enalapril and Thromboembolism

The incidence of thromboembolism and the benefit of anticoagulation in congestive heart failure are controversial.. The data base provided by the Veterans Affairs Vasodilator-Heart Failure Trials (V-HeFT I and II) was examined retrospectively to address these issues. In V-HeFT I, 642 men with heart failure were followed an average of 2.28 years, providing 1,464 patient-years of follow-up. In V-HeFT II, 804 men were followed an average of 2.56 years, with 2,061 patient-years of follow-up. Mean left ventricular ejection fraction was 30% in V-HeFT I and 29% in V-HeFT II: Functional capacity was at the interface of classes II and III with a peak exercise oxygen consumption of 14.7 mL.kg-1 x min-1 in V-HeFT I and 13.7 mL.kg-1 x min-1 in V-HeFT II: Warfarin and antiplatelet agents were administered at the discretion of individual investigators. The incidence of all thromboembolic events during 1,068 patient-years without warfarin in V-HeFT I was 2.7/100 patient-years and during 1,188 patient-years in V-HeFT II was 2.1/100 patient-years and was not reduced in patients treated with warfarin. Patients experiencing events had a lower peak exercise oxygen consumption (p < 0.03 in V-HeFT I and p < 0.001 in V-HeFT II) and a lower mean ejection fraction (p = 0.10 in V-HeFT I and p = 0.07 in V-HeFT II). Atrial fibrillation was not associated with an increased risk of thromboembolic events.. The incidence of thromboembolism and stroke in class II or III congestive heart failure is not high and may not be significantly reduced with warfarin treatment. Routine use of anticoagulants in patients with heart failure may not be justified.

Topics: Cerebrovascular Disorders; Drug Therapy, Combination; Enalapril; Heart Failure; Humans; Hydralazine; Incidence; Isosorbide Dinitrate; Male; Middle Aged; Platelet Aggregation Inhibitors; Prazosin; Thromboembolism; Warfarin

This study compared the antithrombotic effect of plasma angiotensin converting enzyme inhibitors (ACE-Is): captopril (CAP), enalapril (ENA) and tissue ACE-Is: perindopril (PER), quinapril (QUIN) in experimental venous and arterial thrombosis. Normotensive Wistar rats were treated p.o. with CAP (75 mg/kg), ENA (20 mg/kg), PER (2 mg/kg) and QUIN (3 mg/kg) for 10 days. The influence of ACE-Is on coagulation and fibrinolytic systems as well as platelet function was evaluated. The hypotensive effect of ACE-Is was equal in all groups. QUIN maintained the final carotid blood flow at the highest value in comparison to PER and plasma ACE-Is. The arterial thrombus weight was reduced in PER and QUIN groups while venous thrombus weight was also reduced after CAP. Tissue and plasma ACE-Is caused the inhibition of platelet adhesion and aggregation. A reduction of fibrin generation, prolongation of prothrombin time (PT), activated partial thromboplastin time (APTT) and shortening of euglobulin clot lysis time (ECLT) were observed after PER and QUIN treatment. In conclusion, given in equipotent hypotensive doses, tissue ACE-Is exerted more pronounced antithrombotic effect than plasma ACE-Is in experimental thrombosis. The differences between tissue and plasma ACE-Is in terms of their more pronounced inhibition of experimental thrombosis may be related to the intensified activation of fibrinolysis and inhibition of coagulation.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Pressure; Captopril; Carotid Arteries; Disease Models, Animal; Enalapril; Fibrillar Collagens; Fibrin; Hemostasis; Male; Perindopril; Platelet Adhesiveness; Platelet Aggregation; Quinapril; Rats; Rats, Wistar; Regional Blood Flow; Tetrahydroisoquinolines; Thromboembolism