(Circulation. 1998;98:1587-1590.)
© 1998 American Heart Association, Inc.
Percutaneous Treatment of Left Main Coronary Stenosis
J. Ernesto Molina, MD
Professor of Surgery Cardiovascular & Thoracic
Surgery,
University of Minnesota,
Minneapolis, Minn
To the Editor:
The multicenter report by Dr Ellis and
colleagues1 of 107 patients with left main
coronary obstruction who were not candidates for surgery and in
whom an attempt was made to reopen the left main coronary
vessel by percutaneous techniques with different
devices has significant implications for the cardiac surgeon when the
patient is a candidate for a surgical procedure. Ellis et al deserve to
be congratulated for this important piece of information.
There have been numerous reports of patients who have undergone direct
attempts to widen the left main trunk of the coronary artery to
provide antegrade flow when the distal branches are not significantly
involved with obstructions. One of the main complications of this
approach is early restenosis of the vessel and, occasionally,
total occlusion, with fatal consequences for the patient.
It appears that the main trunk of the coronary artery reacts
unfavorably to endarterectomy procedures or any
type of trauma damaging the intima. Occlusion of the left main artery
has been reported after radiofrequency ablation for left-sided
tachycardias2 3 4 and after PTCAs done
in the left coronary system.5 6 This has
been seen after plain cardiac catheterization when the
tip of the catheter injures the intima or when perfusion cannulas are
positioned in coronary arteries directly to infuse cardioplegia
during aortic valve surgery.7 8 9 10
In our institution, we had a case in which the left anterior descending
artery (LAD) and the circumflex had separate origins from the aorta,
both showing ostial obstructions. The LAD was given a saphenous patch
at the ostia to widen its diameter, and the circumflex vessel was
treated with an endarterectomy because its orifice
was immediately below the LAD origin. Within a few days, the artery
undergoing endarterectomy developed severe
obstruction that required reoperation, but not so the LAD.
My question addresses this issue: In 53 patients, stents were
implanted; in the other 54, only balloon angioplasty was performed. At
the time of repeated angiography, 14.3% of the case patients who
underwent stent implants were restenosed versus 50% of patients in
whom only PTCA was performed (Table 6).1
The authors mention under "Post–Hospital Discharge Outcome" that 9
survivors (10.6%) died of cardiac causes within 6 months. I wonder
whether the important factor is not the presence of unstable angina or
age but the fact that these patients did not have stents placed. In
this same section, we read: "Of patients eligible for >4-month
angiography, 70% had known studies, of whom 22.0% had
restenosis (stenosis 
50%)." The only variable
related to risk of restenosis was ostial left main trunk, but I
wonder whether the complication occurs due to lack of use of
stents.
References
1.
Ellis SG, Tamai H, Nobuyoshi M, Kosuga K, Colombo A,
Holmes DR, Macaya C, Grines CL, Whitlow PL, White HJ, Moses J,
Teirstein PS, Serruys PW, Bittl JA, Mooney MR, Shimshak TM, Block PC,
Erbel R. Contemporary percutaneous treatment of
unprotected left main coronary stenoses: initial
results from a multicenter registry analysis 1994–1996.
Circulation. 1997;96:3867–3872.[Abstract/Free Full Text]
2.
Kosinski DJ, Burket MW, Durzinsky D. Occlusion of the
left main coronary artery during radiofrequency ablation for
the Wolff-Parkinson-White syndrome. Eur J Cardiac
Pacing Electrophysiol. 1993;1:63–66.
3.
Hope EJ, Haigney MC, Calkins H, Resar JR. Left main
coronary thrombosis after radiofrequency ablation: successful
treatment with percutaneous transluminal angioplasty.
Am Heart J. 1995;129:1217–1219.[Medline]
[Order article via Infotrieve]
4.
Pons M, Beck L, Leclercq F, Ferriere M, Albat B, Davy
JM. Chronic left main coronary artery occlusion: a complication
of radiofrequency ablation of idiopathic left ventricular
tachycardia. Pacing Clin Electrophysiol. 1997;20:1874–1876.[Medline]
[Order article via Infotrieve]
5.
