M-TEER procedure effectively treats mitral regurgitation in patients with calcification

Results from a new analysis show that patients with mitral annular calcification (MAC) who undergo minimally invasive mitral transcatheter edge-to-edge repair (M-TEER) experience similar reductions in mitral regurgitation (MR) and improvement in quality of life compared to those seen in patients without calcification. Researchers presented the late-breaking data today at the Society for Cardiovascular Angiography & Interventions (SCAI) 2026 Scientific Sessions & Canadian Association of Interventional Cardiology/Association Canadienne de cardiologie d'intervention (CAIC-ACCI) Summit in Montreal.

MAC occurs when calcium builds up on the ring of tissue, known as the annulus, that supports the mitral valve in the heart. This buildup can affect how the valve closes, sometimes leading to complications such as symptomatic mitral regurgitation, where blood flows back towards the heart, and contributes to a lower quality of life. Patients with severe symptoms who are considered high risk for surgery may undergo M-TEER, a minimally invasive procedure in which a small clip is placed on the mitral valve to help it close more tightly and reduce the amount of blood leaking backward into the heart. There is limited evidence on the feasibility and outcomes of M-TEER in patients with MAC.

In the EXPANDed study, researchers analyzed data from the EXPAND and EXPAND G4 studies, which included patients who underwent M-TEER with the MitraClip™ G3 or G4 systems (Abbott) at 91 sites across the United States, Europe, Canada, the Middle East, and Japan between 2018 and 2022. Of the 1,907 patients who participated, 327 had MAC. These patients were older, had greater surgical risk, a higher prevalence of primary MR, and were more likely to be female. In addition, half of the patients in both groups had been hospitalized for heart failure within the previous year.

The study found that acute procedural success was higher in the group without calcification (96% vs. 92%). All-cause mortality was higher in the MAC group at 30 days (3.4% vs. 1.7%, p=0.04) as well as one year (18.3% vs. 12.1%, p=0.003). Patients with MAC also had higher rates of heart failure hospitalizations at one year (24.2% vs. 16.4%, p=0.001). There were no safety concerns through one year with low rates of replacement, single-leaflet device attachment, myocardial infarction, and stroke in both groups. The reduction in MR was similar, with 87.9% of MAC and 91.3% of no MAC patients having ≤1+ at one year. Quality of life also improved significantly in both groups and was sustained through one year, with 81% of patients with mild to no symptoms at normal activity (defined as NYHA class I/II). Patients also experienced large gains in KCCQ-OS (Kansas City Cardiomyopathy Questionnaire–Overall Summary, which measures how patients with heart failure feel and function in everyday life) scores (21.8 ± 26.3 for MAC and 19.0 ± 24.5 for No MAC).

We know that the presence of mitral annular calcification can complicate mitral valve disease. However, this first large real-world study shows that the MitraClip procedure is a safe and effective option for patients with severe symptoms, leading to significant reductions in mitral regurgitation and meaningful improvements in quality of life regardless of the presence of MAC. Differences observed in one-year mortality and heart failure hospitalizations likely reflect the greater burden and complexity of comorbidities among patients with MAC compared with those without calcification."

Karim Al-Azizi, MD, FSCAI, interventional cardiologist at Baylor Scott & White in Plano, Texas

Researchers noted that not all registries currently capture data on MAC, and further subanalyses will explore whether certain patient groups within the MAC population may benefit more than others.