Prognostic impact of disproportionate secondary tricuspid regurgitation

Funding Acknowledgements Type of funding sources: None. Background Current quantitative parameters used to assess the severity of secondary tricuspid regurgitation (STR) do not account for the size of the right ventricle (RV). To address this issue, the concept of proportionality of the severity of the STR to the size of the RV has been recently mutuated from the mitral regurgitation field to improve the prognostic stratification of patients with STR. Purpose We sought to compare the prognostic value of a classification of STR based on the proportionality of the regurgitant volume (Reg Vol) to the RV stroke volume with the guideline-recommended grading scheme of STR severity. Methods Patients with at least mild STR were prospectively enrolled and underwent complete 2D, Doppler and 3D echocardiography with the measurement of RV volumes. To determine STR proportionality status, we evaluated the difference between the measured and the theoretical RegVol of severe STR (the latter was defined as the RV stroke volume needed to have a regurgitant fraction [RF] ≥ 50% according to the actual RV stroke volume). This classification took into account a bias of 8 ml in the computation of Reg Vol, derived from Bland-Altman analysis (picture 1). Accordingly, patients were classified as non severe (NS_STR, measured RegVol< theoretical RegVol), severe proportionate (SP_STR, measured RegVol ≈ theoretical RegVol), and severe disproportionate (SD_STR, measured RegVol > theoretical RegVol) STR (picture 1). The incidence of the combined endpoint of heart failure (HF) hospitalization and death for any cause was used as the primary endpoint. Results We enrolled 333 consecutive patients (mean age 71±14 years, 53.3 % women). After a median follow up of 20 months (10–32), 134 patients (40.2%) reached the combined end point. Patients with SD_STR showed a significantly higher incidence of events (67.9%) in comparison to patients with SP_STR (40.6%, p = 0.005 for difference) and NS_STR (31.3%, p<0.001 for difference) (picture 2). At Cox multivariate analysis, the proportionality of STR (adjusted for age, atrial fibrillation, right atrial volume, RV free-wall longitudinal strain, and RV ejection fraction) independently correlated with the combined endpoint (adjusted hazard ratio: 1.785; 95% confidence interval [CI]: 1.249–2.550; p = 0.002). When tested with the same variables, the conventional STR severity grade lost its independent correlation with combined end point (p = 0.258). Conclusions Disproportionate STR is independently associated with all-cause mortality or heart failure hospitalization, and it improves the risk stratification of patients compared to the guideline-recommended grading scheme of STR severity.