Warfarin therapy for atrial fibrillation in the elderly.
OBJECTIVE
To evaluate a clinical practice model that addresses special needs for managing anticoagulation in a community-dwelling elderly population with atrial fibrillation and high risk of stroke.


METHODS
Medical records of 18 patients (mean age 82 y) followed by the Geriatric Ambulatory Program over 2 years, with a target international normalized ratio (INR) of 2.0-3.0, were reviewed. Risk factors for stroke, number and results of INR tests, suspected reasons for suboptimal response, and adverse events were analyzed. Patients were defined as having cognitive impairment if they had a Folstein Mini-Mental State Exam score < or = 26. Functional impairment was defined by > or = 2 disabilities in activities of daily living.


RESULTS
Eighty-three percent (15/18) had > or = 2 additional stroke risk factors. Fifty-one percent (273/541) of INR responses were therapeutic. Female gender (p = 0.015) and cognitive (p = 0.019) and functional impairment (p = 0.001) were associated with supratherapeutic INR response. All patients with cognitive impairment and 85% of those with functional impairment received caregiver support for medication administration. There were 4 minor bleeding events and no thromboembolic events. The mean number of medications was 9.3 in those with bleeding versus 6.8 in those without bleeding (p = 0.052).


CONCLUSIONS
Elderly patients with high stroke risk achieved therapeutic INR responses. However, those with significant cognitive or functional impairment require caregiver support and special consideration for anticoagulation management.
Lackie
Cynthia L
CL
School of Pharmacy and Pharmaceutical Sciences, State University of New York at Buffalo, Buffalo, USA. Clackie@kaleidahealth.org
Garbarino
Kenneth A
KA
Pruetz
Jennifer A
JA
D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy*; D001777:Blood Coagulation / Q000187:drug effects*; D003072:Cognition Disorders / Q000150:complications; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000209:etiology / Q000517:prevention & control*; D014859:Warfarin / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*
D000925:Anticoagulants; D014859:Warfarin