D Allele of the Angiotensin I–Converting Enzyme Is a Major Risk Factor for Restenosis After Coronary Stenting

Abstract

Background Although intracoronary stent implantation significantly reduces restenosis compared with balloon angioplasty, a minority of patients still develop restenosis predominantly due to neointimal hyperplasia. Experimental studies suggest that the renin-angiotensin system is involved in neointimal hyperplasia after arterial injury. In humans, the plasma and cellular levels of ACE are associated with an I/D genetic polymorphism in the ACE gene, DD patients having higher levels. Methods and Results We investigated a possible relation between the ACE I/D polymorphism and restenosis in 146 patients who underwent successful implantation of a Palmaz-Schatz stent and had 6-month follow-up angiography. The minimal lumen diameter (MLD) before and after the procedure did not differ significantly among the three groups of genotypes ( DD , ID , and II ). At follow-up, MLD had a significant inverse relationship to the number of D alleles present ( DD , 1.65±0.71 mm; ID , 1.84±0.60 mm; II , 2.05±0.61 mm; P <.007). Late luminal loss during the follow-up period was significantly related to the number of D alleles ( DD , 0.89±0.61 mm; ID , 0.60±0.52 mm; II , 0.40±0.53 mm; P <.0001). The relative risk of restenosis (defined as a >50% diameter stenosis at follow-up) approximated by the adjusted odds ratio was 2.00 per number of D alleles (95% confidence interval, 1.03 to 3.88, P <.04). Conclusions The ACE I/D polymorphism influences the level of late luminal loss after coronary stent implantation. These results suggest that the renin-angiotensin system may be implicated in the pathogenesis of restenosis after coronary stenting.