Presentation of acute venous thromboembolism (VTE) is comparable between young adults and older adults, but risk factors differ between these patient populations, according to research published in the Journal of Thrombosis and Haemostasis.

Researchers used data from an ongoing, prospective, non-interventional international registry, RIETE (Registro Informatizado Enfermedad TromboEmbólica), to assess clinical characteristics, risk factors, and management and outcomes during anticoagulation in adolescents (12-18 years), young adults patients (18-21 years), and older adults (>21 years) with acute VTE.

The study identified 104,253 patients with VTE enrolled in RIETE as of August 2022. Of those, there were 234 adolescents (0.22%; mean age, 16±1 years; 45% male), 884 young adults (0.85%, mean age, 20±1 years; 36% male), and 103,103 older adults (98.89%; mean age, 65±17 years; 50% male).

Continue Reading

Initial presentation of VTE as pulmonary embolism (PE) with or without concomitant deep vein thrombosis (DVT) was more common in older adults (52%) and less common in adolescents (30%) compared with young adults (47%; P <.01 and P <.001, respectively).

The initial presentation of VTE as lower limb DVT was similar between young adults and older adults (both 40%) and more common in adolescents (52%; P <.001). Initial presentation of VTE as upper extremity DVT was similar between young adults and adolescents (both 11%) and less common in older adults (4.1%; P <.001).

Estrogen use was the most prevalent risk factor for VTE in young adult (48%) and a common risk factor between this group and adolescents (31%;  P <.001). Active cancer and immobilization ≥4 days were more common in older adults than younger adults (18% vs 2.6%; P <.001; 22% vs 13%; P <.001, respectively).

Most patients in all groups were initially treated with low-molecular-weight heparin (87% of adolescents; 87% of older adults vs 80% of young adults; P <.001). Rates of VTE recurrence, major bleeding, and all-cause mortality were similar between adolescents and young adults; older adults experienced more major bleeding events and higher all-cause mortality than younger adults (3.58 vs 0.86 events per 100 patient years; P <.001; 12.0 vs 0.86 events per 100 patient years; P <.001, respectively).

“Although often grouped with adults in VTE studies, real world data from the RIETE registry indicates that patients aged 18-21 years have some different VTE risk factors, including higher prevalence of hormone use and thrombophilia, and lower rates of active cancer and immobilization,” the authors wrote in their report.

Limitations of the study included its observational nature, lack of central adjudication of events and outcomes, and differences in the sizes of the sub-cohorts.


Cohen O, Barg AA, Nowak-Göttl U, et al. Venous thromboembolism characteristics, treatment and outcomes in young adults: Findings from the RIETE registry. J Thromb Haemost. Published online July 3, 2023. S1538-7836(23)00517-2. doi:10.1016/j.jtha.2023.06.031