Incidence of factor V Leiden in patients with acute myocardial infarction.

The genetic defect of coagulation factor V known as factor V Leiden produces a resistance to degradation by activated protein C (APC) and increases the risk of venous thromboembolism. The data on arterial thrombosis associated with APC resistance are still not clearly defined. We conducted a study in patients presenting with acute myocardial infarction (MI) to assess whether factor V Leiden increases the risk of arterial thrombosis. We studied 109 patients who had a diagnosis of acute MI (69 males and 40 females, aged 25-91 years), and 112 controls. The study population was identified by characteristic ECG changes and elevation of serum CK-MB, whereas the control subjects were anonymous healthy blood donors with no known history of coronary artery disease. Blood samples from the patients and controls were analyzed for the factor V Leiden mutation by DNA analysis, using the polymerase chain reaction. Heterozygous factor V Leiden mutation was found in 9 of 109 (8%) MI patients and 5 of 112 (4%) control subjects (P =.42). In conclusion, this study shows no evidence of an association between factor V Leiden and acute MI.