mortality (5.8% vs. 20.6%, p = 0.0003), which was confined to those receiving at least one internal mammary artery graft.
G. Comparison With Medicine
There has been a considerable effort made to evaluate the relative
effectiveness of bypass surgery as compared to PCI for coronary artery
revascularization. In contrast to this, very little effort has been
directed toward comparing medical therapy with PCI for the management
of stable and unstable angina.
Based on the limited data available from randomized trials (Table 6) comparing medical therapy with PTCA,
it seems prudent to consider medical therapy for the initial management
of most patients with Canadian Cardiovascular Society Classification
Class I and II and reserve PTCA and CABG for those patients with more
severe symptoms and ischemia. The symptomatic individual patient
who wishes to remain physically active, regardless of age, will more
often require PCI. The results of the ACIP trial indicate that
higher-risk patients with asymptomatic ischemia and significant
CAD who undergo complete revascularization with CABG or PTCA may have a
better outcome as compared to those with medical management.
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IV. Institutional and Operator Competency |
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TopI. IntroductionII. General Considerations and...III. OutcomesIV. Institutional and Operator...V. IndicationsVI. Management of Patients...VII. Special ConsiderationsVIII. Future Directions |
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A. Quality Assurance
A mechanism for valid peer review must be established and ongoing at each institution performing PCI. Interventional cardiology procedures are associated with complications that in general are inversely related to operator and institutional volume. The mechanism for institutional review should provide an opportunity for interventionalists as well as physicians who do not perform angioplasty, but are knowledgeable about it, to review overall results of the program on a regular basis. The responsible supervising authority should monitor the following issues as outlined in Table 7
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The institutional credentialing committee should document that an
interventionalist wishing to start practice meets the established
training criteria, including those of the ACC Task Force on Training in
Cardiac Catheterization and Interventional Cardiology. This Writing
Committee agrees with the ACC Task Force recommendations for the
Assessment and Maintenance of Proficiency in Coronary Interventional
Procedures. Institutions performing PCI should meet the following
standards as outlined in Tables 8 and 9.
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B. Operator and Institutional Volume
The proliferation of small angioplasty or small surgical programs
to support such angioplasty programs is strongly discouraged. Several
studies have identified procedural volume as a determining factor for
frequency of complications with PCI.
Although some investigators have suggested that low procedure volume does not contribute to poor outcomes, these studies are small in number and underpowered for analysis. Development of small cardiovascular surgical programs to support angioplasty is a poor use of resources that will likely lead to suboptimal results.
Given the concerns regarding operator volume and surgical standby, it
is recommended that PCI be performed by higher volume operators (
75
cases/year) with advanced technical skills (e.g., subspecialty
certification) at institutions with fully equipped interventional
laboratories and experienced support staff. This setting will most
often be in a high-volume center (>400 cases/year) associated with an
on-site cardiovascular surgical program. Similar concerns have been
identified and supported by the Task Force for Practice Guidelines for
Coronary Angiography.
This Committee acknowledges that not every cardiologist desiring to do PCI should perform these procedures and not every hospital anxious to have an interventional program should start one. This caveat is particularly true where there are high-volume programs and operators nearby. In these situations, operators should be subspecialty board certified.
Recommendations for PCI Institutional and Operator Volumes at
Centers With On-Site Cardiac Surgery
Class I
- 1. PCI done by operators with acceptable volume (75) at high-volume centers (>400). (Level of Evidence: B)
Class IIa
- 1. PCI done by operators with acceptable volume (75) at low-volume centers (200 to 400). (Level of Evidence: C)
- 2. PCI done by low volume operators (<75) at high-volume centers (>400). Note: Ideally operators with annual procedure volume <75 should only work at institutions with an activity level of >600 procedures/year.* (Level of Evidence: C)
- 2. PCI done by low volume operators (<75) at high-volume centers (>400). Note: Ideally operators with annual procedure volume <75 should only work at institutions with an activity level of >600 procedures/year.* (Level of Evidence: C)
Class III
- 1. PCI done by low volume operators (<75) at low-volume centers (200 to 400). Note: An institution with a volume <200 procedures/year, unless in a region that is underserved because of geography, should carefully consider whether it should continue to offer service.1 (Level of Evidence: C)
C. On-Site Cardiac Surgical Backup
Cardiac surgical backup for PCI has evolved from the formal
surgical standby in the 1980s to an informal arrangement of first
available operating room and, in some cases, off-site surgical backup.
