Effect of 5 years of exercise training on the cardiovascular risk profile of older adults: the Generation 100 randomized trial.

AIMS: The aim of this study was to compare the effects of 5 years of supervised exercise training (ExComb), and the differential effects of subgroups of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT), with control on the cardiovascular risk profile in older adults. METHODS AND RESULTS: Older adults aged 70-77 years from Trondheim, Norway (n = 1567, 50% women), able to safely perform exercise training were randomized to 5 years of two weekly sessions of HIIT [∼90% of peak heart rate (HR), n = 400] or MICT (∼70% of peak HR, n = 387), together forming ExComb (n = 787), or control (instructed to follow physical activity recommendations, n = 780). The main outcome was a continuous cardiovascular risk score (CCR), individual cardiovascular risk factors, and peak oxygen uptake (VO2peak). CCR was not significantly lower [-0.19, 99% confidence interval (CI) -0.46 to 0.07] and VO2peak was not significantly higher (0.39 mL/kg/min, 99% CI -0.22 to 1.00) for ExComb vs. control. HIIT showed higher VO2peak (0.76 mL/kg/min, 99% CI 0.02-1.51), but not lower CCR (-0.32, 99% CI -0.64 to 0.01) vs. control. MICT did not show significant differences compared to control or HIIT. Individual risk factors mostly did not show significant between-group differences, with some exceptions for HIIT being better than control. There was no significant effect modification by sex. The number of cardiovascular events was similar across groups. The healthy and fit study sample, and contamination and cross-over between intervention groups, challenged the possibility of detecting between-group differences. CONCLUSIONS: Five years of supervised exercise training in older adults had little effect on cardiovascular risk profile and did not reduce cardiovascular events. REGISTRATION: ClinicalTrials.gov: NCT01666340.

Effect of Continuous Positive Airway Pressure on Arrhythmia in Atrial Fibrillation and Sleep Apnea: A Randomized Controlled Trial.

Rationale: Sleep apnea (SA) is highly prevalent in patients with atrial fibrillation (AF), and both conditions are associated with adverse cardiovascular outcomes.Objectives: To determine the effect of continuous positive airway pressure (CPAP) on AF burden.Methods: This open-label, parallel-group, randomized controlled trial included patients with paroxysmal AF and moderate to severe SA (apnea-hypopnea index ⩾15). A computerized system randomized eligible patients (1:1) to 5 months' treatment with CPAP plus usual care (CPAP, n = 55) or usual care alone (control, n = 54). The outcome assessment was blinded. The planned primary outcome was the difference between CPAP treatment and control groups in change of AF burden (percentage of time in AF) as measured by implantable loop recorder.Measurements and Main Results: A total of 579 patients with paroxysmal AF had respiratory polygraphy, of whom 244 (42%) had moderate to severe SA. Of these, 158 (65%) participated in the CPAP run-in period, of whom 39 (25%) patients did not tolerate the treatment. A total of 108 patients were available for the primary analysis. The mean time in AF decreased from 5.6% at baseline to 4.1% during the last 3 months of CPAP intervention and from 5.0% to 4.3% in the control group. The adjusted between-group difference at follow-up was -0.63 (95% confidence interval, -2.55 to 1.30) percentage points (P = 0.52). Seven serious adverse events (13%) occurred in the CPAP group, and two (4%) occurred in the control group.Conclusions: In patients with paroxysmal AF and SA, treatment with CPAP did not result in a statistically significant reduction in the burden of AF.Clinical trial registered with www.clinicaltrials.gov (NCT02727192).

Comparing manual and automatic scoring of sleep monitoring data from portable polygraphy.

