Role of Echocardiogram in Predicting Prognosis in Pulmonary Arterial Hypertension: A Meta-Analysis

Abstract

Right ventricular (RV) failure is the most common cause of mortality in PAH. RV structure & function is commonly assessed using transthoracic echo (TTE) but its role in estimating prognosis is limited to small-scale studies, evaluating a limited range of parameters. Therefore, we sought to conduct an updated meta-analysis to investigate the role of various TTE parameters in predicting PAH outcomes. Scopus, PubMed & Cochrane Central databases were searched by 2 independent reviewers from inception of these databases through Jan 2019 for original studies reporting TTE parameters & outcomes in adult PAH patients. Studies enrolling >50 patients, including >95% PAH, either prospectively or retrospectively were included. Primary outcomes were mortality & clinical worsening. Hazard ratios (HRs) with 95% confidence intervals were extracted & pooled using a random-effects model. P<0.05 was considered significant. From 44 studies that met inclusion criteria, presence of pericardial effusion on TTE was significantly associated with increased mortality (HR 2.13 [95% CI 1.61-2.83]; p < 0.01). Higher right atrial pressure (RAP) was also significantly associated with increased mortality (HR 1.31 [95% CI 1.04-1.65]; p=0.02). However, RV fractional area change, TR severity, TAPSE, RA size & RV systolic pressure did not significantly predict outcomes. TTE parameters such as pericardial effusion & higher RAP can help in risk stratify PAH patients. These should be used in conjunction with clinical presentation, laboratory findings & invasive hemodynamics to assess patients' prognosis.