Anticoagulation in the Elderly

Abhay J. Dhond, MD, MPH, Hector I. Michelena, MD, Michael D. Ezekowitz, MD, PhD


Am J Geriatr Cardiol. 2003;12(4) 

In This Article

The Risk Factors for Stroke in AF

Stroke is a major cause of death and disability in the elderly. AF is the most common cardiac disease associated with cerebral embolism, responsible for as much as 25% of strokes in individuals between 75 and 84 years of age.[10] The prevalence of silent cerebral infarction is an important consideration in asymptomatic patients with AF.[11] It is known that multiple silent infarcts lead to cognitive dysfunction and subtle neurologic deficits. Furthermore, a large population study found that impaired cognitive function (dementia, subtypes of Alzheimer's disease, and vascular dementia) was related to AF even in the absence of clinical stroke.[12]

All patients with AF over age 75 are at high risk for stroke.[5] For people older than 85 years, the stroke rate is 50 times higher than for those in their 50s.[10] The Atrial Fibrillation Investigators (AFI)[13] found that increasing age is an independent risk factor for stroke in patients with AF ( Table I ). The Stroke Prevention in Atrial Fibrillation III (SPAF III)[14] study found women >75 years old to be at high risk and increasing age to be a statistically significant independent risk factor for primary events (relative risk, 1.7/10 years). Other "high-risk" factors for stroke in patients with AF include hypertension, diabetes, heart failure, and previous transient ischemic attack (TIA) or stroke. The Stroke Prevention in Atrial Fibrillation I (SPAF I) study,[15] the Boston Area Anticoagulation Trial in Atrial Fibrillation (BAATAF) study,[16] and the Veterans Affairs Stroke Prevention in Nonrheumatic Atrial Fibrillation (SPINAF) study,[17] collected echocardiographic data at baseline to determine whether there were echocardiographic predictors of increased risk of stroke. The only independent predictor of an increased risk of stroke was moderate to severe left ventricular dysfunction (relative risk, 2.89; 95% confidence interval [CI], 1.67-5.01; p <0.001).[7]