Residual Pulmonary Vascular Obstruction Index Computed With Ventilation/Perfusion SPECT/CT Imaging to Predict the Risk of Venous Thromboembolism Recurrence in Patients With Pulmonary Embolism (PRONOSPECT)

Inclusion Criteria: * Patients ≥ 18 years, * who experienced an objectively proven PE, * who have been treated initially with anticoagulant therapy for 3 to 6 uninterrupted months (180 - 210 days) and for whom anticoagulation will not be prolonged. Exclusion Criteria: * Unwilling or unable to give written informed consent (protected adults, under tutorship or curatorship) * Patients deprived of their liberty by a judicial or administrative decision, patients undergoing psychiatric care by virtue of Articles L. 3212-1 and L. 3213-1 who are not covered by the provisions of Article L. 1121-8 and patients admitted to a health or social establishment for purposes other than research * No Social security affiliation * Isolated DVT * Pregnant women and parturients * Other indication for anticoagulant therapy (e.g. atrial fibrillation, mechanic valve) * Life expectancy \< 6 months * Any patients for whom there is a strong indication to treat longer than 6 months: * PE provoked by a major persistent factor (e.g. cancer) * Recurrent unprovoked PE PE provoked by a major transient risk factor (e.g. surgery with general anesthesia for greater than 30 min, confined to bed in hospital for at least 3 days with an acute illness, cesarean section) AND none of the following persistent factors : * BMI ≥ 30 * Chronic respiratory disease * Chronic inflammatory disease (e.g., ulcerative colitis, rheumatoid arthritis, etc.) * Hepatocellular insufficiency * Renal insufficiency with creatinine clearance \< 60 mL/min * Chronic or persistent immobilization