With the advent of intracoronary stenting, there has been a decrease in
the need for emergency coronary bypass, ranging between 0.4 and 2%.
1. Primary PCI Without On-Site Cardiac Surgery
Although thrombolytic trials demonstrated that early reperfusion
saves myocardium and reduces mortality, the superiority and greater
applicability of primary PCI for the treatment of acute MI has raised
the question of whether primary PCI should be performed at institutions
with diagnostic cardiac catheterization laboratories that do not
perform elective PCI or have on-site cardiac surgery. For this reason,
the establishment of PCI programs at institutions without on-site
cardiovascular surgery has been promoted as necessary to maintain
quality of care. It must be realized that PCI in the early phase of an
acute MI can be difficult and requires even more skill and experience
than routine PCI in the stable patient. The need for an experienced
operator and experienced laboratory technical support with availability
of a broad range of catheters, guidewires, stents, and other devices
(e.g., IABP) that are required for optimum results in an acutely ill
patient is of major importance (Table 9). If these complex
patients are treated by interventionalists with limited experience at
institutions with low volume, then the gains of early intervention may
be lost because of increased complications. In such circumstances,
transfer to a center that routinely performs complex PCI will often be
a more effective and efficient course of action. Thrombolysis is still
an acceptable form of therapy and is preferable to acute PCI by an
inexperienced team.
Criteria have been suggested for the performance of primary PCI at
hospitals without on-site cardiac surgery (Tables 9 and 10). Of note, large-scale
registries have shown an inverse relationship between the number of
primary angioplasty procedures performed and in-hospital mortality. The
data suggest that both door-to-balloon time and in-hospital mortality
are significantly lower in institutions performing a minimum of 36
primary angioplasty procedures per year. Communities may identify a
unique qualified and experienced center wherein the on-site
intervention for acute MI could be performed. Suboptimal results may
relate to operator/staff inexperience and capabilities and delays in
performing angioplasty for logistical reasons. From clinical data and
expert consensus, the Committee recommends that primary PCI for acute
MI performed at hospitals without established elective PCI programs
should be restricted to those institutions with a proven plan for rapid
and effective PCI as well as rapid access to cardiac surgery in a
nearby facility (Table 11).
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2. Elective PCI Without On-Site Surgery
Technical improvements in interventional cardiology have led to
the development of elective angioplasty programs without on-site
surgical coverage. Caution is warranted before endorsing an
unrestricted policy for PCI in hospitals without appropriate
facilities. Several outstanding and critically important clinical
issues, such as timely management of ischemic complications,
adequacy of specialized post-interventional care, logistics for
managing cardiac surgical or vascular complications and
operator/laboratory volumes, and accreditation must be addressed. At
this time, the Committee, therefore, continues to support the
recommendation that elective PCI should not be performed in facilities
without on-site cardiac surgery (Table 11). As with many
dynamic areas in interventional cardiology, these recommendations may
be subject to revision as clinical data and experience increase.
Recommendations for PCI With and Without On-Site Cardiac Surgery
(Table 11)
Class I
- 1. Patients undergoing elective PCI in facilities with on-site cardiac surgery. (Level of Evidence: B)
- 2. Patients undergoing primary PCI in facilities with on-site cardiac surgery. (Level of Evidence: B)
- 2. Patients undergoing primary PCI in facilities with on-site cardiac surgery. (Level of Evidence: B)
Class IIb
- 1. Patients undergoing primary PCI in facilities without on-site cardiac surgery, but with a proven plan for rapid access (within 1 h) to a cardiac surgery operating room in a nearby facility with appropriate hemodynamic support capability for transfer. The procedure should be limited to patients with ST-segment elevation MI or new LBBB on ECG, and done in a timely fashion (balloon inflation within 90 ± 30 min of admission) by persons skilled in the procedure (75 PCIs/year) and only at facilities performing a minimum of 36 primary PCI procedures per year. (Level of Evidence: B)
Class III
- 1. Patients undergoing elective PCI in facilities without on-site cardiac surgery. (Level of Evidence: C)
- 2. Patients undergoing primary PCI in facilities without on-site cardiac surgery and without a proven plan for rapid access (within 1 h) to a cardiac surgery operating room in a nearby facility with appropriate hemodynamic support capability for transfer or when performed by lower skilled operators (<75 PCIs/year) in a facility performing <36 primary PCI procedures per year. (Level of Evidence: C)
- 2. Patients undergoing primary PCI in facilities without on-site cardiac surgery and without a proven plan for rapid access (within 1 h) to a cardiac surgery operating room in a nearby facility with appropriate hemodynamic support capability for transfer or when performed by lower skilled operators (<75 PCIs/year) in a facility performing <36 primary PCI procedures per year. (Level of Evidence: C)
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V. Indications |
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TopI. IntroductionII. General Considerations and...III. OutcomesIV. Institutional and Operator...V. IndicationsVI. Management of Patients...VII. Special ConsiderationsVIII. Future Directions |
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A broad spectrum of clinical presentations exists wherein patients may be considered candidates for PCI, ranging from asymptomatic to severely symptomatic or unstable, with variable degrees of jeopardized myocardium. Each time that a patient is considered for revascularization, the potential risk and benefits of the particular procedure under consideration must be weighed against alternative therapies.
