Parental atrial fibrillation as a risk factor for atrial fibrillation in offspring.

CONTEXT: Atrial fibrillation (AF) is the most common cardiac dysrhythmia in the United States. Whereas rare cases of familial AF have been reported, it is unknown if AF among unselected individuals is a heritable condition.

OBJECTIVE: To determine whether parental AF increases the risk for the development of offspring AF.

DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study (1983-2002) within the Framingham Heart Study, a population-based epidemiologic study. Participants were 2243 offspring (1165 women, 1078 men) at least 30 years of age and free of AF whose parents had both been evaluated in the original cohort.

MAIN OUTCOME MEASURES: Development of new-onset AF in the offspring was prospectively examined in association with previously documented parental AF.

RESULTS: Among 2243 offspring participants, 681 (30%) had at least 1 parent with documented AF; 70 offspring participants (23 women; mean age, 62 [range, 40-81] years) developed AF in follow-up. Compared with no parental AF, AF in at least 1 parent increased the risk of offspring AF (multivariable-adjusted odds ratio [OR], 1.85; 95% confidence interval [CI], 1.12-3.06; P =.02). These results were stronger when age was limited to younger than 75 years in both parents and offspring (multivariable-adjusted OR, 3.23; 95% CI, 1.87-5.58; P<.001) and when the sample was further limited to those without antecedent myocardial infarction, heart failure, or valve disease (multivariable-adjusted OR, 3.17; 95% CI, 1.71-5.86; P<.001).

CONCLUSIONS: Parental AF increases the future risk for offspring AF, an observation supporting a genetic susceptibility to developing this dysrhythmia. Further research into the genetic factors predisposing to AF is warranted.