Impact of Atrial Fibrillation on Mortality, Stroke, and Medical Costs

Abstract

ATRIAL fibrillation (AF), the most common persistent cardiac arrhythmia, has been estimated to affect 2.2 million people in the United States.¹ Prevalence of AF increases with age, approximately doubling in each decade in individuals older than 50 years. In those older than 65 years, prevalence of AF is estimated to be 6%.¹ In the absence of rheumatic heart disease with mitral stenosis, AF had long been considered to pose no significant hazard for disease or death. However, in recent years, nonrheumatic AF has been identified as an important force in mortality and one of the most powerful independent risk factors predisposing to stroke.^2,3 The incidence of stroke is increased nearly 5-fold in the presence of AF with average annual incidence rates of stroke varying from 5% to more than 12% depending on age and other associated risk factors.^4,5 Since AF often develops with a background of heart disease, the increased mortality and stroke rates had been attributed to the associated cardiovascular disease (CVD) rather than to the AF itself. However, demonstration that more than two thirds of stroke events could be averted by anticoagulation with warfarin sodium, which had its major impact on the prevention of the formation of intra-atrial thrombi, confirmed the primary importance of AF.⁶