Background

TMVI represents a novel treatment option for patients with relevant mitral regurgitation, who are ineligible for surgical treatment. Secondary relevant paravalvular leakage (PVL) due to prothesis dislodgement is a rare but potentially severe complication. The apical anchoring mechanism of a tethered transapical (TA) TMVI device appears to allow repositioning of the valve stent by retensioning of the tether. This multicenter-study examines procedural and short-term safety as well as efficacy of retensioning maneuvers.

Methods

From 2017 to 2021, N=18 patients who underwent secondary tether retensioning were identified from a total sample size of over 1000 patients after initial implantation of a tethered TA TMVI device. Baseline, index-procedural, retensioning procedural, and short-term follow-up data were available from N=11 patients and analyzed according to the Mitral Valve Research Consortium (MVARC) definitions.

Results

Patients [age 75 years (73.5 - 85.0), 63.6% male (N=7), EuroSCORE II 6.2% (5.8 - 11.6)] presented with relevant PVL [PVL³3 63.6%, (N=7)], device malposition (63.6%, N=7), and/or hemolysis (54.5%; N=6). Patients were severely symptomatic [NYHA ³ III (90.9%, N=10)]. Median time between initial TMVI and retensioning procedure was 42 days (29.5 – 104.0). Procedural outcomes revealed no acute conversion to open heart surgery and no procedural mortality. Technical success was achieved in 90.9% (N=10) with 1 case of unsuccessful PVL reduction by tether-retensioning. At discharge PVL was completely eliminated in 90.9% (N=10) of patients with one case of remaining moderate PVL. No severe complications such as valve embolization/migration, valve thrombosis, stroke, myocardial infarction or life-threatening bleeding occurred. After 30 days device success was achieved in 81.8% (N=9) of patients due to 2 cases of open surgical mitral valve replacement for one patient with persistent PVL and one patient with recurrent PVL, respectively. 90.9% (N=10) of patients were in NYHA class I/II. There was no 30-day mortality but 1 in-hospital mortality.

Conclusion

This multicenter-study demonstrates technical feasibility, procedural safety and acute efficacy of retensioning procedures in the majority of patients. Retensioning of the tether is an important future bailout strategy after TA TMVI with a tether-based device and may provide additional management advantages in populations at high surgical risk.