Clinical and Hemostatic Studies in Nonvalvular Atrial Fibrillation

It is generally accepted that atrial fibrillation (Af) is associated with an increased risk of thromboembolism, especially in valvular Af. In recent years, several major studies have established that patients with nonvalvular atrial fibrillation (NVAf) are at increased risk of thromboembolism. I studied whether clinical and coagulation factors contribute to an increased risk of thromboembolism in NVAf. In 518 patients with NVAf (361 males and 157 females), 279 patients had heart disease and 239 patients were lone Af. Seventy four (14%) patients had prior thromboembolism. The left atrial diameter was larger in patients with prior thromboembolism than in those without it. During a mean follow-up of 8.5 months, the rate of primary embolic event in patients with NVAf was 2.7% per year. Various coagulation and fibrinolysis markers were assayed in 73 patients with NVAf. Thrombin-antithrombin III complex (TAT) levels increased in 22 patients (30%) and D-dimer levels increased in 11 patients (15%). TAT and D-dimer levels decreased after warfarin therapy in patients with their increases. In this study, it was suggested that NVAf increased the risk of thromboembolism and warfarin was effective for prevention of thromboembolism in NVAf