Transcatheter edge-to-edge repair in anatomically complex degenerative mitral regurgitation: 3-year outcomes from a real-world registry.

Background: Recent developments in transcatheter mitral valve repair (M-TEER) have expanded the indication for the procedure beyond conventional criteria to include patients with anatomically complex degenerative mitral regurgitation (DMR), but long-term outcomes are not well known.

Objective: To investigate outcomes by specific anatomical criteria in patients with severe DMR and complex valve anatomy enrolled in the prospective MitraUlm registry.

Methods: Clinical and echocardiographic 3-year outcomes of 304 patients with DMR and complex mitral valve anatomy, defined according to the CLASP IID registry criteria, were investigated. Outcomes were analysed separately for specific anatomical complexities.

Results: 33.5% of patients had ≥ independent significant jets, 12% multisegmental prolapse, 12.3% mitral valve orifice area < 4 cm2, 10.9% commissural lesions with wide/multiple jets, and 10.1% large flail. Mitral regurgitation (MR) reduction ≤ 2 was achieved in 93.8% of patients at discharge and in 85.9% at 3-year follow-up. Patients with multisegmental prolapse and commissural lesions with multiple/wide jets had the lowest MR reduction at discharge. Compared to patients treated with MitraClip Generation 1-3, patients treated with MitraClip Generation 4 had significantly better post-procedural MR reduction (MR ≤ 1 in 74.3% vs 50.7%, P < 0.001) and higher 3-year survival rates (80.2% vs 61.6%, Log Rank P = 0.002). Postprocedural MR reduction to MR ≤ 1 was the strongest independent predictor of 3-year survival, whereas the presence of at least two anatomical complexities and elevated post-procedural left atrial pressure predicted 3-year all-cause mortality.

Conclusions: In patients with anatomically complex DMR, advances in procedural techniques for M-TEER have allowed successful treatment with sustained MR reduction and improved long-term survival.