Acute Valve Syndrome in Patients With Primary Mitral Regurgitation Undergoing Transcatheter Edge-to-Edge Repair

BACKGROUND: Acute or advanced valve syndrome (AVS), originally proposed in aortic stenosis to describe rapid clinical deterioration, has not been evaluated in mitral regurgitation (MR). OBJECTIVES: This study sought to investigate the prognostic impact of AVS in patients with primary MR undergoing mitral transcatheter edge-to-edge repair (M-TEER). METHODS: We analyzed 961 patients with primary MR enrolled in the multicenter OCEAN-Mitral registry who underwent M-TEER. AVS was defined as the presence of one or more acute or advanced signs of MR, including NYHA functional class Ⅲ-Ⅳ, left ventricular ejection fraction (LVEF) <50%, elevated B-type natriuretic peptide, atrial fibrillation, hypotension, or inotropic drug use before M-TEER. Progressive valve syndrome (PVS) was defined as the absence of these signs. The primary outcome was a composite of all-cause death and heart failure hospitalization over 2 years. RESULTS: AVS was present in 804 patients (83.7%). These patients had more comorbidities and lower LVEF than the PVS group. Despite comparable procedural success and symptomatic improvement in both groups, event-free survival during a median follow-up of 400 (232-731) days was significantly lower in the AVS group (P < 0.001). Multivariable analysis identified AVS as an independent predictor of the composite endpoints (HR: 2.236; 95% CI: 1.105-4.415; P = 0.023). CONCLUSIONS: Although M-TEER yields favorable procedural and symptom outcomes in both PVS and AVS, AVS was independently associated with worse prognosis in patients with primary MR. These findings suggest that early intervention, before the development of AVS, may be beneficial. CLINICAL TRIAL REGISTRATION: The OCEAN-Mitral trial is registered with the University Hospital Medical Information Network (UMIN000023653).