Coronary artery bypass grafting vs. percutaneous coronary intervention in severe ischaemic cardiomyopathy: long-term survival

The optimal revascularization strategy in patients with ischaemic cardiomyopathy remains unclear with no contemporary randomized trial data to guide clinical practice. This study aims to assess long-term survival in patients with severe ischaemic cardiomyopathy revascularized by either coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI).

Using the Australian and New Zealand Society of Cardiac and Thoracic Surgeons and Melbourne Interventional Group registries (from January 2005 to 2018), patients with severe ischaemic cardiomyopathy [left ventricular ejection fraction (LVEF) <35%] undergoing PCI or isolated CABG were included in the analysis. Those with ST-elevation myocardial infarction and cardiogenic shock were excluded. The primary outcome was long-term National Death Index–linked mortality up to 10 years following revascularization. Risk adjustment was performed to estimate the average treatment effect using propensity score analysis with inverse probability of treatment weighting (IPTW).

A total of 2042 patients were included, of whom 1451 patients were treated by CABG and 591 by PCI. Inverse probability of treatment weighting–adjusted demographics, procedural indication, coronary artery disease extent, and LVEF were well balanced between the two patient groups. After risk adjustment, patients treated by CABG compared with those treated by PCI experienced reduced long-term mortality [adjusted hazard ratio 0.59, 95% confidence interval (CI) 0.45–0.79, P = .001] over a median follow-up period of 4.0 (inter-quartile range 2.2–6.8) years. There was no difference between the groups in terms of in-hospital mortality [adjusted odds ratio (aOR) 1.42, 95% CI 0.41–4.96, P = .58], but there was an increased risk of peri-procedural stroke (aOR 19.6, 95% CI 4.21–91.6, P < .001) and increased length of hospital stay (exponentiated coefficient 3.58, 95% CI 3.00–4.28, P < .001) in patients treated with CABG.

In this multi-centre IPTW analysis, patients with severe ischaemic cardiomyopathy undergoing revascularization by CABG rather than PCI showed improved long-term survival. However, future randomized controlled trials are needed to confirm the effect of any such benefits.