Evaluation of the Correlation of Pulmonary Arterial Hypertension (PAH) with the Pulmonary Artery Trunk Diameter and Serum Level of N-Terminal Pro B-Type Natriuretic Peptide (NT-proBNP) in Patients with PAH

Background: Due to its non-specific symptoms, pulmonary arterial hypertension (PAH) is difficult to diagnose via non-invasive methods. Various diagnostic tests are required to evaluate PAH patients. The increased diameter of the main pulmonary artery in computed tomography (CT) imaging represents a high probability of PAH. Moreover, N-terminal pro B-type natriuretic peptide (NT-proBNP) and pro B-type natriuretic peptide (proBNP) can be considered as prognostic predictors in patients with PAH. Objectives: This study aimed to evaluate the correlation of CT-based main pulmonary artery diameter (MPAD) and the serum level of NT-proBNP (as a strong pro-inflammatory factor) with the severity of PAH in echocardiography among patients with PAH. Patients and Methods: In this cross-sectional study, a total of 63 hospitalized patients with PAH due to chronic obstructive pulmonary disease were recruited from 2019 to 2020 after initial evaluations and collection of serum NT-proBNP measurements and echocardiographic findings. On the chest CT scans, the largest diameter of the pulmonary artery trunk was determined, and then, correlation of CT-based MPAD with both PAH severity on echocardiography and NT-proBNP level in patients with PAH were evaluated. Results: The results of the present study on 63 patients (70% male; mean age, 67.02 years) showed a significant positive correlation between the MPAD and NT-proBNP level (r = 0.444, P < 0.001). Moreover, a significant positive relationship was observed between the pulmonary artery pressure (PAP) and NT-proBNP (r = 0.353, P = 0.005) and also between MPAD and PAP (r = 0.306, P = 0.015). In PAH patients, the mean values of MPAD, PAP, and NT-proBNP were 32.58 mm, 47.9 mmHg, and 6563 pg/mL, respectively. Conclusion: Considering the significant positive correlation between PAP, MPAD, and NT-proBNP level in subgroup comparisons based on MPAD and PAP, if the MPAD is abnormal on CT scan, additional echocardiographic assessments and serum NT-proBNP measurements can be helpful.