Objective: To investigate the effect of a daylong exposure to high altitude on peak exercise capacity and safety in stable patients with pulmonary arterial and chronic thromboembolic pulmonary hypertension (PAH/CTEPH).Methods: In a randomised controlled cross-over trial, stable patients with PAH or distal CTEPH without resting hypoxemia at low altitude performed two incremental exercise tests to exhaustion, one after 3–5 h at high (2500 m) and one at low altitude (470 m).Results: In 27 patients with PAH/CTEPH (44% women, 61±14 y), maximal work-rate was 110±64 watts at 2500 m and 123±64 watts at 470 m (−11%, 95%CI: −16 to −11, p<0.001). SpO₂and PaO₂at end-exercise were 83±6%versus91±6% and 6.1±1.9 kPaversus8.6±1.9 kPa (−8%; −29%; both p<0.001) at 2500 mversus470 m, respectively. Maximal oxygen uptake at high altitude was 17.8±7.5 L·min⁻¹·kg⁻¹versus20±7.4 L·min⁻¹·kg⁻¹at low altitude (−11%, p<0.001). At end-exercise, the ventilatory equivalent for CO₂was 43±9 at 2500 mversus39±9 at 470 m (+9%, 95%CI: 2 to 6; p=0.002). No adverse events occurred during or after exercise.Conclusion: Among predominantly low-risk patients with stable PAH/CTEPH, cycling exercise during the first day at 2500 m was well tolerated, but peak exercise capacity, blood oxygenation and ventilatory efficiency were lower compared to 470 m.

Background: The course of pulmonary arterial wedge pressure (PAWP) during exercise in patients with pulmonary arterial or chronic thromboembolic pulmonary hypertension (PAH/CTEPH), further abbreviated as pulmonary vascular disease (PVD), is still unknown. The aim of the study was to describe PAWP during exercise in patients with PVD.Methods: In this cross-sectional study, right heart catheter (RHC) data including PAWP, recorded during semi-supine, stepwise cycle exercise in patients with PVD, were analysed retrospectively. We investigated PAWP changes during exercise until end-exercise.Results: In 121 patients (59 female, 66 CTEPH, 55 PAH, 62±17 years) resting PAWP was 10.2±4.1 mmHg. Corresponding peak changes in PAWP during exercise were +2.9 mmHg (95% CI 2.1–3.7 mmHg, p<0.001). Patients ≥50 years had a significantly higher increase in PAWP during exercise compared with those <50 years (p<0.001). The PAWP/cardiac output (CO) slopes were 3.9 WU for all patients, and 1.6 WU for patients 2 WU are common in patients with PVD aged ≥50 years without exceeding the PAWP of 25 mmHg during exercise.

Pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension are the main precapillary forms of pulmonary hypertension (PH) summarized as pulmonary vascular diseases (PVD). PVDs are characterized by exertional dyspnoea and oxygen desaturation, and reduced quality of life and survival. Medical therapies improve life expectancy and physical performance of PVD patients, of whom many wish to participate in professional work and recreational activities including traveling to high altitude. The exposure to the hypobaric hypoxic environment of mountain regions incurs the risk of high altitude adverse events (AE_HA) due to severe hypoxaemia exacerbating symptoms and further increase in pulmonary artery pressure, which may lead to right heart decompensation. Recent prospective and randomized trials show that altitude‐induced hypoxaemia, pulmonary haemodynamic changes and impairment of exercise performance in PVD patients are in the range found in healthy people. The vast majority of optimally treated stable PVD patients who do not require long‐term oxygen therapy at low altitude can tolerate short‐term exposure to moderate altitudes up to 2500 m. PVD patients that reveal persistent severe resting hypoxaemia ( 30 min) at 2500 m respond well to supplemental oxygen therapy. Although there are no accurate predictors for AE_HA, PVD patients with unfavourable risk profiles at low altitude, such as higher WHO functional class, lower exercise capacity with more pronounced exercise‐induced desaturation and more severely impaired haemodynamics, are at increased risk of AE_HA. Therefore, doctors with experience in PVD and high‐altitude medicine should counsel PVD patients before any high‐altitude sojourn. This review aims to summarize recent literature and clinical recommendations about PVD patients travelling to high altitude. image

