Effect of eplerenone according to duration of heart failure in EMPHASIS-HF: It is never too late to start an MRA in HFrEF

Abstract

Abstract Background In the Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure trial (EMPHASIS-HF), the mineralocorticoid receptor antagonist (MRA) eplerenone reduced both the risk of death and heart failure (HF) hospitalization in patients with HF and reduced ejection fraction (HFrEF) and mild symptoms. However, many patients are still not prescribed an MRA and physicians may be reluctant to add another treatment in patients with longstanding HF who appear to be "stable" on their current therapy. Purpose As little is known about how the effect of MRA therapy varies by the duration of HF, we examined the efficacy of eplerenone according to time from HF diagnosis among patients in EMPHASIS-HF. The primary trial outcome was the composite of a first hospitalization for HF or cardiovascular death. Methods Three patient groups of similar size were created according to the duration of HF: <1 year, ≥1 to <5 years, and ≥5 years. Outcomes were analysed using Cox regression and the Kaplan-Meier estimate. Treatment effects were examined according to HF duration category and also using the duration of HF as a continuous variable. Results The number of patients in each group was: 975 (<1 year), 769 (1 - <5 years), and 988 (≥5 years), respectively. Patients with longer duration of HF were older and more frequently had an ischaemic aetiology of HF. Additionally, a longer duration of HF was associated with lower eGFR levels, wider QRS duration, and a higher proportion of atrial fibrillation at baseline. The rate of the primary outcome (per 100 person-year) increased with HF duration: 9.8 (95% CI: 8.4-11.4) for <1 year, 13.5 (11.6-15.7) for 1 - <5 years, and 17.6 (15.6-19.8) for ≥5 years. Similar trends were seen in all other outcomes (Figure 1). The hazard ratios for the effect of eplerenone compared to placebo on the primary outcome were 0.57 (95% CI: 0.42-0.79) for <1 year, 0.81 (0.60-1.10) for 1- <5 years, and 0.61 (0.48-0.78) for ≥5 years; P for interaction = 0.24. The benefits of eplerenone were also consistent across the duration of HF examined as a continuous variable (Figure 2). For the primary outcome, The number needed to treat (NNT) over the duration of the trial, for the primary outcome, was 14 for <1 year, 13 for 1 - <5 years and only 10 for ≥5 years duration. Conclusions Patients with a longer duration of HF had worse clinical status and a higher rate of events, but the benefit of eplerenone was consistent in people with longer-standing HF and HF of shorter duration. These data suggest that it is never too late to start an MRA in patients with HFrEF. Figure 1. Outcomes according to heart failure duration category Abbreviations: CV cardiovascular; HF heart failure Figure 2. Treatment effects according to the duration of heart failure Abbreviations: CV cardiovascular; HF heart failureFigure 1Figure 2