The rate of recurrent venous thromboembolism is higher than expected for patients with subsegmental pulmonary embolism managed without anticoagulation who do not have proximal deep venous thrombosis, according to a study published online Nov. 23 in the Annals of Internal Medicine.
Grégoire Le Gal, M.D., Ph.D., from the Centre Hospitalier Régional et Universitaire de Brest in France, and colleagues examined the rate of recurrent venous thromboembolism in patients with subsegmental pulmonary embolism managed without anticoagulation in a prospective cohort study conducted at 18 sites between February 2011 and February 2021. Patients underwent bilateral lower-extremity venous ultrasonography at diagnosis; if results were negative, it was repeated one week later. Anticoagulant therapy was not given to patients without deep vein thrombosis.
After the predefined stopping rule was met when 292 of a projected 300 patients were enrolled, recruitment was stopped prematurely. The researchers found that the primary outcome of recurrent venous thromboembolism during the 90-day follow-up period occurred in eight of 266 patients included in the primary analysis, for a cumulative incidence of 3.1 percent. For patients with single and multiple isolated subsegmental pulmonary embolism, the incidence of recurrent venous thromboembolism was 2.1 and 5.7 percent, respectively, during the 90-day follow-up. None of the patients had a fatal recurrent pulmonary embolism.
“Our study can inform patients and clinicians about the risks of managing isolated subsegmental pulmonary embolism without anticoagulation,” the authors write.