Aims: Outcomes according to the status of renal insufficiency have not been fully evaluated in left main coronary artery disease (LMCAD). In the present study therefore, we sought to evaluate clinical outcomes in patients with significant LMCAD stratified by the degree of renal insufficiency and the relative clinical outcomes after PCI and CABG stratified by the differential levels of renal function using data from the large multinational "all-comers" Interventional Research Incorporation Society-Left MAIN Revascularization (IRIS-MAIN) registry.
Methods and results: Among 4,894 patients with LMCAD, renal insufficiency was graded according to the estimated glomerular filtration rate (eGFR). The primary outcome was major adverse cardiac and cerebrovascular events (MACCE), defined as death, myocardial infarction, stroke, or any revascularisation. The patients were stratified into three groups according to eGFR: 3,824 (78%) in group 1 (eGFR ≥60 ml·min-1·1.73 m2), 838 (17%) in group 2 (eGFR ≥30 and <60), and 232 (5%) in group 3 (eGFR <30). At two years, after adjustment, compared with group 1, the risk of MACCE was significantly higher in group 2 (hazard ratio [HR] 1.46, 95% confidence interval [CI]: 1.18-1.79) and in group 3 (HR 3.39, 95% CI: 2.61-4.40). The p interaction for MACCE across groups was 0.20. The adjusted risk of MACCE was similar between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in groups 1 and 2. However, PCI was associated with a significantly higher risk of MACCE compared to CABG (HR 1.88, 95% CI: 1.08-3.25) in group 3.
Conclusions: The degree of renal insufficiency was proportionately associated with unfavourable outcomes in patients with LMCAD. In group 3, PCI was associated with a higher risk of MACCE compared with CABG. Also, the effect of PCI versus CABG on MACCE was consistent, with PCI being associated with less bleeding and CABG being associated with less repeat revascularisation.