Correspondence
Stents versus Bypass Grafting for Left Main Coronary Artery Disease
N Engl J Med 2008; 359:423-425July 24, 2008
- Article
To the Editor:
Seung et al. (April 24 issue)1 report that there was no significant difference in rates of death and major cardiovascular events between matched cohorts of patients undergoing coronary-artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) for left main coronary artery disease — a finding that contrasts with recently published data.2 The authors, however, did not consider variables that are significantly and independently associated with in-hospital or 30-day mortality and are currently included in risk-scoring algorithms for coronary bypass operations or interventional procedures.2-5 Cardiogenic shock was an exclusion criterion, but two thirds of the patients had unstable angina or non–ST-elevation myocardial infarction, and the prevalence of emergency procedures and other critical conditions (which might not always imply cardiogenic shock) — namely, inotropic drug support, aortic counterpulsation, mechanical ventilation, or ongoing heart failure — is not reported. Similar considerations apply to the occurrence and timing of recent myocardial infarction (within 90 days). These potentially confounding variables should be considered for more appropriate propensity-score matching and, eventually, in randomized trials.
5 ReferencesMarco Pocar, M.D., Ph.D.
Francesco Donatelli, M.D.
University of Milan, I-20099 Milan, Italy
marco.pocar@unimi. it Andrea Moneta, M.D.
IRCCS MultiMedica, 20099 Milan, Italy1
Seung KB ,Park DK ,Kim YH , et al. Stents versus coronary-artery bypass grafting for left main coronary artery disease. N Engl J Med 2008;358:1781-1792
Full Text | Web of Science | Medline2
Taggart DP ,Kaul S ,Boden WE , et al. Revascularization for unprotected left main stem coronary artery stenosis: stenting or surgery. J Am Coll Cardiol 2008;51:885-892
CrossRef | Web of Science | Medline3
Nilsson J ,Algottson L ,Hoglund P ,Luhrs C ,Brandt J . Early mortality in coronary bypass surgery: the EuroSCORE versus The Society of Thoracic Surgeons risk algorithm. Ann Thorac Surg 2004;77:1235-1240
CrossRef | Web of Science | Medline4
Wu C ,Hannan EL ,Walford G , et al. A risk score to predict in-hospital mortality for percutaneous coronary interventions. Am Coll Cardiol 2006;47:654-660
CrossRef | Web of Science | Medline5
Hannan EL ,Wu C ,Bennett EW , et al. Risk stratification of in-hospital mortality for coronary artery bypass graft surgery. J Am Coll Cardiol 2006;47:661-668
CrossRef | Web of Science | Medline
To the Editor:
Seung et al. conclude that in patients with unprotected left main coronary artery disease, PCI and CABG were associated with similar long-term rates of death, myocardial infarction, or stroke, but PCI was associated with higher rates of target-vessel revascularization than was CABG. Their conclusions have confirmed the findings of previous studies,1 which did not change the American College of Cardiology–American Heart Association guidelines allocating virtually all cases of unprotected left main coronary artery disease to CABG.2 Unprotected left main coronary artery disease is not a uniform disease entity, and several clinicoanatomical subgroups should be evaluated separately. Some studies indicate that PCI for ostial-midshaft lesions has much better outcomes, with minimal restenosis, than PCI for distal bifurcation lesions.3,4 Clinical risk status is also an independent determinant of outcomes. Seung et al. could have separated their large numbers of patients into subgroups more likely to benefit from PCI or CABG. We need not identify a single superior technology. Instead, we need to identify the best therapeutic strategy for each subgroup of patients.
