(Circulation. 1995;92:2480-2487.)
© 1995 American Heart Association, Inc.
Articles |
From the Cardiovascular Division, Beth Israel Hospital, Boston, Mass (D.J.C., C.A.S., K.K.L.H., D.S.B.); the Department of Health Policy and Management, Harvard School of Public Health, Boston, Mass (D.J.C., R.B.S.); Yale School of Medicine, New Haven, Conn (H.M.K., M.C.); Arizona Heart Institute, Phoenix (R.R.H.); Johns Hopkins Hospital, Baltimore, Md (J.A.B.); Lenox Hill Hospital, New York, NY (J.W.M.); Jefferson Medical College, Philadelphia, Pa (M.P.S.); the University of Pittsburgh (Pa) (K.D.); and the Washington (DC) Cardiology Center (M.B.L.).
Correspondence to David J. Cohen, MD, MSc, Cardiovascular Division, Beth Israel Hospital, 330 Brookline Ave, Boston, MA 02215. E-mail djc@hsph.harvard.edu.
| Abstract |
|---|
|
|
|---|
Methods and Results Between January 1991 and June 1993, 207
consecutive patients with symptomatic coronary
disease requiring revascularization of a single
coronary lesion were randomized to receive initial treatment by
either PTCA (n=105) or Palmaz-Schatz coronary stent
implantation (n=102) in the multicenter STRESS trial. Detailed resource
utilization and cost data were collected for each patient's initial
hospitalization and for any subsequent hospital visits for 1 year after
randomization. Compared with conventional angioplasty, coronary
stenting resulted in additional catheterization
laboratory costs, increased vascular complications, and longer length
of stay. Initial hospital costs were thus
$2200 higher for stenting
than for PTCA ($9738±3248 versus $7505±5015;
P<.001).
Over the first year of follow-up, however, patients assigned to
initial stenting were less likely to require rehospitalization for a
cardiac condition and underwent fewer subsequent
revascularization procedures. Follow-up medical
care costs thus tended to be lower for stenting than for conventional
angioplasty ($1918±4841 versus $3359±7100,
P=.21).
Nonetheless, cumulative 1-year medical care costs remained higher for
patients undergoing initial stenting ($11 656±5674 versus
$10 865±9073, P<.001). Even after adjustment for the
higher incidence of vascular complications in the stent group, total
1-year costs were $300 higher for stenting than for balloon
angioplasty.
Conclusions Elective coronary stenting, as performed in
the randomized STRESS trial, increased total 1-year medical care costs
by
$800 per patient compared with conventional angioplasty. Future
studies will be necessary to determine whether ongoing refinements in
stent design, implantation techniques, and anticoagulation regimens can
narrow this cost difference further by reducing stent-related
vascular complications or length of stay.
Key Words: stents angioplasty trials cost-benefit analysis coronary disease
| Introduction |
|---|
|
|
|---|
Several single-center observational studies have suggested that hospital costs for coronary stenting may be 50% to 100% higher than for conventional angioplasty, an absolute increase of $2500 to $4000 per patient.9 10 11 12 13 These studies suffer from a number of important limitations, however. As observational studies, they may be subject to selection bias; thus, the observed cost differences may partly reflect underlying differences in patient or lesion characteristics rather than the revascularization procedures themselves. Moreover, the results of single-center studies may not be applicable to other institutions or to the healthcare system in general. Finally, the existing studies have focused only on the costs of the initial hospitalization. In practice, cumulative medical care costs during the first year after coronary angioplasty are 40% to 60% higher than those of the initial revascularization procedure itself because of procedural failure or restenosis requiring subsequent bypass surgery or repeat angioplasty.14 15 16 Since coronary stenting appears to improve late clinical outcomes compared with conventional balloon angioplasty, it is possible that savings in the cost of follow-up care could partially or completely offset the higher initial cost of the stent procedure. Accordingly, the present study was designed to determine the true costs of coronary stenting and conventional PTCA in the setting of a multicenter, randomized clinical trial. In addition to examining initial hospital costs, we extended clinical and economic follow-up for 1 year after randomization in an attempt to compare the long-term economic impacts of these alternative revascularization procedures.
| Methods |
|---|
|
|
|---|
Entry and
exclusion criteria have been described
previously.6 All patients had symptomatic
coronary artery disease requiring
revascularization of a single, de novo lesion <15
mm long in a native coronary artery with reference vessel size
3.0 mm. Exclusion criteria included myocardial infarction within 7
days of revascularization, left
ventricular ejection fraction <40%, or a contraindication
to anticoagulation. In addition, patients with multiple focal lesions,
diffuse coronary artery disease, significant left main disease,
or severe vessel tortuosity that was thought to make stent implantation
difficult were also excluded.
Randomization and Treatment Protocol
As previously described,
eligible patients were randomized to
undergo either balloon angioplasty or stent implantation using a
permuted block design, stratified by enrolling hospital.
Revascularization procedures were performed
according to a treatment protocol designed to optimize clinical
outcomes for each procedure, without specific attention to hospital
costs. Balloon angioplasty was performed by standard techniques with a
goal of achieving a residual diameter stenosis of
30%.
Crossover to stent implantation was permitted only as a "bailout"
procedure in the case of abrupt or threatened vessel closure.
Palmaz-Schatz coronary stent implantation was performed as
previously described using the approved anticoagulation regimen,
including aspirin, dipyridamole, dextran, and
heparin.17 After successful stent implantation, heparin
was discontinued and vascular access sheaths were removed 4 to 6 hours
later. Once hemostasis was obtained, intravenous heparin
was resumed and continued until adequate oral anticoagulation
(prothrombin time 16 to 18 seconds or international normalized ratio
2.0 to 3.5) was achieved. After hospital discharge,
dipyridamole and warfarin were continued for 1 month,
and aspirin was continued indefinitely.
All procedural coronary angiograms underwent quantitative analysis at a central core laboratory using a validated edge-detection algorithm as previously described.18 Angiographic success was defined as achievement of a residual diameter stenosis <50% by quantitative angiography. Clinical success was defined as angiographic success in the absence of a major ischemic complication (death, Q-wave myocardial infarction, bypass surgery, or repeat percutaneous coronary revascularization before hospital discharge). Vascular complications included the need for surgical vascular repair or bleeding requiring transfusion.
