Warfarin: Prescribe with Care in the Elderly

Journal Watch CardiologyJune 13, 2007

Warfarin: Prescribe with Care in the Elderly

Mark S. Link, MD

Journal Watch. 2007;6(6) ©2007 Massachusetts Medical Society

In a real-world cohort of elderly patients, the hazards of warfarin therapy were found to be greater than previously reported.

Summary
Randomized controlled trials have shown that warfarin significantly reduces the risk for stroke in patients with atrial fibrillation. Therefore, warfarin has become a standard component of the armamentarium for patients with AF and a CHADS2 (congestive heart failure, hypertension, age ≥75, diabetes, previous stroke or transient ischemic attack) score of 1 or 2 (depending on individual patient characteristics) or higher. However, these trials have generally included few individuals older than 80, and the investigators may have preselected, whether by design or unintentionally, participants at a lower risk for bleeding during warfarin treatment. Recently, researchers at an anticoagulation clinic studied a real-world cohort of 472 patients (including 153 aged ≥ 80 years) who were taking warfarin. Prospectively tracked outcomes were major hemorrhage, time to discontinuation of warfarin, and physician-stated reason for warfarin termination.

Within 1 year, 26 patients experienced a major hemorrhage. Patients aged ≥80 years had a markedly increased risk for major hemorrhage (13.10 events per 100 person-years, vs. 4.75 per 100 person-years in patients aged <80>

Comment
Prevention of cerebrovascular accidents in elderly patients with AF is an important and laudable goal. Unfortunately, the hazards of prophylactic warfarin are heightened by advanced age, recent initiation, and higher INRs. Aspirin use, a predisposition to falls, and frailty are also likely to increase the risk for hemorrhage. An accompanying editorial emphasizes the difficulties of treating AF in the elderly and the apparent increase in major bleeding reported in recent trials. Careful analysis of the risks and benefits of anticoagulation is essential in managing such patients.

References:

Hylek EM et al. Major hemorrhage and tolerability of warfarin in the first year of therapy among elderly patients with atrial fibrillation. Circulation 2007 May 29; 115:2689-96.

Wyse DG. Bleeding while starting anticoagulation for thromboembolism prophylaxis in elderly patients with atrial fibrillation: From bad to worse. Circulation 2007 May 29; 115:2684-6.