Absolute and Attributable Risks of Atrial Fibrillation in Relation to Optimal and Borderline Risk Factors: The Atherosclerosis Risk in Communities (ARIC) Study

Study Questions:

What is the proportion of the burden of atrial fibrillation (AF) in blacks and whites that could theoretically be avoided by the maintenance of an optimal risk profile?


This study included 14,598 middle-aged Atherosclerosis Risk in Communities (ARIC) Study cohort members. Previously established AF risk factors, namely high blood pressure, elevated body mass index, diabetes mellitus, cigarette smoking, and prior cardiac disease, were categorized into optimal, borderline, and elevated levels. On the basis of their risk factor levels, individuals were classified into one of these three groups. The population-attributable fraction (PAF) of AF resulting from having a nonoptimal risk profile was estimated separately for black and white men and women. PAFs were calculated to determine the possible impact of altering risk profiles on AF occurrence.


During a mean follow-up of 17.1 years, 1,520 cases of incident AF were identified. The age-adjusted incidence rates were highest in white men and lowest in black women (7.45 and 3.67 per 1,000 person-years, respectively). The overall prevalence of an optimal risk profile was 5.4%, but varied according to race and gender: 10% in white women versus 1.6% in black men. Overall, 56.5% of AF cases could be explained by having ≥1 borderline or elevated risk factors, of which elevated blood pressure was the most important contributor.


The authors concluded that more than one-half of the AF burden is potentially avoidable through the optimization of cardiovascular risk factor levels.


In this US cohort of middle-aged adults, 57% of incident AF could be attributed to elevated or borderline levels of risk factors for AF, namely elevated blood pressure, overweight/obesity, diabetes mellitus, smoking, and prior cardiac disease. A previous study based on the Framingham cohort had reported that cigarette smoking, diabetes mellitus, hypertension, and prevalent coronary heart disease combined explained 44% of the burden in men and 58% in women. These studies reinforce the need for successful primary prevention strategies that enable individuals to adopt and maintain healthy diet and behavioral patterns as a means of reducing future cardiovascular risk including AF.

Clinical Topics: Prevention, Hypertension

Keywords: Follow-Up Studies, European Continental Ancestry Group, Cardiovascular Diseases, Coronary Disease, Risk Factors, Blood Pressure, Obesity, Hypertension, Diabetes Mellitus

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