Treatment of Left Main Disease: Let the Patient Choose

Abstract

The choice between percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG) for the treatment of left main coronary artery (LMCA) disease has been debated for over a decade. When tackling the controversy, we need to take into account the heterogeneity of the disease, that is, location (ostial, body, or bifurcation), with or without involvement of the coronary tree, with or without diabetes mellitus, young versus elderly, and men versus women. Further, the lack of uniformity of end points across trials makes it difficult to pool studies together for metaanalyses. The 2 largest published randomized trials with 5year followup data showed conflicting results. The EXCEL1 (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial (N=1905) demonstrated that at 5 years, both PCI and CABG had similar incidence of the primary composite end point (allcause death, myocardial infarction [MI], and stroke). In contrast, the NOBLE (Nordic– Baltic– British Left Main Revascularisation) trial2 (N=1201) demonstrated superiority of CABG over PCI for the primary composite end point of allcause death, nonprocedural MI, repeated revascularization, and stroke at 5 years. These results are mainly driven by the differences in MI and repeat revascularization rates in both groups. Importantly, allcause mortality was higher in the PCI group versus the CABG group in the EXCEL trial (odds ratio [OR], 1.38; 95% CI, 1.03– 1.85), with no differences noted in cardiovascular mortality (OR, 1.26; 95% CI, 0.85– 1.85). Adding to this, 3 recent metaanalyses also demonstrated conflicting results. In the metaanalysis of 5 randomized trials (4612 patients) done by Ahmad et al, both PCI and CABG showed no differences in mortality and clinical events at 10year followup.3 Zhang et al4 performed a metaanalysis of 4 randomized trials including 4394 patients and showed that there are no significant differences in allcause mortality, stroke, or MI in patients with a low or intermediate SYNTAX (Synergy Between PCI With TAXUS and Cardiac Surgery) score (hazard ratio [HR], 1.20; 95% CI, 0.85– 1.70), but there was a higher incidence following PCI in patients with a higher SYNTAX score (HR, 1.64; 95% CI, 1.20– 2.24). In the largest metaanalysis, of 23 clinical trials and retrospective studies (13 260 patients),5 the PCI arm was noted to have significantly higher cardiovascular mortality (incidence ratio, 1.24; 95% CI, 1.05– 1.45) and noncardiovascular mortality (incidence ratio, 1.19; 95% CI, 1.00– 1.41) relative to CABG. However, a major criticism of this metaanalysis is the heterogeneity of the patient population, with varying clinical presentation limiting broad conclusions about treatment effect. In response to the results from the clinical trials and the metaanalyses, the 2018 European clinical practice guidelines for myocardial revascularization supported PCI of the LMCA, with a Class I recommendation and level of evidence A if the SYNTAX