D/D polymorphism of the ace gene might be a risk factor for in-stent restenosis

Introduction. Although intracoronary stenting has decreased restenosis rate compared to percutaneous balloon angioplasty, still a high number of patie nts develop in-stent restenosis, which is an entity primarily due to tissue proliferation. Experimental studies have indicated that the renin-angioten sin system is involved in neointimal hyperplasia. Plasma and cellular level s of ACE are associated with an VD polymorphism in the ACE gene. Indeed, DD subjects have the higher ACE levels. The purpose of this study was to expl ore the possibility that the I/D polymorphism might be related with instent restenosis. Methods. We studied the ACE polymorphism in 48 consecutive patients who und erwent successful implantation of an elective coronary stent in native coro nary vessels and had a 6 month angiographic follow up. Restenosis (50% of t he reference vessel) was observed in 23/48 patients. Patients with or witho ut restenosis did not differ in demographic or clinical variables like diab etes, plasma cholesterol levels or in quantitative angiographic parameters such as vessel reference size or minimal lumen diameter after stent implant ation. Results. I/D polymorphism was distributed as follows: 22.9% of the patients were D/D; 14.5% were I/I and 62.5% of the patients were heterozygous I/D. The presence of restenosis was strongly related with the I/D polymorphism: 81.8% of the patients with D/D genotype had restenosis, compared with 40.0% of I/D patients and only 14.2% of the I/I patients (chi(2) p < 0.01). Conclusions, In this limited cohort, homocygous D/D of the ACE gene was sig nificantly associated with in-stent restenosis, whereas restenosis was infr equent in patients with the I/I genotype.