PB0285 - Use of systemic thrombolysis in pediatric cardiac-related thrombosis; A retrospective cohort study

Background: In children with cardiac disease, intracardiac and caval thromboses can be life threatening, requiring rapid recanalization. Often, catheter-directed thrombolysis may not be technically feasible, and systemic thrombolysis (s-tPA) is considered, albeit with limited data to inform its use.

Aims: Describe the use of s-tPA in pediatric cardiac-related thrombosis.

Methods: All patients between the age of 0-21 who received s-tPA for a cardiac-related thrombus were included. Data were collected via chart review. An objective decrease in size of the thrombus, improvement in cardiac function or detection of new flow on imaging was defined as a clinically meaningful response. Dose of s-tPA was categorized as high (=/> 0.1 mg/kg/hr) and low ( < 0.1 mg/kg/hr). Descriptive statistics were computed for all demographic and clinical variables. Categorical variables were compared using a Chi-square test or Fisher’s Exact test while Student’s t-test or the Wilcoxon-Mann-Whitney test was used for categorical variables.

Results: Twenty patients with cardiac and caval clots were included, the most common location being left ventricle (30%). Majority had congenital heart disease (n=11, 55%). Patients and thrombus characteristics are summarized in table 1 and the covariate analysis in table 2. 75% patients (n=15) had clinically meaningful response. The median duration of s-tpa was 19 hours (min 8, max 88). Over half of the cohort (n=11, 55%) received high dose s-tPA. Neither the location of thrombus (p=0.7), s-tPA dose (p=1.0) or duration (p=0.16) had an effect on the outcome. Four minor (20%) and one major bleeding event (5%) occurred with no relation to dose (p=0.59) or duration (p=0.11) of s-tPA use.

Conclusion(s): We conclude that the use of s-tPA in pediatric-cardiac related thrombosis may be an effective and safe management alternative if endovascular thrombolysis is not feasible. Furthermore, lower dose s-tPA may be equally effective in maintaining a favorable outcome in efforts to mitigate the bleeding risk.