The initial simplicity and associated low morbidity of PCI as compared to surgical therapy is always attractive, but the patient and family must understand the limitations inherent in current PCI procedures, including a realistic presentation of the likelihood of restenosis and the potential for incomplete revascularization as compared with CABG surgery. In patients with CAD who are asymptomatic or have only mild symptoms, the potential benefit of antianginal drug therapy along with an aggressive program of risk reduction must also be understood by the patient before a revascularization procedure is performed.
A. Asymptomatic or Mild Angina
In the previous ACC/AHA Guidelines for PTCA, specific
recommendations were made separately for patients with single- or
multivessel disease. The current techniques of PCI have matured to the
point where, in patients with favorable anatomy, the competent
practitioner can perform either single- or multivessel PCI at low risk
and with a high likelihood of initial success. For this reason, in this
revision of the Guidelines, recommendations will be made largely based
upon the patients’ clinical condition, specific coronary lesion
morphology and anatomy, LV function, and associated medical conditions,
and less emphasis will be placed on the number of lesions or vessels
requiring PCI. The CCS Class of angina (I to IV) is used to define the
severity of symptoms. The categories described in this section refer to
an initial PCI procedure in a patient without prior CABG surgery.
The Committee recognizes that the majority of patients with asymptomatic ischemia or mild angina should be treated medically. The published ACIP study casts some doubt on the wisdom of medical management for those higher-risk patients who are asymptomatic or have mild angina, but have objective evidence by both treadmill testing and ambulatory monitoring of significant myocardial ischemia and CAD. In addition, there is a substantial portion of the middle and older age populations in this country that remains physically active, participating in sports, such as tennis and skiing, or performing regular and vigorous physical exercise, such as jogging, who have CAD. For such individuals with moderate or severe ischemia and few symptoms, revascularization with PCI or CABG surgery may reduce their risk of serious or fatal cardiac events. For this reason, patients in this category of higher-risk asymptomatic ischemia or mild symptoms and severe anatomic CAD are placed in Class I or II. PCI may be considered if there is a high likelihood of success and a low risk of morbidity or mortality. The judgment of the experienced physician is deemed valuable in assessing the extent of ischemia.
Recommendations for PCI in Asymptomatic or Class I Angina Patients
Class I
- 1. Patients who do not have treated diabetes with asymptomatic ischemia or mild angina with 1 or more significant lesions in 1 or 2 coronary arteries suitable for PCI with a high likelihood of success and a low risk of morbidity and mortality. The vessels to be dilated must subtend a large area of viable myocardium (Table 12). (Level of Evidence: B)
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Class IIa
- 1. The same clinical and anatomic requirements for Class I, except the myocardial area at risk is of moderate size or the patient has treated diabetes. (Level of Evidence: B)
Class IIb
- 1. Patients with asymptomatic ischemia or mild
angina with 3 coronary arteries suitable for PCI with a high
likelihood of success and a low risk of morbidity and mortality. The
vessels to be dilated must subtend at least a moderate area of viable
myocardium. In the physician’s judgment, there should be evidence of
myocardial ischemia by ECG exercise testing, stress nuclear
imaging, stress echocardiography or ambulatory ECG monitoring, or
intracoronary physiologic measurements. (Level of Evidence: B)
Class III
- 1. Patients with asymptomatic ischemia or mild
angina who do not meet the criteria as listed under Class I or Class II
and who have:
- a. Only a small area of viable myocardium at risk.
