Feasibility, Efficacy, and Safety of the Mitral Annulo-TRIpsy in eXtreme Risk Patients

Severe calcific mitral stenosis is common and therapeutically challenging. Intravascular lithotripsy (IVL) can facilitate percutaneous balloon mitral valvuloplasty in patients not amenable to conventional therapies. We describe a modified technique using larger IVL balloons to ensure maximal annular contact and delivery of ultrasonic shockwaves to restore mitral leaflet pliability and reduce transvalvular gradients without the need for noncompliant valvuloplasty balloons.

Seven patients underwent the Mitral Annulo-TRIpsy in eXtreme risk patients (MATRIX) procedure at 3 tertiary structural heart disease centers in the United States. Transcatheter mitral valve replacement was contraindicated due to prohibitive risk of left ventricular outflow tract obstruction or insufficient annular calcification for anchoring of a balloon-expandable valve. IVL balloons were delivered using a large-bore transseptal sheath over three 0.014 wires. Runs of delivery of IVL therapy were repeated until satisfactory results in terms of mean mitral gradient (mMG) reduction were achieved.

Median age was 78 years, and 14.3% were female. All patients presented with progressive New York Heart Association class III-IV symptoms and functional limitations. Pre-MATRIX mMG was 9.0 mmHg. The final mMG was 3.0 mmHg (absolute difference 6.3 mmHg; 95% CI 2.6-10.1 mmHg; p <0.01). No conventional valvuloplasty balloons were used after IVL. All patients successfully underwent MATRIX. No major periprocedural complications were observed including death, stroke, major bleeding, or reintervention. No patients experienced worsening mitral regurgitation. All patients were discharged alive.

This small multicenter series demonstrates that IVL of calcified mitral stenosis using the MATRIX technique is feasible and safe and associated with effective reductions in mMG.