Clinical and Angiographic Follow-up
Patients were contacted
at 1, 3, 6, and 12 months after
randomization to determine their symptomatic status, need
for repeat revascularization, and need for
hospitalization for any reason. Clinical follow-up was available
for 100% of the study population. In addition, patients were required
to undergo repeat coronary angiography between 4 and 6 months
after study entry. Patients were excluded from angiographic
follow-up, however, if they had undergone coronary artery
bypass surgery or repeat angioplasty for abrupt closure during the
first 2 weeks after initial revascularization.
Determination of Medical Care Costs
Itemized bills were
obtained for each patient's initial
hospitalization and any subsequent hospitalizations during the 1-year
follow-up period. Complete baseline and follow-up economic data
were available for 204 of 207 patients (99%); data were incomplete for
1 PTCA and 2 stent patients because of repeat hospitalizations at
outside hospitals during follow-up. Hospital admissions that were
purely for the purpose of protocol-mandated cardiac
catheterization (ie, compulsory 6-month angiographic
follow-up) were excluded from the economic analysis unless
clinically indicated coronary
revascularization (ie, for recurrent chest pain or
inducible myocardial ischemia by noninvasive testing) was
performed at the time of angiographic follow-up. Determination of
which follow-up hospitalizations were excluded from the economic
analysis was made by two independent reviewers (C.A.S.,
K.K.L.H.) blinded to initial treatment assignment.
Cardiac catheterization laboratory costs. The costs of each cardiac catheterization laboratory procedure were determined by standard, "bottom-up" cost-accounting methods.19 Detailed resource utilization including the number of angioplasty balloons, stents, other devices, guiding catheters, guide wires, and contrast volume were recorded on a standardized data collection form for each procedure, and the costs of each item were estimated on the basis of the mean hospital acquisition costs for the item during the study period. Costs of additional disposable equipment, depreciation and overhead for catheterization laboratory maintenance, and nonphysician personnel were estimated on the basis of the average cost per procedure at Boston's Beth Israel Hospital (one of the study sites) and adjusted for actual procedure duration.10
Other hospital costs. All other hospital costs were determined by "top-down" cost-accounting methods based on each hospital's annual Medicare Cost Report.20 Hospital room and nursing costs were based on the average per diem cost for the specific patient care unit (eg, coronary care unit, cardiac step-down unit, general medical unit) multiplied by the length of stay on the particular unit. Ancillary costs were obtained by multiplying the number of units of each service used (eg, laboratory tests, x-rays, drugs, blood products) by the average cost per unit. Unit costs were estimated as the hospital charge for the specific item or service multiplied by the cost centerspecific cost-to-charge ratio from the hospital's Medicare Cost Report. All costs were converted to 1994 dollars on the basis of the medical care component of the Consumer Price Index.
Professional fees. Physicians' professional fees for percutaneous revascularization and surgical procedures were based on the 1994 Medicare reimbursement levels for each procedure according to the Resource-Based Relative Value Scale.21 The angioplasty professional fee was also applied to coronary stenting, because third-party payers did not distinguish between these procedures at the time of this study.
Statistical Analysis
Discrete data are reported as
frequencies, while continuous data
are reported as mean±SD. Selected cost data are also reported as
medians with interquartile ranges. All analyses were based on
the intention-to-treat principle. Discrete variables were
compared by
2 analysis or Fisher's exact
test where appropriate. Normally distributed continuous variables
were compared by Student's t test. Cost data and other
nonnormally distributed data were compared by the Wilcoxon
rank-sum test. All analyses were performed with SASversion 6.08
statistical software (SAS Institute). All
P values are two-tailed, and a value of
P
.05 was considered statistically significant.
Relationship With Sponsor
This study was performed according
to published guidelines for
the conduct of industry-sponsored economic
analyses.22 Before initiation of the economic
substudy, the data collection instruments and analytic protocol were
specified and agreed upon by the study investigators and sponsor. A
written agreement was obtained between the sponsor and principal
investigators stipulating the right of the investigators to publish the
study's findings regardless of their nature. According to this
agreement, data collection and analysis were subsequently
carried out at the individual study sites and central data coordinating
center completely independent of the study sponsor.
| Results |
|---|
|
|
|---|
|
Initial procedural results and
in-hospital complications in our
study were similar to those observed in the overall STRESS trial (Table
2
). Clinical success, defined as achievement of <50%
diameter stenosis without in-hospital ischemic
complications, was achieved in 98% of the stent group compared with
91% of the PTCA group (P=.03). Although there were no
differences in any of the individual ischemic end points
between the treatment groups, patients undergoing initial stenting were
somewhat less likely to require either repeat intervention or
"relook" coronary angiography before hospital discharge
than patients undergoing initial PTCA (2% versus 8%,
P=.08). In contrast, the incidence of major vascular
complications requiring surgical repair was significantly higher in the
stent group than in the PTCA group (7% versus 1%,
P=.03).
|
Cardiac Catheterization Laboratory Resource
Utilization and Costs
Cardiac catheterization laboratory resource
utilization was generally somewhat greater for the stent group than for
the PTCA group (Table 3
). As expected, patients
undergoing initial coronary stenting had significantly more
coronary stents implanted than did patients undergoing initial
balloon angioplasty (1.1±0.4 versus 0.1±0.4 stents per patient,
P<.001). Moreover, patients undergoing initial stenting
required more radiographic contrast (265±110 versus
234±123 mL, P=.05) and used more balloon catheters
(2.0±0.9 versus 1.7±1.0, P=.03)excluding
the balloon
used for stent deliverycompared with the PTCA group, reflecting
the frequent need for adjunctive balloon dilation both before and after
coronary stent placement. As a result, initial
catheterization laboratory resource costs were nearly
$1200 higher in the stent group than in the PTCA group ($4691±1156
versus $3505±1505, P<.001).
