Thrombolytic Use and Outcomes in Pediatric Congenital and Acquired Heart Disease: A Single-Center Quaternary Care Experience.

Patients with congenital heart disease (CHD) have a propensity towards thrombotic events (TE) that can carry significant hemodynamic impact, morbidity, and mortality. Tissue plasminogen activator (tPA), a fibrinolytic agent, can be used in the acute treatment of thrombotic conditions but its use in pediatric patients with heart disease is not well described. We present our single-center experience of tPA infusion use in pediatric patients with congenital and acquired heart disease. This was a retrospective cohort study conducted between January 2008 and January 2024. Chart review was conducted to collect variables of interest. The primary outcome was thrombus resolution; secondary outcomes included major and minor bleeding events and in-hospital mortality. We identified 33 patients with 40 TE instances. 70% of patients had single ventricle circulation with cavopulmonary circulation being the most common thrombus location (39% of TE). The overall mortality among all patients was 39%; all patients with a major bleed experienced mortality. Major bleeding occurred in 12.5% of TE, associated with higher maximum tPA dose administered (0.2 vs. 0.1 mg/kg/hr, p = 0.036) and with recent surgery within 14 days of tPA administration (p = 0.0058). Fibrinogen nadir (< 150 mg/dL) and INR > 2 were associated with major bleeding (fibrinogen OR 13.5, CI 1.3-138.6, p = 0.02; INR OR 11.6, CI 1.5-92.1, p = 0.03). In our single-center experience, we demonstrated TE resolution of 58% and overall major bleeding rate of 12.5%. We also demonstrated the importance of tPA dosing, considering recent surgical intervention when determining tPA candidacy, and possible biomarkers to predict bleeding risk. Further investigation with a larger cohort is necessary.