HERSHEY, PENNSYLVANIA. A recent study carried out by researchers at Pennsylvania State University concludes that the prevalence in the US (total number of cases at a specific time) of atrial fibrillation and atrial flutter is substantially higher than previously assumed. The study involved over 21 million people enrolled in various employer- and government-funded (Medicare) healthcare insurance plans and covered the period July 1, 2004 to December 31, 2005.

The researchers found that 242,900 (1.12%) of the study participants had been diagnosed with atrial fibrillation (AF) and atrial flutter (AFL) during the 18-month study period. The prevalence of AF (91.6%) was substantially higher than that of AFL (2.0%) with the remaining 6.4% having both AF and AFL. The prevalence of AF was somewhat higher among men than among women (54% vs 46%) whereas the prevalence of AFL was substantially higher among men (63% vs 37%). The prevalence of AF and AFL increased sharply with age with 74% of AF patients and 58% of AFL patients being 65 years or older.

The study, unfortunately, did not distinguish between lone atrial fibrillation (LAF) and AF with underlying heart disease. Most patients with AF had one or more comorbidities such as congestive heart failure (30.3%), valvular heart disease (30.3%), coronary artery disease (43%), and hypertension (62%). Matched controls with no AF or AFL had much lower rates of these conditions (congestive heart failure 6.5%, valvular heart disease 7.9%, coronary artery disease 19.4%, and hypertension 45.1%).

Based on this 21 million population sample, the researchers estimate that 3.03 million people in the US were struggling with AF in 2005 with corresponding numbers for AFL and AF and AFL being 0.07 million and 0.19 million. The estimate for 2050 is 7.56 million with AF, 0.15 million with AFL and 0.44 million with both AF and AFL. They conclude that the prevalence of AF has increased since 1996-1997 to a greater extent than would be attributed to the population growth and aging alone.

Naccarelli, GV, et al. Increasing prevalence of atrial fibrillation and flutter in the United States. American Journal of Cardiology, Vol. 104, 2009, pp. 1534-39

Editor�s comment: It is most unfortunate that this study did not distinguish between lone and heart disease-related AF; however, it is certainly clear that atrial fibrillation and flutter are becoming increasingly common and that an affordable protocol for effectively managing these conditions is urgently needed.