The independent reduction in mortality associated with guideline-directed medical therapy in patients with coronary artery disease and heart failure with reduced ejection fraction

AIMS: Guideline-directed medical therapy (GDMT) is underutilized in patients with coronary artery disease (CAD). However, there are no studies evaluating the impact of GDMT adherence on mortality among patients with CAD and heart failure with reduced ejection fraction (HFrEF). We sought to investigate the association of GDMT adherence with long-term mortality in patients with CAD and HFrEF. METHODS AND RESULTS: Surgical Treatment for Ischaemic Heart Failure (STICH) was a trial of patients with an left ventricular ejection fraction ≤35% and CAD amenable to coronary artery bypass graft surgery (CABG) who were randomized to CABG plus medical therapy (N = 610) or medical therapy alone (N = 602). Median follow-up time was 9.8 years. We defined GDMT for the treatment of CAD and HFrEF as the combination of at least one antiplatelet drug, a statin, a beta-blocker, and an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. The primary outcome was all-cause mortality. Assessment of the independent association between GDMT and mortality was performed using multivariable Cox regression with GDMT as a time-dependent covariate. In the CABG arm, 63.6% of patients were on GDMT throughout the study period compared to 66.5% of patients in the medical therapy arm (P = 0.3). GDMT was independently associated with a significant reduction in mortality (hazard ratio 0.65, 95% confidence interval 0.56-0.76; P < 0.001). CONCLUSION: GDMT is associated with reduced mortality in patients with CAD and HFrEF independent of revascularization with CABG. Strategies to improve GDMT adherence in this population are needed to maximize survival.