Anticoagulation and venous thromboembolism in patients aged 90 years and older: Data from the RIETE registry

Background: Age is a major risk factor for venous thromboembolism (VTE), yet patients aged ≥90 years are under-represented in clinical trials of anticoagulant therapy. The objectives were to describe and compare patient clinical characteristics, treatments, and outcomes (VTE recurrence, bleeding, and mortality) during the first 3 months of anticoagulation between VTE patients aged ≥90 years and those aged <90 years.

Methods: We analyzed data from the Registro Informatizado Enfermedad TromboEmbὀlica (RIETE), an ongoing global observational registry of patients with objectively confirmed acute VTE.

Results: From January 2001 to October 2022, 96,701 patients were registered in RIETE, of whom 3262 (3.4%) were aged ≥90 years. Patients aged ≥90 years were less likely to be men, and to have experienced cancer or recent surgery, but more likely to manifest immobility, chronic heart failure, anemia, renal insufficiency, or dementia than those aged <90 years. Most (99.6%) patients aged ≥90 years were receiving anticoagulant therapy. During the first 3 months, 26 patients aged ≥90 years developed VTE recurrences, 116 experienced major bleeding, and 564 died. Among patients initially presenting with pulmonary embolism (PE), deaths due to PE exceeded those due to fatal bleeding (76 vs. 19). Among those initially presenting with isolated deep-vein thrombosis (DVT), it was the reverse (2 vs. 11 deaths).

Conclusions: In patients aged ≥90 years, the difference in the outcome of anticoagulant treatment depending on the initial presentation of VTE could suggest a need for different management approaches. Clinical trials evaluating the optimal duration of anticoagulation according to initial VTE presentation are warranted to limit excess deaths in this particular population.