Mineralocorticoid receptor antagonist pattern of use in heart failure with reduced ejection fraction: findings from BIOSTAT-CHF

Aims Mineralocorticoid receptor antagonists (MRAs) are recommended (unless contraindicated) to all patients with heart failure with reduced ejection fraction (HFrEF). However, MRAs are still largely underused in routine clinical practice. This study aims to describe the determinants and pattern of use of MRAs in HFrEF. Methods and results BIOSTAT-CHF is a European multicentre, prospective study which enrolled patients suboptimally treated with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARBs) and/or beta-blockers, with the aim of optimizing guideline-based use of these agents. From the original 2516 subjects, this retrospective post hoc analysis included the 1325 patients with an indication for MRA therapy (i.e. left ventricular ejection fraction 35%, estimated glomerular filtration rate >= 30 mL/min/1.73m(2), K+ <= 5.0mmol/L). The mean age was 66.1 +/- 12.2years. At baseline an MRA was prescribed to 741 (56%) patients. Patients who were prescribed MRAs at baseline were younger, more often male, had higher body mass index, lower sodium, higher proportion of hypertension history and ACEi/ARB prescription (all P < 0.05). Of the 1049 patients who completed the baseline plus the 9 month visit, 585 (56%) had an MRA prescribed at baseline and 662 (63%) had an MRA prescribed at 9 months. Among the 585 patients with MRA at baseline, 91 (16%) had discontinued therapy and among the 461 (44%) patients without MRA at baseline 168 (36%) had initiated therapy subsequently. MRA discontinuation was more likely in subjects with higher left ventricular ejection fraction and NYHA class III/IV (P < 0.05 for both). MRA prescription both at baseline and 9 months was not associated with the outcome of death or heart failure hospitalization (adjusted hazard ratio 1.02, 95% confidence interval 0.66-1.58; P=0.93). Conclusions In this prospective observational study across Europe, MRAs were largely under-prescribed and frequently discontinued. Owing to these dynamic changes, outcome inferences are inconclusive.