Exercise training improves peak oxygen consumption and haemodynamics in patients with severe pulmonary arterial hypertension and inoperable chronic thrombo-embolic pulmonary hypertension: a prospective, randomized, controlled trial.

AIMS: The impact of exercise training on the right heart and pulmonary circulation has not yet been invasively assessed in patients with pulmonary hypertension (PH) and right heart failure. This prospective randomized controlled study investigates the effects of exercise training on peak VO2/kg, haemodynamics, and further clinically relevant parameters in PH patients. METHODS AND RESULTS: Eighty-seven patients with pulmonary arterial hypertension and inoperable chronic thrombo-embolic PH (54% female, 56 ± 15 years, 84% World Health Organization functional class III/IV, 53% combination therapy) on stable disease-targeted medication were randomly assigned to a control and training group. Medication remained unchanged during the study period. Non-invasive assessments and right heart catheterization at rest and during exercise were performed at baseline and after 15 weeks. Primary endpoint was the change in peak VO2/kg. Secondary endpoints included changes in haemodynamics. For missing data, multiple imputation and responder analyses were performed. The study results showed a significant improvement of peak VO2/kg in the training group (difference from baseline to 15 weeks: training +3.1 ± 2.7 mL/min/kg equals +24.3% vs. control -0.2 ± 2.3 mL/min/kg equals +0.9%, P < 0.001). Cardiac index (CI) at rest and during exercise, mean pulmonary arterial pressure, pulmonary vascular resistance, 6 min walking distance, quality of life, and exercise capacity significantly improved by exercise training. CONCLUSION: Low-dose exercise training at 4-7 days/week significantly improved peak VO2/kg, haemodynamics, and further clinically relevant parameters. The improvements of CI at rest and during exercise indicate that exercise training may improve the right ventricular function. Further, large multicentre trials are necessary to confirm these results.

Principles of rehabilitation and reactivation: pulmonary hypertension.

Most recently, a specialized and carefully monitored exercise training and rehabilitation program has been recommended as add-on to medical treatment in patients with pulmonary arterial hypertension (class I, level of evidence A). Three prospective randomized, controlled trials, 10 prospective uncontrolled trials, 2 retrospective studies and 2 case series in more than 470 patients with severe pulmonary hypertension (PH) and right heart failure reported beneficial effects of a specialized exercise training and rehabilitation program, i.e. significant improvement in symptoms, exercise capacity, cardiorespiratory function and quality of life, compared with untrained controls. All training studies reported an acceptable safety profile, and some uncontrolled studies showed excellent 1- and 2-year survival rates. However, most studies had a quite small sample size (ranging from 2 to 183 patients) and an uncontrolled design, and they were not designed to assess hemodynamic changes, time to clinical worsening and survival. Nevertheless, there is large evidence that exercise training programs should be performed by centers experienced in both PH patient care and rehabilitation. The best method and duration of the training, characteristics of supervision, and the mechanisms resulting in symptom improvement and increased functional capacity are unclear. In this review, we summarize data of molecular and clinical effects of exercise training in PH patients. Furthermore, we discuss safety data and the role of a self-care management of exercise training in these patients.

Endoscopic lung volume reduction with endobronchial valves in patients with severe emphysema and established pulmonary hypertension.

BACKGROUND: One of the most common forms of pulmonary hypertension (PH) is that associated with chronic obstructive pulmonary disease (COPD). So far, patients with severe emphysema and established PH have been excluded from endoscopic lung volume reduction (ELVR) therapy due to the risk of right heart decompensation. OBJECTIVE: The aim of this pilot study was to evaluate the feasibility and efficacy of ELVR using one-way endobronchial valves (EBV) in this specific group of patients. METHODS: We prospectively included 6 patients with COPD, severe heterogeneous emphysema, and established PH who underwent right heart catheterization and clinical assessments before and 90 days after ELVR with unilateral EBV placement. RESULTS: This study was not powered to measure any statistical differences in endpoints. Ninety days after ELVR, the symptoms, lung function, and hemodynamics improved in 5 out of 6 patients (1 patient normalized and 1 slightly worsened). The mean hemodynamics improved from baseline to 90 days after ELVR as follows: mean pulmonary artery pressure, -2.5 ± 3.5 mm Hg; pulmonary arterial wedge pressure, -4.3 ± 8.3 mm Hg; cardiac index, +0.3 ± 0.6 l/min/m(2), and 6-min walk distance, +59 ± 99 m. ELVR was performed without PH-related complications in all patients. CONCLUSION: To our knowledge, this is the first prospective, single-center pilot study to evaluate the feasibility and efficacy of ELVR in patients with established PH. ELVR was feasible and resulted in an improvement of clinical and hemodynamic parameters in 5 out of 6 patients. These results have to be further confirmed in larger-scale controlled studies.

