Risk of recurrent venous thromboembolism is 3% in patients with subsegmental pulmonary embolism who are not anticoagulated

Reference

Le Gal G, Kovacs MJ, Bertoletti L, et al, for the SSPE Investigators. Risk for recurrent venous thromboembolism in patients with subsegmental pulmonary embolism managed without anticoagulation. Ann Intern Med 2022;175(1):29-35.

Synopsis

The clinical significance of subsegmental pulmonary embolism (PE) is unknown and current guidelines suggest that low-risk patients with this diagnosis may not require anticoagulation. In this multisite study, investigators enrolled patients presenting to emergency departments with newly diagnosed single or multiple subsegmental PEs. Those with active cancer or a history of venous thromboembolism (VTE) and those who required oxygen therapy or hospitalization were excluded. Overall, 292 patients were enrolled — the mean age was 56 years, 53% were female, and the most common presenting symptoms were chest pain and shortness of breath. All patients underwent venous ultrasonography at day 0 (and again at days 5 to 7 if initial result was negative). Those without evidence of proximal deep venous thrombosis (DVT) were managed without anticoagulation. Of the 266 patients with isolated subsegmental PE without evidence of proximal DVT, 8 patients (3.1%) had recurrent VTE over the 90-day follow-up period. There were no deaths due to recurrent PEs. The incidence of recurrent VTE was higher with multiple subsegmental PEs than with a single subsegmental PE (5.7% vs 2.1%). Additionally, patients older than 65 years had a higher incidence than younger patients (5.5% vs 1.8%). Of note, recruitment into this study was stopped before the targeted 300 patients due to a higher-than-expected number of events.