Treatment of Chronic Nonvalvular Atrial Fibrillation in the Elderly

Abstract

The objective of the study was to determine the preferred treatment strategy for elderly patients with chronic nonvalvular atrial fibrillation (CNVAF). A Markov decision-analytic model was used to compare three treatment strategies for CNVAF: 1) warfarin; 2) aspirin; and 3) no treatment. Five-year quality-adjusted life years (QALYs) were calculated for male and female cohorts aged 70 and 75 years. In the baseline analysis (effectiveness of warfarin = 0.70, effectiveness of aspirin = 0.45, utility of warfarin = 0.99, and utility of aspirin = 0.999) the quality-adjusted survival rates for 70-year-old males were 4.03 QALYs on warfarin, 4.02 QALYs on aspirin, and 3.95 QALYs on no treatment. Results were similar for all age and sex cohorts. Sensitivity analyses revealed that the results were very sensitive to the effec tiveness of aspirin and the disutility of warfarin. The authors conclude that the optimal strategy for the treatment of CNVAF in elderly patients varies with the disutility assigned to warfarin therapy and the effectiveness value for aspirin therapy. Key words: chronic atrial fibrillation; elderly; anticoagulation; warfarin; aspirin; decision analysis; Markov analysis; quality of life. (Med Decis Making 1992;12:239-249)