Venous thromboembolism in patients aged ≥90 years: Trends in clinical features, treatment, and outcomes-RIETE registry

Background: Data on patients aged 90 or older are rare. This study aims to describe clinical characteristics, treatment strategies, and clinical outcomes (rates of VTE recurrence, major bleeding, and mortality), during the first 3 months of anticoagulant treatment for VTE, depending on the treatment period.

Methods: We analyzed data from RIETE, an ongoing global observational registry of patients with objectively confirmed acute VTE, grouped in 5-year intervals (2004-2008, 2009-2013, 2014-2018, and 2019-2023).

Results: Among 3477 patients aged 90 or older, clinical characteristics have changed over time (less heart failure, more dementia), with an increase in PE diagnoses from 57% in 2004-2008 to 69% in 2019-2023 (p-trends <0.001), but of lower severity. For long-term therapy, there was an increase in patients receiving DOACs (p-trends <0.001), with a decrease in patients on VKAs (p-trends <0.001). Mortality and fatal PE respectively showed a temporal trend: 19% and 4% in 2004-2008 to 15% (p-trends 0.026) and 2% (p-trends 0.002) in 2019-2023. In multivariable analyses, fatal PE declined from 2004 to 2023 (HR: 0.91; 95% CI: 0.87-0.96). Compared with VKAs, receiving LMWH during the first 3 months of anticoagulation was associated with a higher risk of major bleeding (HR: 1.91; 95% CI: 1.16-3.14) and death (HR: 2.20; 95% CI: 1.71-2.82). The effect seems to be the opposite for DOACs (HR: 0.50; 95% CI: 0.20-1.30 for major bleeding; HR: 0.86; 95% CI: 0.57-1.28 for all-cause death).

Conclusions: Fatal PE declined from 2004 to 2023, despite an increase in the diagnosis of PE. Since the arrival of DOACs, there seems to be better management of the therapeutic and diagnostic aspects of VTE in this population, underlining the need for further research on patients aged 90 or older.