Page 24 - Assessing right ventricular function and the pulmonary circulation in pulmonary hypertension Onno Anthonius Spruijt

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Abstract
Introduction: The most common feature of pulmonary hypertension (PH) on computed tomography pulmonary angiography (CTPA) is an increased diameter-ratio of the pulmonary artery to the ascending aorta (PA/AAAX). The aim of this study was to investigate whether combining PA/AAAX measurements with ventricular measurements improves the predictive value of CTPA for precapillary PH.
Methods: Three predicting models were analyzed using baseline CTPA scans of 51 treatment naïve precapillary PH patients and 25 non-PH controls: model 1: PA/AAAX only; model 2: PA/AAAX combined with the ratio of the right ventricular and left ventricular diameter measured on the axial view (RV/LVAX); model 3: PA/AAAX combined with the RV/LV-ratio measured on a four chamber view (RV/LV4CH). Prediction models were compared using multivariable binary logistic regression, ROC analyses and decision curve analyses (DCA).
Results: Multivariable binary logistic regression showed an improvement of the predictive value of model 2 (-2LL=26.48) and 3 (-2LL=21.03) compared to model 1 (-2LL=21.03). ROC analyses showed significantly higher AUCs of model 2 and 3 compared to model 1 (p=0.011 and p=0.007, respectively). DCA showed an increased clinical benefit of model 2 and 3 compared to model 1. The predictive value of model 2 and 3 was almost equal. We found an optimal cut-off value for the RV/LV-ratio for predicting precapillary PH of RV/LV≥1.20.
Conclusions: The predictive value of CTPA for precapillary PH improves when ventricular and pulmonary artery measurements are combined. A PA/AAAX ≥1 or a RV/LVAX ≥1.20 needs further diagnostic evaluation to rule out or confirm the diagnosis.