Resting heart rate is a predictor of mortality in COPD

The clinical significance of high heart rate in chronic obstructive pulmonary disease (COPD) is unexplored. We investigated the association between resting heart rate, pulmonary function, and prognosis in subjects with COPD. 16 696 subjects aged ≥40 years from the Copenhagen City Heart Study, a prospective study of the general population, were followed for 35.3 years, 10 986 deaths occurred. Analyses were performed using time-dependent Cox-models and net reclassification index (NRI). Resting heart rate increased with severity of COPD (p<0.001). Resting heart rate was associated with both cardiovascular and all-cause mortality across all stages of COPD (p<0.001). Within each stage of COPD, resting heart rate improved prediction of median life expectancy; the difference between <65 bpm and >85 bpm was 5.5 years without COPD, 9.8 years in mild (Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I), 6.7 years in moderate (GOLD stage II) and 5.9 years in severe/very severe COPD (GOLD stage III/IV), (p<0.001). Resting heart rate significantly improved risk prediction when added to GOLD stage (categorical NRI 4.9%, p = 0.01; category less NRI 23.0%, p<0.0001) or forced expiratory volume in 1 s % predicted (categorical NRI 7.8%, p = 0.002; category less NRI 24.1%, p<0.0001). Resting heart rate increases with severity of COPD. Resting heart rate is a readily available clinical variable that improves risk prediction in patients with COPD above and beyond that of pulmonary function alone. Resting heart rate may be a potential target for intervention in COPD.