Advanced Imaging Assessment of the Impact of Tricuspid Regurgitation on Cardiac Remodeling: The TRILUMINATE Pivotal Imaging Substudy

Background: The impact of tricuspid regurgitation (TR) on cardiac remodeling has not been thoroughly studied in a randomized controlled trial using advanced imaging. Objectives: The goal of this analysis was to provide comparative longitudinal changes in right heart remodeling using cardiac magnetic resonance and time-resolved functional computed tomography (4D-CT) in patients with symptomatic severe TR randomized to TriClip vs medical therapy (control). Methods: TRILUMINATE Pivotal (Clinical Trial to Evaluate Cardiovascular Outcomes In Patients Treated With the Tricuspid Valve Repair System Pivotal) is an international randomized controlled trial in symptomatic patients with severe TR. A prospective imaging substudy was performed on TRILUMINATE Pivotal subjects at 10 sites. Cardiac magnetic resonance and 4D-CT were performed following dedicated imaging protocols at baseline and at 30 days, and a final 4D-CT at 1 year (all assessed by an imaging core lab). Results: Sixty-nine randomized subjects (31 TriClip, 38 control) were enrolled. TR volume significantly decreased with TriClip at 30 days (P < 0.0001; 70% reduction). A strong association (r = 0.90; P < 0.0001) was observed between changes in TR volume and right ventricular end-diastolic volume at 30 days. Significant reductions in right ventricular end-diastolic volume (12% reduction; P < 0.001) and tricuspid annular area (11% reduction; P < 0.0001) were seen at 30 days and sustained through 1 year with TriClip. No meaningful changes were observed in the control group. Conclusions: Advanced imaging from the TRILUMINATE Pivotal imaging substudy demonstrated that TriClip effectively reduced TR. Significant cardiac remodeling was observed at 30 days and sustained at 1 year. With TriClip, the extent of cardiac remodeling was associated with the degree of TR reduction.