Early Detection of CTEPH in Patients After APE

Inclusion Criteria: * Age over 18 years * Signed consent to participate in the project and GDPR * Patients with an episode of acute pulmonary embolism in the last 3-12 months, with ongoing anticoagulation therapy: 1. Patients with new-onset and ongoing or progressive dyspnea (min. NYHA II) after a pulmonary embolism episode or worsening of dyspnea after a pulmonary embolism episode compared to the status before the episode (at least 1 HYHA grade) or 2. Asymptomatic patients after a pulmonary embolism episode and at least one of the following risk factors: * ECHO evidence of severe PH at diagnosis of PE (PASP \>60 mmHg) * Antiphospholipid syndrome with triple positivity (presence of lupus anticoagulans + anti-beta-2-glycoprotein I (B2GPI) antibodies + anticardiolipin) * Infected permanent venous inlets and cardiac pacing/defibrillation intravascular systems * Presence of ventriculoatrial shunt for treatment of hydrocephalus * Nonspecific intestinal inflammation (ulcerative colitis, Crohn's disease) * History of splenectomy * Myeloproliferative disorders * Chronic osteomyelitis Exclusion Criteria: * Not agreeing to participate in the project * Contraindications to treatment