We used sleep monitoring data from a study that investigated the prevalence, characteristics, risk factors and type of sleep apnea (SA) in 579 patients with paroxysmal atrial fibrillation. Most patients were screened for two nights, resulting in 1,043 sleep recordings that each contained data from one night. SA was diagnosed using the Nox T3 portable sleep monitor. An experienced sleep specialist scored the recordings manually using Noxturnal software. A total of 157 women (27%) and 422 men (73%) were examined; 477 (82.7%) had an apnea-hypopnea index (AHI) ≥ 5/hr, whereas moderate to severe SA (AHI ≥ 15/hr) was diagnosed in 243 patients (42.1%). The AHI derived from automatic and manual scoring showed a good agreement (Pearson's r coefficient of 0.96). The median difference in AHI was very small (i.e., 0.72 [mean difference, 1.06]), but was statistically significant (p < .0001). Automatic scoring classified sleep recordings with more than 90% accuracy into SA categories of mild (AHI ≥ 5/hr), moderate (AHI ≥ 15/hr) and severe (AHI ≥ 30/hr). We found a minor (11%-21%) mis-estimation of the number of recordings right above and below the boundary separating mild and moderate SA. The accuracy of automatic scoring differed from recording to recording, especially regarding the sensitivity of detecting disrupted breathing events. We found low to moderate agreement for the duration of disrupted breathing events (r = .53), for which the automatic scoring led to a statistically significant overestimation by 5.22 s (p < .0001).

The association between dynamic lung volume and peak oxygen uptake in a healthy general population: the HUNT study.

BACKGROUND: Although dynamic lung volume is not considered a limiting factor of peak oxygen uptake (VO2peak) in healthy subjects, an association between forced expiratory lung volume in one second (FEV1) and VO2peak has been reported in a healthy population aged 69 - 77 years. We hypothesized that a corresponding association could be found in a healthy general population including young and middle-aged subjects. METHODS: In a population-based study in Norway, we investigated the association between FEV1 above the lower limit of normal (LLN) and VO2peak using linear regression and assessed the ventilatory reserve (VR) in healthy subjects aged 20 - 79 years (n = 741). RESULTS: On average, one standard deviation (SD) increase in FEV1 was associated with 1.2 ml/kg/min (95% CI 0.7 - 1.6) higher VO2peak. The association did not differ statistically by sex (p-value for interaction = 0.16) and was similar (0.9 ml/kg/min, 95% CI 0.2 - 1.5) in a sensitivity analysis including only never-smokers (n = 376). In subjects below and above 45 years of age, corresponding estimates were 1.2 ml/kg/min (95% CI 0.5 - 1.8) and 1.2 ml/kg/min (95% CI 0.5 - 1.9), respectively. Preserved VR (≥ 20%) was observed in 66.6% of men and 86.4% of women. CONCLUSIONS: Normal dynamic lung volume, defined as FEV1 above LLN, was positively associated with VO2peak in both men and women, in never-smokers and in subjects below and above 45 years of age. The majority of subjects had preserved VR, and the results suggest that FEV1 within normal limits may influence VO2peak in healthy subjects even when no ventilatory limitation to exercise is evident.

Comparison of procalcitonin, C-reactive protein, white blood cell count and clinical status in diagnosing pneumonia in patients hospitalized with acute exacerbations of COPD: A prospective observational study.

Lower respiratory tract infection is the most common cause of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). The aim of the present study was to compare the accuracy of procalcitonin (PCT), C-reactive protein (CRP) and white blood cell count (WBC) as single diagnostic tests and in combination with clinical signs and symptoms to diagnose pneumonia in patients hospitalized with AECOPD. This was a prospective, single centre observational study. Patients with spirometry-confirmed COPD who were hospitalized due to AECOPD were consecutively recruited at the hospital's Emergency Unit. Pneumonia was defined as a new pulmonary infiltrate on chest X-ray. The values of PCT, CRP and WBC were determined at admission. Receiver operating characteristic (ROC) curve analysis was used to study the accuracy of various diagnostic tests. Of the 113 included patients, 35 (31%) had pneumonia at admission. Area under the ROC curve (AUC) for PCT, CRP and WBC as a single test to distinguish between patients with and without pneumonia was 0.67 (95% CI 0.55-0.79), 0.73 (95% CI 0.63-0.84) and 0.67 (95% CI 0.55-0.79), respectively ( p = 0.42 for the test of difference). The AUC for a model of clinical signs and symptoms was 0.84 (95% CI 0.76-0.92). When biomarkers were added to the clinical model, the AUCs of the combined models were not significantly different from that of the clinical model alone ( p = 0.54). PCT had about the same accuracy as CRP and WBC in predicting pneumonia in patients hospitalized with AECOPD both as a single test and in combination with clinical signs and symptoms.