Graf RH, Verani MS. Left main coronary artery
stenosis: a possible complication of transluminal
coronary angioplasty. Cathet Cardiovasc Diagn. 1984;10:163–166.[Medline]
[Order article via Infotrieve]
6.
Waller BF, Finkerton CA, Foster LN. Morphologic
evidence of accelerated left main coronary artery
stenosis: a late complication of percutaneous
transluminal balloon angioplasty of the proximal left anterior
descending coronary artery. J Am Coll
Cardiol. 1987;9:1019–1023.[Abstract]
7.
Pennington DG, Dincer B, Bashiti H, Barner HB, Kaiser
GC, Tyras DH, Codd JE, Willman VL. Coronary artery
stenosis following aortic valve replacement and intermittent
intracoronary cardioplegia. Ann Thorac Surg. 1982;33:576–584.[Abstract]
8.
Prachar H, Muhlbauer J, Pollack H, Enenkel W.
Iatrogenic left main coronary artery stenosis following
aortic valve replacement. Eur Heart J. 1988;9:1151–1154.[Abstract/Free Full Text]
9.
Molina JE. Coronary stenosis following
aortic valve replacement. Ann Thorac Surg. 1983;35:473–474. Letter.
10.
Barner HB, Fiore AC. Update on left
coronary ostial stenosis: comparison with left main
coronary artery stenosis. Ann Thorac
Surg. 1997;64:282–283.[Free Full Text]
Response
Stephen G. Ellis, MD
Director, Sones Cardiac Catheterization
Laboratories The Cleveland Clinic Foundation,
Professor of Medicine,
The Ohio State University,
Cleveland, Ohio
Hideo Tamai, MD;
Masakiyo Nobuyoshi, MD;
Kunihiko Kosuga, MD;
Antonio Colombo, MD;
David R. Holmes, MD;
Carlos Macaya, MD;
Cindy L. Grines, MD;
Patrick L. Whitlow, MD;
Harvey J. White, MD;
Jeffrey Moses, MD;
Paul S. Teirstein, MD;
Patrick W. Serruys, MD;
John A. Bittl, MD;
Michael R. Mooney, MD;
Thomas M. Shimshak, MD;
Peter C. Block, MD;
; Raimund Erbel, MD
The Cleveland Clinic Foundation,
Cleveland, Ohio
Dr Molina addresses a key issue with regard to assessment of the
clinical safety and utility of percutaneous
interventions for patients with unprotected left main coronary
stenoses. In experienced centers and in patients with
relatively well-preserved left ventricular function, a
percutaneous approach (either stenting or directional
atherectomy) seems to be reasonably safe, at least in the short run. A
better understanding of the risk of cardiac death within the first year
after treatment is needed, however, and Dr Molina suggests that perhaps
the 11% incidence of this untoward outcome in our initial series is
due to the fact that only half the patients received coronary
stents. This issue has certainly drawn our attention also, and in fact,
we have extended our registry to include over 270 consecutively treated
patients and specifically addressed this issue in a recent
analysis (J Am Coll Cardiol. 1998;31:214A). In
this analysis, 9% of patients died within 9 months after
initially successful treatment, and in multivariate
logistic regression analysis, left ventricular
ejection fraction 
30% and initial presentation with rest
or progressive angina were both significant independent correlates of
death (multivariate odds ratios 17.1 and 4.3,
respectively). Stenting and directional atherectomy tended to be
offered to lower-risk patients more often than was balloon angioplasty.
After adjustment for the aforementioned risk factors, there was only a
trend suggesting added risk with balloon angioplasty
(P=0.13) compared with both stenting and directional
coronary atherectomy. There was no discernible difference with
regard to outcome between stenting and atherectomy. We recognize that
this sort of analysis cannot always fully adjust for unmeasured
variables, but short of a randomized trial, this is the best answer
we have. Given that the in-hospital cardiac mortality rate for patients
with ejection fraction >30% who present with stable angina and
who are treated with directional atherectomy or stenting is only 1.3%
in this series and their 9-month mortality rate is 4.4%, it may be
that now is an appropriate time for a randomized, controlled trial in
such patients against the current gold standard: bypass
surgery.
