Benefit of revascularization for stable ischaemic heart disease: the jury is still out

Abstract

Patients with stable ischaemic heart disease (SIHD) and moderate to severe ischaemia are at increased risk of death and myocardial infarction (MI) when compared with those with no or mild ischaemia.1,2 Relatively old studies have shown that revascularization using coronary artery bypass grafting (CABG) improves survival in patients with high-risk anatomical features (such as left main coronary disease or triple vessel disease) compared with medical management.3–5 Since then, percutaneous coronary intervention (PCI) has progressively replaced CABG as the dominant method of revascularization for SIHD. While there have been important improvements in both percutaneous and surgical revascularization techniques, there has been simultaneous progress in medical therapy and to a certain extent, all comparisons of treatments are time-sensitive and plagued by the continuous technical advances which tend to render obsolete previous trial results. The ACIP study, a pilot randomized trial in the older medical therapy era, had suggested benefit of revascularization (using balloon angioplasty or CABG) over optimal medical therapy (OMT) in patients with SIHD.6 Furthermore, data from large retrospective cohorts have consistently shown that revascularization was associated with a lower risk of cardiac death in patients with >10% ischaemic myocardium as assessed by scintigraphy.7–9 Finally, a recent meta-analysis of randomized trials also concluded that PCI and CABG were associated with improved survival.10 Nevertheless, modern large randomized trials comparing PCI added to OMT vs. OMT alone for SIHD, such as COURAGE and BARI 2D, have found that PCI and OMT resulted in comparable clinical outcomes in terms of death or MI.11,12 Therefore, given the current evidence, one interpretation of COURAGE is that stable patients in whom coronary artery disease extent is known can be treated first with OMT, postponing a decision of revascularization to the time point when …