Preoperative Evaluation of Pulmonary Hypertension in Lung Transplant Candidates: Echocardiography Versus Right Heart Catheterization

Abstract

Background - Right heart catheterization (RHC) and echocardiography are both routinely used for pulmonary artery systolic pressure (PASP) assessment in lung transplantation (LT) candidates, although this is not mandated by current guidelines. We aimed to explore the correlation between PASP estimated by echocardiography to that measured by RHC, in this population in order to assess the necessity of RHC. Methods - From a retrospective registry of 393 LT candidates undergoing RHC and echocardiography during 2015-2019, patients were assessed for the presence of pulmonary hypertension (PH), defined as mean pulmonary artery pressure (mPAP) above 20 mmHg, according to two methods – echocardiography and RHC. The primary outcome was the correlation between the PASP estimated by echocardiography to that measured by RHC. Secondary outcomes were the prediction value of the echocardiographic evaluation and its accuracy. Results - The mean value of PASP estimated by echocardiography was 49.5±20.0 mmHg, compared to 42.5±18.0 mmHg measured by RHC. The correlation between the two measurements was moderate (Pearson’s correlation: r=0.609, p<0.01). Echocardiography PASP measurements were moderately discriminative to diagnose PH, with an area under the curve (AUC) of 0.72 (95% CI 0.66-0.76). Echocardiographic overestimation of PASP of more than 10 mmHg was found in 35.0% of the patients, and underestimation was found in 11.6% of the patients.Conclusion - In the pre-surgical evaluation of LT candidates, echocardiographic estimation of PASP had moderate correlation and limited accuracy compared to the PASP measured by RHC. We thus recommend performing routine RHC to all LT candidates, regardless of the echocardiographic estimation of PASP.