Mineralocorticoid Receptor Antagonist Improves Cardiac Structure in Type 2 Diabetes Data From the MIRAD Trial

OBJECTIVES This study investigated the impact of the MR antagonist (MRA) eplerenone on LVM in type 2 diabetes patients at high risk for cardiovascular disease (CVD). BACKGROUND MRA activation is associated with cardiac fibrosis and increased left ventricular mass (LVM), which is an independent predictor of adverse CVD, including heart failure in patients with type 2 diabetes. METHODS A prespecified analysis of secondary endpoints in a randomized, double-blinded clinical trial of 140 patients with type 2 diabetes at high risk of or established CVD. Patients were randomized to receive high-dose eplerenone therapy (100 mg-200 mg) or placebo as an add-on to standard care for 26 weeks. Indexed LVM (LVMi) and T1 time were measured using cardiac magnetic resonance (CMR) imaging. Biomarkers included N-terminal pro-B-type natriuretic peptide (NT-proBNP), pro-collagen type I N-terminal propeptide (P1NP), and type III N-terminal propeptide (P3NP). RESULTS Of 140 patients in the MIRAD trial, 104 patients were subject to CMR imaging (eplerenone: 54 patients; placebo: 50 patients). Mean LVMi at baseline was 74.2 +/- 16 g/m(2). The treatment effect (ie, between-group differences) was a decrease of 3.7 g/m(2) following the eplerenone treatment (95% CI: -6.7 to -0.7; P = 0.017), with a corresponding decrease in absolute LVM. Plasma NT-proBNP concentrations decreased by 22% (P = 0.017) using eplerenone compared with placebo, and P1NP decreased 3.3 ng/mL (P = 0.019). No differences in T1 times or P3NP concentrations were observed between groups. CONCLUSIONS The addition of high-dose eplerenone in high-risk type 2 diabetes was associated with a clear reduction in LVMi and in NT-proBNP and P1NP levels, which may suggest a clinical benefit in heart failure prevention. (C) 2021 by the American College of Cardiology Foundation.