Influence of eNOS gene polymorphisms (894G/T; - 786C/T) on postoperative hemodynamics after cardiac surgery

Abstract

Background: Differences in vascular reactivity have been associated with variable NO release due to 894G/T and -786C/T polymorphisms of the eNOS gene. Carriers of the 894T and -786C alleles are known to have enhanced vascular responsiveness to vasoconstrictor stimulation due to decreased NO generation. Thus, we hypothesized that eNOS gene polymorphism could influence perioperative hemodynamics and catecholamine support in patients undergoing cardiac surgery with CPB.

Methods: In 105 patients undergoing elective CABG with CPB, systemic hemodynamics, cardiac index (CI), systemic and pulmonary vascular resistance indices (SVRI, PVRI) and catecholamine support were measured at baseline and 1 h, 4 h, 10 h and 24 h after CPB. Genotyping for the 894G/T and -786C/T eNOS gene polymorphisms was performed by polymerase chain reaction amplification. Patients were divided according to their genotype (894G/T: GG=group 1, GT and TT=group 2; -786C/T: TT=group 3, CT and CC=group 4).

Results: Genotype distribution for 894G/T polymorphism was 41% (GG), 52.4% (GT), 6.6% (TT) and for -786C/T polymorphism 37.1% (TT), 41.9% (CT) and 21% (CC). Pre- and intraoperative characteristics and systemic hemodynamics did not differ between groups. CI, SVRI and PVRI remained unaffected by genotype distribution. Statistical analysis of postoperative data revealed no difference between groups, especially for pharmacologic inotropic or vasopressor support. Also, coexistence of the 894T and -786C alleles had no impact on perioperative variables compared to homozygous 894G and -786T allele carriers.

Conclusions: In contrast to current suggestions, the 894G/T and -786C/T genetic polymorphisms of the eNOS gene do not influence early perioperative hemodynamics after cardiac surgery with CPB.