Juan Antonio Aviña-Zubieta
Patients with ankylosing spondylitis demonstrate an increased risk for venous thromboembolism, particularly in the first year after diagnosis, according to findings published in the Annals of the Rheumatic Diseases.
“Several studies have demonstrated an increased risk of VTE among patients with chronic inflammatory and autoimmune diseases,” Juan Antonio Aviña-Zubieta, MD, MSc, PhD, FRCP, of the University of British Columbia, and colleagues wrote. “A number of studies have demonstrated an increased risk of cardiovascular and overall mortality in patients with AS but there is a paucity of literature on the incidence of VTE in this population.”
To analyze the risk for venous thromboembolism among patients with AS compared with the general population, Aviña-Zubieta and colleagues studied data from Population Data BC, the provincial health care database of British Columbia, Canada, that includes all outpatient medical visits, hospital admissions and discharges, interventions, investigations, demographic data, cancer registry and vital statistics for all residents.
Patients with AS demonstrate an increased risk for venous thromboembolism, particularly in the first year after diagnosis, according to findings.
The researchers conducted a matched cohort analysis of incident pulmonary embolism, deep venous thrombosis and overall venous thromboembolism among patients with AS, and compared them with randomly selected members of the general population without AS. The incident cohort included 7,190 patients with AS, representing first-time diagnoses between January 1996 and December 2012. These were matched based on age, sex and entry time to 71,900 comparison cases in the general population, with a mean follow-up time of 6.2 years. The researchers determined incidence rates of venous thromboembolism using Cox models.
According to the researchers, out of 7,190 patients with AS, 35 developed pulmonary embolism while 47 developed deep venous thrombosis. Among patients with AS, the incident rates for pulmonary embolism, deep venous thrombosis and venous thromboembolism were 0.79, 10.6 and 1.56 per 1,000 person-years, respectively. Among the comparison cases in the general populations, these incidence rates were 0.4, 0.5 and 0.77 respectively.
Aviña-Zubieta and colleagues noted that this corresponds to fully adjusted HRs of 1.36 (95% CI, 0.92-1.99) for pulmonary embolism, 1.62 (95% CI, 1.16-2.26) for deep vein thrombosis and 1.53 (95% CI, 1.16-2.01) for venous thromboembolism.
In addition, risks for all three outcomes were highest in the first year of AS diagnosis, with HRs of 2.88 (95% CI, 0.87-9.62) for pulmonary embolism, 2.2 (95% CI, 0.8-6.03) for deep vein thrombosis and 2.1 (95% CI, 0.88-4.99) for venous thromboembolism.
“Clinicians should have an increased awareness of this complication so that they can provide the best care possible to their patients,” Aviña-Zubieta said in a press release. “These results call for awareness of this complication, increased vigilance and preventive intervention by controlling the inflammatory process or by anticoagulation in a high-risk ankylosing spondylitis population.” – by Jason Laday
Disclosure: Aviña-Zubieta reports no relevant financial disclosures. Please see the study for all other relevant financial disclosures.