Anterior mitral leaflet modification to prevent left ventricular outflow tract obstruction during transcatheter mitral valve replacement: the PROTECT-LVOT registry
Year: 2026
Type: article
Abstract: BACKGROUND: Left ventricular outflow tract (LVOT) obstruction remains the major limitation of transcatheter mitral valve replacement (TMVR). Anterior mitral leaflet (AML) modification has emerged as a key preventive strategy, yet real-world data remain limited and residual risk is still unknown. AIMS: We sought to evaluate the outcomes of TMVR with concomitant AML modification across valve-in-mitral annular calcification (ViMAC), valve-in-ring (ViR), and valve-in-valve (ViV) substrates. METHODS: We established a multicentre retrospective registry of consecutive patients undergoing TMVR with AML modification between 2017 and 2025. The co-primary in-hospital safety endpoint was a composite of cardiovascular death, stroke/transient ischaemic attack, and major bleeding. RESULTS: A total of 55 patients were included (67% females). The median age was 78 years (interquartile range [IQR] 73-81); the median Society of Thoracic Surgeons Predicted Risk of Mortality was 6.7% (IQR 4.8-9.5). AML modification was performed in 65.5% of cases with the Laceration of the Anterior Mitral leaflet to Prevent Outflow ObstructioN technique and in 34.5% with the Balloon-Assisted Translocation of the Mitral Anterior Leaflet technique. AML modification was successful in 96.4% of cases. Despite successful AML modification, haemodynamically significant LVOT obstruction occurred in 12.7% of cases. The co-primary in-hospital safety endpoint occurred in 20.0% of patients, driven by cardiovascular death in 14.5% of patients. Overall in-hospital mortality was 16.4%. The ViMAC substrate was associated with the numerically highest LVOT obstruction rate (ViMAC 20.7%, ViR 0.0%, ViV 8.3%, odds ratio [OR] 4.72, 95% confidence interval [CI]: 0.89-47.86; p=0.070). The aortomitral angle showed a borderline association with LVOT obstruction (OR 1.22 per degree, 95% CI: 0.99-1.48; p=0.059). CONCLUSIONS: AML modification enables TMVR in high-risk anatomies with high feasibility but does not eliminate LVOT obstruction. ViMAC represents the most challenging substrate.
Source: EuroIntervention
Authors: Andrea Ruberti, Fabien Praz, Gerard Martí, Ole De Backer, Ignacio Amat-Santos, Rodrigo Estevez-Loureiro, Philippe Garot, Volker Rudolph, Manel Sabaté, Julio Echarte-Morales, Gerard Roura, Josep Comin, Muhammed Gercek, Guillem Muntané-Carol, Josep Gómez-Lara, Giovanni Occhipinti, Mattia Basile, Domenico Angellotti, Myriam Akodad, Damiano Regazzoli, Pedro Martin, Raúl Moreno, Ander Regueiro, Rafael Romaguera
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7225659580