Effect of ACE inhibitors on angiographic restenosis after coronary stenting (PARIS): a randomised, double-blind, placebo-controlled trial

Background The DD genotype for the angiotensin-I converting enzyme (ACE I) deletion allele (D) polymorphism is a possible genetic risk factor for restenosis after coronary stent implantation. We aimed to establish whether or not blockade of ACE with high doses of ACE inhibitors could reduce this risk of angiographic restenosis. Methods We characterised the ACE I/D polymorphism in 345 consecutive patients who were undergoing coronary stenting. 115 had the DD genotype. We assigned 91 of these 115 patients to quinapril 40 mg daily (n=46) or placebo (n=45). Treatment was started within 48 h after stent implantation and continued for 6 months. 79 patients complied with the protocol and underwent follow-up angiography after 6 months. Findings Our primary endpoint of late loss in minimum lumen diameter (a quantitative index of restenosis) was significantly higher in the quinapril group than in the controls (mean 1–11 mm [SD 0–70] vs 0–76 mm [0–60]; p=0–018). Secondary endpoints also showed consistent trends towards increased angiographic restenosis in the treatment group. Interpretation Contrary to our expectations, ACE inhibitor treatment did not reduce restenosis after coronary stent implantation in patients with DD genotype, but was associated with an exaggerated restenotic process when compared with administration of placebo.