Infection as cause of immobility and occurrence of venous thromboembolism: analysis of 1635 medical cases from the RIETE registry

Several risk assessment models include infection and immobility among the items to be considered for venous thromboembolism (VTE) prevention. However, information on patients with infection leading to immobility and developing VTE are limited, as well as on the role of specific types of infection. Data were collected from the worldwide RIETE registry, including patients with symptomatic objectively confirmed VTE, and followed-up for at least 3 months. The overall population of RIETE at June 2013 (n = 47,390) was considered. Acute infection leading to immobility was reported in 3.9 % of non-surgical patients. Compared with patients immobilized due to dementia, patients with infection had a shorter duration of immobilization prior to VTE (less than 4 weeks in 94.2 vs. 25.9 % of cases; p < 0.001). During the 3-month follow-up, VTE patients with infection versus those with dementia had a lower rate of fatal bleeding (0.5 vs. 1.1 %; p < 0.05) or fatal PE (1.7 vs. 3.5 %; p < 0.01). Patients with respiratory tract infections had more likely PE as initial VTE presentation than other types of infection (62.3 vs. 37.7 %; p < 0.001). Significantly more patients with pneumonia than those with other respiratory infections had received VTE prophylaxis (50.2 vs. 30.6 %; p < 0.001). Following VTE, patients with sepsis showed a significantly higher risk of fatal bleeding. Based on our real-world data, infection seems to contribute to the pathogenesis of VTE by accelerating the effects of immobility. Its role as VTE risk factor probably deserves further attention and specific assessment in order to optimize VTE prophylaxis and treatment.