Determining pulmonary artery diameter on CT scans as basis for performing transthoracic echocardiography to screen for pulmonary hypertension in patients with pulmonary artery enlargement

Background: The current guidelines recommend patient stratification based on transthoracic echocardiography (TTE) to identify individuals with potential pulmonary hypertension (PH). We validated the relationship between PH and the pulmonary artery diameter (PAD) on computed tomography (CT) with peak tricuspid regurgitant velocity (TRV) measured by TTE for referral of patients with suspected PH for TTE screening.

Methods: We performed a retrospective analysis of CT-based PAD of 2356 patients who underwent TTE from February 2, 2013 to December 25, 2019 at our institution. The thresholds for suspected PH based on TRV were determined using receiver operating characteristic curves based on PAD. Pearson's rank correlation coefficient was used to assess the relationship between PAD and TRV.

Results: The area under the curve (AUC) of the PAD for suspected PH was statistically greater or comparable to others. The sex-specific PAD threshold for high PH probability were 29.4 mm (male: AUC, 0.86; sensitivity, 84.9%; specificity, 72.3%) and 27.8 mm (female: AUC, 0.83; sensitivity, 78%; specificity, 75.6%). Pearson's rank correlation coefficient showed a correlation between the PAD and TRV (male: ρ = 0.40, P < 0.001, female: ρ = 0.43, P < 0.001).

Conclusions: The main PAD on CT findings served as a suitable marker for referral of patients with suspected PH for TTE screening. Patients exceeding the CT-derived PAD threshold, even incidentally, should undergo additional TTE for a comprehensive PH assessment.