|
Initial Hospital Resource Utilization and Costs
Table
4
summarizes hospital resource utilization
and cost data for the initial hospitalization. Mean length of stay was
significantly greater for the stent group (7.5±3.4 days overall,
5.8±2.7 days postprocedure) than for the PTCA group (4.8±3.6
days
overall, 3.5±3.4 days postprocedure; P<.001 for both
comparisons). Initial hospital costs were thus approximately $2200
higher for coronary stenting than for conventional PTCA
($9738±3248 [median $8869] versus $7505±5015
[median $6165];
P<.001). Exclusion of physician professional fees from this
analysis decreased the absolute costs of both procedures by
approximately $1000 but did not alter the relative difference (stent,
$8675±3056; PTCA, $6387±4356; P<.001). On average,
$1062 (47%) of this cost increase was due to increased resource
utilization in the catheterization laboratory, while
the remaining $1171 (53%) was due to increased room/nursing costs and
other ancillary services relating primarily to the longer hospital stay
after coronary stenting.
|
Follow-up Medical Resource Utilization and Costs
During the
1-year follow-up period, patients randomized to
initial PTCA were somewhat more likely to require repeat
revascularization than were patients assigned to
initial stenting (21% versus 15%, P=.24; Table
5
). In particular, PTCA patients were more likely to
undergo multiple revascularization procedures
during follow-up (8% versus 2%, P=.10). As a result,
the PTCA group required more repeat
revascularization procedures overall (35 versus 19)
and more repeat hospitalizations for cardiovascular
conditions (43 versus 28) than the stent group. The overall difference
in the number of hospitalizations was partially attenuated,
however, by an increased need for hospitalizations for noncardiac
conditions in the stent group (11 versus 5), related mainly to bleeding
complications due to high-dose oral anticoagulation.
|
For the entire
1-year study period, cumulative medical care costs were
$800 higher for patients randomized to initial stent implantation
compared with initial PTCA ($11 656±5674 [median $10 436]
versus
$10 865±9073 [median $7172], P<.001; Table
6
). Although follow-up medical care costs tended to
be lower for the stent group than for the PTCA group ($1918±4841
versus $3359±7100, P=.21), these cost savings were
insufficient to fully offset the higher initial cost of stenting. The
Figure
displays the time course of cumulative medical
care costs in the two treatment groups. Although the cost difference at
the 6-month time point (ie, before protocol-mandated cardiac
catheterization) was >$1200, this difference
continued to narrow between months 6 and 12, reflecting the greater
need for third and fourth hospital admissions for
percutaneous coronary
revascularization and late bypass surgery in the
group randomized to initial PTCA.
|
|
Since recent studies have suggested that modification of the poststent anticoagulation protocol may reduce the incidence of vascular complications compared with that seen in our study,23 24 25 we performed subgroup analyses to examine the impact of vascular complications on the short- and long-term costs of stenting. Among patients randomized to initial stenting, major vascular complications were associated with increased postprocedure length of stay (8.2±2.5 versus 5.6±2.7 days, P=.03) and a $3000 increase in initial hospital costs ($12 516±5810 versus $9436±2726, P=.05). Nevertheless, even in those patients who did not experience a vascular complication, stenting was associated with significantly higher (+$300) 1-year treatment cost than conventional angioplasty ($10 869±3852 versus $10 564±8830, P<.001).
| Discussion |
|---|
|
|
|---|
In this study, we examined medical resource utilization and costs of
two alternative revascularization strategies,
conventional balloon angioplasty and Palmaz-Schatz coronary
stenting, in patients undergoing percutaneous
revascularization of a single coronary
lesion in a multicenter randomized clinical trial. In accord with
previous studies,9 10 11 12
we found that the initial hospital
costs for coronary stenting were
30% higher than those for
conventional PTCA. During the first year after initial
revascularization, however, follow-up medical
care costs were nearly $1400 lower in the stent group, making the
cumulative 1-year cost for coronary stenting only 7% higher
than that for conventional PTCA.
Comparison With Previous Studies
Several previous studies
have examined in-hospital costs in
patients undergoing balloon angioplasty and coronary stenting.
Among patients undergoing elective single-vessel coronary
revascularization, Dick et al9 found
that hospital charges were increased by 103% in patients undergoing
stenting compared with balloon angioplasty. It is well recognized,
however, that hospital charges frequently bear little relation to true
costs.19 More recent single-center observational
studies have shown that coronary stenting increased length of
stay by 1.9 to 2.5 days and increased medical care resource costs by
$2400 to $3000 relative to conventional PTCA.10 11
Despite
key differences in study design, the results of these observational
studies are remarkably similar to those of the present randomized
trial.
The results of the present study enhance the findings of previous studies in several important ways. First, by using detailed, resource-based cost-accounting methods in the setting of a randomized clinical trial, our study avoids selection bias and provides the best available estimate of the true in-hospital cost difference between these two procedures. Moreover, while the single-center studies have provided important insights into relative cost differences and patterns of resource consumption, cost-effectiveness analysis from a societal standpoint requires economic data that apply to the overall healthcare system.28 Since we studied costs using a consistent resource-based accounting method across a range of hospital types and locations, our results should be generalizable to the US healthcare system and thus should provide an accurate assessment of the potential impact of such procedures on overall healthcare spending. Finally, our study is the first to compare the long-term medical care costs associated with coronary stenting and conventional angioplasty. Given the potential for improved late clinical outcomes to partially offset the higher initial cost of stenting, this long-term perspective is critical to any assessment of the relative cost-effectiveness of these alternative revascularization procedures.
Clinical Implications
The major finding of the present study
is that
coronary stenting, as performed in the STRESS trial, failed to
reduce long-term medical care costs compared with conventional
PTCA. Despite a $1400 reduction in follow-up medical care costs by
stenting, cumulative 1-year costs remained nearly $800 higher than
those for patients undergoing conventional balloon angioplasty. The
savings in the cost of follow-up medical care were thus
insufficient to fully offset the $2200 greater initial hospital cost of
elective stenting, driven by greater catheterization
laboratory resource utilization (ie, additional balloon, stent, and
contrast dye use), increased length of stay, and more frequent vascular
complications associated with coronary stenting.
