BACKGROUND AND OBJECTIVE: Within recent years, transcatheter tricuspid edge-to-edge repair (T-TEER) has emerged as a safe and effective treatment option in patients with secondary tricuspid regurgitation (TR). However, for primary TR, data on the robustness and durability of TR reduction 1 year following T-TEER is limited. METHODS: All consecutive patients treated with T-TEER for TR at two high-volume centers between September 2018 and December 2022 were enrolled in a registry. Primary TR was defined as tricuspid valve (TV) prolapse or flail TV leaflets as assessed by pre- and peri-interventional transesophageal echocardiography (TEE). RESULTS: 201 patients were included in this analysis, of whom 27 (13.4%) were classified as primary TR and 174 (86.6%) as TR of secondary origin. All-cause mortality during 1-year follow-up was reached by 50 patients (24.9%) [primary: 7 (25.9%), secondary: 43 (24.7%)], and 151 (75.1%) completed follow-up with transthoracic echocardiography (TTE). Patients' median age was 80 (76-83) years, 112 (55.7%) were female and 181 (90.1%) reported a New-York heart association functional class (NYHA-FC) of III or IV. The remaining baseline clinical and echocardiographic parameters were comparable between the groups, but secondary TR patients had a significantly higher TRI-SCORE (5 (4-8) vs. 7 (5-14), P = 0.010). In both groups, an immediate reduction of TR-Grade post-intervention was observed. This reduction was sustained at follow-up with 80.0% of the primary TR patients classified as moderate or less and 61.8% of the secondary TR patients. This translated to a significant improvement of NHYA-FC in both groups. Kaplan-Meier analysis revealed no differences regarding rates for all-cause mortality between the groups (P <
0.99). CONCLUSION: T-TEER achieves a robust TR reduction in primary TR patients 1 year after intervention with noninferior clinical results to treatment for secondary TR with regards to mortality, re-hospitalization, and NYHA-FC.