Reference ranges for and determinants of right ventricular area in healthy adults by two-dimensional echocardiography.

BACKGROUND: The right ventricular (RV) area is important for diagnosis and follow-up in patients with various diseases, such as in pulmonary hypertension. OBJECTIVES: The aim of this study was to define the reference ranges of the end-diastolic RV area in healthy adults and to assess the determining factors. METHODS: In the first part of the study 860 healthy subjects (37.6% female; mean age 28 ± 5.84; 395 endurance athletes, 255 strength athletes and 210 non-athletes) were prospectively assessed. In the second part we performed a pooled analysis of studies published between 1979 and 2014 describing the RV area in healthy subjects (n = 5,248). Statistical analysis included the calculation of reference ranges and the analysis of determining factors. RESULTS: Mean end-diastolic RV areas in 860 healthy subjects were significantly larger in endurance athletes (25.1 ± 2.0 cm(2)) compared with strength athletes (22.9 ± 1.7 cm(2)) and non-athletes (16.7 ± 2.0 cm(2), p < 0.001). In the synopsis of both data sets, mean end-diastolic RV area was significantly larger in European/American males (17 cm(2)) compared with females (14 cm(2), p < 0.001) and in Asian males (16 cm(2)) compared with females (13 cm(2), p < 0.001). The area increased with body surface area and older age. CONCLUSION: This is the largest data set to define RV size in healthy adults aged <50 years. RV area was determined by age, gender, body surface area, ethnicity and high-level exercise training. High standard deviations resulted in high values for the upper limit of the reference range, which might therefore not be useful as cut-off values for screening purposes. Gender- and ethnicity-specific reference ranges should be used. Further studies in subjects aged >50 years as well as in children are needed.

Safety and long-term efficacy of transition from sildenafil to tadalafil due to side effects in patients with pulmonary arterial hypertension.

INTRODUCTION: Two phosphodiesterase-type 5 (PDE-5) inhibitors, sildenafil and tadalafil, are approved for treatment of pulmonary arterial hypertension (PAH). It has not yet been observed if transition from sildenafil to tadalafil is beneficial in patients suffering from adverse reactions. Aim of this study was to analyze safety and long-term effects in PAH patients whose treatment was transitioned from sildenafil to tadalafil due to intolerable side-effects. METHODS: A retrospective analysis of PAH-patients who were stable on sildenafil for >3 months and transitioned to tadalafil due to adverse events was performed. Data collected included demographics, PAH-etiology, WHO-functional class, 6 min walking distance (6MWD), echocardiography, lung function tests, and NTproBNP pre-transition and 3, 6, and 12 months post-transition. RESULTS: Included were 13 PAH patients (8 females mean age 64 ± 10 years) who had been on sildenafil for a mean of 12 ± 8.4 months. In six patients (46.1 %) a switch to tadalafil was feasible and resulted in tolerable side effects and a stable clinical course with improvement of symptoms, 6MWD, stable echocardiographic findings, and NTproBNP-levels during a follow-up of 11 ± 3 months. In 5 out of 13 patients (38.5 %) adverse events occurred under tadalafil as well and therapy with PDE-5 inhibitors was discontinued. In two patients (15.4 %) sildenafil-treatment could be successfully restarted after an intermittent switch to tadalafil. CONCLUSIONS: The observations of this study indicate that a transition of sildenafil to tadalafil in case of intolerable side effects is a reasonable therapy option in about 50 % of the patients. These results should be verified by a larger prospective study.

Assessment and prognostic relevance of right ventricular contractile reserve in patients with severe pulmonary hypertension.

