Confidence intervals for the number needed to treat

Chronic obstructive pulmonary disease has been associated with a high frequency of arrhythmias. Few studies have analysed the role of reduced lung function in predicting atrial fibrillation (AF). The aim of the present study was to investigate the relationship between forced expiratory volume in one second (FEV1) and risk of first episode of AF in a prospective study. Data from 13,430 males and females without previous myocardial infarction, who participated in the Copenhagen City Heart Study, were analysed. New AF was assessed at re-examination after 5 yrs and by hospital admission for AF during a period of 13 yrs. Multivariate analyses were used with adjustment for cardiopulmonary risk factors. There were 62 new cases of AF at 5-yr follow-up (0.58%) and 290 cases (2.20%) diagnosed at hospitalisations. Risk of new AF at re-examination was 1.8-times higher for FEV1 between 60–80% of predicted compared with FEV1 ≥80% after adjustment for sex, age, smoking, blood pressure, diabetes and body mass index. The risk of AF hospitalisation was 1.3-times higher for FEV1 between 60–80% and 1.8-times higher for FEV1 1 ≥80%, when additional adjustment was made for education, treatment with diuretics and chest pain at activity. The authors conclude that reduced lung function is an independent predictor for incident atrial fibrillation.