Nitric oxide synthase gene polymorphism and in-stent restenosis: clinical and angiographic follow-up

ABSTRACT

Coronary stent deployment is a major advance in the treatment of ischaemic heart disease, but angiographic in stent restenosis still occurs in 10-40% at 6 months due to neointimal hyperplasia. Patient specific factors, including genetic factors, can contribute to this process. Was to examine the 894 G/T single nucleotide polymorphism [SNP] of the endothelial nitric oxide synthase [eNOS] in causing adverse angiographic and clinical events after coronary artery stenting. Our study included 47 patients [40 males, 7 females, mean age 54.4 +/- 8.1] who underwent elective and successful coronary artery stenting to de novo lesions in the Critical Care Department [Cairo University]. Patients were followed up for major adverse cardiac event [MACE] defined as death, acute coronary syndromes and target vessel revascularization; and restudied by coronary angiography at 6 months. The stented lesions were assessed using an automated quantitative angiography system. Genotype was determined by real time polymerase chain reaction [PCR] and restriction enzyme digestion. Restenosis rate was defined as >/= 50% diameter stenosis. The pts were distributed into two groups, Group linvolved pts of the G allele carriers i.e. patients of genotype PG or GT [n=40] and group II consisting of patients genotype IT, which represented the proposed risk genotype [n=7]. Patients in group I showed greater prevalence of diabetes mellitus [DM] and greater severity of lesions. Patients with GGIGT genotype presented with higher incidence of acute coronary syndromes compared to patients with TT genotype [45% vs 14.3%, p 0.004]. The same genotype group had significantly higher incidence of MACE [45% compared to 28 0.001]. Patients with TI' genotype had insignificantly higher restenosis rate [42.9% in comparison to 37.5% in group GG/GT genotype, p 0.8]. Although GG/GT genotype showed higher incidence of acute coronary syndromes and MACE compared to patients with TI genotype, yet the latter had in significantly higher restenosis rate