- b. No objective evidence of ischemia.
- c. Lesions that have a low likelihood of successful dilation.
- d. Mild symptoms that are unlikely to be due to myocardial ischemia.
- e. Factors associated with increased risk of morbidity or mortality.
- f. Left main disease.
- g. Insignificant disease <50%. (Level of Evidence: C)
- a. Only a small area of viable myocardium at risk.
B. Angina Class II to IV or Unstable Angina
Many patients with moderate or severe stable angina or unstable
angina do not respond adequately to medical therapy and often have
significant coronary artery stenoses that are suitable for
revascularization with CABG surgery or PCI. In addition, a proportion
of these patients have reduced LV systolic function which places them
in a group that is known to have improved survival with CABG surgery
and possibly with revascularization by PCI. In nondiabetic patients
with 1- or 2-vessel disease in whom angioplasty of 1 or more lesions
has a high likelihood of initial success, PCI is the preferred
approach. In a minority of such patients, CABG surgery may be
preferred, particularly for those in whom the left anterior descending
coronary artery can be revascularized with the internal mammary artery
or in those with left main coronary disease. In patients with unstable
angina or non–Q-wave MI, intensive medical therapy should be initiated
prior to revascularization with PCI or CABG surgery. Patients with
unstable angina and non–ST-segment elevation MI have been randomized
to medical therapy or PCI in the FRISC II and TACTICS TIMI 18 trials.
These trials utilizing stenting as the primary therapy have favored the
invasive approach.
The indications for coronary angiography are summarized in the ACC/AHA Coronary Angiography Guidelines and recommendations for PCI are summarized in the ACC/AHA Unstable Angina Guidelines. Indications for PCI for patients with angina Class II to IV, unstable angina, or non–Q-wave infarction follow.
Recommendations for Patients With Moderate or Severe Symptoms
(Angina Class II to IV, Unstable Angina or Non–ST-Elevation MI) With
Single- or Multivessel Coronary Disease on Medical Therapy
Class I
- 1. Patients with 1 or more significant lesions in 1 or
more coronary arteries suitable for PCI with a high likelihood of
success and low risk of morbidity or mortality (Table 5). The
vessel(s) to be dilated must subtend a moderate or large area of viable
myocardium and have high risk (Table 12). (Level of
Evidence: B)
Class IIa
- 1. Patients with focal saphenous vein graft lesions or
multiple stenoses who are poor candidates for reoperative surgery.
(Level of Evidence: C)
Class IIb
- 1. Patient has 1 or more lesions to be dilated with
reduced likelihood of success (Table 5) or the vessel(s) subtend
a less than moderate area of viable myocardium. Patients with 2- or
3-vessel disease, with significant proximal LAD CAD and treated
diabetes or abnormal LV function. (Level of Evidence: B)
Class III
- 1. Patient has no evidence of myocardial injury or
ischemia on objective testing and has not had a trial of medical
therapy, or has:
- a. Only a small area of myocardium at risk.
- b. All lesions or the culprit lesion to be dilated with morphology with a low likelihood of success.
- c. A high risk of procedure-related morbidity or mortality. (Level of Evidence: C)
- 2. Patients with insignificant coronary stenosis (e.g., <50% diameter). (Level of Evidence: C)
- 3. Patients with significant left main CAD who are candidates for CABG. (Level of Evidence: B)
- a. Only a small area of myocardium at risk.
It is recognized by the Committee that the assessment of
risk of unsuccessful PCI or serious morbidity or mortality must always
be made with consideration of the alternative therapies available for
the patient, including more intensive or prolonged medical therapy or
surgical revascularization (Table 13),
especially in patients with unstable angina pectoris.
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When CABG surgery is a poor option because of high risk due to special considerations or other organ system disease, patients otherwise in Class IIb may be appropriately managed with PCI. Under these special circumstances formal surgical consultation is recommended.
C. Myocardial Infarction
The results of randomized clinical trials of intravenous
thrombolysis and subsequent management strategies of immediate,
delayed, and deferred PCI have established the benefits of early
pharmacologic and mechanical reperfusion therapies for patients with
acute MI.