Despite its higher long-term costs, coronary stenting may nonetheless be cost-effective. In fact, few modern medical advances are truly cost-saving. Many widespread practices, including bypass surgery for left main disease,29 ß-blocker therapy after acute myocardial infarction,30 and thrombolytic therapy for acute myocardial infarction,31 prolong life only at the expense of increased healthcare costs. Nonetheless, such treatments are viewed as cost-effective because their benefits are "worth the additional cost." Thus, in the case of coronary stenting, its cost-effectiveness depends on whether its clinical benefitsmainly a reduction in recurrent angina and the need for repeat revascularization proceduresare sufficient to justify the additional long-term costs of the procedure. While these questions have not been addressed directly in the context of this randomized clinical trial, decision-analytic modeling using population-based utility estimates to reflect patient preferences for various short- and long-term health states suggests that the incremental cost-effectiveness ratio for primary coronary stenting compared with conventional PTCA may be comparable to many other generally accepted medical treatments.32 Of note, the $600-per-patient increase in long-term medical care costs with stenting predicted by this simulation model was very close to the $800 increase observed in the current randomized trial.
Definitive studies to address these issues will ultimately require direct assessment of quality of life and patients' preferences after stenting or conventional angioplasty or, alternatively, contingent valuation of individual "willingness to pay" for the potential clinical benefits of stenting.33 Until such data become available, however, it is clear that coronary stenting increases overall healthcare costs and that continued efforts to reduce its in-hospital costs are warranted to improve the cost-effectiveness of this promising technology.
Cost-Saving Potential of Coronary Stenting
While present
stent technology is clearly more expensive than
conventional PTCA, our findings suggest that, with improvements in
design and technique, coronary stenting might eventually offer
the potential for long-term cost savings relative to conventional
angioplasty. Realization of such long-term cost savings will
require significant reductions in the initial cost of stenting,
however. Although it is tempting to speculate that cost savings could
be achieved simply by eliminating stent-related vascular
complicationsby modification of the poststent anticoagulation
protocol23 24 25 or by use of a vascular
closure
device,34 35 for exampleour study suggests
that such
changes would be insufficient to render coronary stenting
"cost neutral" relative to balloon angioplasty. Even after
adjusting for the difference in vascular complication rates between the
two procedures, we found that the long-term cost of stenting was
still $300 greater than that for PTCA. If recent developments in stent
technique, such as the use of ticlopidine,23
high-pressure postdilation,24 intravascular
ultrasound,36 or heparin-coated stents,37
can provide late clinical results comparable to those seen in the
present study while simultaneously reducing both
vascular complications and length of stay, true long-term cost
savings might be possible. Given that stenting reduced follow-up
costs by only $1400 in this study, however, any modifications that add
significantly to the procedural cost of stenting (already $1200 higher
than that for PTCA) could overwhelm this potential for cost savings. On
the other hand, if "optimal stent deployment" confers further
reductions in restenosis, even greater follow-up cost
savings might be possible.
Ultimately, realization of any cost-saving potential of coronary stenting is likely to require a combination of technical, procedural, and operational modifications to limit both catheterization laboratory and ancillary hospital costs. Such modifications may include a reduced stent profile (eliminating the need for routine predilation); use of a single high-pressure balloon for predilation, stent delivery, and postdilation; development of a nonthrombogenic stent that does not require prolonged hospitalization for initiation of oral anticoagulation; or improved manufacturing techniques with resulting reductions in the cost of the stent itself.
Study Limitations
Our study has several limitations. By using
cost
centerspecific, direct cost-to-charge ratios to estimate
the costs of ancillary services from itemized hospital bills, we
measured average rather than variable costs. As a result, our study
may tend to overestimate the true increase in overall healthcare costs
that would result from a shift from conventional angioplasty to
coronary stenting, at least in the short run. Nonetheless, in
the absence of a uniform cost-accounting system across US
hospitals, this is the best method currently available for measuring
costs in the setting of a multicenter clinical trial.20 To
minimize any errors introduced by this method, we measured actual
resource utilization and resource costs associated with
catheterization laboratory procedures, the single
largest component of cost in our study.
An additional limitation of our study is the inclusion of those initial hospital costs incurred before randomization and performance of the index revascularization procedure in our overall cost estimates. As a result, our cost estimates for the initial hospitalization may tend to somewhat overestimate the absolute costs directly attributable to the revascularization procedures themselves. Nonetheless, since preprocedure length of stay was similar for the two treatment groups, the relative cost differences we measured should be valid and unbiased.
Finally, we did not include the costs of outpatient medical care (such as physician visits, outpatient testing, and medications) in our study. Although it is possible that coronary stenting and PTCA might be associated with important differences in outpatient medical resource utilization, in the setting of a clinical trial, most outpatient testing and physician visits are protocol driven and thus unlikely to differ significantly between the two groups. Moreover, although the need for warfarin and associated monitoring is likely to increase the outpatient cost of stenting somewhat, these differences may well be offset by other cost savings and are likely to be small compared with the overall cost of outpatient care during the period of our study.38 39 Thus, inclusion of these modest costs in our study would not be expected to change our findings appreciably.
Conclusions
Analysis of the in-hospital and cumulative 1-year
costs of elective stenting and conventional balloon angioplasty in the
multicenter randomized STRESS trial supports earlier single-center
observations and simulation models. The increased in-hospital cost
of stenting (+$2200) was only partially offset by the reduction in
follow-up medical care costs (-$1400), so that the cumulative
1-year treatment cost remained nearly $800 greater for stenting. In the
future, refinements in stent design, implantation techniques, and
associated anticoagulation regimens could narrow this cost difference
further by reducing stent-related vascular complications or length
of stay.
| Acknowledgments |
|---|
| Footnotes |
|---|
1 Additional participants in the STRESS trial are listed in the
"Appendix." ![]()
The following institutions and investigators participated in the STRESS Economic Substudy.
Arizona Heart Institute, Phoenix, Ariz. Principal investigator, Richard Heuser, MD; coinvestigator, Robert K. Strumpf, MD; research coordinators, Walt Catron, Sue Spooner, RN, Kathy Sniderski, RN.
Beth Israel Hospital, Boston, Mass. Principal investigator, Donald S. Baim, MD; coinvestigators, Daniel Diver, MD, Joseph P. Carrozza, MD; research coordinators, Cindy Senerchia, RN, Paula S. Rooney, RN.
