The prognostic value of right ventricular longitudinal strain and 3D ejection fraction in patients with dilated cardiomyopathy

Abstract

Several studies showed that right ventricular (RV) dysfunction is a powerful predictor in heart failure (HF). Advanced echocardiographic techniques such as speckle-tracking imaging and three-dimensional (3D) echocardiography proved to be accurate tools for RV assessment, but their clinical significance remains to be clarified. The aim of this study was to evaluate the role of two-dimensional (2D) RV strain and 3D ejection fraction (RVEF) in predicting adverse outcome in patients with non-ischemic dilated cardiomyopathy (DCM). We prospectively screened 81 patients with DCM and sinus rhythm, 50 of whom were enrolled and underwent comprehensive echocardiography, including RV strain and 3D RV volumetric assessment. Patients were followed for a composite endpoint of cardiac death, nonfatal cardiac arrest and acute worsening of HF requiring hospitalization. After a median follow-up of 16 months, 29 patients reached the primary endpoint. Patients with events had more impaired RV global longitudinal strain (- 10.5 ± 4.5% vs. - 14.3 ± 5.2%, p = 0.009), RV free wall longitudinal strain (- 12.9 ± 8.7% vs. - 17.5 ± 7.1%, p = 0.046) and 3D RVEF (38 ± 8% vs. 47 ± 9%, p = 0.001). By Cox proportional hazards multivariable analysis, RV global longitudinal strain and RVEF were independent predictors of outcome after adjustment for age and NYHA class. RVEF remained the only independent predictor of events after further correction for echocardiographic risk factors. By receiver-operating characteristic analysis, the optimal RVEF cut-off value for event prediction was 43.4% (area under the curve = 0.768, p = 0.001). Subjects with RVEF > 43.4% showed more favourable outcome compared to those with RVEF < 43.4% (log-rank test, p < 0.001). In conclusion, 3D RVEF is an independent predictor of major adverse cardiovascular events in patients with DCM.

Keywords: Dilated cardiomyopathy; Right ventricular ejection fraction; Right ventricular strain.

Fig. 1

Illustration of right ventricular strain measurement using speckle-tracking echocardiography. GLS-RV global longitudinal strain of the RV, RVFW-LS RV free wall longitudinal strain

Fig. 2

Three-dimensional assessment of the right ventricle using dedicated software. ESV end-systolic volume, EDV end-diastolic volume, EF ejection fraction, SV stroke volume

Fig. 3

Comparative analysis of RV function in two patients, one from the MACE group (panels B and D) and one from the group free of MACE (panels A and C). A Strain analysis of the RV showing normal values of both GLS-RV and RVFW-LS. B Strain analysis of the RV showing impaired values of both GLS-RV and RVFW-LS. C 3D volumetric analysis of the RV showing a preserved 3D RVEF. D 3D volumetric analysis of the RV showing a reduced 3D RVEF. RV right ventricle, MACE major adverse cardiovascular events, GLS-RV global longitudinal strain of the RV, RVFW-LS RV free wall longitudinal strain, 3D three dimensional, ESV end-systolic volume, EDV end-diastolic volume, EF ejection fraction, SV stroke volume

Fig. 4

Receiver-operating characteristic analysis of right ventricular functional parameters for the prediction of adverse events. TAPSE tricuspid annular plane systolic excursion, SWV S wave velocity, RV_GLS right ventricular global longitudinal strain, RVEF_3D right ventricular ejection fraction

Fig. 5

Unadjusted Kaplan-Meier analysis for adverse events stratified by cut-off values obtained by ROC curves for tricuspid annular plane systolic excursion (upper left), right ventricular ejection fraction (upper right), S wave velocity (lower left) and right ventricular global longitudinal strain (lower right)