The findings of a 20-year study of the inhabitants of Olmsted County, Minn, showed a sharp rise in new cases of atrial fibrillation (AF). During the study, 4618 new cases of electrocardiogram- confirmed AF were identified. The incidence of new AF, measured in cases per 1000 person-years rose approximately 20%. Based on these findings, the group estimated that the current incidence of AF in the United States is approximately 5.1 million, not 2.5 million as previously estimated. The investigators projected that, by 2050, the number of individuals with AF will increase to 12 million if the rate of new AF does not continue to increase. If it does continue to rise, 16 million patients could be affected by 2050.

If their estimate of 5.1 million people with AF in the United States is correct and if, as several studies have found, about 50% of those do not receive anticoagulation, it would be reasonable to expect that failure to use anticoagulation would produce approximately 125,000 strokes per year. Warfarin is very effective for stroke prevention and may reduce the risk by up to 83%. Greater awareness of the rise in AF prevalence and more widespread use of warfarin in appropriate patients have the potential to save the health care system between $8.1 and $10.5 billion annually.

The authors of the study suggest that increasing obesity may account for as much as 60% of the increase.

Dr. Garrett is a clinical pharmacist practitioner at Cornerstone Health Care in High Point, NC.