Evaluation of serum troponin I in patients with acute exacerbations of chronic obstructive pulmonary disease

Introduction Chronic obstructive pulmonary disease is a common, preventable, and treatable disease. Troponin I is a component of the contractile proteins present in all muscles. The amino acid sequence of cardiac troponin I (cTnI) contains a section that is unique to cardiac muscle. Aim The aim of the study was to evaluate the incidence of cTnI elevation in patients with acute exacerbation of chronic obstructive pulmonary diseases (AECOPDs) and study the possible association of the level of cTnI with the severity of AECOPD, need for assisted ventilation, and length of hospital stay. Patients and methods This study was performed on 30 patients with AECOPD admitted to the Chest Department and Respiratory ICU at Benha University Hospital. On admission, all patients were subjected to full medical history taking and full clinical examination. We examined the patients for signs and symptoms of right ventricular (RV) failure. Echocardiography was performed for every patient. Serum troponin I levels (upon admission and 24 h later) were evaluated. Results The study showed 21 (70%) of 30 patients with positive troponin I versus nine (30%) with negative troponin I. There was a nonsignificant statistical difference among all studied AECOPD patients as regards smoking habits, as 89% of troponin I-negative patients were smokers versus 81% of troponin I-positive patients. When assessed on the basis of pulmonary function tests, 75% of troponin I-negative patients were found to be in moderate stage, 53% of troponin I-positive patients were in severe stage, and 33% of troponin I-positive patients were in very severe stage. There was a significant statistical difference in troponin elevation as regards pulmonary hypertension (71% of cTnI-positive patients vs. 11% of cTnI-negative patients), RV strain (90% of cTnI-positive patients vs. 33% of cTnI-negative patients), and tricuspid regurge (52% of cTnI-positive patients) but a nonsignificant difference as regards left ventricular dysfunction among all studied AECOPD patients. Conclusion cTnI in AECOPD patients is mostly positive in tachypneic, tachycardiac, hypoxemic, and hypercapnic patients with more severe pulmonary hypertension and RV dysfunction. Positive cTnI in AECOPD patients may suggest exacerbation severity, the need for mechanical ventilation (MV), and longer duration of hospitalization.