Children are Less Likely Than Adults to Develop Complete Heart Block Following TAVR.

TAVR is an alternative to surgical aortic valve [AoV] replacement. In adults, rates of atrioventricular block [AVB] requiring permanent pacemaker [PPM] placement in the modern era are 4-24%. Post-TAVR conduction abnormality incidence and risk factors are unknown in children and young adults. Describe post-TAVR conduction abnormalities in children and young adults. Retrospective single-center review of patients undergoing TAVR (9/2014 to 6/2021). Patients with pre-existing complete AVB or PPM were excluded (N = 1). The relationship between described adult risk factors for AVB and primary outcome of new conduction abnormality was assessed. Of 28 cases (Ages 3.5-22 y), 50% were male and 43% had isolated AoV disease, and the remainder with multilevel obstructive left-sided heart disease (29%) or complex congenital heart disease (29%). Baseline conduction abnormality was present in 57% (16/28), with right bundle branch block the most prevalent (9, 56%). Post-TAVR, acute- and late-onset conduction abnormalities occurred in 9 and 2 patients, respectively, and resolved in 8/11 patients during follow-up. One patient required PPM for complete heart block. There was no association between new conduction abnormality and previously reported adult risk factors-baseline RBBB, membranous septum length, valve implantation depth, or degree of valve oversizing. There was no relationship between outcome and baseline conduction abnormality nor history of multiple AoV interventions. In our pediatric series, AVB requiring PPM was rare following TAVR, with an incidence 3.6%-lower than average rates reported in adult literature. We identified no association of conduction abnormality with described adult risk factors.