Abstract 13938: Right Atrial Emptying Fraction: A Novel Non-Invasive Predictor of Mortality in Pulmonary Hypertension
Background: Right ventricular (RV) failure is the most common cause of death in pulmonary hypertension (PH). Although right atrial (RA) size is associated with worse outcome in PH, RA emptying fraction (RAEF) has not been well-described. We hypothesize that RAEF as assessed by cardiac MRI (cMRI) is associated with RV ejection fraction (RVEF) and predicts death independent of RVEF.
Methods: 170 PH patients (WHO groups 1-5) at a tertiary care academic medical center who underwent cMRI and right heart catheterization (RHC) within 6 weeks of each other were included. RA maximum (RAmax) and minimum (RAmin) volumes were measured via the area-length method from cMRI 4 chamber cine images. All volumes were indexed to body surface area (BSA). RAEF was calculated as: (RAmax - RAmin)/(RAmax) x 100. Correlation with risk factors was assessed across sex-specific tertiles of RAEF. Cox proportional hazard models were performed to evaluate the association between RAEF and incident death, adjusted for age, RVEF, BNP, mean RA pressure (mRAP), mean pulmonary artery pressure (mPAP), cardiac index (CI), RV end-diastolic volume indexed (RVEDV/BSA), and RAmax/BSA.
Results: The cohort was 70% White, 16% Black, 9% Hispanic, and 81% women with a mean age of 55±15 years. A total of 60 deaths occurred during a median follow-up of 3.5 years. RAEF was significantly correlated with RVEF (Spearman rho = 0.42, p<0.0001). Increasing RAEF tertiles were associated with increasing left ventricular ejection fraction (LVEF) and CI, and inversely associated with age, BNP, mRAP, and prevalent pericardial effusion. In univariate analysis, decreasing tertiles of RAEF were significantly associated with increased death (p<0.0001; Figure 1). In multivariate analysis, RAEF was independently and inversely associated with death (HR per 5%: 0.78 [95%CI 0.66-0.94]; p=0.007).
Conclusion: In PH patients, decreased RAEF is associated with worse RVEF and is independently associated with worse survival.
- © 2013 by American Heart Association, Inc.