Johns Hopkins Hospital, Baltimore, Md. Principal investigator, Jeffrey Brinker, MD; coinvestigator, Jon Resar, MD; research coordinator, Vicki Coombs, RN.
Lenox Hill Hospital, New York, NY. Principal investigator, Jeffrey Moses, MD; coinvestigator, Alex Shaknovich, MD; research coordinators, Nancy Cohen, Jill Higgins, RN.
Scripps Clinic and Research Foundation, San Diego, Calif. Principal investigator, Richard Schatz, MD; research coordinator, Nancy Morris, RN.
Thomas Jefferson University Hospital, Philadelphia, Pa. Principal investigator, Michael P. Savage, MD; coinvestigators, Sheldon Goldberg, MD, David L. Fischman, MD; research coordinators, Doranne Porter, RN, Sharon Gebhardt, RN.
Washington Cardiology Center, Washington, DC. Principal investigator, Martin B. Leon, MD; research coordinator, Kathi Donovan.
Yale University, New Haven, Conn. Principal investigator, Michael Cleman, MD; coinvestigator, Henry Cabin, MD; research coordinator, Robin Rosen.
Received March 9, 1995; revision received May 22, 1995; accepted May 24, 1995.
| References |
|---|
|
|
|---|
2.
Serruys PW, Luijten HE, Beatt KJ, Geuskens R, de
Feyter PJ, van den Brand M, Reiber JHC, ten Katen HJ, van Es GA,
Hugenholtz PG. Incidence of restenosis after
successful coronary angioplasty: a time-related phenomenon:
a quantitative angiographic study in 342 consecutive patients at 1, 2,
3, and 4 months. Circulation. 1988;77:361-371.
3. Noboyoshi M, Kimura T, Nosaka H, Mioka S, Ueno K, Yokoi H, Hamasaki N, Honuchi H, Ohishi H. Restenosis after successful percutaneous transluminal coronary angioplasty: serial angiographic follow-up of 229 patients. J Am Coll Cardiol. 1988;12:616-623. [Abstract]
4. Hirshfeld JW, Schwartz JS, Jugo R, Macdonald RG, Goldberg S, Savage MP, Bass TA, Vetrovec G, Cowley M, Taussig AS, Whitworth HB, Margolis JR, Hill JA, Pepine CJ. Restenosis after coronary angioplasty: a multivariate statistical model to relate lesion and procedure variables to restenosis. J Am Coll Cardiol. 1991;18:647-656. [Abstract]
5.
Serruys PW, de Jaegere P, Kiemeneij F, Macaya C,
Rutsch W, Heyndrickx G, Emanuelsson H, Marco J, Legrand V, Materne P,
Belardi J, Sigwart U, Colombo A, Goy JJ, van den Heuvel P, Delcan J,
Morel M. A comparison of balloon-expandable-stent
implantation with balloon angioplasty in patients with coronary
artery disease. N Engl J Med. 1994;331:489-495.
6.
Fischman DL, Leon MB, Baim DS, Schatz RA, Savage MP,
Penn I, Detre K, Veltri L, Ricci D, Nobuyoshi M, Cleman M, Heuser R,
Almond D, Teirstein PS, Fish RD, Colombo A, Brinker J, Moses J,
Shaknovich A, Hirshfeld J, Bailey S, Ellis S, Rake R, Goldberg S.
A randomized comparison of coronary-stent placement
and balloon angioplasty in the treatment of coronary artery
disease. N Engl J Med. 1994;331:496-501.
7. Block PC. Coronary-artery stents and other endoluminal devices. N Engl J Med. 1991;324:52-53. [Medline] [Order article via Infotrieve]
8.
Topol EJ. Caveats about elective
coronary stenting. N Engl J Med. 1994;331:539-541.
9. Dick RJ, Popma JJ, Muller DW, Burek KA, Topol EJ. In-hospital costs associated with new percutaneous coronary devices. Am J Cardiol. 1991;68:879-885. [Medline] [Order article via Infotrieve]
10. Cohen DJ, Breall JA, Ho KKL, Weintraub RM, Kuntz RE, Weinstein MC, Baim DS. The economics of elective coronary revascularization: comparison of costs and charges for conventional angioplasty, directional atherectomy, stenting, and bypass surgery. J Am Coll Cardiol. 1993;22:1052-1059. [Abstract]
11. Lazzam C, Lazzam LM, McLaughlin PR, Almond DG, Liu P. Implications of higher initial in-hospital costs on restenosis rates with new devices. Circulation. 1992;86(suppl I):I-513. Abstract.
12. Charles E, Mark DB. The economics of percutaneous intervention. In: Roubin G, Phillips HR III, O'Neill WW, Califf RM, Stack RS, eds. Interventional Cardiovascular Medicine. New York, NY: Churchill Livingstone; 1993.
13. Weintraub WS, Waksman R, Bernard J, Hicks F, Canup D, Becker E, Mauldin P, King SB. The influence of new devices on the costs of interventional procedures. Circulation. 1994;90(suppl I):I-44. Abstract.
14. Reeder GS, Krishan I, Nobrega FT, Naessens J, Kelly M, Christianson JB, McAfee MK. Is percutaneous coronary angioplasty less expensive than bypass surgery? N Engl J Med. 1984;311:1157-1162. [Abstract]
15. Kelly ME, Taylor GJ, Moses HW, Mitchell FL, Dove JT, Batchelder JE, Wellons HA, Schneider JA. Comparative cost of myocardial revascularization: percutaneous transluminal angioplasty and coronary artery bypass surgery. J Am Coll Cardiol. 1985;5:16-20. [Abstract]
16.
Van den Brand M, Van Halem C, Van Den Brink F, De
Feyter P, Serruys P, Suryapranata H, Meeter K, Bos E, Van Dalen FJ.
Comparison of costs of percutaneous transluminal
coronary angioplasty and coronary bypass surgery for
patients with angina pectoris. Eur Heart J. 1990;11:765-771.
17.
