The impact of Initial Pulmonary Vascular Obstruction on the Risk of Recurrence of Pulmonary Embolism: a French prospective cohort

Background: Anticoagulation is the mainstay of pulmonary embolism (PE) therapy, but it exposes patients to a risk of bleeding. Recent studies identified a high pulmonary vascular obstruction index (PVOI) as a risk factor for recurrent venous thromboembolism (VTE). Method: We used data from a French prospective cohort gathering consecutive PE events. PVOI was assessed based on the available diagnostic exam (V/Q lung scan or CT-spiral scan) at the time of PE diagnosis. All consecutive patients aged 18 or older were included except those with unavailable diagnosis exam or who received anticoagulation for other purpose than VTE. All patients had standardized follow-up, and independent clinicians adjudicated all events. Main outcome was recurrence of thromboembolic disease after stopping the anticoagulation. Results: 418 patients with PE were included, 293 (70,1%) being unprovoked, 89 (21.3%) provoked by major transient risk factor and 36 (8.6%) with active cancer. Mean follow-up after stopping anticoagulation was 3.60±2.69 years, during which 78 deaths and 109 recurrent VTE occurred. In multivariate analysis, PVOI ≥ 40% was an independent risk factor for recurrent VTE (Hazard ratio 1.77, 95%CI 1.2-2.62, p Conclusion: PVOI ≥ 40% at PE diagnosis is associated with a higher risk of recurrence. This information may help clinician to guide the duration of anticoagulation.