Native aortic leaflets and permanent pacemaker implantation risk following balloon-expandable transcatheter aortic valve implantation

OBJECTIVE: Permanent pacemaker implantation (PPI) risk is higher following transcatheter aortic valve implantation (TAVI) than surgical valve replacement. Native aortic leaflets are retained in patients undergoing TAVI, unlike in surgical valve replacement. Whether the retained leaflets influence PPI risk because of their proximity to the conduction system is unknown. The study sought to determine the association between infra-annular extension of native right coronary cusp/noncoronary cusp (RCC/NCC) post balloon-expandable TAVI and PPI risk. METHODS: We performed a retrospective analysis of 190 patients undergoing balloon-expandable TAVI at a single center. Manifestation of infra-annular extension of RCC/NCC was considered to be present when part of leaflet extended below aortic–annular plane on post-implantation aortic-root angiography. RESULTS: Infra-annular extension of RCC/NCC was observed in 33 patients (17.37%). PPI incidence post-TAVI was higher in patients with infra-annular extension of RCC/NCC than in those without (36.36% versus 8.92%, relative-risk: 4.08, p˂0.0001). On logistic-regression analysis, preexisting right bundle-branch block (RBBB) (odds-ratio: 12.73, 95% confidence-interval: 2.16–74.93, p = 0.005), and infra-annular extension of RCC/NCC (odds-ratio: 5.63, 95% confidence-interval: 2.17–14.58, p < 0.0001) were independently associated with PPI risk. Preexisting RBBB (φ = +0.25, p = 0.001) and infra-annular extension of RCC/NCC (φ = +0.30, p < 0.0001) showed a positive-correlation with PPI risk. Infra-annular extension of RCC/NCC was a significant predictor of PPI risk on receiver-operating-characteristic curve analysis (area under-the-curve 0.67; 95% confidence-interval: 0.54–0.79, p = 0.006). CONCLUSION: The retained native aortic leaflets play a significant role in PPI risk following balloon-expandable TAVI. Infra-annular extension of RCC/NCC is a novel predictor, and is associated with a four-fold higher risk of PPI.