Schatz RA, Baim DS, Leon M, Ellis SG, Goldberg S,
Hirshfeld JW, Cleman MW, Cabin HS, Walker C, Stagg J, Buchbinder M,
Teirstein PS, Topol EJ, Savage M, Perez JA, Curry RC, Whitworth H,
Sousa JE, Tio F, Almagor Y, Ponder R, Penn IM, Leonard B, Levine SL,
Fish RD, Palmaz JC. Clinical experience with the Palmaz-Schatz
coronary stent: initial results of a multicenter study.
Circulation. 1991;83:148-161.
18.
Mancini GBJ, Simon SB, McGillem MJ, LeFree MT, Friedman
HZ, Vogel RA. Automated quantitative coronary
arteriography: morphologic and physiologic validation in vivo of a
rapid digital angiographic method.
Circulation. 1987;75:452-460.
19. Finkler SA. The distinction between cost and charges. Ann Intern Med. 1982;96:102-109.
20. Mark DB. Medical economics and health policy issues for interventional cardiology. In: Topol EJ, ed. Textbook of Interventional Cardiology. Philadelphia, Pa: WB Saunders; 1994:1323-1354.
21. Hsiao WC, Braun P, Dunn D, Becker ER, DeNicola M, Ketcham TR. Results and policy implications of the resource based relative-value study. N Engl J Med. 1988;319:881-888. [Abstract]
22. Hillman AL, Eisenberg JM, Pauly MV, Bloom BS, Glick H, Kinosian B, Schwartz JS. Avoiding bias in the conduct and reporting of cost-effectiveness research sponsored by pharmaceutical companies. N Engl J Med. 1991;324:1362-1365. [Medline] [Order article via Infotrieve]
23. Barragan P, Sainsous J, Silvestri M, Bouvier JL, Comet B, Simeoni JB, Charmasson C, Bremondy M. Ticlopidine and subcutaneous heparin as an alternative regimen following coronary stenting. Cathet Cardiovasc Diagn. 1994;32:133-138. [Medline] [Order article via Infotrieve]
24. Gaglione A, Tiecco F, Hall P, Maiello L, Nakamura S, Martini G, Colombo A. High pressure assisted intracoronary stent implantation without subsequent anticoagulation. Circulation. 1994;90(suppl I):I-622. Abstract.
25. Morice MC, Bourdonnec C, Lefevre T, Blanchard D, Monassier JP, Lienhart Y, Commeau P, Makowski S, Labrunie P, Cribier A, Joly P. Coronary stenting without Coumadin: phase III. Circulation. 1994;90(suppl I):I-125. Abstract.
26. Hlatky MA, Califf RM, Kong Y, Harrel FE, Rosati RA. Natural history of patients with single-vessel disease suitable for percutaneous transluminal coronary angioplasty. Am J Cardiol. 1983;52:225-229. [Medline] [Order article via Infotrieve]
27.
Mark DB, Nelson CL, Califf RM, Harrell FE, Lee KL,
Jones RH, Fortin DF, Stack RS, Glower DD, Smith LR, DeLong ER, Smith
PK, Reves JG, Jollis JG, Tcheng JE, Muhlbaier LH, Lowe JE, Phillips HR,
Pryor DB. Continuing evolution of therapy for coronary
artery disease: initial results from the era of coronary
angioplasty. Circulation. 1994;89:2015-2025.
28.
Eisenberg JM. Clinical economics: a guide to the
economic analysis of clinical practices.
JAMA. 1989;262:2879-2886.
29. Weinstein MC, Stason WB. Cost-effectiveness of coronary artery bypass surgery. Circulation. 1982;66(suppl III):III-56-III-66.
30. Goldman L, Sia STB, Cook EF, Rutherford JD, Weinstein MC. Costs and effectiveness of routine therapy with long-term beta-adrenergic antagonists after acute myocardial infarction. N Engl J Med. 1988;319:152-157. [Abstract]
31. Krumholz HM, Pasternak RC, Weinstein MC, Friesinger GC, Ridker PM, Tosteson ANA, Goldman L. Cost effectiveness of thrombolytic therapy with streptokinase in elderly patients with suspected acute myocardial infarction. N Engl J Med. 1992;327:7-13. [Abstract]
32.
Cohen DJ, Breall JA, Ho KKL, Kuntz RE, Goldman L, Baim
DS, Weinstein MC. Evaluating the potential
cost-effectiveness of stenting as a treatment for
symptomatic single-vessel coronary disease: use
of a decision-analytic model.
Circulation. 1994;89:1859-1874.
33. Johannesson M. Economic evaluation of lipid lowering: a feasibility test of the contingent valuation approach. Health Policy. 1992;20:309-320. [Medline] [Order article via Infotrieve]
34. Sanborn TA, Gibbs HH, Brinker JA, Knopf WD, Kosinski EJ, Roubin GS. A multicenter randomized trial comparing a percutaneous collagen hemostasis device with conventional manual compression after diagnostic angiography and angioplasty. J Am Coll Cardiol. 1993;22:1273-1279. [Abstract]
35. Vetter JW, Ribeiro EE, Hinohara T, Carrozza JP, Simpson JB. Suture mediated percutaneous closure of femoral artery access sites in fully anticoagulated patients following coronary interventions. Circulation. 1994;90(suppl I):I-621. Abstract.
36.
Colombo A, Hall P, Nakamura S, Almagor Y, Maiello L,
Martini G, Gaglione A, Goldberg SL, Tobis JM.
Intracoronary stenting without anticoagulation
accomplished with intravascular ultrasound guidance.
Circulation. 1995;91:1676-1688.
37. Van der Giessen WJ, Hardhammar PA, van Beusekom HMM, Emanuelsson HU, Tang ZH, Verdouw PD, Serruys PW. Prevention of subacute thrombosis using heparin-coated stents. Circulation. 1994;90(suppl I):I-650. Abstract.
38. Hemenway D, Sherman H, Mudge GH, Flatley M, Lindsey NM, Goldman L. Comparative costs versus symptomatic and employment benefits of medical and surgical treatment of stable angina pectoris. Med Care. 1985;23:133-141. [Medline] [Order article via Infotrieve]
39. Wong JB, Sonnenberg FA, Salem DN, Pauker SG. Myocardial revascularization for chronic stable angina: analysis of the role of percutaneous transluminal coronary angioplasty based on data available in 1989. Ann Intern Med. 1990;113:852-871.
