Resistance to activated protein C and FV Leiden mutation in patients with a history of acute myocardial infarction or primary hypertension

This study was designed to investigate both resistance to activated protein C (APC-R) and the factor FV Q506 mutation incidence in patients with a his tory of acute myocardial infarction (AMI) and patients with primary hyperte nsion (PH), a highrisk group for arterial thrombosis. Eighty patients with a history of AMI (group A), 160 patients with a history of PH (group B), an d 124 age-matched controls without arterial disease (group C) were studied. APC-R was determined using the Coatest APC Resistance Kit of Chromagenix, Sweden. The prevalence of the FV Q506 mutation was estimated by DNA analysi s (Bertina method). The prevalence of the FV Q506 mutation was 20%, 13.75%, and 8% in groups A, B, and C, respectively (A v C P = .0466). The prevalen ce of APC-R was 47.5% in group A v 13% in group C (P < .0001) and 36.25% in group B v13% in group C (P < .0001). The response to activated protein C e xpressed as mean value +/- SD was 2.05 +/- 0.33 in group A v 2.56 +/- 0.46 in group C (P < .05) and 2 +/- 0.22 in group B v 2.56 +/- 0.46 in group C ( P < .05). These findings suggest that patients with a history of AMI or PH have a significantly increased incidence of both APC-R and FV Q506 mutation compared with the control group. These findings support the hypothesis tha t these anticoagulant defects may be risk factors for arterial thrombosis. (C) 2000 American Journal of Hypertension, Ltd.