4 ReferencesHaruo Tomoda, M.D., Ph.D.
Tokyo Heart Institute, Tokyo 195-0061, Japan
tokyoheart@abelia.ocn. ne. jp 1
Taggart DP ,Kaul S ,Boden WE , et al. Revascularization for unprotected left main stem coronary artery stenosis: stenting or surgery. J Am Coll Cardiol 2008;51:885-892
CrossRef | Web of Science | Medline2
Smith SC Jr ,Feldman TE ,Hirshfeld JW Jr , et al. ACC/AHA/SCAI 2005 guideline update for percutaneous coronary intervention -- summary article: a report of the ACC/AHA Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention). J Am Coll Cardiol 2006;47:216-235
CrossRef | Web of Science | Medline3
Valgimigli M ,Malagutti P ,Rodriguez-Granillo GA , et al. Distal left main coronary disease is a major predictor of outcome in patients undergoing percutaneous intervention in the drug-eluting stent era: an integrated clinical and angiographic analysis based on the Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) and Taxus-Stent Evaluated At Rotterdam Cardiology Hospital (T-SEARCH) registries. J Am Coll Cardiol 2006;47:1530-1537
CrossRef | Web of Science | Medline4
Chieffo A ,Park SJ ,Valgimigli M , et al. Favorable long-term outcome after drug-eluting stent implantation in nonbifurcation lesions that involve unprotected left main coronary artery: a multicenter registry. Circulation 2007;116:158-162
CrossRef | Web of Science | Medline
To the Editor:
Recent data suggest that the risk of death is similar whether patients with unprotected left main coronary artery disease undergo CABG or stent placement. Statin therapy has been a cornerstone of treatment provided by cardiologists for patients with coronary artery disease, whereas statins have been prescribed less often by cardiovascular surgeons. For example, according to one report, statin therapy was administered in 96% of patients who underwent PCI but in only 73% of patients who underwent CABG.1 Statin therapy reduces mortality among patients undergoing CABG by 2% at 30 days2 and reduces cardiac-related mortality by 3.7% after 1 year of treatment.3 This effect may have been greater after three years of therapy. What were the rates of statin use in the two study groups described by Seung et al.? An adjustment for statin use should be performed to fairly represent the benefits of CABG surgery when concomitant statin therapy is provided.
3 ReferencesJohn A. Tayek, M.D.
Harbor–UCLA Medical Center, Torrance, CA 90509
jtayek@ladhs.org 1
Fox DJ ,Kibiro M ,Eichhofer J ,Curzen NP . Patients undergoing coronary revascularisation: a missed opportunity for secondary prevention? Postgrad Med J 2005;81:401-403
CrossRef | Web of Science | Medline2
Pan W ,Pintar T ,Anton J ,Lee VV ,Vaughn WK ,Collard CD . Statins are associated with a reduced incidence of perioperative mortality after coronary artery bypass graft surgery. Circulation 2004;110:Suppl 1:I-1453
Dotani MI, Elnicki DM, Jain AC, Gibson CM. Effect of preoperative statin theapy and cardiac outcomes after coronary artery bypass grafting. Am J Cardiol 2000:86:1128-30, A6.
To the Editor:
The study by Seung et al. represents a major contribution to the evolution of revascularization for unprotected left main coronary artery disease. They show that a favorable outcome is achievable with PCI and that it is similar to the outcome with CABG. However, the main drawback with PCI, even with drug-eluting stents, appears to be a higher rate of target-vessel revascularization.
A limitation of this study is that the median follow-up of 3 years may pick up most cases of target-vessel revascularization secondary to stent restenosis but is arguably insufficient to pick up bypass graft failure, which may take 5 to 10 years to develop. Therefore, limited follow-up introduces bias against PCI.
An alternative to prolonged follow-up is the use of clinical correlates of the long-term outcome. Periprocedural myocardial injury has been shown to correlate with long-term mortality among patients treated with PCI and those treated with CABG.1-3 Did the authors compare periprocedural enzyme elevation between the two groups and consequent changes in global and regional left ventricular systolic function?
3 ReferencesJayanth R. Arnold, M.A.
Adrian P. Banning, M.D.
John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom1
Brener SJ ,Lytle BW ,Schneider JP ,Ellis SG ,Topol EJ . Association between CK-MB elevation after percutaneous or surgical revascularization and three-year mortality. J Am Coll Cardiol 2002;40:1961-1967
CrossRef | Web of Science | Medline2
Costa MA ,Carere RG ,Lichtenstein SV , et al. Incidence, predictors, and significance of abnormal cardiac enzyme rise in patients treated with bypass surgery in the Arterial Revascularization Therapies Study (ARTS). Circulation 2001;104:2689-2693
CrossRef | Web of Science | Medline3
Prasad A ,Singh M ,Lerman A ,Lennon RJ ,Holmes DR Jr ,Rihal CS . Isolated elevation in troponin T after percutaneous coronary intervention is associated with higher long-term mortality. J Am Coll Cardiol 2006;48:1765-1770
CrossRef | Web of Science | Medline
Author/Editor Response
In response to Pocar et al.: several risk-stratification systems are suggested to predict early mortality with PCI or CABG.1-3 However, there are limited data regarding the optimal uniform risk index for both treatments. The preprocedural risk variables in our study were mostly consistent with candidate variables included in risk-prediction models for early mortality. Urgent procedures were more common among patients undergoing PCI than among those undergoing CABG (28% vs. 18%), but this difference did not significantly affect clinical outcomes. Although the timing of recent myocardial infarction was not classified and data for the other potential confounders mentioned were not available, these variables are unlikely to have biased the treatment effect, since several concordant variables with possible collinearity (previous myocardial infarction, congestive heart failure, ejection fraction, clinical indication, and severe coexisting conditions) were accounted for in the adjusted models.