Percutaneous coronary intervention is a very effective method for
re-establishing coronary perfusion and is suitable for 90% of
patients. Considerable data support the use of PCI for patients with
acute MI. Reported rates of achieving TIMI 3 flow, the goal of
reperfusion therapy, range from 70 to 90%. Late follow-up angiography
demonstrates that 87% of infarct arteries remain patent. Although most
evaluations of PCI have been in patients who are eligible to receive
thrombolytic therapy, considerable experience supports the value of PCI
for patients who may not be suitable for thrombolytic therapy due to an
increased risk of bleeding.
Intracoronary stents appear to augment the results of PCI for MI (Table 14). Preliminary results suggest that
stenting achieves a better immediate angiographic result with a larger
arterial lumen, less reclosure of the infarct-related artery, and fewer
subsequent ischemic events than PTCA alone. Results from a
randomized clinical trial suggest that stenting enhances late clinical
outcomes (reduction in composite end point attributable to a decrease
in target-vessel revascularization) when compared to PTCA alone.
However an increase in mortality at 1 year among the stent group has
been reported in the Stent-PAMI trial.
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Primary PTCA performed without routine stenting has been compared to thrombolytic therapy in several randomized clinical trials. These investigations consistently demonstrate that PTCA-treated patients experience less recurrent ischemia or infarction than those treated by thrombolysis. Trends favoring a survival benefit with PTCA are noted. Two meta-analyses showed superiority of PCI over thrombolysis for mortality with risk reductions of 0.34 and 0.56. It is important to note that these results of PCI have been achieved in medical centers with experienced providers and under circumstances where angioplasty can be performed immediately following patient presentation.
1. PCI in Thrombolytic-Ineligible Patients
Randomized, controlled clinical trials evaluating the outcome of
PCI for patients who present with ST-segment elevation but who are
ineligible for thrombolytic therapy and for patients who experience
infarction without ST-segment elevation have not been
performed. Nevertheless, there is a general consensus that PCI is an
appropriate means for achieving reperfusion in patients who cannot
receive thrombolytics because of increased risk of hemorrhage. Other
reasons also exclude acute MI patients from thrombolytic therapy and
the outcome of PCI in these patients may differ from those eligible for
lytic therapy. For example, patients who present without ST-elevation
are more often older and female and have higher in-hospital mortality
than those with ST-segment elevation. Little data are available to
characterize the value of primary PCI for this subset of acute MI
patients (Table 15).
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2. Post-Thrombolysis PCI
In asymptomatic patients, the strategies of routine PCI of the
stenotic infarct-related artery immediately after successful
thrombolysis show no benefit with regard to salvage of jeopardized
myocardium or prevention of reinfarction or death. In some
studies this approach was associated with increased incidence of
adverse events, which include bleeding, recurrent ischemia,
emergency coronary artery surgery, and death. Routine PCI immediately
after thrombolysis may increase the chance for vascular complications
at the catheterization access site and hemorrhage into the
infarct-related vessel wall.
3. Rescue PCI
Rescue (also known as salvage) PCI is defined as PCI after failed
thrombolysis for patients with continuing or recurrent myocardial
ischemia. Rescue PCI has resulted in higher rates of early
infarct-artery patency, improved regional infarct zone wall motion, and
greater freedom from adverse in-hospital clinical events compared to a
deferred PCI strategy. The randomized evaluation of rescue PCI with
combined utilization end points trial (RESCUE) demonstrated a reduction
in rates of in-hospital death and combined death and congestive heart
failure maintained up to 1 year after study entry for patients
presenting with anterior wall MI who failed thrombolytic therapy.
Improvement in TIMI grade flow from 
2 to 3 may offer additional
clinical benefit.
4. PCI for Cardiogenic Shock
Observational studies support the value of PCI for patients who
develop cardiogenic shock in the early hours of MI. For patients who do
not have mechanical causes of shock, such as acute mitral regurgitation
or septal or free wall rupture, mortality among those having PCI is
lower than those treated by medical means.
A randomized clinical trial has further clarified the role of emergency revascularization (ERV) in acute MI complicated by cardiogenic shock. This multicenter trial supports the use of ERV with PCI in appropriate candidates for patients <75 years old with acute MI complicated by cardiogenic shock. After 6 months, there was significant survival benefit to early revascularization. These data strongly support the approach that patients <75 years with acute MI complicated by cardiogenic shock should undergo emergency revascularization and support measures.
