Right Ventricular-Pulmonary Artery Coupling in Transcatheter Tricuspid Repair: Metrics Under Scrutiny

The management of severe tricuspid regurgitation (TR) has evolved rapidly with the advent of transcatheter tricuspid valve repair (TTVr) and replacement, providing less invasive alternatives for patients often deemed high-risk or inoperable for surgery.1,2 Chronic volume overload from severe TR progressively impairs right ventricular (RV) function, exacerbates pulmonary hypertension, and drives adverse outcomes.Accurate prognostic stratification is essential for optimal patient selection and intervention timing, yet reliable markers remain limited.RV-pulmonary artery (RV-PA) coupling-capturing the balance between RV contractility and afterload-has gained traction.The RV's myofiber architecture-subepicardial circumferential fibers continuous with the left ventricle and subendocardial longitudinal fibers (contributing ~75% systolic function)-underpins its sensitivity to afterload, as seen in adaptive (concentric hypertrophy) vs. maladaptive remodeling (eccentric dilation, dyssynchrony) in chronic TR. 3 This explains why coupling indices like tricuspid annular plane systolic excursion (TAPSE)/PA systolic pressure (PASP) remain robust in real-world TTVr populations with severe remodeling.More recently, RV free wall longitudinal strain (RVFWS)/PASP has been proposed as a potentially more sensitive, less load-dependent alternative, leveraging strain's ability to detect early myocardial impairment.4 In this issue of Structural Heart, von Stein et al. 5 deliver a multicenter, retrospective analysis of 349 symptomatic patients undergoing TTVr (2017-2023) across three German centers.Patients were stratified by strain analysis vendor: GE EchoPAC (Vendor-A, n = 137) and TomTec (Vendor-B, n = 212).Procedures included tricuspid valve transcatheter edge-to-edge repair with the TriClip device (Abbott Vascularr, Abbott Park, Illinois) or the PASCAL device (Edwards Lifesciences, Irvine, California), or direct transcatheter tricuspid valve annuloplasty with Cardioband (Edwards Lifesciences), selected based on anatomy.The primary endpoint was a 2-year composite of all-cause mortality or first heart failure hospitalization. ORCIDs