Clinical experience with alteplase in the management of intracardiac and major cardiac vessels thrombosis in pediatrics: a case series

BACKGROUND AND OBJECTIVES: Experience with alteplase in pediatric patients is limited and recommendations are extrapolated from adult data. Comprehensive guidelines on the management of thromboembolic events in this group are lacking. We assessed the efficacy and safety of alteplase (recombinant tissue plasminogen activator) in the management of intracardiac and major cardiac vessel thrombosis in pediatric patients. METHODS: All pediatric patients, 14 years of age and younger, with intracardiac or major cardiac vessel thrombus who were treated with alteplase from 1997 to 2004 at our tertiary care institute were identified through the pharmacy database. Patient data were retrospectively evaluated for the efficacy and safety of altepase. RESULTS: Five cases were eligible out of nineteen who received alteplase. Patient ages ranged from 40 days to 13 years. The initial dose of alteplase ranged from 0.3 to 0.6 mg/kg followed by a continuous infusion in three patients with a dosage range between 0.05 and 0.5 mg/kg/hr, while intermittent infusion was used in the other two patients. The duration of therapy ranged from 2 to 4 days. By the end of the treatment, two patients had complete resolution of thrombus and one had partial resolution. Two patients failed to respond and had “old” thrombus. Major bleeding events were reported in three patients. The rest had minor bleeding events. CONCLUSION: Alteplase may effectively dissolve intracardiac thrombi, particularly when freshly formed. Continuous infusion for a long duration appears to be associated with an increased risk of major bleeding. Optimal dose and duration of infusion are still unknown.