Aims: New-onset conduction disturbances still represent a considerable problem after transcatheter aortic valve implantation (TAVI). The aim of this study was to identify calcification patterns with an elevated risk for permanent pacemaker implantation (PPI) after TAVI and investigate underlying mechanisms in an ex vivo setting.
Methods and results: One hundred and sixty-two patients who underwent TAVI with the Edwards SAPIEN XT® or Medtronic CoreValve® at our institution were analysed. The calcium load of the device landing zone was quantified with 3mensio®, and calcium patterns with an elevated risk for PPI were identified. Ex vivo simulations of balloon valvuloplasty were performed in 3D-printed silicone annuli of patients matching the identified risk profile. Patients with a calcium load of the left coronary cusp (LCC) above 209 mm3 had a higher rate of PPI than patients below this threshold (16.7 vs. 2.6%, P = 0.003). Multivariate regression revealed pre-existing right bundle branch block (RBBB) and increased LCC calcification as independent predictors for PPI. Simulation of the TAVI procedure in a silicone annulus revealed an off-centreline shift of the valvuloplasty balloon and transcatheter heart valve away from the LCC towards the commissure between right- and non-coronary cusp.
Conclusion: Pre-existing RBBB and elevated LCC calcification were identified as independent predictors for PPI. These two risk factors enabled us to distinguish between patients according to their risk for PPI after TAVI. Ex vivo simulations suggested an off-centreline shift of the balloon as a possible explanation.
Keywords: 3D printing; calcium distribution; pacemaker; simulation; transcatheter aortic valve implantation.
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