Echocardiographic assessment of right ventricular function and right ventriculoarterial coupling in tricuspid regurgitation

Abstract

Echographic evaluation of the cardiopulmonary unit may be difficult in the presence of TR. Purpose: To assess the variation of simple and combined echographic parameters analysing the cardiopulmonary unit according to the severity of TR. Echographic images were reviewed in 179 patients to assess TR grade according to Hahn's 5 grades classification. Classical morphological (RV end diastolic length and area), function [TAPSE, RVFAC, S’,RVFWS (RV free wall longitudinal strain)] and load [PASP,TRTVI (TR Time-velocity integral)] parameters analysing RV were assessed. Combined parameters of function and load (TAPSE/PASP, TR TVI × RVFWS), morphology and load (load adaptation index = TRTVIxRVED length/area) and morphology, load, and function [myomechanical index (MMI = RV-RA mean pressure gradient × RVFWS/indexed RAED area × 10–2) and morphology-load-function index (MLF = RVED length/area xTRTVIx RVFWS)] were calculated. We used ROC curves to analyze the diagnostic value of echocardiographic parameters to predict potential high (> 3) or low (< 6) surgical risk of mortality according to TRISCORE. Simple parameters were significatively different among groups with a nonlinear progression between the 5 levels of TR. Combined parameters were also significatively different. Among them, MMI and MLF had a linear progression (MMI: grade 1: 0.20 ± 0.09; grade 2: 0.15 ± 0.08; grade 3: 0.10 ± 0.05, grade 4: 0.09 ± 0.08; grade 5: 0.05 ± 0.04 P = 0.000; MLF: grade 1: 7.56 ± 2.06; grade 2: 6.57 ± 2.14; grade 3: 4.85 ± 2.29, grade 4: 4.79 ± 3.17; grade 5: 3.06 ± 1.82 P = 0.000) and had the best predictive value for TRISCORE (MMI: AUC = 0.889 P = 0.000 for low risk, 0.855 P = 0.000 for high risk; MLF: AUC = 0.873 P = 0.000 and 0.822 P = 0.000). Combined parameters are relevant to evaluate cardiopulmonary unit in a population presenting with TR, especially when combining morphology, function and load (Fig. 1).