Clinical and radiological characteristics of CTEPH patients without a history of acute venous thromboembolism

Chronic thromboembolic pulmonary hypertension (CTEPH) is thought to result from incomplete resolution of vascular obstruction following acute pulmonary embolism (PE). However, about 25% of CTEPH patients do not have a documented previous acute venous thromboembolism (VTE). We hypothesized that patients without a VTE in their past medical history have different clinical and functional characteristics compared to CTEPH patients who had a previous acute VTE. All CTEPH patients from the CTEPH registry of Amsterdam UMC between 2014-2022 were identified. Their baseline data and history of VTE were retrieved from their charts. As part of our clinical protocol, baseline data were collected and CT pulmonary angiography (CTPA), right heart catheterization (RHC) and pulmonary function tests were performed. The location of disease was evaluated by CTPA. 262 CTEPH patients were included; 47 patients (18%) had no previous history of VTE. In patients without a previous VTE, radiological assessment showed more frequent subsegmental disease (n=17/47; 36%, 95%CI: 24-50) compared to the patients with previous VTE (n= 30/207; 15% (95%CI: 10-20); p=0.001). Patients without a previous VTE were less frequently subjected to pulmonary endarterectomy (PEA) (30%, (95%CI: 18-44) versus 56%, (95%CI: 49-62); p <0.001) and received more often a balloon pulmonary angioplasty (BPA) (n=25/47, 53% (95%CI: 39-67) versus n=73/207, 34% (95%CI: 28-41); p=0.011) and medical therapy only (n=8/47; 17%, (95%CI: 8-30) versus n=22/207; 10%, (95%CI: 7-15); p=0.143). CTEPH patients without a documented previous VTE ha more subsegmental located disease and were more likely to have a BPA and receive medical therapy only.