Right atrial remodeling and outcome in patients with secondary tricuspid regurgitation

Abstract Funding Acknowledgements Type of funding sources: None. Background Secondary tricuspid regurgitation (STR) is independently associated with patients’ morbidity and mortality and right atrial remodeling (RAR) is a proven marker of disease progression. Purpose The aim of our study is to investigate the prognostic value of RAR in terms of RA volume (RAVi) and strain (RAS) in patients with STR. Methods We retrospectively enrolled 400 adult patients (46% men, 72.5±14.0 years) with both atrial and ventricular STR (mild 26%, moderate 40%, severe 34%). Exclusion criteria were primary TR, cardiac implantable electronic device, previous TV intervention, poor apical acoustic window, and lack of follow-up. Complete two-dimensional echocardiography, including right atrial volume (RAVi), speckle-tracking analyses of RA reservoir strain (RARS) and right ventricular strain (RVLS) on focused apical 4-chamber views, were obtained. The primary outcome was the composite endpoint of death from any cause and heart failure hospitalization. Results After a median follow-up of 13 months (IQR: 6–23), the combined endpoint was reached by 158 patients (39%). Patients who experienced events had larger RV and RA size, more impaired RVLS and RARS, and higher pulmonary artery pressure. By receiving operating curve (ROC) analysis, the ideal cut-offs for RARS and RAVi were 14% and 48 mL/m2 (p<0.0001). RAS < 14% [HR 2.40, p<0.0001] and RAVi > 48 mL/m2 [HR 2.10, p<0.0001] were strongly associated with outcome. Patients with both RAS < 14% and RAVi > 48 mL/m2 had significantly lower survival rates compared to patients with RAS ≥ 14% and RAVi ≤ 48 mL/m2 (log-rank χ²= 31 and χ²= 22 respectively, p<0.001) (Figure 1). RAS <14% was associated with higher cumulative event rates, regardless of baseline patients’ rhythm (log-rank χ²= 35, p<0.001). Moreover, patients having both RAS <14% and RAVi >48 mL/m2 had a higher rate of adverse events (log-rank χ²= 53, p<0.001) compared to those with a single RA parameter abnormal, or those who had both parameters normal. On multivariable analysis, RAS >14% (HR1.53; 95% CI, 1.00–2.33; p = 0.02) and RAVi >48 mL/m2 (HR 1.42; 95% CI, 0.96–2.11; p = 0.04) remained independently associated with the combined endpoint. RAR provided incremental prognostic value over RV size and function, including RVLS. Conclusions In patients with STR, RARS is associated with an increased risk for HF hospitalization and all-cause mortality. Assessment of RARS could improve risk stratification of patients with STR, potentially identifying those who may benefit from optimization of medical therapy and earlier surgical/percutaneous treatment. Figure 1. Kaplan-Meier plots for the analysis of the cumulative event-free survival according to RAS (Panel A) and RAVi (Panel B) values.