Alternative to mitral valve surgery shows promise, but research criticized

Editor's Note

Although data suggest transcatheter edge-to-edge repair (TEER) using the MitraClip device may offer similar outcomes to mitral valve surgery in patients with heart failure and functional mitral regurgitation (FMR), experts have criticized the research, TCT MD reported September 1.

Presented at the recent European Society of Cardiology (ESC) Congress and published in the New England Journal of Medicine, the MATTERHORN study is a small, long-running randomized trial involving 205 patients with FMR who were at high surgical risk, TCT MD reports. The study compared TEER with mitral valve surgery regarding primary endpoints such as death, heart failure rehospitalization, stroke, reintervention, or ventricular assist device implantation over one year.

The results showed that 16.7% of the TEER group and 22.5% of the surgery group experienced at least one primary endpoint event, meeting the noninferiority criteria. The TEER group also demonstrated a significantly better safety profile, with 14.9% experiencing a primary safety event compared to 54.8% in the surgery group. However, the trial's design was questioned due to its exclusion of a medical management control group, which is a common approach for managing these patients, TCT MD reports. Additionally, critics pointed out that the noninferiority margin of 17.5% was too large and could mask significant differences between the treatments.

Other concerns highlighted in the article relate to the fact that FMR is fundamentally a ventricular disease; that neither surgical nor TEER approaches effectively change the long-term prognosis; and that the trial compared two invasive procedures without a clear standard of care group.