Use of Anticoagulation in Elderly Patients with Atrial Fibrillation Who Are at Risk for Falls

Candice L Garwood, PharmD BCPS; Tia L Corbett, PharmD


The Annals of Pharmacotherapy. 2008;42(4):523-532. 

In This Article

Stroke Risk and Stratification in Patients with Atrial Fibrillation

Treating elderly patients with AF who are at risk for falls requires the clinician to weigh the risks and benefits of warfarin use. Therefore, it is necessary to consider stroke risk in the patient. The AFI (Atrial Fibrillation Investigators) trial pooled data from 5 randomized studies using warfarin or aspirin versus a control group and presented data on stroke risk.[16] In this analysis, the annual risk of stroke in the absence of anticoagulation averaged 5.0% per year and varied from 1.0% for patients less than 65 years with no other risk factors to 8.1% in patients older than 75 years who had one or more risk factors. Stroke risk increases by a factor of 1.4 per decade of life and also increases based on independent risk factors such as hypertension, prior stroke, and diabetes. AF-associated stroke is nearly twice as likely to be fatal, and functional deficits are more likely to be severe compared with non-AF-associated stroke.[17]

Several risk stratification schemes have been developed to facilitate appropriately targeting anticoagulation use.[18] The CHADS2 (congestive heart failure, hypertension, age, diabetes, stroke) risk score, derived from the AFI and the SPAF (Stroke Prevention in Atrial Fibrillation) trials, is a commonly used and well-validated stroke risk strategy for patients with AF. The scheme gives 1 point each for congestive heart failure, hypertension, age greater than 75 years, and diabetes, with 2 points being assigned for stroke/transient ischemic attack. With an assigned score according to the CHADS2 scheme, one can quantify the corresponding annual adjusted stroke risk ( Table 2 ).[19] Subjects with a CHADS2 score of 0-1 are considered to be at low risk for stroke, 2-3 indicates moderate risk, and 4 or more is considered high risk.[18,19] The CHADS2 risk-scoring system demonstrated greater predictive value for stroke than other risk stratification schemes.[18] Many elderly patients with AF will have a moderate or high CHADS2 score. Patients with the greatest number of risk factors carry a stroke risk that is actually higher than in patients with some types of mechanical valve replacement in absence of anticoagulation.[20] Therefore, the use of effective anticoagulation in patients at high risk for stroke should be regarded as exceedingly important. Stroke risk assessment in elderly patients at risk for falls is essential in objectively weighing the therapeutic options of aspirin versus warfarin.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.