027 Impact of Gamma’ Fibrinogen in Premature Acute Coronary Syndrome: a cardiovascular risk factor?

Abstract

Gamma’ fibrinogen (γ’Fg) is a Fg isoform that constitutes about 15% of total plasma Fg and contains an additional binding site for factor XIII and for IIa forming clots that are resistant to fibrinolysis in vitro. Little is known about γ’Fg in the pathophysiology of Acute Coronary Syndrome (ACS) patients. To compare γ’Fg level and the relation with fibrin clot physical properties in a young post-MI patients matched for age and gender and age with healthy controls. γ’Fg was measured in duplicates in 260 young post-MI patients and n=260 controls. Maximum fibrin elastic modulus (EM in dyne/cm2), a measure of clot stiffness (G’) and Clot Lysis Time (CLT in sec) a measure of fibrinolysis rate were measured in all subject. Patients produced stiffer plasma fibrin with increased EM (24.4±15.9 vs 13.5±5.9 kdynes/cm 2 ; p<0.0001) with reduced fibrinolysis speed (1038±797 vs 595±416 sec; p<0.0001) in comparison with controls. γ’Fg concentration was significantly higher in patients compared to control (Figure 1) (p=0.037). However the ratio of γ’Fg over total Fg concentration (% of γ’Fg) was similar in both groups (3.7± 2% vs 3.5± 2.7% in controls; p=0.49). In patients there was a stepwise increase in clot stiffness (EM) with tertile of γ’Fg concentration (T1=13.7±7 T2=19.8±14 T3=23.7±16 in kdynes/cm 2 ) with a similar effect on hypofibrinolysis (CLT) (T1=675±550 T2=829±680 T3= 940±750) (p<0.0001 for both). γ’Fg concentration was found to be significantly higher in young post-MI patients as compared to healthy controls matched for age and gender and may account for the great differences in fibrin clot physical properties between patients and controls, an independent correlate of premature coronary artery disease.