BACKGROUND: This study sought to analyze a new approach to assess exercise-induced pulmonary artery systolic pressure (PASP) increase by means of stress Doppler echocardiography as a possible measure of right ventricular contractile reserve in patients with severe pulmonary hypertension and right heart failure. METHODS AND RESULTS: In this prospective study, patients with invasively diagnosed pulmonary arterial hypertension or inoperable chronic thromboembolic pulmonary hypertension and impaired right ventricular pump function despite a stable targeted pulmonary arterial hypertension medication underwent a broad panel of noninvasive assessments, including stress echocardiography and cardiopulmonary exercise testing. On the basis of the assumption that exercise-induced PASP is a measure of right ventricular contractile reserve, patients were classified into 2 groups according to an exercise-induced PASP increase above or below the median. Patients were followed up for 3.0 ± 1.8 years. Univariate and multivariate analyses were used for factors predicting survival. Of 124 patients, 66 were below the median exercise-induced PASP increase of 30 mm Hg (low PASP), and 58 patients were above the median (high PASP). These groups were not significantly different in terms of medication and resting hemodynamics. Low PASP was associated with a significantly lower 6-minute walking distance, peak o2 per kilogram, and 1-, 3-, and 4-year survival rates (92%, 69%, and 48%, respectively, versus 96%, 92%, and 89%). In the multivariate Cox model analysis adjusted for age and sex, PASP increase during exercise and peak o2 per kilogram remained independent prognostic markers (hazard ratio, 2.56 for peak o2 per kilogram and 2.84 for PASP increase). CONCLUSIONS: Exercise-induced PASP increase is of high clinical and prognostic relevance in pulmonary hypertension patients and may indicate right ventricular contractile reserve. Stress Doppler echocardiography may be a useful tool for prognostic assessment in pulmonary hypertension patients.

Economic evaluation of exercise training in patients with pulmonary hypertension.

PURPOSE: Exercise training as an add-on to medical therapy has been shown to improve exercise capacity, quality of life, and possibly prognosis in patients with pulmonary hypertension (PH). The purpose of this study was to analyze the impact of exercise training on healthcare costs in PH. METHODS: Estimated healthcare costs have been compared between patients with severe PH under optimized medical therapy only (control group) versus patients who received exercise training as an add-on to medical therapy (training group). Cost-analysis included a cost-estimation model of costs for baseline and follow-up visits and all PH-related healthcare events that occurred within the follow-up period. Time to clinical worsening and survival were assessed by clinical records, phone, and/or control visits. RESULTS: At baseline, the training (n = 58) and control group (n = 48) did not differ in age, gender, WHO-functional class, 6-min walking distance, hemodynamic parameters, or PH-targeted medication. During a follow-up of 24 ± 12 months, the training group had significantly better survival rates at 1 and 3 years and less worsening events (death, lung transplantation, hospitalization due to PH, new PAH-targeted medication) than the control group (15 vs. 25 events, p < 0.05), which also led to lower estimated healthcare costs of 657 within a period of 2 years. CONCLUSIONS: This is the first study to investigate the cost-effectiveness of exercise training in PH. Due to less worsening events within 2 years, healthcare costs were lower in patients performing exercise training as add-on to medical therapy than in patients with medical treatment only. Further prospective, randomized studies are needed to confirm these findings.

The combination of exercise and respiratory training improves respiratory muscle function in pulmonary hypertension.

