Transcatheter edge to edge repair of functional mitral regurgitation as bridge to heart transplantation: 2-years follow up results from MitraBridge international registry

Abstract Background Chronic severe functional mitral regurgitation (FMR) is a common finding in patients with advanced heart failure (AHF) who undergo evaluation for heart transplantation (HTx). Nevertheless, access to surgical strategies for AHF could be limited by scarce availability of donors and by temporary or definitive contraindications. MitraBridge registry already proved that transcatheter edge to edge repair (TEER) of FMR performed as a bridge to HTx is an effective and safe treatment strategy at 1-year follow up with 64% of patients free from composite primary endpoint of all-cause death, new admission for HF, urgent HTx or LVAD implantation. Purpose The aim of this study is to determine whether 1-year results of MitraBridge registry were maintained at 2-years follow up. Methods Mitrabridge is a retrospective, multicenter observational study that enrolled 153 adult patients with AHF and moderate-to-severe or severe FMR and considered candidates for HTx who underwent TEER between 2018 and 2021. Depending on the strategy TEER was performed for, patients were classified in bridge to transplant, candidacy or decision. Primary endpoint of the current analysis was the 2-year composite rate of all-cause death, new admission for HF, urgent HTx or LVAD implantation. Results Median age was 59 years old [53-63], most patients were in INTERMACS class 5-6 (47.5%) and mean left ventricle ejection fraction (LVEF) was 26.9±7.7%. Baseline right heart catheterization was available for 112 (73%) patients, of them 87.5% had pulmonary hypertension with mean pulmonary artery pressure (mPAP) of 33±10 mmHg. Procedural success was achieved in 89.5% of cases and no deaths at 30 days were reported. At 2-years follow up, freedom from primary endpoint was maintained in 47% of patients. A significant reduction of echocardiographic systolic pulmonary artery pressure (sPAP) was observed (from 50 [40-61] mmHg to 43 [33-53] mmHg, p-value<0.001). At the end of follow-up (median time of 26 months, IQR 9-52), elective HTx was successfully performed in 30 cases (21%), 19 patients (13.5%) maintained or obtained the eligibility for transplant, and 32 patients (22.5%) had no longer indication for HTx, due to clinical improvement. Nine patients underwent LVAD implantation for clinical worsening and nine (8%) urgent HTx (15% of already listed population). Conclusions MitraBridge 2-years follow up confirms that TEER is a safe option in AHF population with FMR and shows that haemodynamic and clinical benefits following the procedure are maintained at long term. In particular, it allowed 21% of patients to receive elective HTx reducing need for urgent organ transplantation and helped to expand the candidacy for HTx.