Echocardiographic measures of pulmonary hypertension and the prediction of end-points in sickle cell disease

Abstract

Introduction The peak tricuspid valve regurgitation jet velocity (TR Vmax) on transthoracic echocardiography (TTE) is used as a screen for pulmonary hypertension (PHT). Our aims were to determine the following: how often TR Vmax was measurable in patients with sickle cell disease (SCD), whether other TTE measures were useful and the ability of TTE to predict end-points. Methods This was a retrospective analysis of 504 patients (aged 17–81 years) referred from a tertiary centre SCD clinic between 2007 and 2014. Data included clinical parameters, echocardiographic assessment, physical evaluation, laboratory results and medical consultation. End-points were death, PHT on right heart catheterisation and sickle cell crisis requiring hospital admission. Results Tricuspid regurgitant signal was measurable in 443 (44%) out of 1002 TTEs. No TTE measure definitively predicted end-points (P > 0.05). However, pulmonary artery acceleration time (measurable in 62% of TTEs) was the best single predictor of end-points with a sensitivity 97% and specificity 9% (Fisher's dot test, P = 0.03). Discussion In a large, unselected population with SCD, TR Vmax was measurable in less than one-half of studies. No echocardiographic measure reliably predicted end-points. It was found that pulmonary artery acceleration time was a potentially useful tool when assessing SCD patients and may be worth investigating prospectively.