Percutaneous intervention versus coronary artery bypass graft surgery in left main coronary artery stenosis: a systematic review and meta-analysis

BACKGROUND The optimal revascularization technique in patients with left main coronary artery disease (CAD) remains controversial. We aimed to compare the long-term performance of percutaneous coronary intervention (PCI) versus coronary artery bypass graft (CABG) surgery in treatment of left main CAD. METHODS PubMed, EMBASE, and the Cochrane Library were searched until November 16, 2016. RESULTS Six randomized controlled trials and 22 matched observational studies including 22,487 patients and 90,167 patient-years of follow-up were included. PCI was associated with an overall higher risk for the major adverse cardiac and cerebrovascular events (hazard ratio (HR), 1.42; 95% confidence interval (CI), 1.14-1.77), mainly driven by higher rates of myocardial infarction (HR, 1.69; 95% CI, 1.22-2.34) and revascularization (HR, 2.80; 95% CI, 1.86-4.22). The overall risks for all-cause death (HR, 1.05; 95% CI, 0.93-1.20), cardiac death (HR, 1.05; 95% CI, 0.69-1.59), stroke (HR, 0.64; 95% CI, 0.33-1.24), and the composite safety endpoint of death, myocardial infarction, or stroke (HR, 1.06; 95% CI, 0.97-1.16) were similar between PCI and CABG. Stratified analysis based on stent types showed that the increased risk for myocardial infarction associated with PCI was only evident in patients with bare-metal stents or early-generation drug-eluting stents (DES), but not newer-generation DES. Stratified analyses based on study designs showed largely similar findings with the overall analyses, except for a significantly higher incidence of myocardial infarction in adjusted studies (HR, 2.01; 95% CI, 1.64-2.45) but a trend toward higher incidence in randomized trials (HR, 1.39; 95% CI, 0.85-2.27) associated with PCI. CONCLUSIONS Compared with CABG, PCI with newer-generation DES might be a safe alternative revascularization strategy for treatment of left main CAD, but is associated with more repeat revascularization.