Mortality and heart failure in patients with severe tricuspid regurgitation. Impact of RV volumes and function by CMR.

Abstract Background Beyond symptoms, right ventricle (RV) dilatation and dysfunction are established criteria for intervention in patients with significant tricuspid regurgitation (TR); however defined thresholds to support intervention are lacking. As a result, the optimal timing for intervention remains controversial and it is commonly undertaken at a late stage. Purpose To describe prognostic cut-off values of RV size and function by Cardiac Magnetic Resonance in a multicentre cohort of patients with at least severe TR. Methods The study enrolled patients with at least severe TR assessed by 2D echocardiography who underwent a contemporary cardiac magnetic resonance (CMR) study. Conventional parameters of biventricular volume and function were assessed in all patients. A combined endpoint of hospital admission due to heart failure (HF) and all-cause mortality was defined. Results 318 patients with severe TR recruited from 5 tertiary care hospitals were included in this study (70 ± 11 years, 67% female, 73% NYHA I or II). Regarding the etiology, 10% were primary TR, 1% CIED-related TR, 46 % atrial secondary TR and 43% ventricular secondary TR. After a median follow-up of 28 months (IQR: 10-54 months), 42% of the patients (n=134) experienced the combined endpoint (n=113 were admitted due to HF, n=61 died). After adjusting for age, NYHA class, comorbidities, type of TR and LVEF in a multivariate Cox proportional model (LR Chi-Square: 88.01, p<0.001), RV-EDV and RVEF were independently associated with all-cause mortality and heart failure (adjusted HR for RV-EDV per ml/m2 =1.008 [1.005-1.012], p<0.001 and RVEF HR per 1%=0.961 [0.942-0.981], p<0.001). Thresholds of RV-EDV ≥ 93 ml/m2, RV-ESV ≥ 39 ml/m2 and RVEF ≤ 58% held the best accuracy to predict outcomes (figure). In multivariable analysis, prognostic cut-off values of RV-EDV, RV-ESV and RVEF was associated with 1.91, 2.03, and 1.76-fold increased risk of HF or all-cause mortality respectively (RV-EDV HR: 1.91 [1.34-2.71], p<0.001, RV-ESV HR 2.03 [1.42-2.89], p<0.001 and RVEF HR1.76 [1.25-2.49], p=0.001). Conclusion RV size and function are crucial for determining optimal timing for TR intervention. CMR remains the gold standard to assess RV remodeling. Cut-off values of RV volume and function by CMR are defined in a multicentre cohort of patients based on outcome data; proposed thresholds differ from those previously established by echocardiography.Kaplan Meier curves