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

Area of Science:

• Cardiology
• Pediatric Cardiology
• Interventional Cardiology

Background:

• Transcatheter aortic valve replacement (TAVR) is an established alternative to surgical aortic valve (AoV) replacement in adults.
• While atrioventricular block (AVB) requiring permanent pacemaker (PPM) placement is known in adult TAVR, its incidence and risk factors in pediatric and young adult populations are not well-defined.

Purpose of the Study:

• To describe the incidence and characteristics of post-TAVR conduction abnormalities in children and young adults.
• To assess the relationship between known adult risk factors for AVB and the occurrence of new conduction abnormalities in this younger cohort.

Main Methods:

• Retrospective single-center review of patients aged 3.5-22 years undergoing TAVR between September 2014 and June 2021.
• Exclusion of patients with pre-existing complete AVB or PPM.
• Assessment of new conduction abnormalities and correlation with baseline characteristics and previously identified adult risk factors.

Main Results:

• Of 28 patients, 57% had baseline conduction abnormalities, most commonly right bundle branch block (RBBB).
• Post-TAVR, 11 patients (39%) developed new conduction abnormalities, with most resolving spontaneously. Only one patient required PPM for complete heart block.
• No association was found between new conduction abnormalities and adult risk factors such as baseline RBBB, implantation depth, or valve oversizing.

Conclusions:

• Atrioventricular block requiring PPM is rare following TAVR in children and young adults, with an incidence lower than reported in adults.
• Established adult risk factors for AVB do not appear to predict conduction abnormalities in the pediatric TAVR population.