Treatment and outcomes of thromboembolism in paediatric patients with cardiac disease in a cardiac ICU: a single-centre retrospective study

Introduction: Data on thromboembolism treatment and outcomes in children with cardiac disease are limited. We sought to characterise thromboembolism treatment and outcomes in paediatric patients with cardiac disease. Methods: A single-centre, retrospective cohort study of children, aged < 21 years, with cardiac disease admitted to a paediatric cardiac ICU from October 2020 to September 2024, diagnosed with acute symptomatic thromboembolism (radiologically confirmed first episode). We analysed demographics, thromboembolism characteristics, antithrombotic drug regimens, and outcomes (recurrent thromboembolism, clinically relevant bleeding). Results: Of 865 eligible patients, 75 (8.7%) developed acute symptomatic thromboembolism: 48 (64%) venous; 16 (21.3%) arterial; 9 (12%) intracardiac; 2 (2.7%) venous+arterial. Of 50 patients with venous or venous+arterial, 33 (66%) received anticoagulation in the acute phase. Of 18 patients with arterial or arterial+venous, 12 (66.7%) received anticoagulation in the acute phase. Recurrent thromboembolism occurred in 28 (37.3%) patients, more likely among single ventricle vs. biventricular physiology [OR 3.2 (95% CI 1.1 to 9.4), p = 0.04]. Clinically relevant bleeding occurred in 10 (13.3%) patients, mostly with concomitant antithrombotics (anticoagulation + antiplatelet) vs. monotherapy [6 (9.2%) vs. 4 (40.0%), p = 0.02] in the subacute phase of treatment. The literature review revealed limited data on treatment strategies. Conclusion: There is variation in the treatment strategy for thromboembolism in children with cardiac disease, with risk for thromboembolism, recurrent thromboembolism, and bleeding. Prospective multicentre studies are needed to extend preliminary findings on treatment strategies and risk factors.