5. PCI Hours to Days After Thrombolysis
Patients who achieve reperfusion and myocardial salvage following
thrombolytic therapy may experience reocclusion of the infarct artery
and recurrent MI. This concern has prompted the routine use of
catheterization and PCI prior to hospital discharge to identify and
dilate the culprit lesion. The SWIFT study examined 800 patients with
acute MI randomly assigned to PCI within 2 to 7 days after thrombolysis
or to conservative management with intervention for spontaneous or
provocable ischemia. There were no differences in the two
treatment strategies regarding LV function, incidence of
reinfarction, in-hospital survival, or 1-year survival rate.
These data indicate that routine PCI of the infarct-related artery in
the absence of spontaneous or provoked ischemia is not warranted.
Initial studies of late (>6 to 12 h) PCI in asymptomatic survivors of MI indicate that opening an occluded artery does not appear to alter the process of LV dilation, the incidence of spontaneous and inducible arrhythmias, or prognosis. Although data supporting the argument to open occluded infarct-related arteries are persuasive, at least for large arteries subtending large areas of myocardium, there are few randomized trials supporting this approach. It should be noted that the overwhelming majority of trials were performed prior to the widespread use of stents and platelet IIb/IIIa receptor blockade and thus, the potential impact and benefit of these newer therapies in this clinical setting needs re-evaluation.
6. PCI After Thrombolysis in Selected Patient Subgroups
a. Young and Elderly Post-Infarct
Patients
Although not supported by randomized trials, routine cardiac
catheterization following thrombolytic therapy for AMI has been a
frequently performed strategy in all age groups. Young (<50 years)
patients often undergo cardiac catheterization after thrombolytic
therapy due to a "perceived need" to define coronary anatomy and
thus establish psychological as well as clinical outcomes. In contrast,
older (>75 years) patients have higher in-hospital and long-term
mortality rates and enhanced clinical outcomes when treated with
primary PCI. Confirmatory studies to determine quality-of-life aspects
of care in younger patients and to define the potential of other modes
of coronary revascularization in older patient groups are not yet
available. Based on the current data, with the exception of patients
presenting with cardiogenic shock, PCI should be based on clinical need
without special consideration of age.
b. Patients With Prior Myocardial
Infarction
A prior MI is an independent predictor of death,
reinfarction, and need for urgent coronary bypass surgery. In
the TIMI-II study, patients with a history of prior MI had a higher
42-day mortality (8.8% vs. 4.3%; p < 0.001), higher prevalence
of multivessel CAD (60% vs. 28%; p < 0.001), and a lower LV
ejection fraction (42% vs. 48%; p < 0.001) compared to patients
with a first MI. Mortality tended to be lower among patients with a
prior MI undergoing the invasive compared to the conservative strategy,
a benefit which persisted up to 1 year following study entry.
Based on the earlier findings in this document and current practice, PCI should be based on clinical need. The presence of prior MI places the patient in a higher risk subset and should be considered in the PCI decision.
Recommendations for Primary PCI for Acute Transmural MI Patients as
an Alternative to Thrombolysis
Class I
- 1. As an alternative to thrombolytic therapy in
patients with AMI and ST-segment elevation or new or presumed new left
bundle branch block who can undergo angioplasty of the infarct artery
12 h from the onset of ischemic symptoms or
>12 h if symptoms persist, if performed in a timely
fashion2 by individuals skilled in the procedure. 3
Individuals who perform 75 PCI procedures/year
and supported by experienced personnel in an appropriate laboratory environment.4
(Level of Evidence: A)
- 2. In patients who are within 36 h of an acute ST elevation/Q-wave or new left bundle branch block MI who develop cardiogenic shock, are <75 years of age, and revascularization can be performed within 18 h of the onset of shock by individuals skilled in the procedure
and supported by experienced
personnel in an appropriate laboratory environment.
(Level of
Evidence: A)
- 2. In patients who are within 36 h of an acute ST elevation/Q-wave or new left bundle branch block MI who develop cardiogenic shock, are <75 years of age, and revascularization can be performed within 18 h of the onset of shock by individuals skilled in the procedure
Class IIa
- 1. As a reperfusion strategy in candidates who have a
contraindication to thrombolytic therapy. (Level of Evidence: C)
Class III
- 1. Elective PCI of a non–infarct-related artery at the
time of acute MI. (Level of Evidence: C)
- 2. In patients with acute MI who:
- a. have received fibrinolytic therapy within 12 h and have no symptoms of myocardial ischemia.
