Direct Implantation of Transcatheter Valve in Mitral Annular Calcification: A Multicenter Study

BACKGROUND: Mitral valve replacement in the setting of severe annular calcification (MAC) is associated with high morbidity and mortality. Direct surgical implantation of a transcatheter heart valve (THV) through a transatrial approach is a strategy to mitigate surgical risk. This study reports the perioperative and 1-year outcomes of mitral valve replacement using a THV in patients with severe circumferential MAC at 3 Canadian centers. METHODS: Charts were reviewed between January 1, 2018 and September 30, 2023 to identify patients with severe circumferential MAC who had undergone direct implantation of a THV. Primary outcomes were 30-day mortality, debilitating stroke, and 1-year mortality. Secondary outcomes included left ventricular outflow tract obstruction, degree of paravalvular leak (PVL), transvalvular mean pressure gradient, and length of stay. RESULTS: Twenty-two patients at the 3 centers underwent direct implantation of a THV. Nineteen patients were female, with mean age of 70.41 ± 9.33 years. A THV was successfully implanted in all patients. There were 2 deaths at 30 days. Four patients died of noncardiac causes at 1 year, and 1 patient had a postoperative stroke. Seventeen (77%) patients had no PVL or trace PVL, 4 had mild PVL, and 1 patient had mild-moderate PVL. The mean transvalvular gradient was 4.42 ± 4.40 mm Hg. There were no cases of left ventricular outflow tract obstruction. CONCLUSIONS: Direct deployment of a THV in patients with severe MAC may be a reasonable option. Thirty-day and 1-year mortality rates of 9% and 18%, respectively, suggest that this approach should be reserved for high-risk patients who are not able to undergo conventional strategies.