Transcatheter edge-to-edge mitral valve repair (M-TEER) has become an established therapeutic option for mitral valve disease. Among the available techniques, M-TEER using the MitraClip (Abbott) system is supported by robust clinical evidence and is now widely adopted as an alternative to surgical treatment. In the management of mitral regurgitation (MR), reducing the severity of regurgitation is undoubtedly a primary therapeutic goal.
However, from the perspective of heart failure (HF) management, optimizing hemodynamics also plays a crucial role. Achieving hemodynamic stabilization is essential for improving clinical outcomes in these patients. Previous studies have suggested that direct intraprocedural pressure measurements, particularly a reduction in mean left atrial pressure (mLAP), are associated with a better prognosis. Nevertheless, the available evidence remains limited, especially from multicenter studies.
The aim of this study was to evaluate whether intraprocedural reduction in mean left atrial pressure (mLAP) during M-TEER has prognostic value, analyzing outcomes according to the etiology of mitral regurgitation: degenerative (DMR) or functional (FMR).
A total of 2,629 patients from the Japanese OCEAN-Mitral registry who underwent M-TEER with direct mLAP measurements were analyzed. Patients were divided into two etiological groups: DMR (825 patients, 31.4%) and FMR (1,804 patients, 68.6%).
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The Primary Endpoint (PE) was a composite of all-cause mortality and hospitalization for heart failure.
Regarding the results, a reduction in mLAP was observed in 58.9% of the overall population (70% in the DMR group and 54% in the FMR group). Among patients with degenerative mitral regurgitation, mLAP reduction was associated with a significantly lower risk of death or HF hospitalization (adjusted HR: 0.66; p=0.028). In contrast, no significant association was found between mLAP reduction and improved clinical outcomes in patients with functional mitral regurgitation (adjusted HR: 0.90; p=0.251). Although pulmonary venous flow patterns improved in both groups, the combination of mLAP reduction and improved pulmonary venous flow predicted better clinical outcomes only in patients with DMR.
Conclusion: Intraprocedural mLAP Reduction Improves Prognosis Only in Degenerative Mitral Regurgitation
The study concludes that intraprocedural reduction in mLAP is an independent predictor of improved clinical outcomes in patients with degenerative mitral regurgitation, but not in those with functional mitral regurgitation.
This difference suggests that, in DMR, the reduction in left atrial pressure reflects a true hemodynamic improvement, likely related to greater left atrial compliance. Therefore, the authors emphasize the importance of real-time hemodynamic assessment during M-TEER, particularly in patients with DMR, considering it a valuable procedural target that extends beyond the simple anatomical reduction of mitral regurgitation.
Original Title: Haemodynamic Outcomes of M-TEER in Degenerative and Functional Mitral Regurgitation.
Reference: Shingo Kuwata et al EuroIntervention 2026;22:e690-e700.