Pulmonary hypertension (PH) is a complex clinical condition, and left heart disease is the leading cause. Little is known about the epidemiology and prognosis of combined post- and pre-capillary PH (CpcPH). This retrospective analysis of the Swiss PH Registry included incident patients with CpcPH registered from January 2001 to June 2019 at 13 Swiss hospitals. Patient baseline characteristics [age, sex, mean pulmonary artery pressure (mPAP), pulmonary artery wedge pressure (PAWP), pulmonary vascular resistance (PVR), and risk factors, including World Health Organization (WHO)-functional class (FC), 6 min walk distance (6MWD), and N-terminal pro-brain natriuretic peptide (NT-proBNP), treatment, days of follow-up, and events (death or loss to follow-up) at last visit] were analysed by Kaplan–Meier and Cox regression analyses. Two hundred and thirty-one patients (59.3% women, age 65 ± 12 years, mPAP 48 ± 11 mmHg, PAWP 21 ± 5 mmHg, PVR 7.2 ± 4.8 WU) were included. Survival analyses showed a significantly longer survival for women [hazard ratio (HR) 0.58 (0.38–0.89); P = 0.01] and a higher mortality risk for mPAP > 46 mmHg [HR 1.58 (1.03–2.43); P = 0.04] but no association with age or PVR. Patients stratified to high risk according to four-strata risk assessment had an increased mortality risk compared with patients stratified to low-intermediate risk [HR 2.44 (1.23–4.84); P = 0.01]. A total of 46.8% of CpcPH patients received PH-targeted pharmacotherapy; however, PH-targeted medication was not associated with longer survival. Among patients with CpcPH, women and patients with an mPAP ≤46 mmHg survived longer. Furthermore, risk stratification by using non-invasively assessed risk factors, such as WHO-FC, 6MWD, and NT-proBNP, as proposed for pulmonary arterial hypertension, stratified survival in CpcPH, and might be helpful in the management of these patients.

Background: Pulmonary endarterectomy (PEA) is the treatment of choice for patients with chronic thromboembolic pulmonary hypertension (CTEPH) with accessible lesions. Breathing pure oxygen (hyperoxia) during right heart catheterization (RHC) allows for the calculation of the right-to-left shunt fraction (Qs/Qt). In the absence of intracardiac shunt, Qs/Qt can be used as a marker of ventilation–perfusion mismatch in patients with CTEPH. This study involved investigating Qs/Qt after PEA and its relation to other disease-specific outcomes. Study design and Methods: This study is a retrospective study that focuses on patients with operable CTEPH who had Qs/Qt assessment during RHC before and 1 year after PEA. Additionally, 6 min walking distance (6MWD), WHO functional class (WHO-FC), and NT-proBNP were assessed to calculate a four-strata risk score. Results: Overall, 16 patients (6 females) with a median age of 66 years (quartiles 55; 74) were included. After PEA, an improvement in mean pulmonary artery pressure (38 [32; 41] to 24 [18; 28] mmHg), pulmonary vascular resistance (5.7 [4.0; 6.8] to 2.5 [1.4; 3.8] WU), oxygen saturation (92 [88; 93]% to 94 [93; 95]%), WHO-FC, and risk score was observed (all p < 0.05). No improvement in median Qs/Qt could be detected (13.7 [10.0; 17.5]% to 13.0 [11.2; 15.6]%, p = 0.679). A total of 7 patients with improved Qs/Qt had a significant reduction in risk score compared to those without improved Qs/Qt. Conclusion: PEA did not alter Qs/Qt assessed after 1 year in operable CTEPH despite an improvement in hemodynamics and risk score, potentially indicating a persistent microvasculopathy. In patients whose shunt fraction improved with PEA, the reduced shunt was associated with an improvement in risk score.