PURPOSE: Increased dyspnea and reduced exercise capacity in pulmonary arterial hypertension (PAH) can be partly attributed to impaired respiratory muscle function. This prospective study was designed to assess the impact of exercise and respiratory training on respiratory muscle strength and 6-min walking distance (6MWD) in PAH patients. METHODS: Patients with invasively confirmed PAH underwent 3 weeks of in-hospital exercise and respiratory training, which was continued at home for another 12 weeks. Medication remained constant during the study period. Blinded observers assessed efficacy parameters at baseline (I) and after 3 (II) and 15 weeks (III). Respiratory muscle function was assessed by twitch mouth pressure (TwPmo) during nonvolitional supramaximal magnetic phrenic nerve stimulation. RESULTS: Seven PAH patients (4 women; mean pulmonary artery pressure 45 ± 11 mmHg, median WHO functional class 3.1 ± 0.4, idiopathic/associated PAH n = 5/2) were included. The training program was feasible and well tolerated by all patients with excellent compliance. TwPmo was I: 0.86 ± 0.37 kPa, II: 1.04 ± 0.29 kPa, and III: 1.27 ± 0.44 kPa, respectively. 6MWD was I: 417 ± 51 m, II: 509 ± 39 m, and III: 498 ± 39 m, respectively. Both TwPmo (+0.41 ± 0.34 kPa, +56 ± 39 %) and 6MWD (+81 ± 30 m, +20 ± 9 %) increased significantly in the period between baseline and the final assessment (pairwise comparison: p = 0.012/<0.001; RM-ANOVA considering I, II, III: p = 0.037/<0.001). CONCLUSIONS: Exercise and respiratory training as an adjunct to medical therapy may be effective in patients with PAH to improve respiratory muscle strength and exercise capacity. Future, randomized, controlled trials should be carried out to further investigate these findings.

Hemodynamic and genetic analysis in children with idiopathic, heritable, and congenital heart disease associated pulmonary arterial hypertension.

BACKGROUND: Aim of this prospective study was to compare clinical and genetic findings in children with idiopathic or heritable pulmonary arterial hypertension (I/HPAH) with children affected with congenital heart defects associated PAH (CHD-APAH). METHODS: Prospectively included were 40 consecutive children with invasively diagnosed I/HPAH or CHD-APAH and 117 relatives. Assessment of family members, pedigree analysis and systematic screening for mutations in TGFß genes were performed. RESULTS: Five mutations in the bone morphogenetic protein type II receptor (BMPR2) gene, 2 Activin A receptor type II-like kinase-1 (ACVRL1) mutations and one Endoglin (ENG) mutation were found in the 29 I/HPAH children. Two mutations in BMPR2 and one mutation in ACVRL1 and ENG, respectively, are described for the first time. In the 11 children with CHD-APAH one BMPR2 gene mutation and one Endoglin gene mutation were found. Clinical assessment of relatives revealed familial aggregation of the disease in 6 children with PAH (HPAH) and one CHD-APAH patient. Patients with mutations had a significantly lower PVR. CONCLUSION: Mutations in different TGFß genes occurred in 8/29 (27.6%) I/HPAH patients and in 2/11 (18.2%) CHD-APAH patients and may influence the clinical status of the disease. Therefore, genetic analysis in children with PAH, especially in those with I/HPAH, may be of clinical relevance and shows the complexity of the genetic background.

Anxiety and depression disorders in patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension.

BACKGROUND: The objective of this prospective study was to assess the prevalence of anxiety and depression disorders and their association with quality of life (QoL), clinical parameters and survival in patients with pulmonary hypertension (PH). METHODS: We prospectively assessed 158 patients invasively diagnosed with pulmonary arterial hypertension (n = 138) and inoperable chronic thromboembolic PH (n = 20) by clinical measures including quality of life (QoL, SF-36 questionnaire), cardiopulmonary exercise testing and six minute walking distance and by questionnaires for depression (PHQ-9) and anxiety (GAD-7). According to the results of the clinical examination and the questionnaires for mental disorders (MD) patients were classified into two groups, 1) with moderate to severe MD (n = 36, 22,8%), and 2) with mild or no MD (n = 122). Patients were followed for a median of 2.7 years. Investigators of QoL, SF-36 were blinded to the clinical data. RESULTS: At baseline the 2 groups did not differ in their severity of PH or exercise capacity. Patients with moderate to severe MD (group 1) had a significantly lower QoL shown in all subscales of SF-36 (p < 0.002). QoL impairment significantly correlated with the severity of depression (p < 0.001) and anxiety (p < 0.05). During follow-up period 32 patients died and 3 were lost to follow-up. There was no significant difference between groups regarding survival. Only 8% of the patients with MD received psychopharmacological treatment. CONCLUSION: Anxiety and depression were frequently diagnosed in our patients and significantly correlated with quality of life, but not with long term survival. Further prospective studies are needed to confirm the results.

