Warfarin for stroke prevention still underused in atrial fibrillation: patterns of omission.

BACKGROUND AND PURPOSE: The value of warfarin in preventing stroke in patients with chronic atrial fibrillation is well established. However, the prevalence of such treatment generally lags behind actual requirements. The aim of this study was to evaluate doctor- and/or patient-related demographic, clinical, and echocardiographic factors that influence decision for warfarin treatment.

METHODS: Between 1990 and 1998, 1027 patients were discharged with chronic or persistent atrial fibrillation. This population was composed of (1) patients with cardiac prosthetic valves (n=48), (2) those with increased bleeding risks (n=152), (3) physically or mentally handicapped patients (n=317), and (4) the remaining 510 patients, the main study group who were subjected to thorough statistical analysis for determining factors influencing warfarin use.

RESULTS: The respective rates of warfarin use on discharge in the 4 groups were 93.7%, 30.9%, 17.03%, and 59.4% (P=0.001); of the latter, an additional 28.7% were discharged on aspirin. In the main study group, warfarin treatment rates increased with each consecutive triennial period (29.7%, 53.6%, and 77.1%, respectively; P=0.001). Age >80 years, poor command of Hebrew, and being hospitalized in a given medical department emerged as independent variables negatively influencing warfarin use: P=0.0001, OR 0.30 (95% CI 0.17 to 0.55); P=0.02, OR 0.59 (95% CI 0.36 to 0.94); and P=0.0002, OR 0.26 (95% CI 0.12 to 0.52), respectively. In contrast, past history of stroke and availability of echocardiographic information, regardless of the findings, each increased warfarin use (P=0.03, OR 1.95 [95% CI 1.04 to 3.68], and P=0.0001, OR 3.52 [95% CI 2.16 to 5.72], respectively).

CONCLUSIONS: Old age, language difficulties, insufficient doctor alertness to warfarin benefit, and patient disability produced reluctance to treat. Warfarin use still lags behind requirements.