Persuing ventricular-arterial coupling: proposing a new cut-off of TAPSE/sPAP to identify patients with pulmonary hypertension after intermediate-high risk pulmonary embolism

Introduction – Pulmonary hypertension (PH) remains a potential long-term complication following pulmonary embolism (PE). Right heart catheterization (RHC) is the gold-standard for the diagnosis while echocardiography is often used as a non-invasive screening tool. The ventricular-arterial coupling accessed by echocardiography in the form of TAPSE/sPAP ratio is increasingly used as an add-on to other echocardiography parameters to better predict the probability of PH. This study aimed to evaluate the predictive power of echocardiographic parameters to detect PH in patients with intermediate-high risk PE submitted to catheter-directed therapy (CDT). Methods – Patients with intermediate-high risk PE submitted to catheter-directed therapy in a tertiary centre are submitted to a multimodality evaluation at 3 to 6-month follow-up to screen for PH. Patients were divided in two groups according to the presence of pre-capillary PH (mPAP >20 mmHg, PVR > 2 WU and PCWP < 15 mmHg in RHC) and echocardiographic parameters were analysed to assess their power to predict PH. Results – From the 78 patients, 42 completed the follow-up and were included in the analysis (median age 59 years [IQR 47-73 years], 57,1% female). 20 patients (47,6%) were diagnosed with PH by RHC at 3-6 month follow-up. Echocardiographic parameters of the right heart that were significantly different between the two groups were the presence of tricuspid regurgitation (p=0,01) and the TAPSE/sPAP ratio (p= 0,03). Peak tricuspid regurgitation velocity (p=0,169) and RVOT acceleration time (p=0,520) showed no statistically significant differences between the two groups. The ROC curve analysis of TAPSE/sPAP showed the best cut-off value of 0,64 (p=0,001, AUC 0,752, Sensitivity 53%, Specificity 93%) when comparing with the guideline recommended cut-off of 0,55 (p=0,389, AUC 0,577, Sensitivity 20%, Specificity 95%). A logistic regression model showed a OR 2,15 (p=0,017) in predicting PH for each increase of 0,1 in TAPSE/sPAP ratio. Conclusion – In our study, for patients after intermediate-high risk PE, the ventricular-arterial coupling accessed by echocardiogram (TAPSE/sPAP) showed to be most valuable echocardiographic parameter to predict the presence of PH 3 to 6 months of effective anticoagulation. However, the optimal cut-off may be outdated taking into account the most recent hemodynamic threshold for the diagnosis of PH. In our cohort, a higher value of TAPSE/sPAP ratio seems to be a better predictor of PH.