Spironolactone does not prevent restenosis after coronary stenting in humans

In animal studies, aldosterone enhanced neointimal proliferation by increasing extracellular accumulation of collagen and potentiating the effects of angiotensin II. Spironolactone, an aldosterone antagonist, is a potent inhibitor of neointimal proliferation. We conducted a placebo-controlled, double-blind, randomised study to assess the effect of spironolactone on angiographic 6-month in-stent restenosis.

Of the 310 randomised patients with significant coronary artery disease, 258 patients were available for analysis: 128 constituted the placebo group and 130 were assigned to receive spironolactone. Eligible patients were randomly assigned to receive a dose of 50 mg spironolactone or placebo orally twice a day for 6 months. The primary endpoint was the angiographic restenosis (>50% stenosis) rate at follow-up angiography.

At 6-month follow-up angiography after stenting, there was no difference between the 2 groups in minimal lumen diameter, percent diameter stenosis, late loss, and net gain. Angiographic restenosis occurred in 46 (35.4%) of 130 patients receiving spironolactone and 50 (39.0%) of 128 in the placebo group with an odds ratio (OR) of 0.85 with a 95% confidence interval (CI) of 0.49 to 1.46 (P = 0.62). Restenosis rate was found in 60 (32.9%) of 182 lesions in the spironolactone group, and 61 (35.5%) of 172 lesions in the placebo group with an OR of 0.89 with a 95% CI of 0.56 to 1.42 (P = 0.89).

Spironolactone did not reduce the incidence of in-stent restenosis as compared with placebo in human, contrary to the fact that reduction of neointimal formation in animal models has been observed upon administration of spironolactone.