This article has been cited by other articles:
![]() |
D. S. Pinto, G. W. Stone, C. Shi, E. S. Dunn, M. R. Reynolds, M. York, J. Walczak, R. H. Berezin, R. Mehran, B. T. McLaurin, et al. Economic Evaluation of Bivalirudin With or Without Glycoprotein IIb/IIIa Inhibition Versus Heparin With Routine Glycoprotein IIb/IIIa Inhibition for Early Invasive Management of Acute Coronary Syndromes. J. Am. Coll. Cardiol., November 25, 2008; 52(22): 1758 - 1768. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.-A. Eastwood, L. Doering, J. Roper, and R. D. Hays Uncertainty and Health-Related Quality of Life 1 Year After Coronary Angiography Am. J. Crit. Care., May 1, 2008; 17(3): 232 - 242. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. T. Stroupe, D. A. Morrison, M. A. Hlatky, P. G. Barnett, L. Cao, C. Lyttle, D. M. Hynes, W. G. Henderson, and for the Investigators of Veterans Affairs Cooperat Cost-Effectiveness of Coronary Artery Bypass Grafts Versus Percutaneous Coronary Intervention for Revascularization of High-Risk Patients Circulation, September 19, 2006; 114(12): 1251 - 1257. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Elezi, A. Dibra, U. Folkerts, J. Mehilli, S. Heigl, A. Schomig, and A. Kastrati Cost Analysis From Two Randomized Trials of Sirolimus-Eluting Stents Versus Paclitaxel-Eluting Stents in High-Risk Patients With Coronary Artery Disease J. Am. Coll. Cardiol., July 18, 2006; 48(2): 262 - 267. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Bakhai, G. W. Stone, E. Mahoney, T. A. Lavelle, C. Shi, R. H. Berezin, B. J. Lahue, M. A. Clark, M. J. Lacey, M. E. Russell, et al. Cost Effectiveness of Paclitaxel-Eluting Stents for Patients Undergoing Percutaneous Coronary Revascularization: Results From the TAXUS-IV Trial J. Am. Coll. Cardiol., July 18, 2006; 48(2): 253 - 261. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Cohen, A. M. Lincoff, T. A. Lavelle, H.-L. Chen, A. Bakhai, R. H. Berezin, D. Jackman, I. J. Sarembock, and E. J. Topol Economic evaluation of bivalirudin with provisional glycoprotein IIB/IIIA inhibition versus heparin with routine glycoprotein IIB/IIIA inhibition for percutaneous coronary intervention: Results from the REPLACE-2 trial J. Am. Coll. Cardiol., November 2, 2004; 44(9): 1792 - 1800. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Cohen, S. A. Murphy, D. S. Baim, T. A. Lavelle, R. H. Berezin, D. E. Cutlip, K. K.L. Ho, R. E. Kuntz, and the SAFER Trial Investigators Cost-effectiveness of distal embolic protection for patients undergoing percutaneous intervention of saphenous vein bypass grafts: Results from the SAFER trial J. Am. Coll. Cardiol., November 2, 2004; 44(9): 1801 - 1808. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Hlatky, D. B. Boothroyd, K. A. Melsop, M. M. Brooks, D. B. Mark, B. Pitt, G. S. Reeder, W. J. Rogers, T. J. Ryan, P. L. Whitlow, et al. Medical Costs and Quality of Life 10 to 12 Years After Randomization to Angioplasty or Bypass Surgery for Multivessel Coronary Artery Disease Circulation, October 5, 2004; 110(14): 1960 - 1966. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Cohen, A. Bakhai, C. Shi, L. Githiora, T. Lavelle, R. H. Berezin, M. B. Leon, J. W. Moses, J. P. Carrozza Jr, J. P. Zidar, et al. Cost-Effectiveness of Sirolimus-Eluting Stents for Treatment of Complex Coronary Stenoses: Results From the Sirolimus-Eluting Balloon Expandable Stent in the Treatment of Patients With De Novo Native Coronary Artery Lesions (SIRIUS) Trial Circulation, August 3, 2004; 110(5): 508 - 514. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Clark, A. Bakhai, M. J. Lacey, E. M. Pelletier, and D. J. Cohen Clinical and Economic Outcomes of Percutaneous Coronary Interventions in the Elderly: An Analysis of Medicare Claims Data Circulation, July 20, 2004; 110(3): 259 - 264. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. J Nordmann, P. Hengstler, B. M Leimenstoll, T. Harr, J. Young, and H. C Bucher Clinical outcomes of stents versus balloon angioplasty in non-acute coronary artery disease: A meta-analysis of randomized controlled trials Eur. Heart J., January 1, 2004; 25(1): 69 - 80. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. T. Gray and D. L. Veenstra Comparative economic analyses of minimally invasive direct coronary artery bypass surgery J. Thorac. Cardiovasc. Surg., March 1, 2003; 125(3): 618 - 624. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Cohen, R. S. Cosgrove, R. H. Berezin, P. S. Teirstein, M. B. Leon, R. E. Kuntz, and on behalf of the Gamma-1 Investigators Cost-Effectiveness of Gamma Radiation for Treatment of In-Stent Restenosis: Results From the Gamma-1 Trial Circulation, August 6, 2002; 106(6): 691 - 697. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Cohen, D. A. Taira, R. Berezin, D. A. Cox, M.-C. Morice, G. W. Stone, and C. L. Grines Cost-Effectiveness of Coronary Stenting in Acute Myocardial Infarction: Results From the Stent Primary Angioplasty in Myocardial Infarction (Stent-PAMI) Trial Circulation, December 18, 2001; 104(25): 3039 - 3045. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Rinfret, C. L. Grines, R. S. Cosgrove, K. K. L. Ho, D. A. Cox, B. R. Brodie, M.-C. Morice, G. W. Stone, D. J. Cohen, and the Stent-PAMI Investigators Quality of life after balloon angioplasty or stenting for acute myocardial infarction: One-year results from the Stent-PAMI trial J. Am. Coll. Cardiol., November 15, 2001; 38(6): 1614 - 1621. [Abstract] [Full Text] [PDF] |
