Multidimensional CT approach to predict hemodynamics in pulmonary hypertension

Aim: Computed tomographic pulmonary angiography (CTPA) allows an excellent visualization of heart chambers and vessels, which may be associated with hemodynamic status in pulmonary hypertension, obviating the need for repetitive right heart catheterization (RHC). In this study, we aimed to evaluate the capacity of CTPA to predict severe hemodynamics and to correlate with clinical status and events.

Material and methods: Retrospective study with 51 patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) in whom a CTPA and RHC were performed within 6 months. The primary endpoint was to evaluate the CTPA performance to predict severe hemodynamics, defined as the best mPAP threshold with clinical impact. Secondary endpoints were the correlation of CTPA measurements with clinical outcomes.

Results: The right ventricle (RV) and right atrium (RA) areas, RV-free wall thickness, septal angle and pulmonary artery diameter assessed by CTPA revealed a good capacity to predict severe hemodynamic status. A CTPA model, incorporating both an RV area above 23 cm² and an RA area above 21 cm², increased the prediction capacity to detect severe hemodynamic status. The presence of both parameters above the threshold predicted severe PH with a 100% specificity and a 52% sensitivity and conveyed a 5-fold increased risk of mortality during follow-up. CTPA-altered parameters were directly associated with higher NT-proBNP levels and worse WHO-FC at baseline and follow-up.

Conclusion: In this pilot study, a CTPA model was able to predict severe PH hemodynamic status and worse clinical events during follow-up.