Abstract
BACKGROUND: No prior reports documenting the safety and diagnostic yield of cardiac catheterization and endomyocardial biopsy (EMB) in heart transplant recipients include multicenter data. METHODS: Data on the safety and diagnostic yield of EMB procedures performed in heart transplant recipients were recorded in the Congenital Cardiac Catheterization Outcomes Project database at 8 pediatric centers during a 3-year period. Adverse events (AEs) were classified according to a 5-level severity scale. Generalized estimating equation models identified risk factors for high-severity AEs (HSAEs; Levels 3-5) and non-diagnostic biopsy samples. RESULTS: A total of 2,665 EMB cases were performed in 744 pediatric heart transplant recipients (median age, 12 years [interquartile range, 4.8, 16.7]; 54% male). AEs occurred in 88 cases (3.3%), of which 28 (1.1%) were HSAEs. AEs attributable to EMB included tricuspid valve injury, transient complete heart block, and right bundle branch block. Amongst 822 cases involving coronary angiography, 10 (1.2%) resulted in a coronary-related AE. There were no myocardial perforations or deaths. Multivariable risk factors for HSAEs included fewer prior catheterizations (p = 0.006) and longer case length (p < 0.001). EMB yielded sufficient tissue for diagnosis in 99% of cases. Longer time since heart transplant was the most significant predictor of a non-diagnostic biopsy sample (p < 0.001). CONCLUSIONS: In the current era, cardiac catheterizations involving EMB can be performed in pediatric heart transplant recipients with a low AE rate and high diagnostic yield. Risk of HSAEs is increased in early post-transplant biopsies and with longer case length. Longer time since heart transplant is associated with non-diagnostic EMB samples.