Usefulness of right atrial volume index in predicting outcome in chronic systolic heart failure

Background: Right ventricular (RV) dysfunction is associated with poor prognosis in patients with heart failure (HF). Echocardiographic assessment of RV systolic function is challenging. The ability to visualize the right atrium (RA) allows a quantitative, highly reproducible assessment of RA volume. Objective: The aim is to study the relationship between the right atrial volume index (RAVI) and prognosis in patients with chronic systolic HF. Methods: 120 patients with chronic systolic HF and left ventricular ejection fraction (LVEF) 40% were enrolled. The RA volume was calculated by Simpson’s method using single-plane RA area and indexed to body surface area (RAVI). RV systolic assessment was done using the RV fractional area change (RVFAC), and peak systolic velocity (Satri) using tissue Doppler imaging at the tricuspid annulus. The primary endpoint was death, urgent transplantation, or acute HF episode requiring hospital admission during a follow-up of 1 year. Results: Follow up was complete for 117 of 120 patients. Fifty-two patients reached the primary endpoint. The mean RAVI was higher in patients with adverse events (45.5 ± 15 ml/m^2 versus 25.2 ± 11 ml/m^2, p 0.001), and increased with worsening LVEF, RVFAC, Satri (Spearman’s r = 0.46, r = 0.45, r = 0.59, p 0.001 for all). RAVI was not correlated with estimates of RV diastolic dysfunction. The cut-off threshold for RAVI to predict the primary endpoint using receiver-operating characteristic curve was 29 ml/m2 (area under the curve was 0.89%, 95% confidence interval: 0.82–0.95) with a sensitivity of 92%, and a specificity of 75%. NYHA 2 (OR = 2.1, p 0.01), and RAVI (OR = 1.6, p 0.05) were found to be independent predictors of adverse outcome. Conclusion: In patients with chronic systolic HF, RAVI is an independent predictor of adverse outcome with a threshold value of 29 ml/m^2.