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-1 converting enzyme (ACE I) deletion allele (D) polymorphism is a possible genetic risk factor for rest enosis after coronary stent implantation. We aimed to establish whether or not blockade of ACE with high doses of ACE inhibitors could reduce this ris k of angiographic restenosis. Methods We characterised the ACE I/D polymorphism in 345 consecutive patien ts who were undergoing coronary stenting. 115 had the DD genotype. We assig ned 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 continu ed for 6 months. 79 patients complied with the protocol and underwent follo w-up angiography after 6 months. Findings Our primary endpoint of late loss in minimum lumen diameter (a qua ntitative index of restenosis) was significantly higher in the quinapril gr oup 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 angi ographic restenosis in the treatment group. Interpretation Contrary to our expectations, ACE inhibitor treatment did no t reduce restenosis after coronary stent implantation in patients with DD g enotype, but was associated with an exaggerated restenotic process when com pared with administration of placebo.