Cardiac troponin I in patients with severe exacerbation of chronic obstructive pulmonary disease

Objectives: Co-morbid conditions including risk factors for cardiovascular diseases and left ventricular dysfunction are common in patients with chronic obstructive pulmonary disease (COPD). This study assessed the incidence of cardiac troponin I (cTnI) elevation, a specific marker for cardiac injury, and its prognostic significance during severe exacerbation of COPD. Design: Prospective cohort study. Setting: Two intensive care units. Participants: Seventy-one consecutive patients admitted for severe exacerbation of COPD. Intervention: None. Measurements and results: Cardiac troponin I was assayed in blood samples obtained on admission and 24 h later (Stratus II immunoassay analyser, Dade International). Levels above 0.5 ng/ml were considered positive. The following data were recorded prospectively: clinical symptoms, co-morbidities, cause of the exacerbation, diagnostic procedures and treatment, general severity score (SAPS II) and in-hospital outcome. CTnI was positive in 18% of patients (95% confidence interval (CI95), 11-29%), with a median value at 1.00 ng/ml; CI95 (0.60-1.70). Eighteen patients died in the hospital (25%; CI95, 17-37%). Only cTnI (adjusted odds ratio (ORa), 6.52; CI95,1.23-34.47) and SAPS II 24 h after admission (ORa, 1.07; CI95, 1.01-1.13) were independent predictors of in-hospital mortality. Conclusion: Elevated cTnI is a strong and independent predictor of in-hospital death in patients admitted for acutely exacerbated COPD.