Magnetic resonance imaging to assess the effect of exercise training on pulmonary perfusion and blood flow in patients with pulmonary hypertension.

OBJECTIVES: To evaluate whether careful exercise training improves pulmonary perfusion and blood flow in patients with pulmonary hypertension (PH), as assessed by magnetic resonance imaging (MR). METHODS: Twenty patients with pulmonary arterial hypertension or inoperable chronic thromboembolic PH on stable medication were randomly assigned to control (n = 10) or training groups (n = 10). Training group patients received in-hospital exercise training; patients of the sedentary control group received conventional rehabilitation. Medication remained unchanged during the study period. Changes of 6-min walking distance (6MWD), MR pulmonary flow (peak velocity) and MR perfusion (pulmonary blood volume) were assessed from baseline to week 3. RESULTS: After 3 weeks of training, increases in mean 6MWD (P = 0.004) and mean MR flow peak velocity (P = 0.012) were significantly greater in the training group. Training group patients had significantly improved 6MWD (P = 0.008), MR flow (peak velocity -9.7 ± 8.6 cm/s, P = 0.007) and MR perfusion (pulmonary blood volume +2.2 ± 2.7 mL/100 mL, P = 0.017), whereas the control group showed no significant changes. CONCLUSION: The study indicates that respiratory and physical exercise may improve pulmonary perfusion in patients with PH. Measurement of MR parameters of pulmonary perfusion might be an interesting new method to assess therapy effects in PH. The results of this initial study should be confirmed in a larger study group.

Safety and efficacy of exercise training in various forms of pulmonary hypertension.

The objective of this prospective study was to assess safety and efficacy of exercise training in a large cohort of patients with different forms and World Health Organization (WHO) functional classes of chronic pulmonary hypertension (PH). 183 patients with PH (pulmonary arterial hypertension (PAH), chronic thromboembolic PH and PH due to respiratory or left heart diseases received exercise training in hospital for 3 weeks and continued at home. Adverse events have been monitored during the in-hospital training programme. Efficacy parameters were evaluated at baseline, and after 3 and 15 weeks. After 3 and 15 weeks, patients significantly improved the distance walked in 6 min (6MWD) compared to baseline, scores of quality of life, WHO functional class, peak oxygen consumption, oxygen pulse, heart rate and systolic pulmonary artery pressure at rest and maximal workload. The improvement in 6MWD was similar in patients with different PH forms and functional classes. Even in severely affected patients (WHO functional class IV), exercise training was highly effective. Adverse events, such as respiratory infections, syncope or presyncope, occurred in 13% of patients. Exercise training in PH is an effective but not a completely harmless add-on therapy, even in severely diseased patients, and should be closely monitored.

The German adaptation of the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR).

BACKGROUND: Individuals with precapillary pulmonary hypertension (PH) experience severely impaired quality of life. A disease-specific outcome measure for PH, the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) was developed and validated in the UK and subsequently adapted for use in additional countries. The aim of this study was to translate and assess the reliability and validity of the CAMPHOR for German-speaking populations. METHODS: Three main adaptation stages involved; translation (employing bilingual and lay panels), cognitive debriefing interviews with patients and validation (assessment of the adaptation's psychometric properties). The psychometric evaluation included 107 patients with precapillary PH (60 females; age mean (standard deviation) 60 (15) years) from 3 centres in Austria, Germany and Switzerland. RESULTS: No major problems were found with the translation process with most items easily rendered into acceptable German. Participants in the cognitive debriefing interviews found the questionnaires relevant, comprehensive and easy to complete. Psychometric analyses showed that the adaptation was successful. The three CAMPHOR scales (symptoms, activity limitations and quality of life) had excellent test-retest reliability correlations (Symptoms = 0.91; Activity limitations = 0.91; QoL = 0.90) and internal consistency (Symptoms = 0.94; Activity limitations = 0.93; QoL = 0.94). Predicted correlations with the Nottingham Health Profile provided evidence of the construct validity of the CAMPHOR scales. The CAMPHOR adaptation also showed known group validity in its ability to distinguish between participants based on perceived general health, perceived disease severity, oxygen use and NYHA classification. CONCLUSIONS: The CAMPHOR has been shown to be valid and reliable in the German population and is recommend for use in clinical practice.