Treatment of sleep apnea in patients with paroxysmal atrial fibrillation: design and rationale of a randomized controlled trial.

RATIONALE: Atrial fibrillation is associated with increased mortality as well as morbidity. There is strong evidence for an association between atrial fibrillation and sleep apnea. It is not known whether treatment of sleep apnea with continuous positive airway pressure (CPAP) will reduce the burden of atrial fibrillation. OBJECTIVE: The Treatment of Sleep Apnea in Patients with Paroxysmal Atrial Fibrillation study will investigate the effects of CPAP in patients with paroxysmal atrial fibrillation and sleep apnea. DESIGN: The trial has a dual center, randomized, controlled, open-label, parallel design. METHODS: Two centers will enroll a total of 100 patients with both paroxysmal atrial fibrillation and sleep apnea (apnea-hypopnea index [AHI] ≥ 15 events/h) who are scheduled for catheter ablation. Patients will be randomized in a 1:1 ratio to CPAP or control group (50 patients in each arm). The effects of CPAP treatment on atrial fibrillation will be determined using an implanted loop recorder (Reveal LINQ™, Medtronic) that detects all arrhythmia episodes. The primary endpoint is a reduction of the total burden of atrial fibrillation in the intervention group, after 5 months' follow-up (preablation). Reduction in the arrhythmia recurrence rate after ablation is the main secondary endpoint. All patients will be followed up for 12 months after ablation. CONCLUSION: This study is the first randomized controlled trial that will provide data on the effects of CPAP therapy in patients with paroxysmal atrial fibrillation and sleep apnea. The results are expected to improve our understanding of the interaction between paroxysmal atrial fibrillation and sleep apnea. ClinicalTrials.gov Identifier. NCT02727192.

The Prevalence and Symptom Profile of Asthma-COPD Overlap: The HUNT Study.

The concept of asthma and COPD as separate conditions has been questioned, and the term asthma-COPD overlap syndrome has been introduced. We assessed the prevalence, symptoms, and lifestyle factors of asthma-COPD overlap (ACO) in a large Norwegian population-based study. From 2006 to 2008, a total of 50,777 residents of Nord-Trøndelag participated in the Nord-Trøndelag Health Study, Norway. They completed questionnaires regarding respiratory symptoms, disease status, and medication use. We estimated the prevalence and 95% confidence intervals of ACO. Additionally, spirometry was used to estimate the prevalence of ACO in a subgroup. The prevalence of self-reported ACO was 1.9%, and in age groups <40, 40-60 and ≥60 years it was 0.7%, 1.4%, and 3.2%, respectively. Among those reporting COPD, the proportion of ACO was 0.56. In the spirometry subgroup when ACO was defined as doctor diagnosed asthma ever and FEV1/FVC < 0.70, the prevalence of ACO was 2.0%. All respiratory symptoms, separately or in combination, as well as medication use were reported most frequently in those with ACO compared to the other groups. Strikingly, we observed a two-fold higher proportion of allergic rhinitis in ACO compared to COPD only. In this Norwegian population, the prevalence of self-reported ACO was 1.9%, and the corresponding proportion of ACO among those with COPD was 0.56. Participants with ACO generally had the highest proportions of respiratory symptoms compared to asthma or COPD.

Long term effects of an integrated care intervention on hospital utilization in patients with severe COPD: a single centre controlled study.

