Venous thromboembolism characteristics, treatment and outcomes in young adults: findings from the Registro Informatizado de Enfermedad TromboEmbólica registry

BACKGROUND: Venous thromboembolism (VTE) is rare in patients younger than 21 years. Young adults aged 18-21 years are frequently included in adult VTE studies, whereas pediatric VTE studies include patients aged up to either 18 or 21 years. The clinical characteristics of young adult VTE patients have not been well defined.

AIM: We aimed to highlight any unique characteristics or treatment considerations that may apply to young adult VTE patients.

METHODS: Data from the prospective international RIETE registry were used. Patients were stratified into sub-cohorts according to age. The clinical characteristics, risk factors, management and outcomes of young adult VTE patients were compared with those of adolescents aged 12-18 years and adults older than 21 years.

RESULTS: Of 104,253 RIETE patients enrolled until August 2022, 234 were adolescents and 884 young adults. Less cases of pulmonary embolism were reported in adolescents (P < 0.001). Estrogen use was a common risk factor, more prevalent in adolescents and young adults (P < 0.001), whereas active cancer and immobilization were uncommon in either. Most patients were initially treated with low-molecular-weight heparin. VTE recurrence, major bleeding and all-cause mortality rates were comparably low among adolescents and young adults. None of the patients younger than 21 years died from VTE recurrence.

CONCLUSION: Young adults have some distinctive VTE risk factors. While VTE presentation may be similar among young adults as compared to older patients, the outcomes of patients younger than 21 years are more favorable.