Feasibility and Influence of Exercise Therapy on Oxygen Uptake and Right Heart Function in CTEPH Patients After PEA

Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of acute pulmonary embolism. According to current knowledge, it is caused by non-resolving fibrothrombotic obstructions of large pulmonary arteries. Some patients show an additional small vessel vasculopathy. Both kinds of obstruction lead to an increase in pulmonary vascular resistance (PVR), increase in mean pulmonary arterial pressure (mPAP), progressive right heart failure, and premature death if left untreated. Current guidelines recommend pulmonary endarterectomy (PEA) as the potentially curative treatment of first choice, which aims to remove fibrotic obstructions from the pulmonary vasculature. The survival of patients undergoing PEA surgery ranges between 76 and 91% after 3 years, which is superior to medical treatment in inoperable CTEPH patients. The majority of operated patients experience almost complete normalisation of haemodynamics and improvements in symptoms. However, 17-51% of operated patients will develop persistent or recurrent pulmonary hypertension (PH). Some patients remain limited in their exercise capacity and prognosis. As patients are monitored on an intensive care unit immediately after PEA, immobilisation after the operation may lead to further peripheral deconditioning. A recent study of 251 CTEPH patients with follow-up until 12 months after PEA showed a persistent exercise limitation in almost 40% of patients despite normalisation of PVR and haemodynamics. This limitation was characterised by a multifactorial aetiology also involving respiratory function abnormalities. Previous studies in patients with inoperable or persistent CTEPH have suggested beneficial effects of exercise training as an add-on to targeted medical therapy, increasing exercise capacity, and quality of life (QoL). However, it is not known, whether early rehabilitation with exercise treatment is safe, feasible, and may further improve exercise capacity after PEA. Prospective studies on exercise training for CTEPH patients shortly after PEA surgery are lacking. Furthermore, to the best of our knowledge, there have been no studies yet describing the early effect within the first weeks after PEA. The aim of this study was therefore to assess the feasibility of supervised exercise training in CTEPH patients shortly after PEA. Furthermore, changes of haemodynamic and clinical parameters including oxygen uptake, QoL, exercise capacity, and right heart function assessed by echocardiography and right heart catheterisation were obtained before and shortly after PEA.