297 Echocardiographic biventricular coupling index to predict pre-capillary pulmonary hypertension

Pulmonary hypertension (PH) affects millions of people worldwide. Right heart catheterization (RHC) is the gold standard to correctly classify the subtype of PH. Biventricular coupling index (BCI) is a new echocardiographic index defined as the ratio between non-invasive right ventricular stroke work index (RVSWI) and E/E′ ratio. Due to his comprehensive functional characterization of the right heart physiology, we hypothesized it might correctly identify pre-capillary PH.

BCI was derived in a cohort of 334 patients from the University Hospital of Trieste (Italy) and Karolinska University Hospital (Sweden) who underwent transthoracic echocardiography and RHC for all indications (<6 h between the exams). The accuracy of BCI to identify pre-capillary PH was high in the derivation cohort (AUC: 0.82, P < 0.001, CI: 0.78–0.88). Subsequently BCI was tested in a large validation cohort of 1349 patients with available transthoracic echocardiography and RHC from the Fondazione Toscana G. Monasterio of Pisa (Italy). Among patients with PH, BCI showed a high accuracy to correctly identify pre-capillary PH (AUC = 0.91, 95% CI: 0.89–0.93, P < 0.001), with an optimal cut-off of 1.9 providing a sensitivity of 82% and a specificity of 89%, PPV 77%, and a NPV 92%. BCI outperformed previous indexes, such as the D’Alto score (Z coefficient 3.56, difference between areas 0.05 95% CI: 0.02–0.07, P < 0.001) and the echocardiographic Pulmonary to Left Atrial Ratio (ePLAR) index (Z coefficient 2.88, difference between areas 0.02 95% CI: 0.01–0.04, P < 0.004).

BCI is a new non-invasive index based on standard echocardiographic parameters that allows, with high accuracy, the identification of patients with pre-capillary PH, outperforming previously proposed indexes. Routine use of BCI index could be implemented in the screening work-up of pre-capillary PH.