Specifically, the authors report, “In patients with systolic HF and mild symptoms, addition of eplerenone to recommended therapy reduced the incidence of new atrial fibrillation by 42%.”
Dr. Karl Swedberg, at Sahlgrenska University Hospital/Ostra in Gothenburg, Sweden, and colleagues point out that the occurrence of atrial fibrillation or flutter (AFF) often leads to further hemodynamic deterioration and is “clearly undesirable.” Aldosterone antagonism to block activation of mineralocorticoid receptors may influence atrial remodeling, they continue, and thereby reduce the risk of AFF.
To see if treatment with the mineralocorticoid receptor eplerenone in this regard benefitted patients already receiving an ACE inhibitor or angiotensin receptor blocker, the team conducted a placebo-controlled trial involving 2737 such patients with NYHA class II heart failure and an ejection fraction no greater than 35%.
At baseline, 1794 of the participants were free of AFF. During follow-up, the incidence of new-onset AFF was 2.7% among patients given eplerenone and 4.5% among those in the placebo arm, the investigators found.
This translated to a hazard ratio of 0.58 (p=0.034), although this was reduced after adjustment for covariables (hazard ratio 0.713; p=0.087).
In discussing the findings, the authors note that they may not be applicable to all HF patients with mild symptoms, “because in this study patients were required to have additional factors known to increase cardiovascular risk, including age >55 years, in most cases an ejection fraction <30%, and a recent cardiovascular hospitalization.”
Dr. Swedberg and colleagues also point out that class III antiarrhythmic drugs can prevent atrial fibriallation in HF, but have unacceptable toxicity. “By comparison, eplerenone is a well-tolerated and safe alternative that has substantial additional clinical benefits, provided it is initiated under monitoring of serum potassium and creatinine as in our study,” they conclude.