Hemodynamic and clinical onset in patients with hereditary pulmonary arterial hypertension and BMPR2 mutations.

BACKGROUND: Mutations in the bone morphogenetic protein receptor 2 (BMPR2) gene can lead to idiopathic pulmonary arterial hypertension (IPAH). This study prospectively screened for BMPR2 mutations in a large cohort of PAH-patients and compared clinical features between BMPR2 mutation carriers and non-carriers. METHODS: Patients have been assessed by right heart catheterization and genetic testing. In all patients a detailed family history and pedigree analysis have been obtained. We compared age at diagnosis and hemodynamic parameters between carriers and non-carriers of BMPR2 mutations. In non-carriers with familial aggregation of PAH further genes/gene regions as the BMPR2 promoter region, the ACVRL1, Endoglin, and SMAD8 genes have been analysed. RESULTS: Of the 231 index patients 22 revealed a confirmed familial aggregation of the disease (HPAH), 209 patients had sporadic IPAH. In 49 patients (86.3% of patients with familial aggregation and 14.3% of sporadic IPAH) mutations of the BMPR2 gene have been identified. Twelve BMPR2 mutations and 3 unclassified sequence variants have not yet been described before. Mutation carriers were significantly younger at diagnosis than non-carriers (38.53 ± 12.38 vs. 45.78 ± 11.32 years, p < 0.001) and had a more severe hemodynamic compromise. No gene defects have been detected in 3 patients with HPAH. CONCLUSION: This study identified in a large prospectively assessed cohort of PAH- patients new BMPR2 mutations, which have not been described before and confirmed previous findings that mutation carriers are younger at diagnosis with a more severe hemodynamic compromise. Thus, screening for BMPR2 mutations may be clinically useful.

Effect of exercise and respiratory training on clinical progression and survival in patients with severe chronic pulmonary hypertension.

BACKGROUND: Even though specific agents for the treatment of patients with pulmonary hypertension (PH) are available, in PH patients, physical capacity and quality of life (QoL) are often restricted and survival is reduced. OBJECTIVES: This study prospectively investigated the long-term effects of respiratory and exercise training in patients with severe chronic PH regarding safety, time to clinical worsening and survival. METHODS: Fifty-eight consecutive patients with severe PH on stable disease-targeted medication received exercise and respiratory training in hospital for 3 weeks and continued at home. They were prospectively followed for 24 ± 12 months. Primary endpoints were time to clinical worsening and survival. Adverse events and changes in the 6-min walking test, QoL, WHO functional class and gas exchange were secondary endpoints and were evaluated at baseline and at weeks 3 and 15. RESULTS: All patients tolerated the exercise training well without severe adverse events. In week 15, 6-min walking test results were significantly improved compared to baseline (by 84 ± 49 m, p < 0.001), as well as QoL scores, WHO functional class (from 2.9 ± 0.5 to 2.6 ± 0.6, p < 0.01), peak oxygen consumption (from 12.5 ± 3.0 to 14.6 ± 3.9 ml/min/kg, p < 0.001), heart rate at rest (from 75 ± 12 to 61 ± 18 beats/min, p < 0.001) and maximal workload (from 65 ± 21 to 80 ± 25 W, p < 0.001). Survival at 1 and 2 years was 100 and 95%, respectively. Fifteen events occurred during the follow-up. CONCLUSION: This study indicates that exercise and respiratory training as add-on to medical treatment may improve exercise capacity and QoL, and that they have a good long-term safety in the described setting.

Stress Doppler echocardiography in relatives of patients with idiopathic and familial pulmonary arterial hypertension: results of a multicenter European analysis of pulmonary artery pressure response to exercise and hypoxia.

