A nationwide study analyzed the incidence, mortality, and case fatality rates of acute pulmonary embolism in children and adolescents in the U.S.

In a recent study published in The Lancet Respiratory Medicine, investigators analyzed 5,733 hospital admissions for children and adolescents (ages 0 to 19 years) who were diagnosed with acute pulmonary embolism (PE). The annual incidence was 3.5 per 100,000 pediatric patients, with two peaks: infants younger than 1 year and adolescents aged 15 to 19 years. The in-hospital case fatality rate for PE was 4.5%.

Among patients with high-risk PE features, mortality was 25.3% in children under 10 years and 13.9% in adolescents aged 10 to 19 years. Patients who required veno-arterial extracorporeal membrane oxygenation (ECMO) had the highest case fatality rates, which exceeded 40% in children under 10 years and 30% in adolescents. Similarly, patients who experienced cardiac arrest or required systemic thrombolysis faced increased risks of both death and intracranial bleeding.

The risk of intracranial bleeding was highest among high-risk PE patients: It reached 8.1% in children under 10 years and 3.6% in adolescents. In contrast, among patients without high-risk features, intracranial bleeding rates were 2.5% in younger children and 0.5% in adolescents.

PE incidence was higher in female adolescents (13.3 per 100,000) than in males (7.7 per 100,000). However, male adolescents had a higher in-hospital case fatality rate (4.5%) compared with females (2.1%).

Beyond age and sex differences, the study found that PE-related hospitalizations were most commonly associated with cardiovascular disease, infections, and cancer. Lemierre syndrome, a rare but potentially fatal condition involving septic emboli, was identified in 1.3% of pediatric PE cases.

"Further research is warranted to improve our understanding of pulmonary embolism in children and adolescents," wrote Simon Wolf, MMed, of the Department of Angiology at the University Hospital Zurich, with colleagues. "First, prospective studies would improve the understanding of the timing of adverse events occurring during hospitalisation and, therefore, the potential causal relationship between comorbidities and acute pulmonary embolism. Second, longitudinal studies focusing on the postdischarge phase could assess functional outcomes and the burden of long-term sequelae after pulmonary embolism. Finally, interventional studies should identify optimal treatment regimens, including reperfusion strategies, across different age groups."

The researchers reported no competing interests.