UNLABELLED: Chronic obstructive pulmonary disease (COPD) is one of the main causes of morbidity and mortality globally. In Trondheim in 2008 an integrated care model (COPD-Home) consisting of an education program, self-management plan, home visits and a call centre for patient support and communication was developed. The objective was to determine the efficacy of an intervention according to the COPD-Home model in reducing hospital utilization among patients with COPD stage III and IV (GOLD 2007) discharged after hospitalization for acute exacerbations of COPD (AECOPD). METHODS: A single centre, prospective, open, controlled clinical study comparing COPD-Home integrated care (IC) with usual care (UC). RESULTS: Ninety-one versus 81 patients mean age 73.4 ± 9.3 years (57% women) were included in the IC group (ICG) and the UC group (UCG) respectively, and after 2 years 51 and 49 patients were available for control in the respective groups. During the year prior to study start there were 71 hospital admissions (HA) in the ICG and 84 in the UCG. There was a 12.6% reduction in HA in the ICG during the first year of follow-up and a 46.5% reduction during the second year (p = 0.01) compared to an 8.3% increase during the first year and no change during the second year in the ICG. During the year prior to study start, the number of hospital days (HD) was 468 in the ICG and 479 in the UCG. In the IC group, the number of HD was reduced by 48.3% during the first year (p = 0.01), and remained low during the second year of follow-up (p=0.02). In the UC group, the number of HD remained unchanged during the follow-up period. There was a trend towards a shorter survival time among patients in the ICG compared to the UCG, hazard ratio 1.33 [95% CI 0.77 to 2.33]. CONCLUSION: Intervention according to the COPD-Home model reduced hospital utilization in patients with COPD III and IV with a persisting effect throughout the 2 years of follow-up. However, there was a trend towards a shorter survival time in the intervention group.

Association between pulmonary function and peak oxygen uptake in elderly: the Generation 100 study.

BACKGROUND: Although reduced function of the respiratory system limits peak oxygen uptake in diseases affecting the lungs or airways, the healthy respiratory system is thought to have a spare capacity for oxygen transport and uptake, and is not considered a limiting factor for peak oxygen uptake in healthy people. However, lung function declines with age and could theoretically limit peak oxygen uptake in elderly. We examined the association between peak oxygen uptake and lung function indices in an elderly population with the hypothesis that lung function indices would be associated with VO2peak up to a threshold value situated above the lower limits of normal lung function for our population. METHODS: Spirometry, gas diffusion tests and incremental work tests were performed in 1443 subjects (714 women) aged 69-77 years. Association between lung function indices and peak oxygen uptake was studied with hockey-stick regression. RESULTS: Forced expiratory volume in 1 s (FEV1) had a positive association with peak oxygen uptake up to, but not above, a threshold value of 2.86 l for men, and 2.13 l for women (lower limit of normal 2.73 and 1.77 l respectively). A corresponding threshold was found for diffusing capacity of the lung for carbon monoxide (DLCO) for men at 9.18 mmol/min/kPa (lower limit of normal 6.84 mmol/min/kPa). DLCO for women and DLCO divided by alveolar volume (DLCO/VA) for both sexes had a significant linear relationship to VO2peak (p < 0.05), but no significant threshold value was found in these associations. CONCLUSIONS: Threshold values for FEV1 for both sexes and DLCO for men were identified. These lung function indices had a positive association with VO2peak up to these threshold values, but not above. The identified threshold values were above lower limits of normal for FEV1 and DLCO.

Effects of exercise training on pulmonary vessel muscularization and right ventricular function in an animal model of COPD.

BACKGROUND: Right ventricular dysfunction in COPD is common, even in the absence of pulmonary hypertension. The aim of the present study was to examine the effects of high intensity interval training (HIIT) on right ventricular (RV) function, as well as pulmonary blood vessel remodeling in a mouse model of COPD. METHODS: 42 female A/JOlaHsd mice were randomized to exposure to either cigarette smoke or air for 6 hours/day, 5 days/week for 14 weeks. Mice from both groups were further randomized to sedentariness or HIIT for 4 weeks. Cardiac function was evaluated by echocardiography and muscularization of pulmonary vessel walls by immunohistochemistry. RESULTS: Smoke exposure induced RV systolic dysfunction demonstrated by reduced tricuspid annular plane systolic excursion. HIIT in smoke-exposed mice reversed RV dysfunction. There were no significant effects on the left ventricle of neither smoke exposure nor HIIT. Muscularization of the pulmonary vessels was reduced after exercise intervention, but no significant effects on muscularization were observed from smoke exposure. CONCLUSIONS: RV function was reduced in mice exposed to cigarette smoke. No Increase in pulmonary vessel muscularization was observed in these mice, implying that other mechanisms caused the RV dysfunction. HIIT attenuated the RV dysfunction in the smoke exposed mice. Reduced muscularization of the pulmonary vessels due to HIIT suggests that exercise training not only affects the heart muscle, but also has important effects on the pulmonary vasculature.

