0038: Addressing the controversy of estimating right ventricular systolic pressure by echocardiography: insights from 307 patients with advanced lung disease or pulmonary arterial hypertension

Abstract

There is a controversy on the reliability of echocardiography in estimating right ventricular systolic pressure (RVSP) in advanced lung disease (ALD) and idiopathic pulmonary arterial hypertension (PAH) patients. This study aimed to develop a quality control method for echocardiographic RVSP assessment to provide guidance. We selected consecutive patients referred from 2001 to 2012 for ALD or PAH, in whom an echocardiogram and a right heart catheterization (RHC) were performed within five days. In order to assess reader level influence on echo interpretation, three levels of readers (multi-reader echo-lab, level 2 and 3) estimated RVSP (based on the tricuspid regurgitation TR maximal velocity). Invasive and non-invasive RVSPs were compared using Pearson’s coefficient and Bland-Altman analysis. PH classification performance was also assessed. Reasons for under- and overestimation were systematically analysed. Among the 307 patients included (mean age 50±13, 41% male), two-thirds had pulmonary hypertension (PH). RVSP was measurable in 56% of patients. There was a strong correlation between echo and RHC (r=0.84 for echo-lab; 0.86 level 2 and 0.96 level 3). For PH classification, areas under the curve of level 2 and 3 RVSPs were excellent (0.94 and 0.97); >45mmHg was associated with 86% sensitivity and 100% specificity. No severe PH (mPAP ≥35mmHg) was missed. The main reason for underestimation was the absence of a well-defined TR envelope and for overestimation the inability to identify the complete envelope by decreasing the gain. Echocardiography’s reliability for RVSP estimation can be improved when careful attention is paid to simple practical signal quality parameters, clearly identified by the present study.