UNDERUTILIZATION OF WARFARIN IN OLDER PERSONS WITH CHRONIC NONVALVULAR ATRIAL-FIBRILLATION AT HIGH-RISK FOR DEVELOPING STROKE

OBJECTIVE: To investigate the prevalence of the use of warfarin to mai ntain an international normalized ratio (INR) between 2.0 and 3.0 in o lder persons with chronic nonvalvular atrial fibrillation (AF), and wi thout contraindications to warfarin, who are at high risk for developi ng new thromboembolic (TE) stroke. DESIGN: A retrospective analysis of charts from all older persons seen during 1997 at an academic hospita l-based geriatrics practice. SETTING: An academic hospital-based geria trics practice staffed by fellows in a geriatrics training program and full-time faculty geriatricians. PATIENTS: Three hundred eighty men a nd 1183 women, mean age 80 +/- 8 years (range 59 to 103 years), were i ncluded in the study. MEASUREMENTS AND MAIN RESULTS: Of 1563 persons s tudied, 141 (9%) had chronic nonvalvular AF. Of 141 persons with AF, 1 27 (90%) were at high risk for developing TE stroke because they had e ither a previous thromboembolism, congestive heart failure, or echocar diographic evidence of abnormal left ventricular systolic function; a systolic blood pressure >160 mm Hg; or they were women older than 75 y ears of age. Of the 127 persons with AF at high risk for developing TE stroke, three (2%) had contraindications to warfarin. Of the 124 pers ons with AF at high risk for developing TE stroke and no contraindicat ions to warfarin, 61 (49%) were treated with warfarin to maintain an I NR between 2.0 and 3.0, and 45 (36%) were treated with 325 mg aspirin daily. Of 14 persons with AF at low risk for developing TE stroke, one (7%) was treated with warfarin to maintain an INR between 2.0 and 3.0 , and six (43%) were treated with 325 mg aspirin daily. CONCLUSIONS: W arfarin is underutilized as a treatment to maintain an INR between 2.0 and 3.0 in older persons with chronic nonvalvular AF at high risk for developing TE stroke.