Objective: We aimed to determine the efficacy of troponin I, D-dimer, and lactate levels and right ventricular diameter (RVD)/left ventricular diameter (LVD) ratio on pulmonary computed tomography angiography (PCTA) in the risk classification of patients who were diagnosed with acute pulmonary embolism (APE) in Emergency Department (ED).
Patients and methods: Patients who were diagnosed as having APE by PCTA in ED were included in this retrospective study. Patients were grouped as high-risk (undergoing cardiopulmonary resuscitation or given thrombolytic therapy), moderate-risk (with non-high-risk and positive ECO findings) and low risk (others). Troponin I, D-dimer, and lactate levels of patients were determined. RVD, RVD/LVD ratio, and interventricular septum deviation were calculated from PCTA images.
Results: A total of 121 patients were included (35 high, 36 moderate, 50 low risk). Lactate was different in the high-risk group from the other groups, whereas there was no difference between the moderate and low-risk groups. Troponin I levels were not different between the high-risk and moderate-risk groups. There were statistically significant differences between the high, moderate, and low-risk groups in terms of mean RVD/LVD ratios. ROC analyses performed in order to define high-risk group revealed a cut-off value of > 2.3 (AUC = 0.848, sensitivity = 70%, specificity = 90%, + Likelihood ratio (LR) = 7, -LR = 0.33, 95% CI = 0.752-0.943) for lactate and > 1.40 (AUC = 0.695 sensitivity = 71%, specificity = 80%, + LR = 3.6, -LR = 0.36, 95% CI = 0.668-0.822) for RVD/LVD ratio.
Conclusions: Lactate levels and RVD/LVD ratio were shown to be useful in distinguishing high-risk patients from other patient groups. Troponin I is important in terms of showing cardiac involvement, but it is inadequate in distinguishing between high and moderate-risk patients. Lactate, troponin I, and RVD/LVD ratio may be used together for a more accurate separation of patients with high, intermediate and low-risk.