Pulmonary Function and Lung Fibrosis up to 12 Years After Breast Cancer Radiotherapy.

PURPOSE: Breast cancer (BC) treatment may affect pulmonary function, but evidence of long-term pulmonary toxicity is scarce. This study aimed to evaluate pulmonary function, radiation fibrosis (RF), and patient-reported dyspnea up to 12 years after different BC treatment modalities. METHODS AND MATERIALS: Two hundred fifty patients with BC referred to postoperative radiotherapy (RT) were included in this study. High-resolution computed tomography, pulmonary function tests (PFTs), clinical examinations, and patient-reported dyspnea were assessed before RT and at 3, 6, and 12 months and up to 12 years after RT. RESULTS: Vital capacity (VC), forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and diffusion capacity of the lungs for carbon monoxide (DLCO) declined at 3 months after RT and remained low at long-term follow-up except for DLCO, which increased up to 12 years after RT. VC, FEV1, and FVC changes differed between patients treated with and without chemotherapy, and FEV1 differed between patients treated with locoregional and local RT. An early decline in VC, FEV1, and FVC predicted a late decline in PFT values up to 12 years after RT (P = .020, P = .004, and P = .020, respectively). RF, mainly grade 1, was observed in 91% of patients at long-term follow-up. Few patients reported severe dyspnea at long-term follow-up, and there was no statistically significant association with concurrent RF or decline in PFT values from baseline. CONCLUSIONS: Chemotherapy and locoregional RT affected performance in PFTs up to 12 years after RT. Reduction in VC, FVC, and FEV1 3 months after RT predicted a decline in PFT values at long-term follow-up. However, a late decline in PFT values was not associated with long-term RF or patient-reported dyspnea.

Aerobic exercise training improves right- and left ventricular systolic function in patients with COPD.

OBJECTIVE: The aim of this study was to investigate the effects of moderate continuous training (MCT) and high intensity aerobic interval training (AIT) on systolic ventricular function and aerobic capacity in COPD patients. METHODS: Seventeen patients with COPD (64 ± 8 years, 12 men) with FEV1 of 52.8 ± 11% of predicted, were randomly assigned to isocaloric programs of MCT at 70% of max heart rate (HR) for 47 minutes) or AIT (~90% of max HR for 4×4 minutes) three times per week for 10 weeks. Baseline cardiac function was compared with 17 age- and sex-matched healthy individuals. Peak oxygen uptake (VO(2-peak)) and left (LV) and right ventricular (RV) function examined by echocardiography, were measured at baseline and after 10 weeks of training. RESULTS: At baseline, the COPD patients had reduced systolic function compared to healthy controls (p < 0.05). After the training, AIT and MCT increased VO(2-peak) by 8% and 9% and work economy by 7% and 10%, respectively (all p < 0.05). LV and RV systolic function both improved (p < 0.05), with no difference between the groups after the two modes of exercise training. Stroke volume increased by 17% and 20%, LV systolic tissue Doppler velocity (S') by 18% and 17% and RV S' by 15% after AIT and MCT, respectively (p < 0.05). CONCLUSION: Systolic cardiac function is reduced in COPD. Both AIT and MCT improved systolic cardiac function. In contrast to other patient groups studied, higher exercise intensity does not seem to have additional effects on cardiac function or aerobic capacity in COPD patients.

High-intensity knee extensor training restores skeletal muscle function in COPD patients.

