What is the difference between FEV1 change in percentage predicted value and change over baseline in the assessment of bronchodilator responsiveness in patients with COPD?

Background

Several criteria are clinically applied in the assessment of significant bronchodilator responsiveness in chronic obstructive pulmonary disease (COPD). The present study aimed to investigate the differences in various degree of severity of COPD among these criteria.

Methods

After 400 micrograms of salbutamol administered via spacer by metered dose inhaler (MDI), forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) changes (including percentage change, absolute change and absolute change in percentage predicted value) were retrospectively analysed in 933 stable patients with mild-to-very-severe COPD. Significant bronchodilator responsiveness was assessed using American Thoracic Society and European Respiratory Society (ATS-ERS) criterion based on FEV₁ or/and FVC (both ≥12% increase over baseline and ≥200 mL) and FEV₁ percentage predicted criterion (≥10% absolute increase in percentage predicted FEV₁) in different grades of COPD.

Results

Of the patients [age 66.8 years, baseline FEV₁ 974 mL (39.3% predicted) and FVC 2,242 mL], mean improvements were 126 mL in FEV₁ and 265 mL in FVC; 21.4% and 45.3% met ATS-ERS criterion based on FEV₁ and FVC, respectively; and 13.5% met FEV₁ percentage predicted criterion. The responsive ratios of ATS-ERS criterion based on FEV₁ to FEV₁ percentage predicted criterion in grade I, II, III and IV of COPD were 0.95^:1.26^:2.53^:6.00, respectively (P<0.01 in grade II and P<0.001 in grade III). As the degree of severity increased, the mean improvement of FEV₁ was reduced; on the contrary, that of FVC was increased.

Conclusions

Compared with FEV₁ percentage predicted criterion, ATS-ERS criterion based on FEV₁ as well as FVC, the later in particular, detected a larger percentage of patients with significant responsiveness. The increasing difference was relevant as a function of the severity of airflow obstruction.KEY WORDS : Airflow obstruction, bronchodilator responsiveness, chronic obstructive pulmonary disease (COPD), forced vital capacity (FVC), forced expiratory volume in one second (FEV₁)     

Postoperative outcome after coronary artery bypass grafting in chronic obstructive pulmonary disease

BACKGROUND:

It is uncertain if the presence and severity of airflow obstruction in chronic obstructive pulmonary disease (COPD) is predictive of surgical morbidity and mortality after coronary artery bypass grafting (CABG).

METHODS:

Retrospective study of patients who underwent CABG between 1998 and 2003 in a university-affiliated hospital for whom a preoperative spirometry was available. COPD was diagnosed in smokers or ex-smokers 50 years of age or older in the presence of irreversible airflow obstruction. Patients were divided into three groups depending on the spirometry: controls (forced expiratory volume in 1 s [FEV₁] 80% or more, FEV₁/forced vital capacity [FVC] greater than 0.7), mild to moderate COPD (FEV₁ 50% or more and FEV₁/FVC 0.7 or less) and severe COPD (FEV₁ less than 50% and FEV₁/FVC 0.7 or less).

RESULTS:

Among the 411 files studied, 322 (249 men, 68±8 years of age) were retained (controls, n=101; mild to moderate COPD, n=153; severe COPD, n=68). The mortality rate (3.0%, 2.6% and 0%, respectively) was comparable among the three groups. Patients with severe COPD had a slightly longer hospital stay than controls (mean difference 0.7±1.4 days, P<0.05). Pulmonary infections were more frequent in severe COPD (26.5%) compared with mild to moderate COPD (12.4%) and controls (12.9%), P<0.05. Atrial fibrillation tended to be more frequent in severe COPD than in the other two groups.

CONCLUSION:

Mortality rate associated with CABG surgery is not influenced by the presence and severity of airflow obstruction in patients with COPD. The incidence of pulmonary infections and length of hospital stay were increased in patients with severe COPD.     

