Faculty Bibliography

OBJECTIVE: To investigate the incidence of new thromboembolic (TE) stroke in older persons with chronic atrial fibrillation treated with oral warfarin versus aspirin. DESIGN: In an observational study of 312 older persons with chronic atrial fibrillation, long-term aspirin 325 mg daily was administered to 187 persons, and oral warfarin, in a dose adjusted to maintain the international normalized ratio (INR) between 2.0 and 3.0, was administered to 115 persons. The incidence of new TE stroke was analyzed in persons treated with warfarin versus aspirin at 36 +/- 17 months (1 to 99 months) follow-up. SETTING: A large, long-term healthcare facility. PATIENTS: The patients included 208 women and 104 men, mean age 84 +/- 7 years (range 62 to 101 years). MEASUREMENTS AND MAIN RESULTS: Four of 125 persons (3%) on warfarin stopped taking warfarin compared with four of 187 persons (2%) on aspirin who stopped taking aspirin because of adverse effects (P not significant). In persons with prior stroke, the incidence of new TE stroke was 40% (27 of 67) in persons treated with warfarin versus 81% (56 of 69) in persons treated with aspirin (P < .001). In persons with no prior stroke, the incidence of new TE stroke was 22% (13 of 58) in persons treated with warfarin versus 56% (66 of 118) in persons treated with aspirin (P < .001). The incidence of new TE stroke in all subjects was 32% (40 of 125) in persons treated with warfarin versus 65% (122 of 187) in persons treated with aspirin (P < .001). Cox regression analysis showed that persons taking warfarin had a 76% less chance of developing a new TE stroke than those taking aspirin after controlling the confounding effects of other risk factors. CONCLUSION: In an observational study of older persons with chronic atrial fibrillation, persons treated with oral warfarin to maintain an INR between 2.0 and 3.0 had a significantly lower incidence of new TE stroke than persons treated with oral aspirin 325 mg daily

In a prospective study of 312 older patients with chronic atrial fibrillation, at 36-month follow-up evaluation, new thromboembolic stroke developed in 162 of 312 patients (52%). Significant independent risk factors for new thromboembolic stroke were prior stroke (risk ratio = 1.6), rheumatic mitral stenosis (risk ratio = 2.0), left ventricular (LV) hypertrophy (risk ratio = 2.8), abnormal LV ejection fraction (risk ratio = 1.8), serum total cholesterol (risk ratio = 1.005), and serum high-density lipoprotein cholesterol (risk ratio = 0.96)

We investigated in a prospective study of 2,148 persons (mean age 81 years), the association between mitral annular calcium and new thromboembolic stroke at 44-month follow-up. Independent risk factors for new thromboembolic stroke were prior stroke (risk ratio 2.4), mitral annular calcium (risk ratio 2.6), atrial fibrillation (risk ratio 3.0), and male gender (risk ratio 1.6)

In older hypertensive persons, male gender, prior coronary artery disease, prior atherothrombotic brain infarction (ABI), and echocardiographic left ventricular (LV) hypertrophy are independent risk factors for new coronary events; age, prior ABI, and echocardiographic LV hypertrophy are independent risk factors for new ABI. The data suggest that high plasma renin activity in hypertensive older persons is associated with a high risk of new coronary events and of new ABI through its association with echocardiographic LV hypertrophy

Comparison of 239 older patients with 40% to 100% extracranial carotid arterial disease (ECAD) with 1,243 older patients with no significant ECAD showed a higher prevalence of systemic hypertension, left ventricular (LV) hypertrophy, and prior atherothrombotic brain infarction (ABI) and a higher incidence of new ABI in patients with ECAD than in patients without ECAD. A multivariate Cox regression model showed that independent predictors of new ABI were ECAD (risk ratio = 2.5), systemic hypertension (risk ratio = 2.3), prior ABI (risk ratio = 2.3), LV hypertrophy (risk ratio = 2.3), and male sex (risk ratio = 1.3)