Risk of recurrent venous thromboembolism and bleeding in patients with interstitial lung disease: a cohort study

Interstitial lung disease (ILD) encompasses various parenchymal lung disorders, which has the potential to increase the risk of venous thromboembolism (VTE). To evaluate, in patients with ILD and VTE, the risk of recurrent VTE during follow-up after stopping anticoagulation. This was a cohort of patients with a first VTE recruited between 1997 and 2015. The primary outcome was adjudicated fatal or nonfatal recurrent VTE after stopping anticoagulation. Main secondary outcomes were major or clinically relevant non-major bleeding under anticoagulation. Among 4314 patients with VTE, 50 had ILD diagnosed before VTE. Of these, anticoagulation was stopped in 30 patients after a median duration of 180 days and continued indefinitely in 20 patients. During a median follow-up of 27.8 months after anticoagulation discontinuation, recurrent VTE occurred in 15 on 30 patients (annual incidence of 19.2 events per 100-person-years [95%CI 12.0-29.3], case-fatality rate of 6.7% [95%CI 1.21-29.8]). The risk of recurrence was threefold higher when VTE was unprovoked and case-fatality rate of recurrence was increased by 3 when VTE index was PE. During the anticoagulant period, (median duration of 8.6 months), 6 patients had a major or clinically relevant bleeding (annual incidence of 7.3 events per 100-person-years [95%CI 3.4-15.1], case-fatality rate of 16.7% [95%CI 3.0-56.4]). In patients with ILD, the risk of recurrent VTE after stopping anticoagulation and the risk of bleeding under anticoagulation were very high. Our results suggest that anticoagulation should not be prolonged beyond 3-6 months of anticoagulation in most of cases.