TCT 2025 | Transcatheter Mitral Valve Replacement with SAPIEN M3: ENCIRCLE 1-Year Outcomes

Transcatheter mitral valve replacement (TMVR) is an emerging option for patients with symptomatic mitral regurgitation (MR) who are not candidates for surgery or currently available percutaneous therapies such as MitraClip. The ENCIRCLE study, the first pivotal trial with SAPIEN M3 system (Edwards Lifesciences), looked into the safety and efficacy of this transseptal TMVR approach in this population.

This was a prospective, multicenter, single-arm study designed to compare outcomes to a pre-specified performance goal. A total of 299 patients with symptomatic moderate-severe or severe (≥3+) MR deemed inoperable or at high surgical risk were recruited in US, European, and Canadian centers. Mean age was 77, and mean left ventricular ejection fraction (LVEF) was 46 ± 12 %.

The primary endpoint was the composite of all-cause mortality or heart failure (HF) rehospitalization at 1 year, compared against a 45 % performance goal. Secondary endpoints included NYHA functional class, KCCQ quality-of-life score, and MR reduction.

At 12 months, primary endpoint incidence resulted 25.1 % (95% CI 20.6–30.6; p < 0.0001 vs performance goal), meeting efficacy criteria by a wide margin. All-cause mortality resulted 8.2 % and HF rehospitalization 18.9 %. 30-day mortality reached a mere 0.7 %, well below the expected surgical risk (observed/expected ratio = 0.1).

Read also: TCT 2025 | PARTNER 3 Trial 7-Year Outcomes: TAVR vs SAVR in Low-Risk Patients.

Clinical benefits were striking: over 95 % of patients had MR ≤ 1+ at 30 days, sustained at 1 year (p < 0.0001), and 85 % were in NYHA functional class I–II. Also, KCCQ score improved significantly (mean >20 points (p < 0.0001), reflecting sustained quality-of-life gains.

Conclusion

In conclusion, TMVR with SAPIEN M3 system showed a significant reduction in death and HF hospitalization, with marked functional and quality of life improvement, and very low perioperative mortality at 1 year. These outcomes position SAPIEN M3 as a safe and effective option to treat symptomatic MR patients who make poor surgical candidates.

Presented by David Daniels at TCT 2025 (Late-Breaking Clinical Trials), October 27, San Francisco, USA.