Gender Differences in Fibrin Polymerization and Lysability of Fibrin in Patients with Atrial Fibrillation.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia for both men and women. The embolic cardiovascular events represent serious complications of AF, and apparently women are affected more seriously than men. Little is known about prothrombotic factors and possible gender differences. The present study aimed to characterize fibrin polymerization, fibrinolysis, and fibrin fiber properties in men and in women with AF.

Materials And Methods: Forty-six female and 101 male patients with AF and without previous stroke were included. Polymerization kinetics, lysis of preformed clot, and fibrin fiber properties were determined by turbidimetric methods.

Results: Women were slightly older than men (P < .01), and the male group had a higher systolic blood pressure (P < .01) and a higher incidence of peripheral arterial disease (P < .01) than the female group. Compared with men, women had a higher Vmax during fibrin polymerization (P < .04) and a lower lysability of fibrin, when recombinant tissue plasminogen activator (rt-PA) was added during clot formation (P < .01), while external lysis (rt-PA added after clot formation), plasma fibrinolytic activity, d-dimer, and fibrin fiber properties did not differ between men and women. A significantly higher number of men received acetylsalicylic acid (ASA) compared with women (P < .004). Subgroup analyses on subjects not receiving ASA demonstrated that women still had higher Vmax (P < .04) and a lower rt-PA-induced fibrinolysis (P < .03).

Conclusion: Women with AF have a higher velocity of lateral aggregation of fibrin fiber protofibrils and a lower lysis of fibrin clots than men.