Is ASA as Good as Warfarin in the Treatment of Atrial Fibrillation?

Findings of a Provocative New Meta-Analysis

Jason M. Burstein, MD
Internal Medicine Resident,
University of Toronto,
Toronto, ON.

Shabbir M.H. Alibhai, MD, MSc, FRCP(C)
Clinical Assistant, Internal
Medicine & Geriatrics,
University Health Network, Toronto, ON.

Atrial fibrillation is a common cardiac condition that challenges many physicians, including primary care and emergency doctors, general internists, geriatricians and cardiologists. One of the best-understood and most studied complications is cardio-embolic stroke. While management of atrial fibrillation may seem straightforward, it is interesting to note that there are still large variations in practice patterns, and a recent meta-analysis was contradictory to many previous studies and guidelines. This paper will focus on the epidemiology and treatment of atrial fibrillation in the older population and will examine both the reasons for variations in practice pattern and the conflicting evidence in major medical journals.

Epidemiology and Causes of Atrial Fibrillation
Age is perhaps the most important influence on the incidence and prevalence of disease. The prevalence rate of atrial fibrillation is 2-3% at age 60 to 65 and 8-10% at age 80. Up to 70% of all affected patients are at least 65 years old. The incidence of atrial fibrillation before age 50 is 0.