Inspiratory capacity and forced expiratory volume in the first second in exacerbation of chronic obstructive pulmonary disease

Object: Periodic exacerbations of symptoms are the major cause of morbidity, mortality and health care costs in patients with chronic obstructive pulmonary disease (COPD). Dyspnea is the major factor affecting the comfort of patients in the exacerbation of COPD. In this study, we aimed to compare the value of forced expiratory volume in the first second (FEV₁) and inspiratory capacity (IC) measured before and after treatment in exacerbations and in the improvement in dyspnea. Methods: Eighty‐seven patients (male/female, 80/7; mean age, 63 ± 7) with COPD exacerbation were included in this study. All subjects underwent spirometric tests on the first day and at the end of treatment. The subjects were asked to quantify the sensation of dyspnea that was described to them as a nonspecific discomfort associated with the act of breathing. The patients quantified dyspnea by pointing to a score on a large Borg scale from 0 to 10 arbitrary units. In the beginning and at the end of treatment, forced vital capacity (FVC), FEV₁, forced expiratory flow rate between 25% and 75% of FVC (FEF25–75), peak expiratory flow rate (PEF), IC and Borg score (BS) values were compared. Results: After treatment of COPD exacerbations, FEV₁, FEF25–75, PEF and IC significantly increased, and the BS significantly decreased compared to the initial values. The increase in IC was more significantly correlated with the improvement in BS compared with FEV₁. Admission and discharge day BS was negatively correlated with FEV₁, FEF25–75 and IC. Conclusion: We have shown a more dramatic improvement in IC compared with FEV₁ in patients treated as a result of acute exacerbation of COPD. These data suggest that IC may be more useful than FEV₁ during acute exacerbation of COPD. Moreover, IC better reflects the severity of dyspnea in these patients. Please cite this paper as: Yetkin O and Gunen H. Inspiratory capacity and forced expiratory volume in the first second in exacerbation of chronic obstructive pulmonary disease. The Clinical Respiratory Journal 2008; 2: 36–40.     

Treatment of giant emphysamous bulla with endobronchial valves in patients with chronic obstructive pulmonary disease: a case series

Background

Giant emphysamtous bulla (GEB) can negatively affect the pulmonary functions of chronic obstructive pulmonary diseases (COPD) patients, including decreased forced expiratory volume in 1 s (FEV₁) and increased functional residual capacity (FRC). The aim of this study was to evaluate the efficacy of endobronchial valve (EBV) to treat bullae and to find efficacy predictors of successful treatment.

Methods

Five COPD patients with giant bulla were treated using EBVs. Before the EBV deployment, collateral ventilation (CV) between the targeted and adjacent lobes was evaluated with Chartis system.

Results

In the two patients with negative CV, the mean value of FEV₁ increased from 27.1±11.4% of predicted value before EBV treatment to 32.8±12.0% (P>0.05) at 1 month after EBV treatment, than to 31.7±24.5% (P>0.05) at 6 months after EBV treatment. Only one patient, whose bulla occupied the whole right middle lung, displayed sustained improvement of FEV₁ at 6 months after EBV treatment. In the three patients with positive CV, the mean value of FEV₁ decreased from 28.8±19.0% of predicted value before EBV treatment to 24.8±12.6% (P>0.05) at 1 month after EBV treatment, than to 22.1±10.8% (P>0.05) at 6 months after EBV treatment.

Conclusions

EBV is an effective measure to treat highly selected COPD patients with giant bulla. Although, EBV treatment can achieve transient improvement of lung function at patients with CV negative bulla, long-term benefit was merely observed at the patient with a bulla at right middle lobe (RML).     

