The present study aimed at investigating the 4G/5G and -844G/A polymorphisms and plasma concentration of PAI-1 in patients with acute myocardial infarction (AMI) and chronic stable angina (CSA) in Indian population. It included 100 patients with AMI and stable angina and 100 healthy controls. All study subjects were typed for two PAI polymorphisms (4G/5G and -844G/A) through PCR-RFLP and level of PAI through ELISA. The comparison of AMI and CSA independently with control in terms of PAI-1 level was statistically significant but not between AMI and CSA. The frequency of 4G/4G and 4G/5G genotype and 4G allele was significantly higher in AMI cases than in control and was found to increase the risk of AMI. There was a significant relationship between 4G/5G polymorphism and AMI risk under the dominant and codominant genotype. The frequency of 4G/4G genotype and 4G allele was significantly higher in CSA cases than in control group and increases the risk of CSA. There was no significant association between 4G/5G polymorphism and CSA risk under recessive, dominant, and codominant models. The genotype and allelic frequencies difference between the cases (AMI and CSA) and control with regard to -844G/A polymorphisms were statistically nonsignificant. Also, we did not detect any significant association of -844G/A polymorphism with AMI and CSA in recessive, dominant, and codominant models. Along with the traditional risk factors, the 4G/5G allele polymorphism is an independent risk factor for the development of AMI. The detection of 4G/5G allele may therefore be helpful in primary prevention. Patients who carry the 4G/5G allele polymorphism have high concentrations of PAI-1, which might be involved in incidents leading to AMI. The present study for the first time revealed significant association of 4G/5G allele polymorphism with high risk of AMI in Indian population and will be helpful in identifying the genetic risk factors associated with AMI and CSA and for better management of diagnostic measures.

Background: Coronary artery disease (CAD) that encompasses acute myocardial infarction (AMI), chronic stable angina (CSA), and unstable angina (UA) has numerous known risk factors. Genetic predispositions contribute as major risk in the development of CAD and the genes regulating atherosclerosis are important for disease prevention. Nitric oxide synthase 3 (NOS3) gene responsible for nitric oxide (NO) production is of special importance. Aim: To evaluate the role of three NOS3 polymorphisms (-786C/T, 894G/T, and 4a4b) in patients with CAD, particularly in AMI and CSA and their comparison with healthy controls. Materials and Methods: One hundred patients in each AMI and CSA group and 100 controls were included and were typed for three NOS3 polymorphisms (-786C/T, 894G/T, and 4a4b) by polymerase chain reaction–restriction fragment length polymorphism. Plasma NO metabolites (NOx) were also evaluated. Results: A significant association of 894G/T polymorphism with AMI in dominant model (P = 0.052) and with CSA in dominant and codominant models was detected (P = 0.008 and P = 0.006, respectively). Plasma NO levels were found to be significantly higher (P < 0.0001) in healthy controls (43.80 ± 6.28) compared to AMI and CSA patients (37.05 ± 6.75 and 38.67 ± 5.61). No significant association of -786C/T and 4a4b polymorphism with AMI and CSA risk under recessive, dominant, and codominant models was detected. Conclusion: Our study revealed a significant association of 894G/T polymorphism with AMI and independent association of NOx levels with CAD, indicating high risk of CAD in the North Indian population. Our findings will be helpful in identifying the genetic risk factors associated with CAD and better management of the diagnostic as well as therapeutic measures.