Abstract 4144725: Frequency of Occurrence of, and Risk Factors for, Thromboembolism Before and After Cardiac Surgery in Children with Surgical Congenital Heart Disease: A Case-Control Study

Background: Thromboembolism (TE) is a common complication in pediatric congenital heart disease (CHD) requiring cardiac surgery. Data describing the frequency, timing, and factors associated with TE and TE recurrence are limited. Aim: To describe frequency, occurrence, and risk factors for, TE before and after cardiac surgery in children with surgical CHD. The secondary aim was to determine frequency of TE recurrence. Methods: A single-center retrospective study (10/2020-11/2023). Patients <18 years of age with radiologically confirmed TE either within 12 months before or after cardiac surgery were compared with randomly selected patients without TE (1:2 ratio). Data included age, CHD diagnosis/surgery type, hemodynamics, hematologic indices, near-infrared spectroscopy (NIRS), infection, respiratory status, length of stay, mortality, timing/location of incident/recurrent TEs. Descriptive and inferential (Mann-Whitney U for continuous, Chi-square for categorical variables) statistics were utilized. Results: Among 302 patients, 45(15%) developed a TE: 16(35.6%) within 12 months before and 29(64.4%) within 12 months after cardiac surgery. TE types were: 11(24.4%) arterial, 32(71.1%) venous, and 2(4.5%) intracardiac. In univariate analyses, age <12 months (p=0.01), single-ventricle (p=0.03), intra-cardiac lines (p=0.02), cardiac-catheterization (p<.001), mechanical ventilation (p<.001), infection (p=<.001), mechanical circulatory support (p=.003), lower cerebral NIRS (p<.001), lower somatic NIRS (p<.001), and higher heart rate (p<.001) were associated with TE. Age <30 days (p<.001), mechanical ventilation (p<.001), and infection (p=.03) were associated with TE before surgery. Single-ventricle (p=0.003), central-venous/intracardiac lines (p=0.04), cardiac-catheterization (p<.001), mechanical ventilation (p<.001), infection (p=.03), lower cerebral NIRS (p<.001), lower somatic NIRS (p<.001), higher heart rate (p<.001) and post-op LOS (p<.001) were associated with TE after surgery. Patients with TE had a longer median (IQR) post-op LOS 20[8-48] vs. 6[4-12] days, p<.001, and higher mortality (11%vs.2.2%,p=0.04). Recurrent TE occurred in 10(22.2%). Conclusions: In children with CHD, the frequency of occurrence of TE before/after surgery and TE recurrence is high. Putative risk factors for the development of TE have been identified and should be further evaluated in multivariable models via future collaborative studies.