Long-term outcomes among patients with severe ischaemic cardiomyopathy undergoing revascularisation by coronary artery bypass grafting or percutaneous coronary intervention.

Abstract

Aims: The optimal revascularisation strategy in patients with ischaemic cardiomyopathy remains unclear. This study aimed to assess the long-term outcomes in patients with stable ischaemic cardiomyopathy revascularised by coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI). Methods: Using the Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and Melbourne Interventional Group (MIG) registries (from Jan 2005 to Jan 2018), patients with severe ischaemic cardiomyopathy (left ventricular ejection fraction <35%) undergoing PCI or isolated CABG were included (ST-elevation myocardial infarction and cardiogenic shock were excluded). The primary outcome was long-term national death index (NDI) linked mortality. Risk adjustment was performed using propensity-score analysis—inverse probability of treatment weighting (IPTW), estimating average treatment effect. Results: A total of 2,042 patients were included, comprising of 1,451 undergoing CABG and 591 PCI. Following propensity score weighting, the groups were well balanced with respect to baseline demographics including age (65.8±13.2 years vs 65.6±10.7 years), sex, comorbidities, procedural indication, and coronary disease extent. Patients treated by CABG had 33% relative risk reduction in long-term mortality (HR=0.67, 95% CI 0.5–0.9, p=0.006). There was no difference for in-hospital mortality (OR=1.0, 95%CI 0.22–4.6, p=0.99), but increased risk of in-hospital stroke (OR=18.8, 95% CI 4.3–81.9, p<0.001) and length of hospital stay (IRR=2.7, 95% CI 2.2–3.4, p<0.001) in patients treated with CABG. Conclusion: In this multi-centre, propensity-score analysis, patients with ischaemic cardiomyopathy treated by CABG rather than PCI had improved long-term survival. Further definitive randomised data are needed to guide optimal revascularisation strategy in this complex cohort of patients.