Population prevalence, incidence, and predictors of atrial fibrillation inthe Renfrew/Paisley study

Objectives-Though atrial fibrillation (AF) is an important cause of cardiov ascular morbidity, there are few large epidemiological studies of its preva lence, incidence, and risk factors. The epidemiological features of AF are described in one of the largest population cohorts ever studied. Methods-The prevalence and incidence of AF were studied in the Renfrew/Pais ley population cohort of 15 406 men and women aged 45-64 years living in th e west of Scotland. This cohort was initially screened between 1972 and 197 6 and again between 1977 and 1979. Incident hospitalisations with AF in the 20 year period following initial screening were also studied. Results-The population prevalence of AF in this cohort was 6.5 cases/1000 e xaminations. Prevalence was higher in men and older subjects. In those who were rescreened, the four year incidence of AF was 0.54 cases/1000 person y ears. Radiological cardiomegaly was the most powerful predictor of new AF ( adjusted odds ratio 14.0). During 20 year follow up, 3.5% of this cohort wa s discharged from hospital with a diagnosis of AF; the rate of incident hos pitalisation for AF was 1.9 cases/1000 person years. Radiological cardiomeg aly (adjusted odds ratio 1.46) and systolic blood pressure (adjusted odds r atio 2.1 for greater than or equal to 169 trim Hg) were independent predict ors of this outcome. Conclusions-Data from one of the largest epidemiological studies ever under taken confirm that AF has a large population prevalence and incidence, even in middle aged people. More important, it was shown that the long term inc idence of hospitalisation related to AF is high and that two simple clinica l measurements are highly predictive of incident AF. These findings have im portant implications for the prevention of AF.