Effect of Aldosterone Antagonism on Exercise Tolerance in Heart Failure With Preserved Ejection Fraction.
We appreciate Mr. Pan’s interest in our trial of spironolactone in patients with heart failure with preserved ejection fraction (HFpEF) (1). Apart from the novel entry criteria using abnormal exercise response as a basis (which allowed more physiologic homogeneity than in previous studies), this study also used functional capacity as the primary endpoint, and it showed both a reduction of exertional filling pressure with and an improvement in exercise tolerance with spironolactone. As clinicians know only too well, the primary concern of these older patients is their impaired functional capacity, and recent guidelines emphasize the importance of this target (2). The finding of improved exercise capacity is consistent with the results of previous studies (3), which are often neglected in the dismay that we have been unable to change the outcome of HFpEF. However, Mr. Pan is referring not just to the selection of patients and the use of exercise as an endpoint, but also to the use of exercise as therapy. We did not study this, but there is no doubt that this consistently provides functional benefit in adherent patients, including in HFpEF (4), with survival benefit being more marked in women (5). The risk of harm with this intervention is extremely low, and it is used far less than it should be. As Mr. Pan points out, the weakness is obtaining adherence, especially among frail older patients. Perhaps better surveillance using wearable devices will help to provide a solution to that problem.