Abstract
Endothelial dysfunction is highly prevalent and associated with adverse outcomes among patients without obstructive coronary artery disease (CAD). Angiotensin II inhibition may improve endothelial function, but with continued treatment, "aldosterone escape" may occur. Thus, it is unknown if adding aldosterone blockade further improves endothelial function. METHODS: In a double-blind, parallel-group, repeated-measures study, women with symptoms and signs of ischemia, no significant CAD, and coronary endothelial dysfunction receiving an angiotensin-converting enzyme inhibitor or receptor blocker were randomized to aldosterone blockade or placebo. The primary outcome at 16 weeks was percent change in coronary diameter to acetylcholine, and secondary outcome, coronary flow reserve to adenosine, both adjusted for baseline reactivity. RESULTS: Forty-one women completed the treatment period with repeat coronary reactivity testing. Their mean age was 54 ± 10 years; body mass index, 30 ± 7.4 kg/m2; 12% had diabetes; and 15% had metabolic syndrome. There were no significant differences between treatment groups. At baseline, the percent change in reference vessel coronary diameter to acetylcholine was -5.0% in the aldosterone blockade group and -3.4% in the placebo group and, at 16 weeks, -7.2% in the aldosterone blockade group versus -14.3% in the placebo group (P = .15). At 16 weeks, the change in coronary flow reserve to intracoronary adenosine was -0.13 in the aldosterone blockade group versus -0.25 in the placebo group (P = .66). CONCLUSION: Adding aldosterone receptor blockade to angiotensin II inhibition did not improve coronary endothelial or microvascular function among women with signs and symptoms of ischemia in the setting of nonobstructive CAD.