Risk for Recurrent VTE in Patients With Subsegmental PE
- Patients who had isolated subsegmental pulmonary embolism (PE) without proximal deep venous thrombosis on repeated bilateral ultrasonography and were managed without anticoagulation had higher-than-expected rates of recurrent venous thromboembolism over the 90-day follow-up.
- These results support the use of anticoagulation in patients with subsegmental PE at this time.
What is the rate of recurrent venous thromboembolism (VTE) in patients with subsegmental pulmonary embolism (PE) managed without anticoagulation?
The investigators conducted a multicenter prospective cohort study. (ClinicalTrials.gov: NCT01455818) at 18 sites between February 2011 and February 2021. Patients with isolated subsegmental PE were enrolled. At diagnosis, patients underwent bilateral lower extremity venous ultrasonography, which was repeated 1 week later if results were negative. Patients without deep venous thrombosis (DVT) did not receive anticoagulant therapy. The primary outcome was recurrent VTE during the 90-day follow-up period. The Kaplan–Meier method was used to calculate the survival estimates. These estimates were used to calculate the cumulative incidence rate and the associated 95% confidence interval (CI). A cumulative incidence plot was created for graphical presentation of the time to the primary outcome.
Recruitment was stopped prematurely because the predefined stopping rule was met after 292 of a projected 300 patients were enrolled. Of the 266 patients included in the primary analysis, the primary outcome occurred in eight patients, for a cumulative incidence of 3.1% (95% CI, 1.6-6.1%) over the 90-day follow-up. The incidence of recurrent VTE was 2.1% (95% CI, 0.8-5.5%) and 5.7% (95% CI, 2.2-14.4%) over the 90-day follow-up in patients with single and multiple isolated subsegmental PE, respectively. No patients had a fatal recurrent PE.
The authors concluded that patients with subsegmental PE who did not have proximal DVT had a higher-than-expected rate of recurrent VTE.
This study reports that patients who had isolated subsegmental PE without proximal DVT on repeated bilateral ultrasonography and were managed without anticoagulation had higher-than-expected rates of recurrent VTE over the 90-day follow-up. This study can inform patients and clinicians about the risks of managing isolated subsegmental PE without anticoagulation. While a subgroup of patients with lower risk for recurrent events might be identifiable in future studies, these results support the use of anticoagulation in patients with subsegmental PE.
Keywords: Anticoagulants, Diagnostic Imaging, Primary Prevention, Pulmonary Embolism, Risk, Ultrasonography, Vascular Diseases, Venous Thromboembolism, Venous Thrombosis
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