Letter-To-The-Editor: Long-term outcomes of patients with isolated subsegmental pulmonary embolism managed without...

The management of patients with subsegmental pulmonary embolism (SSPE) is controversial. The long-term risk of recurrent venous thromboembolism (VTE) in patients with SSPE managed without anticoagulation is unknown. We sought to establish the long-term incidence of recurrent VTE and clinically relevant bleeding complications in this patient population.

We performed a retrospective cohort study of patients enrolled in the SSPE prospective management cohort study included at The Ottawa Hospital between 2011 and 2021. The outcomes included major recurrent VTE (proximal deep vein thrombosis or pulmonary embolism) and clinically relevant bleeding (major + clinically relevant non-major bleeding). Incidence rates along with their 95 % confidence intervals (CI) for the primary and secondary outcome measures were computed by performing time-to-event analyses.

A total of 138 patients with SSPE were included in the analysis. Mean age was 57 ± 15.5 years and 50.7 % were female. Median follow-up period was 69 months (IQR: 44-96 months). Overall, recurrent major VTE occurred in 15 out of the 138 patients leading to an incidence of 1.9 per 100 patient-years (95 % CI: 1.2-3.2). Clinically relevant bleeding was reported in 15 patients corresponding to a cumulative incidence of 1.9 per 100 patient-years (95 % CI: 1.1-3.1). Of these, 3 patients experienced major bleeding.

The long-term incidence of VTE is relatively low in patients with isolated SSPE managed without anticoagulation. Future studies are needed to assess the risk benefit ratio of anticoagulation in this patient population.