Calcification of aortic valve cusps as independent predictor for permanent pacemaker requirement after transcatheter aortic valve implantation

Abstract Background High-degree atrioventricular (AV) block represents a frequent complication after transcatheter aortic valve implantation (TAVI). Extension of indication for TAVI towards subjects with lower surgical risk requires to reduce the likelihood for the need of permanent pacemaker (PPM) implantation. Purpose We examined the role of calcification of the aortic valve cusps and left ventricular outflow tract (LVOT) as potential predictors for PPM implantation after TAVI. Methods In a cohort of 1200 consecutive patients without PPM who underwent transfemoral TAVI, clinical and procedural characteristics as well as requirement for PPM implantation after TAVI were assessed systematically. In all patients, cardiac computed tomography (CT) was performed before TAVI including quantitative assessment of calcium volume of the aortic valve cusps and the LVOT in mm3 (see figure). Results Median patient age was 81 (IQR 7) years, 50% were male. 9.8% of patients had a pre-existing complete right bundle branch block (RBBB) in ECG. 68% of subjects received a balloon-expandable valve, 32% a self-expandable valve. Postinterventional PPM implantation was necessary in n=155 subjects (13%) due to high-degree AV block. In this group of subjects, calcification of the aortic valve cusps was more pronounced than in the group of subjects without high-degree AV block (see table). Univariate regression analysis revealed pre-existing complete RBBB (p<0.001, OR 8.564), implantation of a self-expandable prosthesis (p=0.013, OR 1.549) as well as calcification of the non-coronary (p=0.016, OR 1.001) and left-coronary cusp (p=0.025, OR 1.001) as significant predictors for PPM implantation. In multivariate regression analysis, these predictors – including calcification of the non-coronary cusp (p=0.037, OR 1.001) remained significant. With every mm3 of calcification, risk for high-degree AV block and PPM implantation increases by 0.1%. With a median calcification of 225 mm3 of the non-coronary cusp, this would make a 22.5% relative risk increase. Conclusion In a large cohort of 1200 patients, the volume of aortic cusp calcification, in particular calcification of the non-coronary cusp, was identified as independent predictor for PPM implantation following transcatheter aortic valve implantation. This might be explained by the anatomical proximity of both the AV node and left Tawara branch to the non-coronary cusp, resulting in a higher risk of compression during valve implantation. Our results may contribute to improved risk stratification regarding the need for PPM implantation after TAVI.Assessment of calcium volumeComparison of calcification