Right Heart End-Systolic Remodeling Index Strongly Predicts Outcomes in Pulmonary Arterial Hypertension Comparison With Validated Models

Background-Right ventricular (RV) end-systolic dimensions provide information on both size and function. We investigated whether an internally scaled index of end-systolic dimension is incremental to well-validated prognostic scores in pulmonary arterial hypertension. Methods and Results-From 2005 to 2014, 228 patients with pulmonary arterial hypertension were prospectively enrolled. RV end-systolic remodeling index (RVESRI) was defined by lateral length divided by septal height. The incremental values of RV free wall longitudinal strain and RVESRI to risk scores were determined. Mean age was 49 +/- 14 years, 78% were female, 33% had connective tissue disease, 52% were in New York Heart Association class >= III, and mean pulmonary vascular resistance was 11.2 +/- 6.4 WU. RVESRI and right atrial area were strongly connected to the other right heart metrics. Three zones of adaptation (adapted, maladapted, and severely maladapted) were identified based on the RVESRI to RV systolic pressure relationship. During a mean follow-up of 3.9 +/- 2.4 years, the primary end point of death, transplant, or admission for heart failure was reached in 88 patients. RVESRI was incremental to risk prediction scores in pulmonary arterial hypertension, including the Registry to Evaluate Early and Long-Term PAH Disease Management score, the Pulmonary Hypertension Connection equation, and the Mayo Clinic model. Using multivariable analysis, New York Heart Association class III/IV, RVESRI, and log NT-proBNP (N-Terminal Pro-B-Type Natriuretic Peptide) were retained (chi(2), 62.2; P<0.0001). Changes in RVESRI at 1 year (n=203) were predictive of outcome; patients initiated on prostanoid therapy showed the greatest improvement in RVESRI. Among right heart metrics, RVESRI demonstrated the best test-retest characteristics. Conclusions-RVESRI is a simple reproducible prognostic marker in patients with pulmonary arterial hypertension.