Association Between Mineralocorticoid Receptor Antagonist Use and Outcome in Myocardial Infarction Patients With Heart Failure

BACKGROUND: There are no studies of mineralocorticoid receptor antagonist (MRA) treatment examining outcome in unselected real‐life patients with myocardial infarction (MI) and heart failure (HF). There is uncertainty regarding effects of MRA in relation to left ventricular ejection fraction (LVEF) and chronic kidney disease (CKD). The aim was to assess MRA use and compare outcomes in MI patients with HF in relation to LVEF and CKD. METHODS AND RESULTS: Patients with MI and HF registered in the Swedish myocardial infarction registry, SWEDEHEART, 2005–2014, were included. Associations between MRA use and all‐cause mortality up to 3 years were assessed with multivariable Cox regression, stratified by EF groups and presence of CKD (estimated glomerular filtration rate <60 mL/min per 1.73 m(2)). Of 45 071 patients with MI and HF, 4470 (9.9%) received MRA. Those with HF and LVEF <40% more often had MRA (19.6%) compared with those with LVEF 40% to 49% (9.1%) or LVEF ≥50% (4.7%). 8.6% of patients with CKD received MRA. After adjustment, MRA use was associated with lower mortality in those with LVEF <40% (hazard ratio [95% confidence interval] 0.81 [0.75–0.88]) and LVEF 40% to 49% (0.88 [0.75–1.03]) but not in those with LVEF ≥50% (1.29 [1.09–1.53]), with significant interaction between MRA and LVEF (P<0.0001). The association between MRA use and mortality was similar in those without (0.96 [0.88–1.05]) and with (0.92 [0.85–0.99]) CKD. CONCLUSIONS: In patients with MI and HF, MRA use was associated with better long‐term survival in patients with LVEF <40% but not in those with LVEF ≥50%, while the mortality risk was similar in MRA‐treated patients with or without CKD.