The Impact of Pulmonary Vascular Obstruction on the Risk of Recurrence of Pulmonary Embolism: A French Prospective Cohort

Background We aimed to assess whether high pulmonary vascular obstruction index (PVOI) measured at the time of pulmonary embolism (PE) diagnosis is associated with an increased risk of recurrent venous thromboembolism (VTE). Study Design and Methods French prospective cohort of patients with a symptomatic episode of PE diagnosed with spiral computerized tomography pulmonary angiography (CTPA) or ventilation-perfusion (V/Q) lung scan and a follow-up of at least 6 months after anticoagulation discontinuation. PVOI was assessed based on the available diagnostic exam (V/Q lung scan or CTPA). All patients had standardized follow-up and independent clinicians adjudicated all deaths and recurrent VTE events. Main outcome was recurrent VTE after stopping anticoagulation. Results A total of 418 patients with PE were included. During a median follow-up period of 3.6 (1.2–6.0) years, 109 recurrences occurred. In multivariate analysis, PVOI ≥ 40% was an independent risk factor for recurrence (hazard ratio 1.77, 95% confidence interval 1.20–2.62, p < 0.01), whether PE was provoked by a major transient risk factor or not. A threshold at 41% was identified as the best value associated with the risk of recurrence 6 months after stopping anticoagulation (area under curve = 0.64). Conclusion PVOI ≥ 40% at PE diagnosis was an independent risk factor for recurrence VTE. Further prospective validation studies are needed.

Predictors for Residual Pulmonary Vascular Obstruction after Unprovoked Pulmonary Embolism: Implications for Clinical Practice—The PADIS-PE Trial

Background We aimed to identify risk factors for residual pulmonary vascular obstruction after a first unprovoked pulmonary embolism (PE). Methods Analyses were based on data from the double-blind randomized “PADIS-PE” trial that included 371 patients with a first unprovoked PE initially treated during 6 uninterrupted months; all patients underwent baseline ventilation–perfusion lung scanning at inclusion (i.e., after 6 months of anticoagulation). Each patient's pulmonary vascular obstruction indexes (PVOIs) at PE diagnosis and at inclusion were centrally assessed. Results Among the 371 included patients, residual PVOI was available in 356 patients, and 150 (42.1%) patients had PVOI ≥ 5%. At multivariable analysis, age > 65 years (odds ratio [OR], 2.81, 95% confidence interval [CI], 1.58–5.00), PVOI ≥ 25% at PE diagnosis (OR, 3.53, 95% CI, 1.94–6.41), elevated factor VIII (OR, 3.89, 95% CI, 1.41–10.8), and chronic respiratory disease (OR, 2.18, 95% CI, 1.11–4.26) were independent predictors for residual PVOI ≥ 5%. Patients with ≥ 1 of these factors represented 94.5% (123 patients) of all patients with residual PVOI ≥ 5%. Conclusion Six months after a first unprovoked PE, age > 65 years, PVOI ≥ 25% at PE diagnosis, elevated factor VIII, or chronic respiratory disease were found to be independent predictors for residual pulmonary vascular obstruction. Clinical Trials Registration URL: http://www.controlled-trials.com. Unique identifier: NCT00740883.