BACKGROUND: This large, prospective, multicentric study was performed to analyze the distribution of tricuspid regurgitation velocity (TRV) values during exercise and hypoxia in relatives of patients with idiopathic and familial pulmonary arterial hypertension (PAH) and in healthy control subjects. We tested the hypothesis that relatives of idiopathic/familial PAH patients display an enhanced frequency of hypertensive TRV response to stress and that this response is associated with mutations in the bone morphogenetic protein receptor II (BMPR2) gene. METHODS AND RESULTS: TRV was estimated by Doppler echocardiography during supine bicycle exercise in normoxia and during 120 minutes of normobaric hypoxia (FIO(2)=12%; approximately 4500 m) in 291 relatives of 109 PAH patients and in 191 age-matched control subjects. Mean maximal TRVs were significantly higher in PAH relatives during both exercise and hypoxia. During exercise, 10% of control subjects but 31.6% of relatives (P<0.0001) exceeded the 90% quantile of mean maximal TRV seen in control subjects. Hypoxia revealed hypertensive TRV in 26% of relatives (P=0.0029). Among control subjects, TRV at rest was not related to age, sex, body mass index, systemic blood pressure, smoking status, or heart rate. Within kindreds identified as harboring deleterious mutations of the BMPR2 gene, a hypertensive TRV response occurred significantly more often compared with those without detected mutations. CONCLUSIONS: Pulmonary hypertensive response to exercise and hypoxia in idiopathic/familial PAH relatives appears as a genetic trait with familial clustering, being correlated to but not caused by a BMPR2 mutation. The suitability of this trait to predict manifest PAH development should be addressed in long-term follow-up studies.

Impairment of respiratory muscle function in pulmonary hypertension.

It has been suggested that impaired respiratory muscle function occurs in patients with PH (pulmonary hypertension); however, comprehensive investigations of respiratory muscle function, including the application of non-volitional tests, needed to verify impairment of respiratory muscle strength in patients with PH have not yet been performed. In the present study, respiratory muscle function was assessed in 31 patients with PH (20 females and 11 males; mean pulmonary artery pressure, 51+/-20 mmHg; median World Health Organization class 3.0+/-0.5; 25 patients with pulmonary arterial hypertension and six patients with chronic thromboembolic PH) and in 31 control subjects (20 females and 11 males) well-matched for gender, age and BMI (body mass index). A 6-min walking test was performed to determine exercise capacity. Volitionally assessed maximal inspiratory (7.5+/-2.1 compared with 6.2+/-2.8 kPa; P=0.04) and expiratory (13.3+/-4.2 compared with 9.9+/-3.4 kPa; P<0.001) mouth pressures, sniff nasal (8.3+/-1.9 compared with 6.6+/-2.2 kPa; P=0.002) and transdiaphragmatic (11.3+/-2.5 compared with 8.7+/-2.5 kPa; P<0.001) pressures, non-volitionally assessed twitch mouth (1.46+/-0.43 compared with 0.97+/-0.41 kPa; P<0.001) and transdiaphragmatic (2.08+/-0.55 compared with 1.47+/-0.72 kPa; P=0.001) pressures during bilateral anterior magnetic phrenic nerve stimulation were markedly lower in patients with PH compared with control subjects. Maximal inspiratory mouth (r=0.58, P<0.001) and sniff transdiaphragmatic (r=0.43, P=0.02) pressures were correlated with the 6-min walking distance in patients with PH. In conclusion, the present study provides strong evidence that respiratory muscle strength is reduced in patients with PH compared with well-matched control subjects. Furthermore, the 6-min walking distance is significantly linked to parameters assessing inspiratory muscle strength.

Exercise and respiratory training improve exercise capacity and quality of life in patients with severe chronic pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) is associated with restricted physical capacity, limited quality of life, and a poor prognosis because of right heart failure. The present study is the first prospective randomized study to evaluate the effects of exercise and respiratory training in patients with severe symptomatic PH. METHODS AND RESULTS: Thirty patients with PH (21 women; mean age, 50+/-13 years; mean pulmonary artery pressure, 50+/-15 mm Hg; mean World Health Organization [WHO] class, 2.9+/-0.5; pulmonary arterial hypertension, n=23; chronic thromboembolic PH, n=7) on stable disease-targeted medication were randomly assigned to a control (n=15) and a primary training (n=15) group. Medication remained unchanged during the study period. Primary end points were the changes from baseline to week 15 in the distance walked in 6 minutes and in scores of the Short Form Health Survey quality-of-life questionnaire. Changes in WHO functional class, Borg scale, and parameters of echocardiography and gas exchange also were assessed. At week 15, patients in the primary and secondary training groups had an improved 6-minute walking distance; the mean difference between the control and the primary training group was 111 m (95% confidence interval, 65 to 139 m; P<0.001). Exercise training was well tolerated and improved scores of quality of life, WHO functional class, peak oxygen consumption, oxygen consumption at the anaerobic threshold, and achieved workload. Systolic pulmonary artery pressure values at rest did not change significantly after 15 weeks of exercise and respiratory training (from 61+/-18 to 54+/-18 mm Hg) within the training group. CONCLUSIONS: This study indicates that respiratory and physical training could be a promising adjunct to medical treatment in severe PH. The effects add to the beneficial results of modern medical treatment.

