In total, 139 patients with precapillary PH (mean age, 55 ± 15 years; 75% women) and 22 control subjects (mean age, 40 ± 17 years; 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 5 years 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 5 years. 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.