Key Points:
- The MATTERHORN trial found that the transcatheter edge-to-edge repair (TEER) procedure was non-inferior to surgical mitral valve repair in reducing functional mitral regurgitation in heart failure patients with depressed left ventricular ejection fraction.
- Both TEER and surgical groups showed similar outcomes in terms of the primary composite efficacy endpoint, and both had low rates of severe MR recurrence at 1 year.
- The TEER group had significantly fewer safety events compared to the surgical group, highlighting its potential as a safer alternative for patients at high risk for surgery.
Functional mitral regurgitation (FMR) is common in heart failure (HF) patients and is associated with poor outcomes. Surgical repair or replacement of the mitral valve has traditionally been the therapy of choice, but involves significant operative risk with unclear benefits. Transcatheter edge-to-edge repair (TEER) via the MitraClip device, which is percutaneously implanted to reduce FMR by approximating the mitral leaflets in the fashion of the Alfieri stitch was shown in the COAPT trial to improve HF hospitalizations and mortality. For patients with primary degenerative MR, the MitraClip was found less effective than surgery in the EVEREST II trial, but no randomized data exist comparing it to surgery in patients with secondary MR and depressed left ventricular ejection fraction (LVEF), who face higher perioperative risks.
In a breaking presentation at the 2024 ESC Congress today, Dr. Volker Rudolph (Heart and Diabetes Center NRW, Germany) and his team presented their study: “MATTERHORN: Transcatheter versus Surgical Mitral Valve Repair in Patients with Heart Failure and Secondary Mitral Regurgitation” MATTERHORN (NCT02371512) was a multicenter, randomized, open-label trial comparing the MitraClip system to reconstructive mitral valve surgery in the setting of MR and depressed LVEF. Inclusion criteria included clinically significant FMR, LVEF between 20% and 45% and high surgical risk determined by the Heart Team. Key exclusion criteria included severe tricuspid regurgitation, other concomitant severe valve disorders, and coronary revascularization or cardiac resynchronization device implantation within 3 months prior to the procedure. The primary efficacy endpoint was the composite of death, HF hospitalization, mitral reintervention, assist device implantation, and stroke at 1 year. The key secondary endpoint was the recurrence of MR grade >=3 at 1 year. The primary safety endpoint was assessed at 30 days and included death, myocardial infarction, major bleeding, stroke, rehospitalization, reinterventions, non-elective cardiovascular surgery, among others.
A total of 210 patients were randomized from 16 centers in Germany with an average age of 70.5 years and a mean LVEF of 43%. In the surgical group, 72% underwent mitral valve repair and 28% underwent replacement. Between the TEER group and the surgical group, there was no significant difference in the primary composite endpoint: 16.7% in the TEER group and 22.5% in the surgery group at 1 year (odds ratio [OR] 0.69, 95% confidence interval [CI] 0.33-1.44, p=0.320; p<0.01 for non-inferiority). There was also no difference in the recurrence of MR grade >=3 at 1 year: 8.9% of patients in the TEER group and 87.3% of patients in the surgery group (OR 6.22, 95% CI 0.75-51.95, p=0.091). The surgery group had a significantly higher rate of safety events: 54.8% in the surgery group vs. 14.9% in the TEER group (p<0.001).
Dr. Rudolph concluded, “In the MATTERHORN trial, we were able to show non-inferiority between the two techniques for improving MR – both methods worked well – with some safety benefits favouring TEER.”