Rehabilitation in patients with pulmonary arterial hypertension.

Exertional dyspnoea is a leading symptom in patients with pulmonary arterial hypertension (PAH). Patients suffering from PAH report poor quality of life, have skeletal muscle dysfunction and in the absence of advanced medical therapy deteriorate progressively due to right heart failure which can lead to death. For decades, patients with PAH were advised to avoid exercise in fear of exacerbated right heart failure. Recently, it has been shown that a highly supervised rehabilitation programme in expert centres leads to significant improvements in symptoms, quality of life, exercise capacity and may even enhance haemodynamics in selected stable patients treated with advanced regimens of PAH-targeted drugs. As a consequence of these promising results, pulmonary rehabilitation performed in an expert centre has been included in recent guidelines. The underlying mechanisms are not completely understood, but positive effects can be measured in different organ systems such as skeletal muscles, the cardiopulmonary system and immune system (inflammation), and also on the psychological level. Thus, improvements in 6-minute walking distance (6MWD), peak oxygen uptake (VO2 peak), muscle strength and muscle endurance, as well as physical and mental quality of life scores (SF-36 questionnaire) have been shown. Different training protocols have been used. Essential are qualified patient selection in expert centres, a low workload endurance and dumbbell (weight lifting) training avoiding strenuous exercise and exhaustion, thorough patient education and close supervision by experts especially during the first weeks. Adverse events may occur (e.g., pre-/syncope, arrhythmia, respiratory infections). PAH patients tend to overestimate their physical capacity, not perceiving their own limits properly, which makes education and expert advice even more important as exercise training can also worsen the right heart failure. Therefore, a core issue of the multidisciplinary rehabilitation is the close cooperation between the experienced rehabilitation clinic offering a specialised programme for PAH patients and the PAH expert centre, which takes care of the patient and is thoroughly involved in the training programme. Further multicentre international randomised trials are needed to evaluate whether this specialised programme is feasible within different healthcare systems and to assess long term effects and survival.

Mutation in BMPR2 Promoter: A 'Second Hit' for Manifestation of Pulmonary Arterial Hypertension?

BACKGROUND: Hereditary pulmonary arterial hypertension (HPAH) can be caused by autosomal dominant inherited mutations of TGF-ß genes, such as the bone morphogenetic protein receptor 2 (BMPR2) and Endoglin (ENG) gene. Additional modifier genes may play a role in disease manifestation and severity. In this study we prospectively assessed two families with known BMPR2 or ENG mutations clinically and genetically and screened for a second mutation in the BMPR2 promoter region. METHODS: We investigated the BMPR2 promoter region by direct sequencing in two index-patients with invasively confirmed diagnosis of HPAH, carrying a mutation in the BMPR2 and ENG gene, respectively. Sixteen family members have been assessed clinically by non-invasive methods and genetically by direct sequencing. RESULTS: In both index patients with a primary BMPR2 deletion (exon 2 and 3) and Endoglin missense variant (c.1633G>A, p.(G545S)), respectively, we detected a second mutation (c.-669G>A) in the promoter region of the BMPR2 gene. The index patients with 2 mutations/variants were clinically severely affected at early age, whereas further family members with only one mutation had no manifest HPAH. CONCLUSION: The finding of this study supports the hypothesis that additional mutations may lead to an early and severe manifestation of HPAH. This study shows for the first time that in the regulatory region of the BMPR2 gene the promoter may be important for disease penetrance. Further studies are needed to assess the incidence and clinical relevance of mutations of the BMPR2 promoter region in a larger patient cohort.