- b. are eligible for thrombolytic therapy and are undergoing primary angioplasty by an inexperienced operator (individual who performs <75 PCI procedures/year).
- c. are beyond 12 h after onset of symptoms and have no evidence of myocardial ischemia. (Level of Evidence: C)
- 2. In patients with acute MI who:
Recommendations for PCI After Thrombolysis
Class I
- 1. Objective evidence for recurrent
infarction or ischemia (rescue PCI). (Level of
Evidence: B)
Class IIa
- 1. Cardiogenic shock or hemodynamic instability. (Level of Evidence: B)
Class IIb
- 1. Recurrent angina without objective evidence of
ischemia/infarction. (Level of Evidence: C)
- 2. Angioplasty of the infarct-related artery stenosis within hours to days (48 h) following successful thrombolytic therapy in asymptomatic patients without clinical and/or inducible evidence of ischemia. (Level of Evidence: B)
- 2. Angioplasty of the infarct-related artery stenosis within hours to days (48 h) following successful thrombolytic therapy in asymptomatic patients without clinical and/or inducible evidence of ischemia. (Level of Evidence: B)
Class III
- 1. Routine PCI within 48 h following failed
thrombolysis. (Level of Evidence: B)
- 2. Routine PCI of the infarct-artery stenosis immediately after thrombolytic therapy. (Level of Evidence: A)
- 2. Routine PCI of the infarct-artery stenosis immediately after thrombolytic therapy. (Level of Evidence: A)
Recommendations for PCI During Subsequent Hospital Management After Acute Therapy for AMI Including Primary PCI
Class I
- 1. Spontaneous or provocable myocardial
ischemia during recovery from infarction. (Level
of Evidence: C)
- 2. Persistent hemodynamic instability. (Level of Evidence: C)
- 2. Persistent hemodynamic instability. (Level of Evidence: C)
Class IIa
- 1. Patients with LV ejection fraction 0.4, CHF, or
serious ventricular arrhythmias. (Level of Evidence: C)
Class IIb
- 1. Coronary angiography and angioplasty for an occluded
infarct-related artery in an otherwise stable patient to revascularize
that artery (open artery hypothesis). (Level of Evidence: C)
- 2. All patients after a non–Q-wave MI. (Level of Evidence: C)
- 3. Clinical HF during the acute episode, but subsequent demonstration of preserved LV function (LV ejection fraction >0.4). (Level of Evidence: C)
- 2. All patients after a non–Q-wave MI. (Level of Evidence: C)
Class III
- 1. PCI of the infarct-related artery within 48 to
72 h after thrombolytic therapy without evidence of
spontaneous or provocable ischemia. (Level of Evidence: C)
D. Percutaneous Intervention in Patients With Prior Coronary Bypass
Surgery
Ischemic symptoms recur in 4% to 8% of
patients/year following CABG. Recurrence of symptoms can be attributed
to progression of native vessel coronary disease (5%/year) and bypass
conduit occlusion, particularly SVG failure (7% in week 1; 15 to 20%
in first year; 1 to 2%/year during the first 5 to 6 years and 3 to
5%/year in years 6 to 10 postoperatively). At 10 years
postoperatively, approximately half of all SVG conduits are occluded
and only half of the remaining patent grafts are free of significant
disease. The requirement for repeat revascularization procedures
increases over time from the initial revascularization, particularly in
younger patients. Although arterial conduits exhibit improved long-term
patency, stenosis or occlusion of these grafts can occur. Thus,
patients with recurrent ischemic symptoms following CABG may
require repeat revascularization due to diverse anatomic problems.
Risk of repeat surgical revascularization is higher (hospital mortality 7 to 10%) than initial CABG and both long-term relief of angina and bypass graft patency are lower than that of the first procedure. In addition, patients with prior bypass surgery may have limited graft conduits, impaired LV function, advanced age, and coexisting medical conditions (cerebrovascular disease; renal and pulmonary insufficiency) which may complicate repeat surgical coronary revascularization and prompt consideration for catheter-based intervention.
1. Early Ischemia After CABG
Recurrent ischemia early (<30 days) postoperatively usually
reflects graft failure, often secondary to thrombosis, and may occur in
both saphenous vein and arterial graft conduits. Incomplete
revascularization and unbypassed native vessel stenoses or stenoses
distal to a bypass graft anastomosis may also precipitate recurrent
ischemia. Urgent coronary angiography is indicated to define the
anatomic cause of ischemia and to determine the best course of
therapy. Emergency PCI of a focal graft stenosis (venous or arterial)
or recanalization of an acute graft thrombosis may successfully relieve
ischemia in the majority of patients. Balloon dilation across
suture lines has been accomplished safely within days of surgery.
