Background: The two primary interventions for patients with multivessel coronary artery disease (CAD) are coronary artery bypass grafting (CABG) and stenting by percutaneous coronary intervention (PCI). Whether one of these treatment options is preferable remains open to debate. Bare-metal coronary stents were introduced as a less-invasive alternative to CABG, but they have a significant risk of restenosis. Despite early reports that drug-eluting stents had lower restenosis rates, there have been emerging reports of late stent thrombosis with these devices, and the U.S. Food and Drug Administration has organized an advisory committee to address their safety. As a result, it is unclear whether the reports from earlier studies about the outcomes of CABG compared with coronary stenting are reflective of current practice outcomes. Hannan and colleagues compared rates of death, death or myocardial infarction, and subsequent revascularization in patients receiving drug-eluting stents or those undergoing CABG.

The Study: This observational study reviewed several databases established to collect information on all residents of New York State who underwent CABG or PCI in nonfederal hospitals. Standardized definitions for adverse outcomes, cardiovascular function, and the nature of diseased vessels were used in the databases, including whether bare-metal or drug-eluting stents were used in PCI. Patient data and records were cross-referenced with a statewide acute care discharge-reporting system that included diagnoses and procedures, admission and discharge dates, and discharge disposition. Data points, including postdischarge deaths and subsequent emergency hospitalizations with myocardial infarction as the primary diagnosis, were also analyzed.

The study included patients with CAD treated with drug-eluting stents or CABG over a 15-month period. Exclusion criteria included having left main CAD, previous revascularization, myocardial infarction within 24 hours before treatment, or not being a New York resident. The end points of the study were death in the hospital or within 30 days after treatment; and death, death or myocardial infarction, and need for repeat revascularization within 18 months after treatment.

Results: A total of 9,963 patients receiving drug-eluting stents and 7,437 patients undergoing CABG were evaluated, with mean follow-up of 18.7 and 19.1 months, respectively. Patients undergoing CABG were generally older than those treated with stents, and were more likely to be male, have lower ejection fractions, have had a previous myocardial infarction, have other coexisting conditions, and have three-vessel disease. No significant differences between the groups were found in risk-adjusted rates on in-hospital or 30-day mortality.

Patients receiving drug-eluting stents were significantly more likely to require revascularization with PCI or CABG within 18 months of the initial procedure (30.6 percent) compared with those who initially underwent CABG (5.2 percent). Of the 28.4 percent of patients who underwent repeat PCI after initial drug-eluting stent placement, approximately one fourth underwent target-vessel revascularization.

CABG was associated with significantly lower rates of death and of death or myocardial infarction at approximately 18 months after the initial procedure (see accompanying table). The adjusted survival rate for patients with three-vessel disease was significantly better with CABG (94.0 percent) versus stents (92.7 percent), and the adjusted rates of survival free from myocardial infarction were 92.1 versus 89.7 percent, respectively. Similar findings were seen in patients with two-vessel disease. Subgroup analysis for high-risk patients with diabetes mellitus, ejection fractions below 40 percent, or age of at least 80 years showed no significant differences in mortality between those receiving CABG and drug-eluting stents, but the latter two subgroups treated with CABG did have lower rates of the combined end point of death or myocardial infarction.

Conclusion: The authors conclude that, in patients with multivessel CAD, CABG had significantly lower rates of mortality, myocardial infarction, or need for repeat revascularization compared with drug-eluting stents. This was true regardless of whether there was proximal left anterior descending artery disease.