Troponin T elevation and long-term mortality after chronic obstructive pulmonary disease exacerbation

Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of cardiovascular disease, exacerbations of which increase strain on the heart. The prognostic value of elevated circulating levels of cardiac Troponins seen during COPD exacerbations has been investigated. From the Akershus hospital database, 897 patients discharged after treatment for COPD exacerbation in the period 2000-2003 were identified and followed-up until June 30, 2005. Median observation time was 1.9 yrs. In 396 patients, measurements of cardiac-specific troponin T (cTnT) were available. Levels of cTnT >= 0.04 mu g(.)L(-1) were considered elevated. Clinical data were retrieved from patient records and date of death was obtained from the Norwegian National Registry. In order to balance the nonrandomised nature of available cTnT measurements, an exposure propensity score (EPS) for cTnT sampling was calculated and used in regression analyses. After adjusting for EPS in Cox regression analyses, elevated cTnT was significantly associated with increased all-cause mortality in the observation period, with a hazard ratio of 1.64 (95% confidence interval 1.15-2.34). In conclusion, chronic obstructive pulmonary disease patients with elevated cardiac-specific Troponin T during exacerbation are at increased risk of death after discharge.