In patients with heart failure and reduced ejection fraction (HFrEF), several therapies have been proven to reduce mortality in clinical trials. However, there are few data on the effect of the use of evidence-based therapies on causes of death in clinical practice.

This study included 2351 outpatients with HFrEF (< 40%) from 2 multicenter prospective registries: MUSIC (n=641, period: 2003-2004) and REDINSCOR I (n=1710, period: 2007-2011). Variables were recorded at inclusion and all patients were followed-up for 4 years. Causes of death were validated by an independent committee.

Patients in REDINSCOR I more frequently received beta-blockers (85% vs 71%; P <.001), mineralocorticoid antagonists (64% vs 44%; P <.001), implantable cardioverter-defibrillators (19% vs 2%; P <.001), and resynchronization therapy (7.2% vs 4.8%; P=.04). In these patients, sudden cardiac death was less frequent than in those in MUSIC (6.8% vs 11.4%; P <.001). After propensity score matching, we obtained 2 comparable populations differing only in treatments (575 vs 575 patients). In patients in REDINSCOR I, we found a lower risk of total mortality (HR, 0.70; 95%CI, 0.57-0.87; P=.001) and sudden cardiac death (sHR, 0.46; 95%CI, 0.30-0.70; P <.001), and a trend toward lower mortality due to end-stage HF (sHR, 0.73; 95%CI, 0.53-1.01; P=.059), without differences in other causes of death (sHR, 1.17; 95%CI, 0.78-1.75; P=.445), regardless of functional class.

In ambulatory patients with HFrEF, implementation of evidence-based therapies was associated with a lower risk of death, mainly due to a significant reduction in sudden cardiac death.