Transcatheter edge-to-edge repair (TEER) is as effective as surgery for treating patients with secondary mitral regurgitation (MR), a new study concludes, with the technique’s better safety profile a key benefit. Findings from the Abbott Vascular-funded MATTERHORN trial demonstrate the noninferiority of TEER in patients with secondary MR and may prove influential in considering patients who are judged inoperable or at high surgical risk by the Heart Team. “TEER is commonly used to treat patients with secondary MR, but there has been no randomized trial comparing it with traditional surgery,” said study presenter Professor Volker Rudolph, MD, of the Heart and Diabetes Center NRW in Bad Oeynhausen, Germany, in a press release on Saturday at the European Society of Cardiology (ESC) Congress 2024. “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 favoring TEER.” In secondary MR, the heart’s mitral valve does not close properly due to structural and functional abnormalities in the left ventricle, and this can lead to blood flowing the wrong way through the valve. ESC Congress 2024 The trial, which featured in a Hot Line session today at ESC Congress 2024, found no significant difference in the primary composite endpoint, which included hospitalization for heart failure, mitral reintervention, assist device implantation and stroke at 1 year. This endpoint occurred in 16.7% of patients in the TEER group and 22.5% in the surgical group at 1 year (odds ratio [OR]: 0.69; 95% confidence interval [CI]: 0.33–1.44; p=0.320), with non-inferiority confirmed (p<0.01 for non-inferiority). Further findings revealed no significant difference in the recurrence of MR grade ≥3 at 1 year: 8.9% of patients in the TEER group vs. 1.5% in the surgical group (OR 6.22; 95% CI: 0.75– 51.95; p=0.091). After 1 year, 73.2% of patients in the TEER group and 87.3% of patients in the surgical group had MR grade ≤1, highlighting the efficacy of both therapies. Extending indications The primary safety endpoint, which included death, myocardial infarction and major bleeding, occurred in significantly more patients in the surgical group (54.8%) than in the TEER group (14.9%; p<0.001). According to the researchers, this was largely driven by more major bleeding (29% in the surgical group vs. 3% in the TEER group), all reinterventions (19% vs. 8%) and new-onset atrial fibrillation (AF) (33% vs. 9%). “The results may extend indication for interventional mitral repair to patients with secondary mitral regurgitation who are eligible for surgery,” commented Rudolph . “The MATTERHORN trial is the first randomized trial to demonstrate the noninferiority of TEER and surgery in patients with secondary MR. Principal Investigator,” added Professor Stephan Baldus, from the University of Cologne in Germany,” Rudolph said at ESC. “These new data may become important to guide decision making as European guidelines currently recommend TEER may be considered in patients who are judged inoperable or at high surgical risk by the Heart Team.” Study Methods The investigator-initiated randomized controlled trial recruited 210 patients from 16 centers in Germany. The average age was 70.5 years and 40% were female. These patients were also diagnosed with secondary MR and left ventricular ejection fraction (LVEF) ≥20% with symptoms of heart failure, and considered at high surgical risk by the local Heart Team. Patients were randomized 1:1 to mitral TEER or surgical mitral valve therapy (mitral valve repair or replacement at the surgeon’s discretion). The primary efficacy endpoint was the composite of death, hospitalization for heart failure, mitral reintervention, assist device implantation and stroke at 1 year. The primary composite safety endpoint, assessed at 30 days, included death, myocardial infarction, major bleeding, stroke or transient ischemic attack, rehospitalization and all reinterventions. Other outcomes that were classed as a primary composite safety endpoint included non-elective cardiovascular surgery, renal failure, deep wound infection, mechanical ventilation >48 hours, gastrointestinal complications requiring surgery, new-onset atrial fibrillation (AF), septicemia and endocarditis. Photo Credit: Screenshot by Bailey G. Salimes, CRTonline.org Photo Caption: Volker Rudolph, MD, presents results from the MATTERHORN Trial on Saturday at ESC 2024.