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. (Clinical Trial to Evaluate Cardiovascular Outcomes In Patients Treated With the Tricuspid Valve Repair System Pivotal; NCT03904147).