High-Sensitivity Cardiac Troponin T in Patients with Acute Myocardial Infarction in Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Background: In clinical work, patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) often have high-sensitivity cardiac troponin T (hs-cTnT) levels that surpass the 99th percentile of the normal reference population, a cutoff used to screen patients for acute myocardial infarction (AMI). However, a large proportion of these patients prove not to have AMI and are frequently misdiagnosed and overtreated. We analyzed whether the cutoff value of hs-cTnT for diagnosing AMI in AECOPD patients should be adjusted. Methods: This was a prospective study of 873 consecutive patients with AECOPD who presented at the emergency department of West China Hospital of Sichuan University from January 2010 to December 2013. Conventional cardiac troponin (cTnT) was measured in patients' blood samples taken at presentation, and values were compared with their final diagnoses. Results: Among patients with a final diagnosis other than AMI, 64.64% had a plasma hs-cTnT concentration above the 99th percentile of a normal reference population (14 ng/L). The median level of hs-cTnT in AECOPD patients without AMI was 16 ng/L. The area under the receiver-operating characteristic curve (AUC) of hs-cTnT for diagnosis of AMI was 0.92 (0.85 - 0.99, p < 0.001) with a cutoff value of 60.5 ng/L. Conclusions: The baseline levels of hs-cTnT were relatively high in AECOPD patients, and the optimal cutoff value of hs-cTnT for AMI diagnosis (60.5 ng/L) was also higher than that for non-AECOPD patients.