Regarding Tomoda's comments, we performed exploratory analyses for major clinical and anatomical subgroups potentially affecting outcomes.4,5 The risk-adjusted mortality after PCI as compared with CABG did not significantly differ among patients with diabetes (hazard ratio, 1.02; 95% confidence interval [CI], 0.56 to 1.87), poor ventricular function with an ejection fraction of less than 40% (hazard ratio, 2.08; 95% CI, 0.51 to 8.56), or involvement of distal bifurcation (hazard ratio, 0.79; 95% CI, 0.49 to 1.29). However, the risk of target-vessel revascularization was consistently higher in the PCI groups.
Regarding Tayek's comments, the percentages of patients who were receiving statins at discharge were similar among patients who underwent stenting and those who underwent CABG (52% and 49%, respectively; P=0.20). In addition, the outcomes were not materially affected after adjustment for statin use or other medications in the multivariable models.
In response to Arnold and Banning: routine angiographic surveillance within 1 year after PCI could have penalized the PCI group with respect to the rate of target-vessel revascularization because of underestimation of asymptomatic graft failure in the CABG group. The incidence and magnitude of elevations in the creatine kinase MB fraction were higher in the CABG group than in the PCI group (>1 to 3 times the upper limit of the reference range, 22% vs. 19%; >3 to 5 times, 20% vs. 4%; >5 to 10 times, 28% vs. 4%; and >10 times, 20% vs. 4%). Levels of creatine kinase MB fraction elevation were not associated with clinical outcomes after PCI. However, in patients undergoing CABG, a creatine kinase MB fraction elevation that was 10 times the upper limit of the reference range was independently correlated with an increase in long-term mortality (hazard ratio, 1.92; 95% CI, 1.20 to 3.07) but not with target-vessel revascularization.
5 ReferencesSeung-Jung Park, M.D., Ph.D.
Duk-Woo Park, M.D., Ph.D.
Young-Hak Kim, M.D., Ph.D.
Asan Medical Center, Seoul 138-736, Korea
sjpark@amc.seoul. kr 1
Nashef SA ,Roques F ,Michel P ,Gauducheau E ,Lemeshow S ,Salamon R . European system for cardiac operative risk evaluation (EuroSCORE). Eur J Cardiothorac Surg 1999;16:9-13
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Parsonnet V ,Dean D ,Bernstein AD . A method of uniform stratification of risk for evaluating the results of surgery in acquired adult heart disease. Circulation 1989;79:I-3[Erratum, Circulation 1990;82:1078.]3
Singh M ,Gersh BJ ,Li S , et al. Mayo Clinic Risk Score for percutaneous coronary intervention predicts in-hospital mortality in patients undergoing coronary artery bypass graft surgery. Circulation 2008;117:356-362
CrossRef | Web of Science | Medline4
Hannan EL ,Wu C ,Walford G , et al. Drug-eluting stents vs. coronary-artery bypass grafting in multivessel coronary disease. N Engl J Med 2008;358:331-341
Full Text | Web of Science | Medline5
Park DW ,Yun SC ,Lee SW , et al. Long-term mortality after percutaneous coronary intervention with drug-eluting stent implantation versus coronary artery bypass surgery for the treatment of multivessel coronary artery disease. Circulation 2008;117:2079-2086
CrossRef | Web of Science | Medline
- Citing Articles (1)
Citing Articles
1
Marco T. Castagna, Mauricio Cavalieri Machado, Jordan Vieira de Oliveira. (2010) Left main intervention in myocardial infarction. Catheterization and Cardiovascular Interventions 75:2, 225-228
CrossRef
