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.