Impacts of Prophylactic Measures on New Thromboembolism in Elderly Patients with Atrial Fibrillation

Choi, S Y; Kim, C H; Kim, Y S; Hwang, E S; Choi, J O

Abstract

BACKGROUND: The purpose of this study was to assess the incidence of new thrombolism, in elderly Korean patients with atrial fibrillation administered with or without the use of prophylatic therapy.
METHODS
One hundred fifty-sis elderly patients with atrial fibrillation were enrolled. The average length of follow up was 42 months.
RESULTS
Among 156 patients, thirty-one patients (19.9%) received anticoagulation therapy with warfarin(Group3). Fifty-six patients(34.0%) received aspirin(Group 2). Seventy-two patients(46. 1%) were under observation without any specific medication(Group 1). The frequencies of patients with previous evidence of thromboembolism were 9.7% in Group 1, 22.6% in Group 2, 67.7% in Group 3(p <0001). The rate of new thromboembolism was 4.5%/patient-year for all patients.7.1 %/patient-year in Group I, and 2.7%/patient-year in Group 2, 0%/patient year in Group 3. The rate of new thromboembolism in the patients with histories of thromboembolism was 36.0% /patient-year in Group 1, 3.8%/ patient-year in Group 2, and 0%/patient-year in Group 3. The cumulative rate of new thromboembolisms was significantly different in the three groups, in the total number of patients, and the patients with histories of thromboembolism(Group I vs. Group, 2 p =0.014; Group I vs. Group 3, p =0.001; and Group 2 vs. Group 3, p=0.12 using the Kaplan-Meier method and log-rank test, respectively), but not in the patients without previous thromboembolism.
CONCLUSION
Warfarin and aspirin are highly efficacious in the treatment of thromboembolism in elderly Koreans with nonvalvular atrial fibrillation and evidence of previous thromboembolism. Warfarin was more effective than aspirin.