Background: Mineralocorticoid receptor antagonists (MRA) improve outcome in the setting of post-myocardial infarction (MI) heart failure (HF).
Objectives: The study sought to assess the benefit of an early MRA regimen in acute MI irrespective of the presence of HF or left ventricular (LV) dysfunction.
Methods: We randomized 1,603 patients to receive an MRA regimen with a single intravenous bolus of potassium canrenoate (200 mg) followed by oral spironolactone (25 mg once daily) for 6 months in addition to standard therapy or standard therapy alone. The primary outcome of the study was the composite of death, resuscitated cardiac arrest, significant ventricular arrhythmia, indication for implantable defibrillator, or new or worsening HF at 6-month follow-up. Key secondary/safety outcomes included death and other individual components of the primary outcome and rates of hyperkalemia at 6 months.
Results: The primary outcome occurred in 95 (11.8%) and 98 (12.2%) patients in the treatment and control groups, respectively (hazard ratio [HR]: 0.97; 95% confidence interval [CI]: 0.73 to 1.28). Death occurred in 11 (1.4%) and 17 (2.1%) patients in the treatment and control groups, respectively (HR: 0.65; 95% CI: 0.30 to 1.38). In a non-pre-specified exploratory analysis, the odds of death were reduced in the treatment group (3 [0.5%] vs. 15 [2.4%]; HR: 0.20; 95% CI: 0.06 to 0.70) in the subgroup of ST-segment elevation MI (n = 1,229), but not in non-ST-segment elevation MI (p for interaction = 0.01). Hyperkalemia >5.5 mmol/l(-1) occurred in 3% and 0.2% of patients in the treatment and standard therapy groups, respectively (p < 0.0001).
Conclusions: The study failed to show the benefit of early MRA use in addition to standard therapy in patients admitted for MI. (Aldosterone Lethal effects Blockade in Acute myocardial infarction Treated with or without Reperfusion to improve Outcome and Survival at Six months follow-up; NCT01059136).
Keywords: left ventricular dysfunction; mineralocorticoid receptor antagonists; mortality.
Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.