Clinical question: Is the risk of recurrence for a venous thromboembolism (VTE) acquired as an inpatient higher than other reversible risk factors?
Background: In patients with acute VTE, transient provoking factors place patients at lower risks for recurrent VTE, while persistent factors (that is, cancer) increase risk for recurrence. Unprovoked VTE places patients at intermediate to high risk, but few data are present for VTE experienced while in the hospital.
Study design: Single-center, population-based, prospective cohort study.
Setting: Tromso, Norway.
Synopsis: Using repeat health surveys from 1994 to 2012, researchers followed 822 patients with a validated, first-lifetime VTE. Hospital-related VTE was defined as a VTE within 8 weeks of hospitalization related to medical illness, surgery, or in patients with active cancer.
This global definition of hospital-related VTE was not associated with an increased risk of recurrent VTE (hazard ratio, 0.99; 0.69-1.41). However, in separate groups, the cumulative risk of recurrence after 5 years in hospital-related VTE due to medical illness was similar to nonhospital-related VTE (20.1% vs. 18.4%), higher than VTE related to surgery (11%), and lower than VTE related to cancer (27.4%).
Risk-adjusted analyses maintained these differences in recurrence risk dependent on reason for hospitalization (cancer, medical illness, surgery). When compared with non-hospital VTE, however, hospital-related VTE was associated with a threefold higher risk of death.
Study limitations included being from a single center, possibly underpowered due to low number of events.
Bottom line: Hospital-related VTE has a high risk of recurrence, but risk level is variable and dependent on the reason for hospitalization.
Citation: Bjøri E, Arshad N, Johnsen HS, Hansen J-B, Brækkan SK. Hospital-related first venous thromboembolism and risk of recurrence [published online ahead of print, Sept. 2, 2016]. J Thromb Haemost.
Dr. Ciarkowski is a clinical instructor at the University of Utah School of Medicine and an academic hospitalist at the University of Utah Hospital.