Right atrio-ventricular strain as a predictor of death in left-sided heart failure

Abstract Background Right ventricular (RV) strain is an established outcome predictor in heart failure (HF). However, the role of right atrial (RA) strain in the setting of left-sided HF is incompletely understood. Purpose We sought to evaluate the RV, RA and combined right atrio-ventricular (RAV) strain using speckle-tracking echocardiography in a cohort of patients with left-sided HF and to assess their prognostic role. Methods 121 consecutive patients (mean age 59±14 years, 74% men) with HF with reduced ejection fraction (HFrEF) referred to our echocardiography department were prospectively enrolled. The main endpoint was all-cause death. RV strain was measured as the average longitudinal strain of the basal, mid, and apical segments of the RV free wall and was reported as a positive value, thus a lower RV strain reflecting a greater longitudinal dysfunction. RA strain was defined as the maximal longitudinal displacement of the atrial wall at end-systole, corresponding to atrial reservoir function. RAV strain was defined as the sum of RV strain and RA strain. Results During a median follow-up of 19±11 months, 26 patients (21%) died. Patients who reached the endpoint had lower left ventricular ejection fraction (LVEF) (21±7% vs. 26±7%, p=0.001), lower tricuspid annular plane systolic excursion (16±3 vs. 18±5, p=0.02) and lower RA strain (13± 10% vs. 18±11%, p=0.03). In univariable Cox regression, RV, RA and RAV strain were all predictors of death: HR=1.05 [95% CI, 1.00-1.11], p=0.045 for RV strain, HR=0.95 [95% CI, 0.91-0.99], p=0.02 for RA strain, HR=0.97 [95% CI, 0.94-0.99], p=0.01 for RAV strain. We constructed a multivariable model with well-established event predictors in HFrEF and one strain index at a time. After adjustment for LVEF, maximal left atrial volume, tricuspid regurgitation severity and pulmonary artery systolic pressure, only RAV strain remained an independent predictor of death (HR=0.97 [95% CI, 0.94-1.00], p=0.04), while RV strain and RA strain did not (p=0.07 for both). LVEF did not emerge as a predictor of death in multivariable regression (p=0.57). Conclusion In left-sided HF, RV and RA strain were predictors of death. Combining the longitudinal strain of both right heart chambers might improve risk stratification, since RAV strain remained the only independent predictor of adverse outcome after adjustment for confounders.