Reviewer: Dr. Muammer Karakayalı

The name of the study: 12-Month outcomes of transcatheter tricuspid valve repair with the PASCAL system for severe tricuspid regurgitation

Published Congress: EuroPCR 2022

Background: TR is a prevalent disease affecting approximately 4% of subjects aged over 75 years. While considered an unrelevant valvular disease with modest prognostic impact for a long time, recent works have clearly demonstrated its detrimental effect and a ten-year mortality exceeding 75%. The high risk of surgical procedures associated with isolated TR (estimated to reach 10% in retrospective series) results in a low annual number of surgical procedures, even in centers with high surgical volumes. Also the clinical results observed with conservative medical treatment are not satisfactory enough. This has led to the need for transcatheter treatment options.

Objectives: This study aimed to assess the feasibility and safety of the PASCAL transcatheter valve repair system in TR.

Methods: The Edwards CLASP TR trial is an early feasibility, prospective, single-arm, multicentre US study including 65 patients (with a meanage of 77±9 years (STS score for MV repair 7.7%±5.5%; EuroScore II 5.0±4.7) with baseline severe symptomatic (dyspnoea class NYHA III/IV [71%]) TR (70% massive and torrential [39%]) underwent transcatheter treatment with the investigational device. No data were provided on the number of patients screened before the enrollment. The primary endpoint is a composite of Major Adverse Events [cardiovascular rmortality, stroke, myocardial infarction, intervention, either percutaneous or surgical, major access site and vascular complications, renal complications requiring unplanned dialysis or renal replacement therapy, and severe MVARC (Mitral Valve Academic Research Council) defined bleeding].

Additional 1-year outcome measures were also specified as:

•          Improvement in NYHA Functional Class.

•          Change in distance at six minutes walking test (6MWD).

•          Reduction in TR grade from baseline.

•          Improvement of health status as measured by Kansas City Cardiomyopathy and SF-36 questionnaires.

Results: The TR etiology was functional in 25 patients (83%), degenerative in three (10%), and mixed in two (7%). All patients had TR severe or greater (massive or torrential in 80%) and heart failure symptoms (90% in NYHA III or IV) under optimal medical treatment. Single-leaflet device attachment occurred in two patients. Moderate or less TR was achieved in 23/28 patients (82%) at 30?days, which was sustained at 12?months (86%). Two patients underwent repeat TTVr due to residual torrential TR (day 173) and recurrence of severe TR (day 280), respectively. One-year survival rate was 93%; 6 patients required rehospitalization due to acute heart failure. NYHA functional class I or II was achieved in 90% and 6-minute walk distance improved from 275?±?122?m at baseline to 347?±?112?m at 12-month (+72?±?82?m, p?<?.01). There was no stroke, endocarditis, or device embolization during the follow-up.

Conclusion: Twelve-month outcomes from this multicenter compassionate use experience with the PASCAL system demonstrated high procedural success, acceptable safety, and significant clinical improvement.

Interpretations: This important study is the very first step in the validation of the PASCAL TTVr for treating TR. As previously described, it confirms the safety and efficacy of the Edwards device at one-year follow-up. The small number of patients in the CLASP study and the small data available in the long-term need caution about a definite statement, but several certainties are here to stay. The last ESC Valvular Guidelines included a recommendation (IIb C: may be considered) for treating symptomatic secondary severe TR using TTVr in patients not suitable for surgery. This study reinforces this recommendation and represents another important step in the confirmation and understanding of this therapy. Further data will come from the CLASP II TR randomized trial which is currently recruiting (estimate enrollment: 825 patients) and will compare the PASCAL system versus optical medical therapy.