Comparison of coronary artery bypass surgery and percutaneous drug-eluting stent implantation for treatment of left main coronary artery stenosis.

OBJECTIVES: The purpose of this study was to compare outcomes for drug-eluting stents (DES) and coronary artery bypass graft (CABG) surgery in patients with unprotected left main coronary artery (ULMCA) stenosis.

BACKGROUND: Expert guidelines recommend coronary artery bypass graft (CABG) surgery for the treatment of significant stenosis of the unprotected left main coronary artery (ULMCA) if the patient is eligible for CABG; however, treatment by percutaneous coronary intervention (PCI) is common.

METHODS: Details of patients (n = 343, ages 69.9 +/- 11.9 years) undergoing coronary revascularization for ULMCA stenosis (April 2003 to January 2007) were recorded. A total of 223 patients were treated with CABG (mean [interquartile range]: follow-up 600 [226 to 977) days) and 120 by PCI (follow-up 362 [192 to 586) days). The hazard ratios (HRs) for death and major adverse cardiovascular and cerebrovascular events (MACCE) were calculated incorporating propensity score adjustment. Survival comparisons were conducted in propensity-matched subjects (n = 134), and in low- and high-risk subjects for CABG.

RESULTS: Patients treated by PCI were more likely to be >or=75 years of age (49% vs. 33%; p = 0.005), and of greater surgical risk (Parsonnet score 17.2 +/- 11.2 vs. 13.0 +/- 9.3; p < 0.001) than patients treated by CABG. Overall, the propensity-adjusted HR for death was not statistically different (HR 1.93, 95% confidence interval [CI] 0.89 to 4.19, p = 0.10), but MACCE was greater in the PCI group (HR 1.83, 95% CI 1.01 to 3.32, p = 0.05). In propensity-matched individuals, neither survival nor MACCE-free survival were different. Survival was equivalent among low-risk candidates, but PCI had a tendency to inferior survival in high-risk candidates (Ellis category IV, log-rank p = 0.05). Interaction testing, however, failed to demonstrate a difference in outcomes of the 2 revascularization techniques as a function of baseline risk assessment.

CONCLUSIONS: Overall, the propensity-adjusted risk of mortality for treatment of ULMCA disease does not differ between PCI- and CABG-treated groups. There appears to be sufficient equipoise that a randomized clinical trial to compare the techniques would not be ethically contraindicated.