Echocardiography in acute pulmonary embolism for the prediction of subsequent CTEPH

Abstract Background Chronic thromboembolic pulmonary hypertension (CTEPH) is a long term complication of acute pulmonary embolism (APE) with poor outcomes if untreated. Identifying already at APE diagnosis patients at risk of subsequent CTEPH can lead to earlier goal-directed management. Since standard echocardiography (TTE) is frequently performed during APE episode for short term risk stratification we aimed to asses prediction vale of echocardiography for subsequent CTEPH. Methods We analyzed retrospectively TTE performed at admission due to APE in consecutive patients, without known CTEPH who were anticoagulated for at least 3 months and were followed up for at least 24 months. After follow-up all patients underwent diagnostic workup for CTEPH according to ESC recommendations. We tried to define a set of echocardiographic parameters recorded during the acute episode predictive for CTEPH. Results The study included consecutive 625 patients with APE diagnosed at computed tomography pulmonary angiogram and managed according to ESC recommendations. During follow up 25 (4%) pts were diagnosed with CTEPH. At APE diagnosis CTEPH(+) group presented more prominent echocardiographic signs of right ventricular (RV) overload than pts without CTEPH (CTEPH(-))(table 1). However, multivariate analysis revealed that only increased TRPG and RV/LV ratio were significant CTEPH predictors with AUC 0.792 (95% CI: 0.683-0.900), p<0.001 and 0.777 (95% CI: 0.675-0.878), p<0.001 respectively (fig 1). Using Youden index in ROC analysis we defined following cut off values useful to identify patients at CTEPH risk and subjects with low probability of CTEPH development. TRPG >44mmHg and RV/LV>1.15 showed PPV for CTPEH 12.9 (95% CI: 9.8-16.7) and 13.8 (95% CI: 10.4-18.1), with high NPV of 98.4 (95% CI: 97.1-99.2) and 98.2 (95% CI: 96.8-99.0) respectively. Importantly, in the group of 61 (9.7%) patients with both signs of RV overload present in the acute phase CTEPH during follow-up was diagnosed in 14 patients (23.0%). Conclusion TRPG above 44 mmHg recorded at APE diagnosis identifies patients at risk of subsequent CTEPH especially in patients with increased RV/LV ratio.