Effect of spironolactone on endothelial function in patients with congestive heart failure on conventional medical therapy.

We prospectively studied the effect of spironolactone, an aldosterone antagonist, on endothelial function in patients with advanced congestive heart failure (CHF) using the brachial artery reactivity method. Twenty patients optimized on conventional CHF therapy were treated with spironolactone, and brachial artery flow- mediated dilation was measured at baseline and at 4 and 8 weeks. Spironolactone improved endothelial function at 4 weeks, and sustained the improvement at 8 weeks, in patients with CHF on conventional medical therapy, presumably due to reversal of aldosterone impairment of endothelial nitric oxide activity.