Long-term trends of treatment effect of stenting or bypass surgery in patients with ostial or shaft left main coronary artery disease

Background: Little is known about how the relative treatment effect of percutaneous coronary intervention (PCI) and coronary-artery bypass grafting (CABG) on clinical outcomes in ostial or shaft left main coronary artery (LMCA) disease has evolved over time. Methods: This study included 2,112 patients with ostial or shaft LMCA disease from IRIS-MAIN registry who underwent PCI (n = 1,329) or CABG (n = 783). Patients were stratified by time period based on stent type availability: wave 1 (1995–2002, bare-metal stent [BMS] era); wave 2 (2003–2006, first-generation drug-eluting stent [DES] era); and wave 3 (2007–2014, second-generation DES era). Results: Compared to CABG, PCI has been used more frequently from wave 1 to wave 3. PCI showed substantial improvements over time with respect to death (P for trend = 0.012); the composite of death, myocardial infarction (MI), or stroke (P for trend = 0.047); repeat revascularization (P for trend < 0.001); and major adverse cardiac and cerebrovascular events (MACCE; a composite of death, MI, stroke, or repeat revascularization) (P for trend < 0.001). By contrast, outcomes of CABG remained relatively stable over time. The gap between the treatment effects of CABG vs PCI for MACCE has narrowed over time; the adjusted hazard ratios for CABG compared to PCI during wave 1, 2, and 3 were 0.41 (95% confidence interval [CI]: 0.22–0.76), 0.47 (95% CI: 0.31–0.71), and 0.78 (95% CI: 0.50–1.20), respectively. Conclusions: In patients with ostial or shaft LMCA disease, significant improvements in PCI outcomes resulted in a progressive decline in the gap between the outcomes of CABG and PCI.