Mitral Valve Lithotripsy With SmartCrack Balloon for Severe Calcified Mitral Stenosis: First‐in‐Human Experience

Abstract

Background Mitral stenosis due to mitral annular calcification and calcific rheumatic heart disease (CRHD) remains challenging to treat. This first‐in‐human study evaluated the safety and feasibility of the dedicated SmartCrack lithotripsy balloon in patients with severe mitral stenosis secondary to mitral annular calcification or calcific rheumatic heart disease. Methods High surgical risk patients underwent mitral lithotripsy with the SmartCrack system. Intraoperative measures included mitral valve area, transmitral pressure gradient, and mitral regurgitation severity, assessed pre‐ and post procedure. Follow‐up computed tomography evaluated calcification changes. The primary safety end point was adverse events within 7 days (death, stroke, or procedural complications). The primary efficacy end point was mitral valve area >1.5 cm 2 , ≥50% reduction in transmitral pressure gradient, or transmitral pressure gradient <5 mm Hg without significant mitral regurgitation. Results Ten patients were enrolled. The primary safety end point occurred in 10% (n=1, minor stroke), with no deaths or major bleeding. Mitral regurgitation worsened from mild to moderate in 1 patient. The primary efficacy end point was achieved in all patients. Median device time was 18 minutes, and 8 of the 10 patients (80%) underwent postdilatation following SmartCrack therapy. Mitral valve area increased from 0.89±0.18 to 1.31±0.40 cm 2 ( P <0.001), transmitral pressure gradient decreased from 7.7±2.6 to 4.4±1.8 mm Hg ( P <0.01). Follow‐up computed tomography revealed calcium cracks in 4 of 5 patients with mitral annular calcification, whereas no cracks were observed in patients with calcific rheumatic heart disease. At 30 days, most patients (n=8/10) reporting symptom improvement. Conclusions This study demonstrates the procedural feasibility of the SmartCrack lithotripsy balloon when combined with balloon mitral valvuloplasty, potentially modifying valvular calcification and improving mitral valve area. Larger studies are needed to confirm its safety, effectiveness, long‐term durability, and clinical benefits.