Screening for chronic thromboembolic pulmonary disease and its association with functional capacity and pulmonary hemodynamics: 4-year follow-up

Chronic thromboembolic pulmonary disease (CTEPD) is a progressive clinical entity caused by wall-adherent, fibrotic thrombi and vascular remodeling in the pulmonary circulation despite prolonged anticoagulation. Aims: We will evaluate clinical factors predictive of CTEPD, as well as its impact on functional capacity and pulmonary hemodynamics at rest and after exercise in the long-term follow-up after the index event of acute thromboembolism We will compare consecutive patients with a history of acute pulmonary embolism and either normal pulmonary vascular imaging (negative Q-scan and/or negative angioTC, group 1) or persistent defects on lung perfusion scan (positive Q-scan, and/or positive angioTC, group 2) despite oral anticoagulation at 4 months. Investigations will include thrombotic load on computed tomography angiography, the Pulmonary Embolism Severity Index (PESI) score, World Health Organization functional class (WHO-FC), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), cardiopulmonary exercise test (CPET) and echocardiography parameters at rest and after exercise (ESE), at 4 months, 1 and 5 years. Our preliminary results in n = 55 patients have shown that compared with group 1, group 2 featured a higher PESI score (p=0.02) and a higher thrombotic load (p=0.004) at hospital admission. At 4 months, group 2 developed exercise-induced pulmonary hypertension (Ex-PH) at CPET (p<0.001) and ESE (p<0.001). At 24 months group 2 showed higher NT-proBNP (p<0.001) and WHO-FC (p<0.001), systolic (p<0.001) and diastolic (p=0.037) RV dysfunction and worse RV-arterial coupling (p<0.001) despite maintaining a low or intermediate echocardiographic probability of PH. Patients with positive Q-scan frequently develop Ex-PH and RV functional deterioration as well as reduced functional capacity. Ex-PH predicts the progression to CTEPD.