Background: Reduced lung function has been associated with increased rates of myocardial infarction. Whether the occurrence and prognostic significance of ventricular arrhythmia is related to lung function is largely unknown.
Methods and results: We performed a population-based study of 68-year-old men without a history of stroke or myocardial infarction; 402 men participated. Mortality and coronary events (fatal or nonfatal) were studied in relation to ventricular arrhythmia during 24 hours, percentage of the predicted forced expiratory volume (FEV1(%pred)), vital capacity (VC(%pred)), and the FEV/VC ratio. During 14 years of follow-up, 181 men died and 87 experienced a coronary event. Occurrence of frequent or complex ventricular arrhythmia (Lown class 2 to 5) was significantly and inversely associated with FEV1(%pred). Men with Lown class 2 to 5 and a low FEV1(%pred) (below median) had significantly higher mortality (71.5 versus 26.8 per 1000 person-years; P<0.0001) and coronary event rates (37.7 versus 18.0; P=0.02) than men with Lown class 2 to 5 and a high FEV1(%pred). These associations remained significant after adjustments for potential confounders (mortality: relative risk [RR], 2.91; 95% CI,1.68 to 5.04; coronary events: RR, 2.16; 95% CI, 1.07 to 4.37). In men without frequent or complex arrhythmia (Lown 0 to 1), a low FEV1(%pred) was not significantly associated with mortality (RR, 1.37; 95% CI, 0.92 to 2.05) or coronary events (RR, 1.24; 95% CI, 0.67 to 2.27) after adjustments for confounders. The FEV/VC ratio showed similar associations with arrhythmia, mortality, and coronary events.
Conclusions: Lung function is inversely associated with the occurrence of ventricular arrhythmia. The increased incidence of myocardial infarction and death associated with arrhythmia was mainly limited to men with a low FEV1(%pred) or FEV/VC. We suggest that lung function should be considered when assessing the prognostic significance of ventricular arrhythmia.