Elevated high-sensitivity cardiac troponin T is associated with increased mortality after acute exacerbation of chronic obstructive pulmonary disease

Abstract

Background: Cardiovascular co-morbidities are common in chronic obstructive pulmonary disease (COPD). Retrospective studies on selected patients have indicated that cardiac troponin elevation is frequent during acute exacerbations of COPD (AECOPD), and that this is associated with poor survival. In the present prospective study the prevalence and prognostic value of elevated cardiac troponin T (cTnT) in unselected patients with AECOPD have been investigated, using a novel high-sensitivity assay (hs-cTnT assay). Methods and results: 99 patients hospitalised for AECOPD were included. They were followed until death or study termination. During a median follow-up time of 1.9 years, 57 patients (58%) died. 97 patients (98%) had measurable levels of hs-cTnT and 73 (74%) had hs-cTnT above the normal range (≥14.0 ng/l). The crude mortality rates in patients having hs-cTnT <14.0, 14.0-39.9 and ≥40 ng/l were 4.6, 30.2 and 58.3 per 100 patient-years, respectively. Adjusting for relevant covariables using an extended Cox regression analysis, the HRs (95% CI) for death were 4.5 (1.2 to 16) and 8.9 (2.4 to 32) among patients having hs-cTnT 14.0-39.9 and ≥40 ng/l, respectively, compared with patients with hs-cTnT <14.0 ng/l. The association between mortality and hs-cTnT was strongly modified by heart rate at admission (p<0.001)dthat is, the association between mortality and hs-cTnT was stronger among patients with tachycardia. Conclusion: Elevated hs-cTnT during AECOPD is frequent, and it is associated with increased mortality. The effect is stronger among patients having tachycardia than among patients with normal heart rate.