Improving reduced skeletal muscle function is important for optimising exercise tolerance and quality of life in chronic obstructive pulmonary disease (COPD) patients. By applying high-intensity training to a small muscle group, we hypothesised a normalisation of muscle function. Seven patients with COPD performed 6 weeks (3 days·week(-1)) of high-intensity interval aerobic knee extensor exercise training. Five age-matched healthy individuals served as a reference group. Muscle oxygen uptake and mitochondrial respiration of the vastus lateralis muscle were measured before and after the 6-week training programme. Initial peak work and maximal mitochondrial respiration were reduced in COPD patients and improved significantly after the training programme. Peak power and maximal mitochondrial respiration in vastus lateralis muscle increased to the level of the control subjects and were mainly mediated via improved complex I respiration. Furthermore, when normalised to citrate synthase activity, no difference in maximal respiration was found either after the intervention or compared to controls, suggesting normal functioning mitochondrial complexes. The present study shows that high-intensity training of a restricted muscle group is highly effective in restoring skeletal muscle function in COPD patients.

Exercise and obstructive sleep apnoea: a 24-week follow-up study.

Objective: Report on long-term follow-up results in the apnoea hypopnea index (AHI) and self-reported daytime sleepiness in participants with moderate to severe obstructive sleep apnoea at 12 weeks after completion of a high-intensity exercise training or control intervention. Methods: Twenty-six participants with obstructive sleep apnoea (body mass index (BMI) 37 (36-39) kg/m, age 52 (49-55) years, apnoea-hypopnoea index 40.5 (31.3-50.2) events/hour), randomised to either 12 weeks of supervised high-intensity interval training (HIIT) (4×4 min of treadmill running or walking at 90%-95% of maximal heart rate) or no intervention (control), underwent a sleep evaluation follow-up 24 weeks after intervention initiation. Respiratory measures during sleep were registered at baseline, 12 weeks (postintervention) and 24 weeks (long-term follow-up). Results: At the 24-week follow-up, there were no statistically significant differences between the groups in the AHI (HIIT 30.7 (17.2-44.1) and control 38.7 (22.8-54.5) events/hour), Epworth score (HIIT 7.0 (4.7-9.3) and control 5.5 (3.9-7.0)), mean oxygen saturation (HIIT 93.2 (92.5-93.9) and control 92.0 (91.1-92.8)) or oxygen desaturation events (HIIT 32.9 (20.4-45.4) and control 44.3 (27.3-61.3) n/hour). BMI remained unchanged from the baseline in both groups. In the HIIT group, only two participants reported having continued with HIIT at 24 weeks. Conclusion: The effect of 12 weeks of supervised high-intensity exercise training on AHI and self-reported daytime sleepiness was lost at the 24-week follow-up.

Identification of exercise-regulated genes in mice exposed to cigarette smoke.

Cigarette smoke (CS) is the major risk factor for COPD and is linked to cardiopulmonary dysfunction. Exercise training as part of pulmonary rehabilitation is recommended for all COPD patients. It has several physiological benefits, but the mechanisms involved remain poorly defined. Here, we employed transcriptomic profiling and examined lung endothelium to investigate novel interactions between exercise and CS on cardiopulmonary alterations. Mice were exposed to 20 weeks of CS, CS + 6 weeks of high-intensity interval training on a treadmill, or control. Lung and cardiac (left and right ventricle) tissue were harvested and RNA-sequencing was performed and validated with RT-qPCR. Immunohistochemistry assessed pulmonary arteriolar changes. Transcriptome analysis between groups revealed 37 significantly regulated genes in the lung, 21 genes in the left ventricle, and 43 genes in the right ventricle (likelihood-ratio test). Validated genes that showed interaction between exercise and CS included angiotensinogen (p = 0.002) and resistin-like alpha (p = 0.019) in left ventricle, with prostacyclin synthetase different in pulmonary arterioles (p = 0.004). Transcriptomic profiling revealed changes in pulmonary and cardiac tissue following exposure to CS, with exercise training exerting rescue effects. Exercise-regulated genes included angiotensinogen and resistin-like alpha, however, it remains unclear if these represent potential candidate genes or biomarkers that could play a role during pulmonary rehabilitation.

