Factor XIII Val34Leu and the risk of myocardial infarction

Background and Objectives. Recent studies have suggested an association bet ween a genetic variation: in-the coagulation factor XIII (FXIII Val34Leu) a nd decreased risk of vascular thrombosis. Design and Methods, We investigated the frequency of the FXIII Val34Leu pol ymorphism in 150 consecutive, unrelated and relatively young (<55 years) su rvivors of myocardial infarction (MI) with angio-graphically-proven severe coronary atherosclerosis and in 150 age, gender- and race-matched controls. Results. FXIII Val34Leu was detected in 54/150 patients and 73/150 controls , yielding an overall odds ratio (OR) for MI of 0.6 (C195: 0.4-0,9), Homozy gosity for FXIII Val34Leu was found in 4/150 patients and in 12/150 control s, yielding an OR for MI of 0.26 (C195: 0.08-0.9), The OR for heterozygotes was 0.65 (C195: 0.4-1.1), FXIII Val34Leu carriership decreased the risk of MI related to metabolic risk factors (RF) (hypertension, diabetes, dyslipi demia, and obesity): non-carriers in the presence of a metabolic RF had a 1 3.9-fold higher risk of MI, whereas in carriers with a metabolic RF the ris k was reduced to 6.8, FXIII Val34Leu also attenuated the risk of M1 among s mokers. Non-carrier smokers had a 6.1-fold higher risk (C195: 3.1-11.9), wh ereas the risk among smokers carrying FXIII Val34Leu was 3.9 (C195: 1.9-8.1 ), : Interpretation and Conclusions. FXIII Val34Leu confers a significant protec tive effect against the occurrence of MI in relatively young patients. FXII I Val34Leu exhibits a gene dosage effect: the protective effect was particu larly strong in homozygous carriers, and heterozygosity conferred moderate protection. Finally, FXIII Val34Leu seems to reduce the risk of MI related to major cardiovascular risk factors. (C)2000, Ferrata Storti Foundation.