Prevalence of factor V gene mutation amongst myocardial infarction patients and healthy controls is higher in Sweden than in other countries

OBJECTIVE: Haemostatic imbalance may be an aetiological factor in the development of acute coronary syndromes. Inherited resistance to activated protein C (APC) is a common disorder associated with hypercoagulability and lifelong risk of venous thrombosis. APC resistance is due to a single mutation in the gene coding for coagulation factor V (FV:Q506). To test the importance of the FV:Q506 mutation in premature myocardial infarction (MI), its prevalence was investigated in Swedish patients with MI before the age of 50 years.

DESIGN, SETTING AND SUBJECTS: In a retrospective case-control study, the FV:Q506 mutation was investigated in 101 survivors of MI (79 men, 22 women) and in 101 healthy sex- and age-matched controls.

MAIN OUTCOME MEASURE: The prevalence of FV:Q506 mutation.

RESULTS: The FV:Q506 mutation was found in 18% of patients versus 11% of controls (P = 0.16). The mutation was significantly more frequent amongst male patients than amongst controls (23 vs. 10%; P = 0.03), the calculated odds ratio being 2.6 (95% CI, 1.1-6.4).

CONCLUSION: The high prevalence of the FV:Q506 mutation found amongst Swedish MI patients, especially amongst men, is noteworthy, and calls for further studies on the outcome of MI in APC-resistant patients. The prevalence of the FV:Q506 mutation in controls is higher than figures reported from other countries, suggesting that at least 10% of the Swedish population are carriers of a congenital prothrombotic disorder.