Survival in COPD: Impact of Lung Dysfunction and Comorbidities

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality in industrialized countries. Recent studies investigated the impact of comorbidities on the survival in COPD, but most of them lacked a referent group of comorbidity-matched, nonobstructed individuals.We examined the 10-year mortality in a sample of 200 COPD patients and 201 nonobstructed controls. They were part of a larger cohort enrolled in a European case–control study aimed at assessing genetic susceptibility to COPD. By design, the COPD group included patients with a forced expiratory volume in 1 second (FEV₁) ≤70% predicted. Cases and controls were matched on age, sex, and cumulative smoking history, and shared a nearly identical prevalence of cardiovascular and metabolic disorders. We estimated the hazard of death with Cox regression and percentiles of survival with Laplace regression. COPD was the main exposure variable of interest. Five comorbidities (hypertension, coronary artery disease, prior myocardial infarction, chronic heart failure, and diabetes) were included as covariates in multiple regression models.The all-cause mortality rate was significantly higher in cases than in controls (43% vs 16%, P < 0.001). The unadjusted hazard of death for COPD was 3-fold higher than the referent category (P < 0.001), and remained nearly unchanged after introducing the 5 comorbidities in multiple regression. Patients with COPD had significantly shorter survival percentiles than comorbidity-matched controls (P < 0.001). Notably, 15% of the nonobstructed controls died by 10.3 years into the study; the same proportion of COPD patients had died some 6 years earlier, at 4.6 years.In a separate analysis, we split the whole sample into 2 groups based on the lower tertile of FEV₁ and carbon monoxide lung diffusing capacity (DL_CO). The hazard of death for COPD patients with low FEV₁ and DL_CO was nearly 3.5-fold higher than in all the others (P < 0.001), and decreased only slightly after introducing age and chronic heart failure as relevant covariates.COPD is a strong predictor of reduced survival independently of coexisting cardiovascular and metabolic disorders. Efforts should be made to identify patients at risk and to ensure adherence to prescribed therapeutic regimens.     

What Predicts Change in Pulmonary Function and Quality of Life in Asthma or COPD?

Information about predictors of decline in pulmonary function (forced expiratory volume in 1 second [FEV₁]) or health-related quality of life (HRQoL) in patients with asthma or (chronic obstructive pulmonary disease [COPD]) might help to determine those who need additional care. A 2-year prospective cohort study was conducted among 380 asthma and 120 COPD patients. In both asthma and COPD patients, a 2-year change in FEV₁ was only weakly associated with a 2-year change in HRQoL (r =. 0.19 and 0.24, respectively). In both groups, older age, living in an urban environment, and a lower peak expiratory flow rate (PEFR) at baseline were associated with a decline in FEV₁. Additional predictors of FEV₁ decline were greater body weight, less chronic cough or sputum production, and less respiratory symptoms in asthma patients and current smoking in COPD patients. A decline in HRQoL was associated with older age, non-compliance with medication, more dyspnea, and a lower PEFR in asthma patients and with male gender, lower education, lower body weight, more dyspnea, and more respiratory symptoms in COPD patients. Our results show that FEV₁ and HRQoL appear to represent different disease aspects influenced by different predictors.     

The paradoxical response to short-acting bronchodilator administration in patients with chronic obstructive pulmonary disease

BackgroundThere are a few studies about paradoxical bronchodilator response (BDR), which means a decrease in forced expiratory volume in 1 second (FEV₁) or forced vital capacity (FVC) after short-acting bronchodilator administration in patients with chronic obstructive pulmonary disease (COPD). We evaluated the effect of paradoxical BDR on the clinical outcomes of COPD patients in South Korea.MethodsWe analyzed the KOrea COpd Subgroup Study team (KOCOSS) cohort data in South Korea between January 2012 and December 2017. BDR was defined as at least a 12% and 200-mL reduction in FEV₁ or FVC after bronchodilator administration.ResultsA total of 1,991 patients were included in this study. A paradoxical BDR was noted in 57 (2.9%) patients and was independently associated with worse dyspnea and poor quality of life. High C-reactive protein (CRP) levels were associated with a paradoxical BDR (OR, 1.05; 95% CI, 1.01–1.09; P=0.003). However, paradoxical BDR was not associated with severe acute exacerbations. Pre-bronchodilator FEV₁ (L) showed a higher area under the curve (AUC) for predicting severe acute exacerbations than the post-bronchodilator FEV₁ (L) in the paradoxical BDR group (0.788 vs. 0.752).ConclusionA paradoxical reduction of FEV₁ or FVC after bronchodilator administration may be associated with chronic inflammation in the airway and independently associated with worse respiratory symptoms and poor quality of life.     

