We determined the physiological effects of exercise training on exercise capacity and quadriceps muscle function in patients with idiopathic pulmonary arterial hypertension (iPAH).In total, 19 clinically stable iPAH patients (New York Heart Association II-III) underwent a supervised exercise training programme for the duration of 12 weeks. Maximal capacity, endurance capacity and quadriceps function were assessed at baseline and after 12 weeks. In 12 patients, serial quadriceps muscle biopsies were obtained.6-min walk distance and peak exercise capacity did not change after training. However, endurance capacity improved significantly after training, demonstrated by a shift of the anaerobic threshold to a higher workload (from 32¡5 to 46¡6 W; p50.003) together with an increase in exercise endurance time (p,0.001). Moreover, exercise training increased quadriceps strength by 13% (p50.005) and quadriceps endurance by 34% (p50.001).Training enhanced aerobic capacity of the quadriceps, by increasing capillarisation (1.36¡0.10 to 1.78¡0.13 capillaries per muscle fibre; p,0.001) and oxidative enzyme activity, especially of the type-I (slow) muscle fibres. No changes were found in cross-sectional area and fibre type distribution.Exercise training in iPAH improves exercise endurance and quadriceps muscle function, which is also reflected by structural changes of the quadriceps.

In contrast to control subjects, patients with PH were unable to increase Ees during submaximal exercise. Failure to compensate for the further increase in Ea during exercise led to deterioration in Ees/Ea. Furthermore, ΔPAP did not reflect ΔEes but rather the change in heart rate.

: CPET parameters predict survival in PH patients and add marginally to the prognostic value of the 6MWD.

In patients with idiopathic pulmonary arterial hypertension (iPAH), iron deficiency is common and has been associated with reduced exercise capacity and worse survival. Previous studies have shown beneficial effects of intravenous iron administration. In this study, we investigated the use of intravenous iron therapy in iron-deficient iPAH patients in terms of safety and effects on exercise capacity, and we studied whether altered exercise capacity resulted from changes in right ventricular (RV) function and skeletal muscle oxygen handling. Fifteen patients with iPAH and iron deficiency were included. Patients underwent a 6-minute walk test, cardiopulmonary exercise tests, cardiac magnetic resonance imaging, and a quadriceps muscle biopsy and completed a quality-of-life questionnaire before and 12 weeks after receiving a high dose of intravenous iron. The primary end point, 6-minute walk distance, was not significantly changed after 12 weeks (409 ± 110 m before vs. 428 ± 94 m after; P = 0.07). Secondary end points showed that intravenous iron administration was well tolerated and increased body iron stores in all patients. In addition, exercise endurance time (P < 0.001) and aerobic capacity (P < 0.001) increased significantly after iron therapy. This coincided with improved oxygen handling in quadriceps muscle cells, although cardiac function at rest and maximal V : O 2 were unchanged. Furthermore, iron treatment was associated with improved quality of life (P < 0.05). In conclusion, intravenous iron therapy in iron-deficient iPAH patients improves exercise endurance capacity. This could not be explained by improved RV function; however, increased quadriceps muscle oxygen handling may play a role. (Trial registration: ClinicalTrials.gov identifier NCT01288651)

A subgroup of patients with idiopathic pulmonary arterial hypertension (IPAH) has severely reduced diffusing capacity of the lung for carbon monoxide (DLCO) and poor prognosis. Their characteristics are currently unknown. The aim of this study is to contrast clinical characteristics and treatment responses of IPAH-patients with a severely reduced and more preserved DLCO.Retrospectively, 166 IPAH patients were included and grouped based on a DLCO cut-off value of 45% pred (IPAH ,45% and IPAH o45% ). Clinical characteristics, treatment responses and survival were compared.IPAH ,45% were older, more often male, had a more frequent history of coronary disease and a higher tobacco exposure. Forced expiratory volume in 1 s (FEV1), FEV1/forced vital capacity, total lung capacity and alveolar volume values were slightly lower and computed tomography scan abnormalities more prevalent in patients with a low DLCO. Age and number of pack years were independently associated with DLCO ,45% pred. IPAH ,45% showed no different haemodynamic profile, yet worse exercise performance and a worse survival rate, which were both related to age, sex and the presence of coronary disease.To conclude, a severely reduced DLCO in IPAH is associated with advanced age and a greater tobacco exposure. These patients have a worse exercise performance despite a similar hemodynamic profile. We confirm the decreased survival in this patient group and now show that this poor outcome is related to age, sex and the presence of coronary disease. @ERSpublications Severely reduced DLCO in IPAH is associated with advanced age and a greater tobacco exposure

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Background: Pulmonary hypertension (PH) is a well-known complication of chronic obstructive pulmonary disease (COPD). It remains unclear whether exercise parameters can be used to discriminate between COPD patients with associated PH (COPD-PH) and COPD patients without associated PH (COPD-nonPH). Objective: To study whether the existence of pulmonary hypertension in COPD is related to characteristic findings in gas exchange and circulatory parameters during cardiopulmonary exercise testing (CPET). Methods: We retrospectively analyzed CPET data in 25 COPD patients in whom right heart catheterization had been performed. Differences were assessed between COPD-PH and COPD-nonPH patients in peak oxygen uptake (VO₂ peak), ventilatory efficiency (VE/VCO₂), oxygen pulse, maximal ventilation and pulse oximetry (S_pO₂). Results: PH was found in 10 of 25 patients (mP_pa = 33 ± 7 mm Hg), in 15 patients mean pulmonary artery pressure (mP_pa) was below 25 mm Hg (18 ± 3 mm Hg). CPET in COPD-PH was characterized by a higher VE/VCO₂ at nadir, a higher VE/VCO₂ slope, and a lower S_pO₂ at rest and during exercise, but values in both groups were overlapping considerably. In the whole group mP_pa was associated with resting P_aO₂ (r = –0.70, p < 0.001), VE/VCO₂ nadir (r = 0.43, p < 0.05), and inversely related to S_pO₂ at rest and during exercise (r = –0.58 and r = –0.64, p < 0.01, respectively). Conclusion: Although CPET characteristics showed a large overlap in both groups, the existence of PH in COPD is associated with a significantly reduced ventilatory efficiency during CPET. However, a low S_pO₂ at rest and a further decrease during exercise similarly suggest the presence of PH in COPD.

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