Troponin I and D-dimer levels as triaging biomarkers to distinguish acute pulmonary thromboembolism from myocardial infarction

Background Acute pulmonary thromboembolism (APTE) is often confused with myocardial infarction. Previous studies have shown that patients with APTE exhibit lower initial and peak cardiac troponin I (CTI) levels, but higher D-dimer (DD) levels, than patients with myocardial infarction. The present study aimed to reaffirm the tree model algorithm using an entirely new set of data. Methods We reviewed retrospective clinical and laboratory data from patients who were diagnosed with APTE or non-ST-elevation myocardial infarction (NSTEMI) between 2015 and 2016. Subjects who were not classified with a diagnosis or did not have their CTI or DD levels assessed were excluded. We categorized patients according to the previous algorithm and compared the outcomes with the previous test dataset. Results The analysis involved data from 156 patients with APTE and 363 patients with NSTEMI. In the validation data set, the APTE group showed higher initial DD levels (9.80±10.84 μg/mL) and lower initial CTI levels (0.17±0.54 μg/mL) than the NSTEMI group. The accuracy rate for the test dataset and the validation set were similar. The test set accuracy rate was 91.0%, while the accuracy rate in the validation set improved to 88.6%. Conclusions Patients with APTE exhibited lower initial and peak CTI levels, but higher DD levels than NSTEMI patients. The accuracy rate estimates were similar between the test set obtained from the tree model algorithm and the validation set. The study findings demonstrate that the assessment of cardiac biomarkers can be useful for differentiating between APTE and NSTEMI.