Background Retrospective studies suggest that plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin T are often elevated in patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) and are associated with increased mortality. These cardiac biomarkers were investigated in an unselected cohort of patients admitted to hospital with exacerbations of COPD. Methods Consecutive patients with physician-diagnosed COPD exacerbation but without clinical evidence of acute cardiac disease admitted to a public hospital over a 1 year period were studied prospectively. NT-proBNP and troponin T were measured on admission. The primary end point was all-cause mortality at 30 days. Results Elevated NT-proBNP (>220 pmol/l) was present in 65/244 patients (27.5%) and significantly predicted 30-day mortality (OR 9.0, 95% CI 3.1 to 26.2, p<0.001). Elevated troponin T (>0.03 mg/l) was found in 40/241 patients (16.6%) and also predicted 30-day mortality (OR 6.3, 95% CI 2.4 to 16.5, p<0.001). These associations persisted after adjusting for other clinical and laboratory predictors of mortality (arterial CO 2 pressure (PaCO 2 ), body mass index and CURB65 score). NT-proBNP and troponin T levels appeared to have additive associations with mortality: 30-day mortality among patients with abnormalities of both NT-proBNP and troponin T was 15-fold higher than among patients with normal values. Conclusion Elevated levels of NT-proBNP and troponin T are strong predictors of early mortality among patients admitted to hospital with acute exacerbations of COPD independently of other known prognostic indicators. The pathophysiological basis for this is unknown, but indicates that cardiac involvement in exacerbations of COPD may be an important determinant of prognosis.

This audit documented the general characteristics, assessment, management and outcome of the COPD admissions to a secondary New Zealand hospital. Further investigations into factors contributing to shorter length of stay and predictors of mortality are needed.

A simple 6-point score based on confusion, blood urea, respiratory rate, blood pressure and age can be used to stratify patients with COPD exacerbation into different management groups. The CURB65 score was as effective in predicting early mortality in our cohort of acute COPD exacerbations as it was in previous cohorts with community acquired pneumonia. Our findings suggest that CURB65 scores can help clinicians to assess patients with exacerbation of COPD.

Background: Patients with chronic obstructive pulmonary disease (COPD)

CPAP treatment of OSA in patients with cardiovascular disease does not alter renal function or the occurrence of renal adverse events. Clinical trial registered with www.clinicaltrials.gov (NCT00738179).