Endothelial nitric oxide synthase genotypes modulate peripheral vasodilatory properties after myocardial infarction

• 894T carriers of eNOS have higher blood flow reserve after myorcardial infarction.
• Also, 894T carriers show increased rise in nitric oxide post-infarction levels.
• The 894T allele apparently improves post-infarction late arterial properties.

BackgroundStudies in population genetics suggest an important relationship between the eNOS G894T polymorphism and occurrence of acute myocardial infarction (AMI), with little known on its influence on the post-AMI period.AimTo investigate the association of allelic variants produced by the G894T transversion in eNOS (rs1799983) with post-AMI variables.MethodsCross-sectional analyses of anthropometric, clinical and laboratory assessments obtained within the first 24 h and after 5 and 30 days of the AMI event across T carriers and G homozygotes of eNOS in 371 consecutive cases of AMI with ST-segment elevation admitted to a Brazilian emergency service in cardiology. Genotypes were determined by polymerase chain reaction followed by enzymatic restriction.ResultsDespite no difference between genotypic groups on aspects as Killip–Kimbal classification scores, extension of infarcted mass, lipid profile or pattern of medication use, an increase in serum nitric oxide from admission to day 5 was higher for T carriers (p < 0.001). Thirty days post-AMI, peripheral blood flow reserve was larger among T carriers either by flow- (p = 0.037) and nitrate-mediated (p = 0.040) dilation testing.ConclusionOur results suggest an association of the eNOS 894T allele with an apparent improvement in late arterial function in post-AMI patients.