Background: Studies 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. Aim: To investigate the association of allelic variants produced by the G894T transversion in eNOS (rs1799983) with post-AMI variables. Methods: Cross-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. Results: Despite 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. Conclusion: Our results suggest an association of the eNOS 894T allele with an apparent improvement in late arterial function in post-AMI patients. © 2015 Elsevier B.V.5682165169Diagnosis and classification of diabetes mellitus (2005) Diabetes Care, 28, pp. S37-S42Andrikopoulos, G.K., Grammatopoulos, D.K., Tzeis, S.E., Zervou, S.I., Richter, D.J., Zairis, M.N., Gialafos, E.J., Hillhouse, E.W., Association of the 894G>T polymorphism in the endothelial nitric oxide synthase gene with risk of acute myocardial infarction (2008) BMC Med. 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