The Prognostic Utility of a Simplified Biventricular Echocardiographic Index of Cardiac Remodeling in Patients with Pulmonary Hypertension

Abstract

Right ventricular (RV) remodeling has been associated with outcomes in patients with pulmonary hypertension (PH). However, the additive prognostic significance of RV remodeling and left ventricular (LV) morphology in PH is unclear. The objective of this study was to test the hypothesis that the ratio of RV end-diastolic area to LV end-diastolic area is a biventricular index predictive of outcome in patients with PH. In total, 139 patients with precapillary PH (mean age, 55±15years; 75% women) and 22 control subjects (mean age, 40±17years; 73% women) were studied. The apical four-chamber view was used to measure the RV-to-LV end-diastolic area ratio as an index of biventricular cardiac remodeling. RV free wall and global strain were measured using speckle-tracking echocardiography. The study design was prospective, with all-cause mortality over 5years predefined as the outcome event. Patients with PH had significantly larger RV to LV end-diastolic area ratios than normal subjects, as expected (1.06 vs 0.67, P<.0001). There were 72 deaths over 5years. Using a cutoff value of 0.93, patients with RV-to-LV ratios≥0.93 had significantly higher all-cause mortality (hazard ratio,1.84; 95% CI, 1.14-2.96; P=.019). RV global strain was also significantly associated with survival using a cutoff of ≥-15% (hazard ratio, 1.66; 95% CI, 1.03-2.67; P=.044). In a multivariate analysis, only age and biventricular index were independent predictors of survival among other clinical and echocardiographic features. The RV-to-LV end-diastolic area ratio is a simplified biventricular echocardiographic index of cardiac remodeling that is predictive of long-term survival in patients with PH.