Background: Mitral annular calcification (MAC) causes degeneration of the mitral valve function. Since these patients are poor surgical candidates, options are limited to percutaneous solutions. Use of balloon lithotripsy (BL) to augment mitral balloon valvuloplasty (MBV) is a novel technique for treatment of MAC-related mitral stenosis (MS).
Methods: Single-center retrospective review of 35 consecutive MBV for MAC cases at Henry Ford from 3/2013 to 4/2021. Outcome variables are reported as median and interquartile ranges (IQR). Chi-squared and Wilcoxon-signed rank tests were used to compare categorical and continuous variables respectively using 95% confidence intervals for statistical significance. Procedural success was defined as a final mitral valve area ≥1.5 cm2 or ≥50% reduction in gradient.
Results: Of 35 MBV cases done for MAC, 5 utilized lithotripsy balloons to augment valvuloplasty results (Table). Mean baseline gradients were similar and right ventricular systolic pressures trended higher for BL cases. Cases utilizing lithotripsy were longer and utilized more fluoroscopy time but the final invasive gradient trended lower (non-BL 7mmHg [4, 9] vs. BL 1 mmHg [0,5] p=0.113), therefore, higher rates of procedural success were seen (non-BL 47% vs. BL 80%, p=0.2). Survival analysis was hampered due to loss of follow-up in the BL group.
Conclusion: BL appears to augment immediate valvuloplasty results. Further studies regarding the durable impact of balloon lithotripsy on MBV are warranted