Adjunctive therapy with abciximab for percutaneous intervention during
the first week following bypass surgery has been limited but
intuitively may pose less risk for hemorrhage than fibrinolysis. As
flow in vein graft conduits is pressure dependent, intra-aortic balloon
pump support should be considered in the context of systemic
hypotension and/or severe LV dysfunction. If feasible, PCI of both
bypass graft and native vessel offending stenoses should be attempted,
particularly if intracoronary stents can be successfully deployed.
When ischemia occurs 1 to 12 months following surgery, the etiology is usually peri-anastomotic graft stenosis. Distal anastomotic stenoses (both arterial and venous) respond well to balloon dilation alone and have a more favorable long-term prognosis than stenoses involving the mid-shaft or proximal vein graft anastomosis. The immediate results of PCI in mid-shaft ostial or distal anastomotic vein graft stenoses may be enhanced by coronary stent deployment.
Percutaneous transluminal coronary angioplasty with or without stent deployment can be successfully performed in patients with distal anastomotic stenoses involving the gastroepiploic artery bypass graft and in patients with free radial artery bypass grafts as well. Percutaneous intervention has also been effective in relieving ischemia for patients with the stenosis of the subclavian artery proximal to the origin of a patent left internal mammary artery bypass graft.
2. Late Ischemia After CABG
Ischemia occurring more than 1 year postoperatively usually
reflects the development of new stenoses in graft conduits and/or
native vessels that may be amenable to PCI. Slow-flow occurs more
frequently in grafts having diffuse atherosclerotic involvement,
angiographically demonstrable thrombus, irregular or ulcerative lesion
surfaces, and with long lesions having large plaque volume.
Final patency after PTCA is greater for distal SVG lesions than for ostial or mid-SVG lesions, and stenosis location appears to be a better determinant of final patency than graft age or the type of interventional device used.
Percutaneous intervention for chronic vein graft occlusion has been problematic. Percutaneous transluminal coronary angioplasty alone has been associated with high complication rates and low rates of sustained patency. Favorable results have been obtained with both local "targeted" and more prolonged infusion of fibrinolytic agents for nonocclusive intragraft thrombus. Thrombolytic catheter-based systems appear to successfully treat SVG thrombosis as well as or better than thrombolytic agents.
3. Early and Late Outcomes of Percutaneous Intervention
Patients with prior bypass surgery who undergo successful PCI have
a long-term outcome that is dependent on patient age, the degree of LV
dysfunction, and the presence of multivessel coronary atherosclerosis.
The best long-term results are observed after recanalization of distal
anastomotic stenoses occurring within 1 year of operation. Conversely,
event-free survival is less favorable following angioplasty of totally
occluded SVGs, ostial vein graft stenoses, or grafts with diffuse or
multicentric disease. Coexistent multisystems disease, the presence of
which may have prompted the choice of a percutaneous revascularization
strategy, may also influence long-term outcomes in this population.
4. Surgery Versus Percutaneous Reintervention
Aged, diffuse, friable and degenerative SVG disease in the absence
of a patent arterial conduit to the left anterior descending artery
represents a prime consideration for repeat surgical revascularization.
The overall risk of repeat operation, especially the presence of
comorbidities such as concomitant cerebrovascular, renal, or pulmonary
disease and the potential for jeopardizing patent, nondiseased bypass
conduits must be carefully considered. Isolated, friable stenoses in
vein grafts may be approached with primary stenting or the combination
of extraction atherectomy and stenting in an attempt to reduce the
likelihood of distal embolization.
In general, patients with multivessel disease, failure of multiple SVGs, and moderately impaired LV function, derive the greatest benefit from the durability provided by surgical revascularization with arterial conduits. Regardless of repeat revascularization strategy, risk-factor modification with cessation of smoking and lipid-lowering therapy should be implemented in patients with prior CABG surgery. An aggressive lipid-lowering strategy that targets a low-density lipoprotein level of less than 90 mg/L can be effective in reducing recurrent ischemic events and the need for subsequent revascularization procedures.
Recommendations for PCI With Prior CABG