Prognostic role of right atrial strain in patients with secondary tricuspid regurgitation: insights from the CARE-TR registry

Abstract Background Recently, right atrial (RA) deformation evaluated with speckle tracking echocardiography has emerged as prognostic parameter in patients with pulmonary hypertension and tricuspid regurgitation (TR). Purpose To explore the prognostic role of right atrial reservoir strain (RASr) in patients atrial and ventricular secondary TR (ASTR; VSTR). Methods The Consecutive pAtients with seveRE Tricuspid Regurgitation evaluated in heart failure (HF) and Valve Clinics (CARE-TR) registry collected data from patients with at least severe TR enrolled at 3 Italian Centres between January 2020 and December 2022. The present analysis includes 402 patients with STR and complete data on right atrial function. Patients were classified as ASTR in presence of all the following echocardiographic parameters: left ventricular ejection fraction ≥ 50%, pulmonary artery systolic pressure ≤ 50 mmHg, right ventricular (RV) mid end-diastolic diameter (RVEDD) ≤ 38 mm and/or RV end-diastolic area ≤ 13 cm2/m2, RV fractional area change ≥ 35% and/or RV free wall longitudinal strain (RVFWLS) ≥ 17%. Right atrial indexed volume (RAVI) and RASr were collected. The lack of at least one of these parameters identified the VSTR aetiology. The study endpoint was a composite of all-cause mortality and heart failure hospitalization at 18-months follow-up. Results Patients’ median age was 79 years (IQR 72-83) and 45% were male. At 18-months follow-up, 139 patients (46%) reached the primary endpoint. After adjustment for age, male sex, glomerular filtration rate (GFR), New York Heart Association (NYHA) class, RAVi and loop diuretic dose, RASr was the only independent predictor of events in patients with ASTR (HR 0.91, 95% CI 0.86-0.96, p = 0.001); in patients with V-FTR after adjustment for age, male sex, coronary artery disease, GFR, NYHA class, loop diuretic dose and RAVi, RVEDD (HR 1.04, 95% CI 1.01-1.07, p = 0.029) and RVFWLS (HR 1.07, 95% CI 1.01-1.12, p = 0.049) were the only echocardiographic parameters associated with poor prognosis, while RASr was not. At receiver operating characteristic analysis, the best cut-off of RASr to predict the composite outcome in the whole population was 12% (sensitivity 74%, specificity 70%, area under the curve [AUC] 0.75, p < 0.001). Cumulative survival free from events was lower in patients with RASr ≤ 12% as compared to those with RASr > 12% in the whole population (52% vs 84%; Log rank p < 0.001) and in both ASTR and VSTR (Figure 1 and Figure 2). Conclusions Right atrial reservoir strain is an useful and reliable tool to identify patients with STR at high risk of death and hospitalization for heart failure and it offers the best prognostic performance in patients with ASTR. ASTR patients survival according to RASr VSTR patients survival according to RASr