New research presented at TCT 2025 suggests that Abbott’s FDA-approved Tendyne TMVR system leads to significantly better health outcomes in patients with severe mitral annular calcification who were previously considered untreatable.
- Severe mitral annular calcification (MAC) with mitral regurgitation or stenosis is typically considered extreme and is excluded from interventional treatment due to technical challenges.
- The Tendyne system received FDA approval earlier in 2025 based on SUMMIT trial data, but its efficacy in severe MAC patients was unknown till now.
The SUMMIT-MAC trial enrolled 103 patients with severe MAC and found that the challenging patient population showed strong outcomes despite extreme pathology…
- The study’s primary composite endpoint of freedom from all-cause mortality and HF hospitalization at 12 months was 60.4%, significantly exceeding the 43% goal.
- Technical success reached 94.2% despite an average MAC volume of 5,679 mm³ (which is considered very extreme).
- Mitral regurgitation resolution was excellent, with 100% of patients having none/trivial MR at discharge, and 91.4% remaining regurgitation free at 12 months.
- Quality-of-life improvements were substantial, with KCCQ scores improving by 18.7 points on average.
However, patients treated with the Tendyne system still faced significant procedural challenges caused by MAC including some outcomes like:
- A 30-day mortality rate of 6.8% (all cardiac deaths) and a 12-month mortality rate of 21% – partially due to 85.4% of patients being significantly frail.
- Bleeding complications occurred in 27.2% of patients including 6.8% life-threatening bleeds – mostly due to Tendyne’s transapical access route.
- The study also had a 74.6% screen failure rate – so careful patient selection is critical as well as the complexity of MR patients with MAC.
Although U.S. guidelines currently do not offer any recommendations for TMVR in MAC patients, there’s a good chance the SUMMIT-MAC data will change this, with European societies already providing class 2b recommendation for TMVR in severe MAC.
The Takeaway
Thanks to SUMMIT-MAC, we now know that Abbott’s Tendyne TMVR system successfully treats severe mitral annular calcification, which is a big win for a patient population that is usually excluded from all interventional options.