||||
![]() |
W.S. Weintraub Economics of coronary stenting and GPIIb/IIIa blockade Eur. Heart J., August 2, 2001; 22(16): 1366 - 1368. [PDF] |
||||
![]() |
C.V Patil, E Nikolsky, M Boulos, E Grenadier, and R Beyar Multivessel coronary artery disease: current revascularization strategies Eur. Heart J., July 2, 2001; 22(14): 1183 - 1197. [PDF] |
||||
![]() |
S. C. Smith Jr, J. T. Dove, A. K. Jacobs, J. Ward Kennedy, D. Kereiakes, M. J. Kern, R. E. Kuntz, J. J. Popma, H. V. Schaff, D. O. Williams, et al. ACC/AHA guidelines for percutaneous coronary intervention (revision of the 1993 PTCA guidelines): 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 J. Am. Coll. Cardiol., June 15, 2001; 37(8): 2239 - 2239. [Full Text] [PDF] |
||||
![]() |
W. J. Cantor, A. S. Hellkamp, E. D. Peterson, J. P. Zidar, P. A. Cowper, M. H. Sketch Jr, J. E. Tcheng, R. M. Califf, and E. M. Ohman Achieving optimal results with standard balloon angioplasty: can baseline and angiographic variables predict stent-like outcomes? J. Am. Coll. Cardiol., June 1, 2001; 37(7): 1883 - 1890. [Abstract] [Full Text] [PDF] |
||||
![]() |
H Suryapranata, J P Ottervanger, E Nibbering, A W J van't Hof, J C A Hoorntje, M J de Boer, M J Al, and F Zijlstra Long term outcome and cost-effectiveness of stenting versus balloon angioplasty for acute myocardial infarction Heart, June 1, 2001; 85(6): 667 - 671. [Abstract] [Full Text] |
||||
![]() |
P. W. Serruys, B. de Bruyne, S. Carlier, J. E. Sousa, J. Piek, T. Muramatsu, C. Vrints, P. Probst, R. Seabra-Gomes, I. Simpson, et al. Randomized Comparison of Primary Stenting and Provisional Balloon Angioplasty Guided by Flow Velocity Measurement Circulation, December 12, 2000; 102(24): 2930 - 2937. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. J. Cantor, E. D. Peterson, J. J. Popma, J. P. Zidar, M. H. Sketch Jr., J. E. Tcheng, and E. M. Ohman Provisional stenting strategies: systematic overview and implications for clinical decision-making J. Am. Coll. Cardiol., October 1, 2000; 36(4): 1142 - 1151. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Gottsauner-Wolf, G. Zasmeta, S. Hornykewycz, M. Nikfardjam, E. Stepan, P. Wexberg, G. Zorn, D. Glogar, P. Probst, G. Maurer, et al. Plasma levels of C-reactive protein after coronary stent implantation Eur. Heart J., July 2, 2000; 21(14): 1152 - 1158. [Abstract] [PDF] |
||||
![]() |
D. E. Cutlip, M. B. Leon, K. K. L. Ho, P. C. Gordon, A. Giambartolomei, D. J. Diver, D. M. Lasorda, D. O. Williams, M. M. Fitzpatrick, A. Desjardin, et al. Acute and nine-month clinical outcomes after "suboptimal" coronary stenting: Results from the STent anti-thrombotic regimen study (STARS) registry J. Am. Coll. Cardiol., September 1, 1999; 34(3): 698 - 706. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. D. Peterson, P. A. Cowper, E. R. DeLong, J. P. Zidar, R. S. Stack, and D. B. Mark Acute and long-term cost implications of coronary stenting J. Am. Coll. Cardiol., May 1, 1999; 33(6): 1610 - 1618. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. B. Leon, D. S. Baim, J. J. Popma, P. C. Gordon, D. E. Cutlip, K. K.L. Ho, A. Giambartolomei, D. J. Diver, D. M. Lasorda, D. O. Williams, et al. A Clinical Trial Comparing Three Antithrombotic-Drug Regimens after Coronary-Artery Stenting N. Engl. J. Med., December 3, 1998; 339(23): 1665 - 1671. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. R. Holmes Jr., J. Hirshfeld Jr., D. Faxon, R. Vlietstra, A. Jacobs, S. B. King III, T. M. Bashore, N. D. Bridges, C. B. Higgins, L. F. Hiratzka, et al. ACC expert consensus document on coronary artery stents: Document of the American College of Cardiology J. Am. Coll. Cardiol., November 1, 1998; 32(5): 1471 - 1482. [Full Text] [PDF] |
||||
![]() |
H S Lee, C Densem, R D Levy, D H Bennett, S G Ray, and N H Brooks Impact of stenting on coronary angioplasty procedures Heart, November 1, 1998; 80(5): 505 - 508. [Abstract] [Full Text] |
||||
![]() |
P. A. Sirnes, S. Golf, Y. Myreng, P. Molstad, P. Albertsson, A. Mangschau, K. Endresen, and J. Kjekshus Sustained benefit of stenting chronic coronary occlusion: long-term clinical follow-up of the Stenting in Chronic Coronary Occlusion (SICCO) study J. Am. Coll. Cardiol., August 1, 1998; 32(2): 305 - 310. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. R. Narins, D. R. Holmes Jr, and E. J. Topol A Call for Provisional Stenting : The Balloon Is Back! Circulation, April 7, 1998; 97(13): 1298 - 1305. [Full Text] [PDF] |
||||
![]() |
I. Moussa, B. Reimers, J. Moses, C. Di Mario, L. Di Francesco, M. Ferraro, and A. Colombo Long-term Angiographic and Clinical Outcome of Patients Undergoing Multivessel Coronary Stenting Circulation, December 2, 1997; 96(11): 3873 - 3879. [Abstract] [Full Text] |
||||
![]() |
D. S. Baim and J. P. Carrozza Jr Stent Thrombosis: Closing in on the Best Preventive Treatment Circulation, March 4, 1997; 95(5): 1098 - 1100. [Full Text] |
||||
![]() |
D. O. Williams Dressing Up the Palmaz-Schatz Stent Circulation, February 1, 1996; 93(3): 400 - 402. [Full Text] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Circulation Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1995 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |