Tendyne Transcatheter Mitral Valve Replacement (TMVR) in Patients with Severe Mitral Annular Calcification (MAC) Found Effective and Safe: SUMMIT-MAC Trial, TCT 2025

This news is covered by the Medical Dialogues Bureau present at the TCT Conference 2025, being held in San Francisco, USA.

The Tendyne Transcatheter Mitral Valve Replacement (TMVR) system significantly improved symptoms, quality of life, and mitral valve function in patients with severe mitral annular calcification (MAC), according to pivotal results from the SUMMIT-MAC trial presented by Dr. Paul Sorajja at TCT 2025 and simultaneously published in JACC.

The SUMMIT-MAC arm of the SUMMIT trial is the first prospective, multicenter study evaluating a dedicated TMVR system specifically designed for severe MAC, a condition historically associated with high surgical risk and limited treatment options. The single-arm trial enrolled 103 symptomatic patients across 37 sites in North America and Europe. Participants were elderly (mean age 78 years), high-risk (mean STS-PROM 7%), and predominantly female (55%), with 74% in NYHA class III/IV and an average baseline KCCQ-OS score of 49.

The Tendyne TMVR system (Abbott) features a self-expanding, dual-frame nitinol design with a tethered apical pad that provides secure anatomic fixation and eliminates mitral regurgitation (MR). The device can be fully retrieved and repositioned, offering procedural control and safety in anatomically challenging cases.

Procedural success was high, with 99% of devices successfully implanted and 94% achieving overall technical success by MVARC-2 criteria. Procedural survival was 98%, and no intraprocedural strokes were reported.

At 30 days, mortality was 6.8%, below the expected STS-PROM risk, and freedom from MR >1+ was achieved in 100% of patients. At one year, freedom from all-cause mortality and heart failure hospitalization was 60.4% (95% CI 50.2–69.2%; p=0.0002 vs. performance goal 43%), meeting the prespecified primary endpoint.

Clinical improvements were substantial. NYHA class I/II increased from 31% at baseline to 88% at one year, while mean KCCQ-OS score improved by +18.7 points (p<0.0001), reflecting marked quality-of-life gains. Six-minute walk distance increased modestly from 218 m to 239 m (p=0.0338). Bleeding (27%), new atrial fibrillation (14%), and acute kidney injury (12%) were the most common 30-day serious adverse events, but disabling stroke occurred in only 2% of patients.

Imaging analyses confirmed durable hemodynamic performance, with a mean transmitral gradient of 3.8 mmHg and 97% of patients showing only mild or no MR at one year. No structural valve dysfunction was reported during follow-up, and reintervention was rare (3%).

Investigators highlighted that the SUMMIT-MAC trial is the first to demonstrate that transcatheter replacement can be performed safely and effectively in this high-risk population.

The study met all prespecified endpoints, confirming the safety, feasibility, and durable performance of the Tendyne TMVR in patients with severe MAC. These findings mark a pivotal step toward expanding transcatheter solutions for complex mitral disease and addressing an important unmet need in structural heart intervention.

Reference: Paul Sorajja, Transcatheter Mitral Valve Replacement with Tendyne For Severe Mitral Annular Calcification Primary Outcomes from the SUMMIT-MAC Pivotal Trial, TCT Conference 2025, San Francisco.

https://www.tctconference.com/

About the Study Presenter: Dr. Paul Sorajja is the Roger L. and Lynn C. Headrick Family Chair of the Valve Science Center at the Minneapolis Heart Institute Foundation, and a cardiologist at Minneapolis Heart Institute where he serves as the Director of the Center for Valve and Structural Heart Disease. He received his medical degree from Mayo Medical School, and completed his Internal Medicine Residency and Cardiology Fellowship at the Mayo Graduate School of Medicine.

Dr. Sorajja’s expertise is interventional cardiology, with a focus on bringing the latest innovative technologies to patients with valvular and structural heart disease. He was part of the team that performed the first transcatheter mitral valve replacement (TMVR) in the US, and has the largest worldwide experience with the therapy. Dr. Sorajja currently serves as a national investigator for TMVR and also for clinical trials in percutaneous treatment for tricuspid regurgitation. He has served on several national practice committees for valvular heart disease and hypertrophic cardiomyopathy. Dr. Sorajja has published more than 250 manuscripts and several books. He routinely lectures at national and international medical conferences, and has received awards for his expertise in medical education. Dr. Sorajja is also highly active in developing intellectual property in these areas.

About the Product: The Tendyn Transcatheter Mitral Valve Replacement (TMVR) system by Abbott offers a less invasive treatment option for select patients with symptomatic, significant mitral regurgitation (MR ≥ grade 3), providing effective relief by eliminating mitral regurgitation. In the SUMMIT–MAC trial, this dedicated TMVR system was evaluated for its ability to improve patient function and quality of life in those with severe mitral annular calcification.