The MATTERHORN study is a noninferiority trial. Patients with heart failure and secondary mitral regurgitation were randomly assigned, in a 1:1 ratio, to undergo either transcatheter edge-to-edge repair (intervention group) or surgical mitral-valve repair or replacement (surgery group). The primary efficacy end point was a composite of death, hospitalization for heart failure, mitral-valve reintervention, implantation of an assist device, or stroke within 1 year after the procedure. The percentage of patients with freedom from a primary end-point event was compared between the treatment groups with the use of multiple logistic-regression analysis, with treatment group as the only predictor variable. The noninferiority bound was defined as 17.5 percentage points for the 90% confidence interval of the estimated marginal mean between-group difference.

A total of 210 patients underwent randomization. Within 1 year, at least one of the components of the primary efficacy end point occurred in 16 of the 96 patients (16.7%) in the intervention group and in 20 of the 89 (22.5%) in the surgery group. The estimated marginal mean difference was −6 percentage points (95%-CI: −17 to 6; p<0.001 for noninferiority). In conclusion patients with heart failure and secondary mitral regurgitation, transcatheter edge-to-edge repair was noninferior to mitral-valve surgery with respect to a composite of death, rehospitalization for heart failure, stroke, reintervention, or implantation of an assist device in the left ventricle at 1 year.

Article source:

Baldus S, Doenst T, Pfister R, Gummert J, Kessler M, Boekstegers P, Lubos E, Schröder J, Thiele H, Walther T, Kelm M, Hausleiter J, Eitel I, Fischer-Rasokat U, Bufe A, Schmeisser A, Ince H, Lurz P, von Bardeleben RS, Hagl C, Noack T, Reith S, Beucher H, Reichenspurner H, Rottbauer W, Schulze PC, Müller W, Frank J, Hellmich M, Wahlers T, Rudolph V; MATTERHORN Investigators. Transcatheter Repair versus Mitral-Valve Surgery for Secondary Mitral Regurgitation. N Engl J Med. 2024 Nov 14;391(19):1787-1798. doi: 10.1056/NEJMoa2408739. Epub 2024 Aug 31. PMID: 39216093