Utility of transthoracic echocardiography to estimate severity of right ventricular dysfunction: an MRI comparison study

Abstract

Prognostic implications of severe right ventricular (RV) dysfunction are difficult to assess because of limitations in functional characterization using standard echocardiography (TTE) and the cost and availability of options such as MRI. We sought to determine how assessments of RV dysfunction via TTE correlate with RV ejection fraction (EF) by MRI. Patients undergoing MRI and TTE within 21days of one another were included. Left ventricular (LV) and RV EF were recorded from MRI and subjective assessment of RV function (normal, mild, moderate, or severe dysfunction), right ventricular index of myocardial performance (RIMP), and right ventricular systolic pressure (RVSP) were recorded from TTE. Patients were considered to have significant RV dysfunction if EF≤35% on MRI and normal function if EF≥45%. A total of 474 patients were included (age 50±12, 57% male). Of these, 363 (76.6%) had normal function, 54 (11.4%) had mild dysfunction, 41 (8.6%) had moderate dysfunction, and 16 (3.4%) had severe dysfunction on TTE. Moderate or severe dysfunction had good sensitivity (80%) and specificity (97%) for RV EF≤35%. Furthermore, RIMP>0.70 and RVSP>70mm Hg were very specific for RV EF≤35% (sensitivity=29%, 22%, respectively; specificity=98%, 99%, respectively). Specificity and sensitivity of TTE assessments did not change if LV function or disease indication was considered. A subjective assessment of moderate to severe RV dysfunction on TTE compares favorably with quantitative MRI assessment of the RV EF. Further study is needed to evaluate whether this comparability is true across institutions.