Characterization of right-sided strain parameters in atrial and ventricular functional tricuspid regurgitation

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial functional tricuspid regurgitation (A-FTR), defined as TR due to prominent right atrial (RA) dilatation without significant right ventricular (RV) remodelling, has recently emerged as a distinct subtype of FTR, and can be distinguished from ventricular FTR (V-FTR), defined by significant RV remodelling leading to annular dilatation and leaflet tethering. However, so far no data has been reported on the values of RV and RA strain in these patients. Purpose To evaluate potential differences in right-sided strain parameters in patients diagnosed with severe atrial and ventricular FTR. Methods Patients with severe FTR, without a cardiac implantable electronic device, were categorized as V-FTR when in sinus rhythm and either having left-sided cardiac disease, pulmonary hypertension, or moderate/severe RV dysfunction. Patients, in sinus rhythm or atrial fibrillation, with no other cause of annular dilatation and impaired leaflet coaptation than RA dilatation were classified as A-FTR. Extensive echocardiographic assessment was performed, including 2D-speckle-tracking strain analysis. Results A total of 525 patients with severe FTR (mean age 66 ± 15 years, 42% male) were included, of which 401 patients (76%) were classified as V-FTR and 124 patients (24%) as A-FTR. Baseline clinical and echocardiographic characteristics are shown in Figure 1. Patients presented with mild RV dilatation (RV end-diastolic area 12.9 ± 4.0cm2/m2) and RV dysfunction (RV free wall longitudinal strain [FWLS] 18.3 ± 6.8%), and with moderate-to-severe RA dilatation (RA max volume 36.8 [26.9 – 52.2] ml/m2) and moderate-to-severe RA dysfunction (RA reservoir strain 17.0 [11.0 – 27.0] %). Corresponding to the phenotype, patients with A-FTR presented with significantly smaller RV size and better RV function (Figure 1). However, despite overall normal values of RV function by RV fractional area change, tricuspid annular plane systolic excursion (TAPSE) and RV FWLS, 27% of A-FTR patients showed reduced RV FWLS based on cut-off value of −20%. In addition, patients with A-FTR showed more dilated RA, as compared to patients with V-FTR, but with better RA function assessed by 2D-strain values (Figure 1). Notwithstanding, still 73% of the A-FTR-patients showed reduced RA strain values, when using the cut-off reported for normality of 34%. Conclusion Approximately 25% of patients diagnosed with severe FTR presented with A-FTR. These patients presented with significantly better right-sided strain parameters as compared to patients with V-FTR, despite more pronounced RA dilatation.