The Turkish Atrial Fibrillation Study

Atrial fibrillation (AF), the prevalence of which reaches 6% in those aged over 60 years, carries an increased risk of thromboembolism. We studied the applicability of anticoagulant therapy and the value of aspirin as an alternative therapy in preventing thromboembolic complications in patients with AF in Turkey. The study included 8 centers from İstanbul, Ankara and İzmir. It started on April 1, 1995, and patient enrolment was terminated on June 1, 1998. The cases were followed-up for at least one year. Seven-hundred and thirty-five patients were included in the study. Two-hundred and thirty-one patients were randomized to aspirin, 223 to coumadine and 231 patients were in the control group. Due to violation of the protocol, 376 cases were eventually excluded from the study. The remaining 359 cases (119 aspirin, 120 coumadine and 120 control) were taken into assessment. The patients in the anticoagulant group received coumadine (Coumadine-Eczacıbaşı) tablets so as to maintain a prothrombin time (PT) 1.5-2 times the normal, an INR between 2-2.5. The aspirin group received 300 mg/day (Coraspin-Bayer). The patients in the coumadine group were followed up every month with PT check, and the ones in the aspirin and the control groups were followed up every 3 months. Thromboembolism occurred in 7 (5.9%) cases in the aspirin group, in 1 (0.8%) case in the coumadine group and in 12 (10.0%) cases in the control group. With respect to the control group, the frequency of thromboembolic events in the coumadine group was significantly lower (p=0.008). No significant difference existed between the frequency of thromboembolic events in the aspirin and the coumadine groups, nor between the control and aspirin groups. There was a 94% decreased risk of thromboembolism in the coumadine group in comparison to the control group. In the aspirin group, though not significantly different, there was a 46% decrease in the risk of emboli as compared to the control group. There was 1 case (0.8%) of major bleeding each in the aspirin and the control group; 5 cases of major bleeding (4.2%) was found in the coumadine group. When the distribution of deaths was analysed among the treatment groups, a total of 25 deaths (6.9%) was observed. Twelve (10.8%) of these were in the aspirin group, 7 (5.8%) in the coumadine group, 6 (5.0%) in the control group. There was no significant difference in terms of mortality among the groups. Thus, in order to decrease the risk of thromboembolic events in patients with AF, the preferred drug should be coumadine. However, considering that aspirin probably decreased the risk of emboli substantially, aspirin 300 mg/day may well be given to patients with AF when use of coumadine is not feasible or practical.