Does an occluded RCA affect prognosis in patients undergoing PCI or CABG for left main coronary artery disease? Analysis from the EXCEL trial

Aims: The impact of an occluded right coronary artery (RCA) in patients with left main coronary artery disease (LMCAD) undergoing revascularisation is unknown. We compared outcomes for patients with LMCAD randomised to percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) according to the presence of an occluded RCA in the EXCEL trial. Methods and results: The EXCEL trial randomised 1,905 patients with LMCAD and SYNTAX scores <= 32 to PCI with everolimus-eluting stents versus CABG. Patients were categorised according to whether they had an occluded RCA at baseline, and their outcomes were examined using multivariable Cox proportional hazards regression. The primary endpoint was a composite of death, stroke, or myocardial infarction at three years. Among 1,753 patients with a dominant RCA by core laboratory analysis, the RCA was occluded in 130 (7.4%) at baseline. PCI was attempted in 34 of 65 patients with an occluded RCA (52.3%) and was successful in 27 (79.4% of those attempted; 41.5% of all RCAs recanalised). The RCA was bypassed in 42 of 65 patients with an occluded RCA (64.6%; p=0.0008 versus PCI). The three-year absolute and relative rates of the primary endpoint were similar between PCI and CABG, in patients with or without an occluded RCA (p(interaction)=0.92). Conclusions: In the EXCEL trial, the presence of an occluded RCA at baseline did not confer a worse three-year prognosis in patients undergoing revascularisation for LMCAD and did not affect the relative outcomes of PCI versus CABG in this high-risk patient cohort.