Background:
Tricuspid regurgitation (TR) has a high morbidity and mortality. Recently, leaflet-based repair (LBR) and direct annuloplasty (DA) emerged as percutaneous treatment options for high risk patients with severe TR with promising results. So far comparative data on these distinct techniques are lacking. 

Methods:
All patients treated with either with LBR (n=108) or DA (n=74) between 2017 and 2020 at two German high-volume centers were included in this retrospective analysis. Patient characteristics, efficacy and safety endpoints were compared using Fischer, Chi-square and Mann-Whitney-U-test in SPSS. Technical success was defined as appropriate placement of the device without intraprocedural death or need for urgent operation.  

Results:
Patient characteristics including age (77.5 years), BMI (26.0 kg/m²), NYHA class (class II 4.1%, class III 90.5%, class IV 5.4%), EuroScore II (6.9%) and comorbidities were similar between groups. Baseline TR was less severe in the LBR  compared to the DA-group (p=0.005), with torrential 7.5% vs. 28.1%, massive 34.0% vs. 31.3% and severe 57.5% vs. 40.6%. There were also more patients with a transvalvular pacemaker lead in LBR-group (28.7% vs. 13.5%, p=0.016).
Procedure time was longer in DA-group with a mean duration of 138 (range 35-253) minutes in LBR-group and 216 (range 121-495) minutes in DA-group (p<0.001). Technical success was achieved in 90.7% patients in LBR-group and 90.5% in DA-group (p=0.964). Frequencies of changes in TR severity by grade are shown in Fig.1. TR reduction ≥1 grade was achieved in 88% vs. 86.5% (p=0.820), and TR reduction of ≥2 grades in 58.3% vs. 66.2% patients  (p=0.264). Residual TR grade ≤2 was established in 70.4% vs. 66.2% (p=0.578).
Procedure-related complications of the right coronary artery were only seen in DA-group with one myocardial infarction (2.7%) and five coronary perforations (6.8%), which all were treated with RCA stenting. Device-related open-heart surgery was necessary in one patient in DA group (2.7%). In DA-group we observed more transfusions of RBCs (5,6% vs. 20,3%, p=0.002). Life-threatening bleeding complications (3,7% vs. 2.7%, p=0.702) and acute kidney failure with need for dialysis (6% vs. 8.1%, p=0.860) was comparable between groups, as well as 30 days stroke with one patient in each group (p=0,761). Till 30 days 1 patient in LBR-group (0.9%) and 3 patients in DA group (8.1%) died (p=0,163).

Conclusion:
This first comparison of transcatheter tricuspid treatment techniques overall demonstrates no significant superiority of one treatment in efficacy endpoints. DA procedure was applied in patients with more advanced disease stage which might explain numerically higher, technique-unrelated adverse outcomes. Further analysis on anatomic predictors of procedural success will help to individually tailor the best repair technique for each Patient.


x = TR grade reduction in grades , y = relative frequency in cohort in %

Fig.1: Comparison of relative frequency of TR grade reduction (worsening of
TR grade in two patients shown as negative values) in leaflet-based repair
(black columns) and direct annuloplasty (grey columns).