The prospective, multicenter SUMMIT-MAC study evaluated the safety and efficacy of transcatheter mitral valve replacement (TMVR) using the Tendyne system in patients with severe mitral annular calcification (MAC) who were not candidates for surgery.

A total of 103 patients were treated (mean age >75 years, most in NYHA functional class III/IV). Inclusion criteria included mitral regurgitation (MR) ≥3+, severe mitral stenosis, or both, under optimal medical therapy. Exclusion criteria were LVEF <25%, severe tricuspid regurgitation, or pulmonary artery pressure >70 mmHg. The mean MAC volume was 5679 ± 5670 mm³, with >45% involvement of the inner annulus.
The primary endpoint was the composite of all-cause mortality and heart failure (HF) hospitalization at 12 months, compared against a performance goal of 43%. The endpoint was met, with 60.4% freedom from events (95% CI 50.2–69.2; p = 0.0002). Total mortality was 21%, HF hospitalization 30%, and complete reduction of MR ≥3+ was achieved at 30 days, with sustained improvement at 12 months.At one year, 88% of patients were in NYHA class I–II.
The mean mitral gradient was 3.8 ± 1.4 mmHg, and the KCCQ score improved by +18.7 points (p < 0.0001). The most frequent complication was apical bleeding (5.8%), with no significant events of thrombosis, endocarditis, or structural valve degeneration during the first year.
Conclusion
Transcatheter mitral valve replacement with the Tendyne system in patients with severe MAC demonstrated acceptable safety and sustained efficacy, achieving marked reduction in mitral regurgitation, clinical improvement, and enhanced quality of life. These results support Tendyne as a viable therapeutic option for inoperable or high-risk patients with mitral disease associated with MAC.
Presented by Paul Sorajja at TCT 2025 (Late-Breaking Clinical Trials), October 27, San Francisco, USA.
Subscribe to our weekly newsletter
Get the latest scientific articles on interventional cardiology





