Liver Extracellular Volume in Patients With Tricuspid Regurgitation: A Novel Prognostic Marker.

BACKGROUND: Liver extracellular volume (L-ECV), a novel cardiac magnetic resonance (CMR) parameter of systemic venous congestion, might help to stratify tricuspid regurgitation (TR) patients at higher risk, but its role in this context is unexplored. OBJECTIVES: The aim of this study was to assess the incremental prognostic relevance of L-ECV in a large TR cohort. METHODS: Data were collected from patients with TR referred to CMR between 2019 and 2024 who had parametric mapping analysis for L-ECV quantification. The primary endpoint was the composite of all-cause mortality and heart failure (HF) hospitalization, under medical management. RESULTS: In 462 patients included (median age: 67 years; 43% female), median left ventricular ejection fraction was 51% (Q1-Q3: 40%-59%), median tricuspid regurgitant fraction was 21% (Q1-Q3: 14%-33%), and median L-ECV was 31% (Q1-Q3: 28%-35%). When dividing the cohort according to median L-ECV value, patients with high L-ECV (≥ median) showed worse baseline status with more clinical and imaging signs of right HF and (after a median follow-up of 2.1 years) poorer survival free from the primary outcome (P < 0.001) compared with patients with low L-ECV. High L-ECV independently predicted the outcome even after multivariable adjustment accounting for TR severity, biventricular ejection fraction, and pulmonary pressure (adjusted HR: 1.82; 95% CI: 1.03-3.18; P = 0.030). Finally, L-ECV showed incremental prognostic value compared with TRI-SCORE when assessed in a nested Cox model. CONCLUSIONS: In our large real-world TR cohort, L-ECV appeared as a novel, powerful CMR marker of right HF with an independent and incremental prognostic value to stratify patients with TR at higher risk of events.