Mineralocorticoid receptor antagonists and atrial fibrillation: a meta-analysis

Aldosterone has been implicated in atrial remodelling representing a potential target for upstream therapies. Accumulating evidence suggests that mineralocorticoid receptor blockade may have favourable effects on atrial fibrillation (AF) development, although some controversial results have been published. We, therefore, conducted a meta-analysis of randomized clinical trials (RCTs) and observational studies in order to examine the protective role of mineralocorticoid receptor antagonists (MRAs) on AF. Of the 1337 initially identified records, 3 RCTs and 2 observational studies with 3640 patients were finally analysed. The pooled analysis of the included studies demonstrated that patients treated with MRAs have 31% lower risk of AF compared with controls [relative ratio (RR): 0.69; 95% confidence interval (CI): 0.58-0.83] without any heterogeneity across the studies (I-2 = 0%). This effect was consistent across RCTs (RR: 0.72; 95% CI: 0.55-0.94) and observational studies (RR: 0.67; 95% CI: 0.53-0.84) without heterogeneity. Also, MRAs reduce the risk of AF in both heart failure (HF) (RR: 0.63; 95% CI: 0.50-0.80) and after cardiac surgery (RR: 0.77; 95% CI: 0.61-0.98). Analysing the relative impact of eplerenone and spironolactone, we showed that only eplerenone significantly reduces AF burden (RR: 0.64; 95% CI: 0.44-0.90). Our meta-analysis suggests that MRAs may be effective in AF prevention especially in the HF setting. However, there are insufficient data for the widespread use of aldosterone antagonists solely for AF prevention. Larger RCTs with long-term follow-up in different clinical settings are needed to clarify the impact of MRAs on AF.