The eNOS 786C/T polymorphism in cardiac surgical patients with cardiopulmonary bypass is associated with renal dysfunction

Abstract

Renal dysfunction is one of the most serious complications following cardiac surgery with cardiopulmonary bypass. The causes of renal dysfunction following cardiac surgery are poorly understood. We hypothesised that T-786C endothelial NO synthase (eNOS) polymorphism may lead to an increase in the occurrence of postoperative renal dysfunction following cardiac surgery with cardiopulmonary bypass. A total of 497 patients undergoing cardiac surgery with cardiopulmonary bypass were included in the study. The T-786C eNOS polymorphism was detected by a polymerase chain reaction. The patients were grouped on the basis of whether they were homozygous or heterozygous for the C allele (TC+CC; n=289) or only homozygous for the T allele (TT; n=208). No significance was demonstrated in the preoperative risk factors, with the exclusion of smoking habits (p=0.04) for the C-allele carrier. The administration of anti-lipid agents (p=0.01) and anti-arrhythmics (p=0.01) was significantly lower in the TC/CC group. The TC+CC genotype group had a significantly greater decrease in creatine clearance (p=0.024), the lowest creatine clearance (p=0.004) and more C-allele carriers received acute renal replacement therapy (p=0.04). The usage of norepinephrine (p=0.02) and dobutamine (p=0.02) was significantly higher in C-allele carriers. In the TC+CC genotype group, cross-clamp time (p=0.02) and administration of red cell transfusion (p=0.04) achieved statistically significant difference. The overall in-hospital mortality rate was 8.2% for all patients and was not significant between genotypes. The present findings support the hypothesis that the T-786C eNOS polymorphism may play a role in the development of renal dysfunction and increase the occurrence of renal replacement therapy following cardiac surgery with cardiopulmonary bypass. This polymorphism may be useful in stratifying the risk for the development of postoperative renal dysfunction.