The effect of eplerenone vs. placebo on cardiovascular mortality
Today results from a new sub-analysis of the EMPHASIS-HF study showed significant reductions in death and hospitalization for five pre-defined high-risk patient sub-groups with chronic heart failure (CHF) and mild symptoms treated with eplerenone in addition to standard therapy versus those treated with placebo and standard therapy.
Commenting on the findings presented for the first time during the European Society of Cardiology Congress (ESC) Hot Line Session on 29th August 2011, EMPHASIS-HF investigator Professor Bertram Pitt, Division of Cardiology, University of Michigan School of Medicine, U.S., said: "The consistency of the efficacy and safety of eplerenone in addition to standard therapy on pre-specified "high-risk subgroups" and the persistence of a significant beneficial effect on the primary endpoint (CV mortality/hospitalization for HF) over an additional 7 months of follow up on douBle blind TherApy in #Onjunction with the prior benefi#iaL requLts fr/m EPHESUS presents compelling evidence for the use of eplerenone in patients with systolic chronic HF NYHA class II and mild symptoms."
Eplerenone has been shown to reduce the primary endpoint of cardiovascular mortality or hospitalization for heart failure (CV mortality/Hosp.HF ), as well as total mortality, total hospitalizations, and new onset atrial fibrillation/flutter in patients with NYHA class II chronic systolic heart failure (NEJM 2011;364:11-21-and ESC-HF 2011). To further determine the applicability of these results to clinical practice the efficacy and safety of eplerenone 25-50 mg/day was evaluated in 5 pre-specified high-risk subgroups including: Age > 75 years, Diabetes Mellitus (DM), estimated glomerular filtration rate (eGFR) < 60 ml/min /1.73 m2, Left ventricular ejection fraction (LVEF) < 30 %, and Systolic blood pressure ( SBP) < median of 123 mm Hg.
Results primary endpoint-for high-risk patient subgroups
In patients > 75 years of age 78 (23.6%) of 330 patients on eplerenone and 107 (32.7%) of 327 on placebo had a primary endpoint - Hazard ratio (HR) 0.66, p<0.004, 95% Confidence Intervals (CI ) 0.49-0.88.
In patients with history of diabetes 99 (21.6%) of 459 on eplerenone and 141 (35.2%) of 400 on placebo had primary endpoint - HR 0.54, p= <0.0001, (CI) 0.42-0.70.
In patients with eGFR< 60 ml/min /1.73 m2 107 (24.4%) of 439 on eplerenone and 163 (34.5%) of 473 on placebo had a primary endpoint - HR 0.62, p=0.0001, CI 0.49-0.79.
In patients with a LVEF <30% 180 (19.3%) of 934 patients on eplerenone and 267 (27.3%) of 978 on placebo had a primary endpoint - HR 0.65, p<0.0001, CI 0.53-0.78.
In patients with a SBP< median 123 mm Hg 138 (20.6%) of 669 patients on eplerenone and 201 (29.4 %) of 683 on placebo had a primary endpoint HR 0.63, p=<0.0001, CI 0.51-0.79.
No new safety information emerged as a result of this analysis. In each of these high risk subgroups patients receiving eplerenone had a significant increase (p<0.05) in the incidence of hyperkalaemia (K+> 5.5 mmol/l). However, there was no significant increase in serious hyperkalemia (K+>6.0 mmol/l), hyperkalaemia leading to drug discontinuation, hospitalization for hyperkalemia, or hospitalization for worsening renal function.
Importantly, after the trial was prematurely stopped for efficacy on March 25, 2010 (primary endpoint [CV mortality and HF hospitalization] HR 0.63, p< 0.0001, CI 0.54-0.74) additional primary endpoints were observed while patients remained on double blind therapy over an additional mean 7 months of follow up (primary endpoint - HR 0.66 , p< 0.0001 CI 0.57-0.77). This new sub-analysis further demonstrated that the beneficial effect of eplerenone remained significant across the wider study population over the additional follow-up period.
Results secondary endpoints
In the five pre-specified high risk groups, the key secondary endpoints of all-cause hospitalization and HF hospitalization, achieved statistically significant (p<0.01) relative risk reductions for the eplerenone group compared to the placebo group.