Effect of continuous positive airway pressure therapy on recurrence of atrial fibrillation after pulmonary vein isolation in patients with obstructive sleep apnea: A randomized controlled trial.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with atrial fibrillation (AF). Whether treatment with continuous positive airway pressure (CPAP) reduces AF recurrence after catheter ablation with pulmonary vein isolation (PVI) is unknown. OBJECTIVE: The purpose of this study was to assess the effect of CPAP treatment on the recurrence and burden of AF after PVI in patients with OSA. METHODS: We randomized patients with paroxysmal AF and an apnea-hypopnea index (AHI) ≥15 events/hour to treatment with CPAP or standard care. Heart rhythm was monitored by an implantable loop recorder. AF recurrence after PVI was defined as any episode of AF lasting >2 minutes after a 3-month blanking period. RESULTS: PVI was performed in 83 patients. Thirty-seven patients were randomized to CPAP treatment and 46 patients to standard care. The AHI was reduced from 26.7 ± 14 events/hour to 1.7 ± 1.3 events/hour at follow-up in the CPAP group (P = .001). A total of 57% of patients in both the CPAP group and the standard care group had at least 1 episode of AF 3-12 months after PVI (P for difference = 1). AF burden after ablation was reduced in both groups, with no between-group difference (P = .69). CONCLUSION: In patients with paroxysmal AF and OSA, treatment with CPAP did not further reduce the risk of AF recurrence after ablation. PVI considerably reduced the burden of AF in OSA patients, without any difference between groups.

High-intensity interval training and pulmonary hemodynamics in COPD with hypoxemia.

BACKGROUND: Exercise is recommended for all patients with COPD. Evidence for its benefit is considerably weaker in the more severe stages of the disease. The aim of this study was to investigate whether high-intensity interval training could improve exercise capacity, pulmonary hemodynamics and cardiac function in patients with severe COPD and hypoxemia. METHODS: Stable patients with COPD GOLD stage III or IV and hypoxemia were included. They underwent extensive cardiopulmonary testing including right heart catheterization, lung function tests, echocardiography and 6-minute walk test before and after completion of 10 weeks of high-intensity interval training performed with supplemental oxygen. Primary endpoint was change in pulmonary artery pressure measured by right heart catheterization. RESULTS: Ten patients with very severe airflow obstruction, mean FEV1 28.7% predicted and mean FEV1/VC 0.39 completed the exercise programme. Pulmonary artery pressure remained unchanged following the intervention (26,3 mmHg vs. 25,8 mmHg at baseline, p 0.673). Six-minute walk distance improved by a mean of44.8 m (p 0.010), which is also clinically significant. We found marginally improved left ventricular ejection fraction on echocardiography (54.6% vs 59.5%, p 0.046). CONCLUSION: High-intensity interval training significantly improved exercise capacity while pulmonary hemodynamics remained unchanged. The improvement may therefore be due to mechanisms other than altered pulmonary artery pressure. The increase in ejection fraction is of uncertain clinical significance. The low number of patients precludes firm conclusions.

Lung function and peak oxygen uptake in chronic obstructive pulmonary disease phenotypes with and without emphysema.

