High prevalence of thrombophilia among young patients with myocardial infarction and few conventional risk factors

Background: Thrombophilia refers to series of acquired and inherited conditions that confer a tendency to thrombus formation. The exact relationship between thrombophilia and MI is not well established. Objectives: To determine the prevalence of thrombophilia in young patients with their first MI and few conventional risk factors. Methods: We evaluated the baseline characteristics and the thrombophilia profile, including anti-cardiolipin antibodies, activated protein C resistance (APCR) with the factor V Leiden mutation, prothrombin G20210A mutation, protein C, protein S, and antithrombin-III levels, among 85 consecutive patients (<50 year old) who were admitted to CCU with their first MI. Patients were divided into two groups: group A - patients with ≤1 risk factor and group B - patients with ≥2 risk factors. Results: 92% were male and 55% with anterior wall MI. Overall, the risk factor profile was: smoking in 60%, hyperlipidemia in 42%, positive family history in 29%, hypertension in 18%, diabetes mellitus in 13%, and obesity in 8%. Forty-seven percent of patients had ≤1 risk factor (n=40, group A) and 53% had ≥2 risk factors (n=45, group B). The prevalence of the prothrombin mutation was 15% in group A compared to 7% in group B (p=0.12). APCR secondary to a heterozygous genotype of factor V Leiden mutation was found in 20% in group A compared to 2% in group B (p<0.01). Anti-cardiolipin antibodies were found in 16% in group A compared to 22% in group B (p=ns). Finally, we have found that the likelihood of identifying at least one thrombophilia marker was 50% in group A compared to 29% in group B (p=0.046). Conclusions: The likelihood to detect at least one thrombophilia marker in young patients with MI and few conventional risk factors is significantly high. Thrombophilia may contribute to the development of MI in this specific group of young patients.