Balloon Over- and Underfilling of Balloon-Expandable Transcatheter Heart Valves for Treatment of Borderline Aortic Annuli Dimensions in Aortic Valve Stenosis

Background: Transcatheter aortic valve implantation (TAVI) using balloon-expandable (BE) transcatheter heart valves (THV) for patients with borderline aortic annuli necessitates precise balloon filling to optimize valve expansion and minimize the risk of dislodgment due to excessive calcification. This study aimed to analyze over- and underfilling strategies in borderline aortic annuli dimensions and evaluate clinical and hemodynamic outcomes.

Methods: Between 2014 and 2024, 126 patients (73% male, 78.6 ± 7.9 years) received TAVI using BE THV with modified balloon filling volumina. Clinical endpoints were adjudicated in accordance with VARC-3 definitions. Propensity score matching was conducted to compare this patient cohort with patients receiving BE THV with nominal balloon filling.

Results: Individualized balloon filling strategies were applied across all valve sizes (23, 26, 29 mm) with annulus diameters of 21 to 32 mm. Underfilling (mean calcium burden 989.6 mm³) occurred in 1.6% of 23 mm (mean perimeter-derived annulus diameter [mPdAD] 23.5 mm), 10.3% of 26 mm ([mPdAD] 24.2 mm), and 13.5% of 29 mm THV ([mPdAD] 27.1 mm), while overfilling (mean calcium burden 697.2 mm³) was applied in 22.2% ([mPdAD] 23.2 mm), 22.2% ([mPdAD] 25.8 mm), and 29.4% ([mPdAD] 29.6 mm). Overfilling was common in patients with mild calcification (<750 mm³, p < 0.001), with significant overfilling (+4–5 mL, 2.4%) seen only in 29 mm THV with calcification ≤893 mm³. Propensity score matching (126 individualized versus 126 nominal filling) revealed no significant differences in VARC-3 endpoints: 30-day PPI (11.1% versus 10.3%, p = 0.838), device success (97.2% versus 91.7%, p = 0.138), mean pressure gradient (10.5 ± 4.2 mm Hg versus 10.0 ± 3.9 mm Hg, p = 0.311), PVL > mild (0.0% versus 1.6%, p = 0.158), and stroke (0.8% versus 2.4%, p = 0.316). Notably, neither death nor myocardial infarction occurred within 30 days in either group.

Conclusion: Modification of balloon filling in TAVI using BE THV is a safe and effective method to address borderline aortic annulus dimensions presenting adequate clinical and hemodynamic results. Overfilling of the balloon due to mild calcification of the aortic annulus complex occurred more often in this patient cohort, while underfilling was less frequent and mainly applied in patients with excessive calcium formation. Especially large aortic annuli (up to 32 mm) outside of the manufacturer’s given sizing algorithm are approachable using this procedural measure.

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Artikel online veröffentlicht:
11. Februar 2025