Fibrinopeptide A (FPA) levels in atrial fibrillation and the effects of heparin administration.

Abstract

It has been reported that a patient with atrial fibrillation (AF) is in the hypercoagulable state and that this state results in a high incidence of systemic thromboembolisms. In this paper, we have investigated plasma fibrinopeptide A (FPA) levels and the effects of subcutaneous administration of heparin on these levels in patients with AF. Forty-five patients with hypertension (HT) or mitral stenosis (MS) were classified into four groups according to whether they had AF complications; i.e. HT with normal sinus rhythm (NSR), HT with AF, MS with NSR and MS with AF. Patients with AF demonstrated significantly higher plasma FPA levels and lower plasma antithrombin III (AT III) activities than those with NSR. When low dose heparin was administered to patients with AF, plasma FPA levels were decreased to the near normal range, accompanied by an increase in heparin-AT III complex activity and heparin concentration 0.5-1.0 h after injection. These levels were maintained for 5 h. From these results it was concluded that patients with AF were in the hypercoagulable state and that the measurement of plasma FPA levels provided a possibility to detect the underlying activation of blood coagulation.