Previous studies of associations of forced expiratory lung volume in one second (FEV1) with peak oxygen uptake (VO2peak) in chronic obstructive pulmonary disease (COPD) have not taken sex, age and height related variance of dynamic lung volumes into account. Nor have such demographic spread of spirometric measures been considered in studies comparing VO2peak between COPD phenotypes characterized by degree of emphysema. We aimed to assess the association of FEV1Z-score with VO2peak in COPD (n = 186) and investigate whether this association differs between emphysema (E-COPD) and non-emphysema (NE-COPD) phenotypes. Corresponding assessments using standardized percent predicted FEV1 (ppFEV1) were performed for comparison. Additionally, phenotype related differences in VO2peak were compared using FEV1Z-score and ppFEV1 as alternative expressions of FEV1. E-COPD and NE-COPD were defined by transfer factor of the lung for carbon monoxide below and above lower limits of normal (LLN), respectively. The associations were assessed in linear regression models. One unit reduction in FEV1Z-score was associated with 1.9 (95% CI 1.4, 2.5) ml/kg/min lower VO2peak. In stratified analyses, corresponding estimates were 2.2 (95% CI 1.4, 2.9) and 1.2 (95% CI 0.2, 2.2) ml/kg/min lower VO2peak in E-COPD and NE-COPD, respectively. The association did not differ statistically by COPD phenotype (p-value for interaction = 0.153). Similar estimates were obtained in analyses using standardized ppFEV1. Compared to NE-COPD, VO2peak was 2.2 (95% CI 0.8, 3.6) and 2.1 (95% CI 0.8, 3.5) ml/kg/min lower in E-COPD when adjusted for FEV1Z-score and ppFEV1, respectively. In COPD, FEV1Z-score is positively associated with VO2peak. This association was stronger in E-COPD but did not differ statistically by phenotype. Both the association of FEV1 with VO2peak and the difference in VO2peak comparing COPD phenotypes seems independent of sex, age and height related variance in FEV1. Mechanisms leading to reduction in FEV1 may contribute to lower VO2peak in E-COPD.

Screening and treatment of latent tuberculosis in a cohort of asylum seekers in Norway.

AIMS: Asylum seekers are screened for tuberculosis at entry to Norway. We aimed to assess follow-up of screening results at different healthcare levels in relation to demographics, screening results and organizational factors, and how this influenced treatment of latent tuberculosis. METHODS: All asylum seekers >or=18 years with a Mantoux test >or=6 mm or positive x-ray findings who arrived at the National Reception Centre from January 2005 to June 2006, were included. Data were collected from public health authorities in the municipality where the asylum seekers had moved, and from internists in case they had been referred to a specialist. Specialists are responsible for treating latent tuberculosis. Individual subjects were matched with the National Tuberculosis Register to which everybody who had started treatment for latent tuberculosis was reported. RESULTS: Of 4,643 asylum seekers, 2,237 fulfilled the inclusion criteria. By May 2008, 30 persons had started treatment for latent TB, a median of 17 months (range 3-36) after arrival. A Mantoux test >or=15 mm on arrival was significantly associated with treatment. Demographic factors influenced follow-up in primary healthcare while screening results did not. Referral to specialist was related to screening results. Several specialists were reluctant to diagnose and treat latent tuberculosis and to treat persons without a permanent visa in particular. CONCLUSIONS: Just 1% of the study group received treatment for latent tuberculosis and with a long time delay. The reason for this may be organizational factors affecting follow-up and referral and specialists not following current guidelines.

The role of entry screening in case finding of tuberculosis among asylum seekers in Norway.

BACKGROUND: Most new cases of active tuberculosis in Norway are presently caused by imported strains and not transmission within the country. Screening for tuberculosis with a Mantoux test of everybody and a chest X-ray of those above 15 years of age is compulsory on arrival for asylum seekers.We aimed to assess the effectiveness of entry screening of a cohort of asylum seekers. Cases detected by screening were compared with cases detected later. Further we have characterized cases with active tuberculosis. METHODS: All asylum seekers who arrived at the National Reception Centre between January 2005--June 2006 with an abnormal chest X-ray or a Mantoux test ≥ 6 mm were included in the study and followed through the health care system. They were matched with the National Tuberculosis Register by the end of May 2008.Cases reported within two months after arrival were defined as being detected by screening. RESULTS: Of 4643 eligible asylum seekers, 2237 were included in the study. Altogether 2077 persons had a Mantoux ≥ 6 mm and 314 had an abnormal chest X-ray. Of 28 cases with tuberculosis, 15 were detected by screening, and 13 at 4-27 months after arrival. Abnormal X-rays on arrival were more prevalent among those detected by screening. Female gender and Somalian origin increased the risk for active TB. CONCLUSION: In spite of an imperfect follow-up of screening results, a reasonable number of TB cases was identified by the programme, with a predominance of pulmonary TB.