Electrocardiogram, Echocardiogram and NT-proBNP in Screening for Thromboembolism Pulmonary Hypertension in Patients after Pulmonary Embolism

Background: The annual mortality of patients with untreated chronic thromboembolism pulmonary hypertension (CTEPH) is approximately 50% unless a timely diagnosis is followed by adequate treatment. In pulmonary embolism (PE) survivors with functional limitation the diagnostic work-up starts with echocardiography. It is followed by lung scintigraphy and right heart catheterization. However, noninvasive test providing diagnostic clues to CTEPH, or ascertain this diagnosis as very unlikely, would be extremely useful since the majority of post PE functional limitations is caused by deconditioning. Methods: Patients after acute PE underwent a structured clinical evaluation with electrocardiogram, routine laboratory tests including NT-proBNP and echocardiography. The aim of study was to verify whether the parameters from echocardiographic or perhaps electrocardiographic examination and NT-proBNP concentration best determine the risk of CTEPH. Results: A total (n = 261, male n = 123) patients after PE were included into the study, in group of 155 patients (59.4%) with reported functional impairment 13 patients (8.4%) had CTEPH and 7 PE survivors had chronic thromboembolic pulmonary disease (CTEPD) (4,5%). Echo parameters differed significantly between CTEPH/CTEPD cases and other symptomatic PE survivors. Patients with CTEPH/CTEPD had also higher level of NT-proBNP (p = 0.022) but concentration of NT-proBNP above 125 pg/ml did not differentiate patients with CTEPH/CTEPD (p>0.05). Additionally, proportion of patients with right bundle brunch block registered in ECG was higher in group with CTEPH/CTED (23.5% vs. 5.8%, p = 0.034) but there were no differences between other ECG characteristics of right ventricle overload. Conclusion: Screening for CTEPH/CTEPD should be performed in patients with reduced exercise tolerance compared to pre PE period, It is not effective in asymptomatic PE survivors. Patients with CTEPH/CTED had predominantly abnormalities indicatingchronic thromboembolism in the echocardiographic assessment. NT-proBNP and electrocardiographic characteristics of right ventricle overload proved to be insufficient in predicting CTEPH/CTEPD development.