Some but not all randomized controlled trials (RCT) have suggested that percutaneous coronary intervention (PCI) with drug-eluting stents may be an acceptable alternative to coronary artery bypass grafting (CABG) surgery for the treatment of unprotected left main coronary artery disease (ULMCAD). We therefore aimed to compare the risk of all-cause mortality between PCI and CABG in patients with ULMCAD in a pairwise meta-analysis of RCT.

Randomized controlled trials comparing PCI vs CABG for the treatment of ULMCAD were searched through MEDLINE, EMBASE, Cochrane databases, and proceedings of international meetings.

Six trials including 4,686 randomized patients were identified. After a median follow-up of 39 months, there were no significant differences between PCI vs CABG in the risk of all-cause mortality (hazard ratio [HR] 0.99, 95% CI 0.76-1.30) or cardiac mortality. However, a significant interaction for cardiac mortality (P_interaction= .03) was apparent between randomization arm and SYNTAX score, such that the relative risk for mortality tended to be lower with PCI compared with CABG among patients in the lower SYNTAX score tertile, similar in the intermediate tertile, and higher in the upper SYNTAX score tertile. Percutaneous coronary intervention compared with CABG was associated with a similar long-term composite risk of death, myocardial infarction, or stroke (HR 1.06, 95% CI 0.82-1.37), with fewer events within 30 days after PCI offset by fewer events after 30 days with CABG (P_interaction < .0001). Percutaneous coronary intervention was associated with greater rates of unplanned revascularization compared with CABG (HR 1.74, 95% CI 1.47-2.07).

In patients undergoing revascularization for ULMCAD, PCI was associated with similar rates of mortality compared with CABG at a median follow-up of 39 months, but with an interaction effect suggesting relatively lower mortality with PCI in patients with low SYNTAX score and relatively lower mortality with CABG in patients with high SYNTAX score. Both procedures resulted in similar long-term composite rates of death, myocardial infarction, or stroke, with PCI offering an early safety advantage and CABG demonstrating greater durability.