COPD in chronic heart failure: Less common than previously thought?

Background

Using a fixed ratio of forced expiratory volume in 1 s to forced vital capacity (FEV₁/FVC) < 0.70 instead of the lower limit of normal (LLN) to define chronic obstructive pulmonary disease (COPD) may lead to overdiagnosis of COPD in elderly patients with heart failure (HF) and consequently unnecessary treatment with possible adverse health effects.

Objective

The aim of this study was to determine COPD prevalence in patients with chronic HF according to two definitions of airflow obstruction.

Methods

Spirometry was performed in 187 outpatients with stable chronic HF without pulmonary congestion who had a left ventricular ejection fraction <40% (mean age 69 ± 10 years, 78% men). COPD diagnosis was confirmed 3 months after standard treatment with tiotropium in newly diagnosed COPD patients.

Results

COPD prevalence varied substantially between 19.8% (LLN-COPD) and 32.1% (GOLD-COPD). Twenty-three of 60 patients (38.3%) with GOLD-COPD were potentially misclassified as having COPD (FEV₁/FVC < 0.7 but > LLN). In contrast to patients with LLN-COPD, potentially misclassified patients did not differ significantly from those without COPD regarding respiratory symptoms and risk factors for COPD.

Conclusions

One fifth, rather than one third, of the patients with chronic HF had concomitant COPD using the LLN instead of the fixed ratio. LLN may identify clinically more important COPD than a fixed ratio of 0.7.     

Association of serum vitamin D levels with disease severity,systemic inflammation,prior lung function loss and exacerbations in a cohort of patients with chronic obstructive pulmonary disease (COPD)

BackgroundVitamin D deficiency has been associated with chronic disorders including chronic obstructive pulmonary disease (COPD) but the relationships with inflammation, exacerbations and disease progression remain unclear.MethodsIn this monocentric cross-sectional observational study we analyzed the disease status, systemic inflammation, prior exacerbation frequency and loss in lung function in relation to serum 25-hydroxyvitamin D (25-OHD) levels in a cohort of 94 patients with COPD. Serum 25-OHD, C-reactive protein, interleukin-6 and tumor necrosis factor-α were quantified. Exacerbation frequencies and sunlight exposure were assessed. These parameters were analyzed in correlation to the current forced expiratory volume in 1 s (FEV₁), the individual average 3-year FEV₁ decline and the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage.ResultsWe observed fair correlation between serum 25-OHD and the current FEV₁ (r=0.38, P<0.001). Furthermore, mean serum 25-OHD was significantly altered between patients of GOLD stages I–IV (P=0.013). There was weak negative correlation of 25-OHD and the average annual change of the FEV₁ (r=−0.26, P<0.05). Furthermore, we observed fair negative correlation between 25-OHD and C-reactive protein (r=−0.32, P<0.01) as well as weak negative correlation with interleukin-6 (r=−0.23, P<0.05). While the exacerbation frequency significantly differed between GOLD stages (P=0.04), there was no direct association between exacerbations and 25-OHD levels.ConclusionOur data confirm frequent vitamin D deficiency in COPD and point out correlations between 25-OHD levels, systemic inflammation, disease severity and progression.     

Six minute walk distance is a predictor of survival in patients with chronic obstructive pulmonary disease undergoing pulmonary rehabilitation

BACKGROUND:Chronic obstructive pulmonary disease (COPD) is a progressive and distressing disease with a trajectory that is often difficult to predict.OBJECTIVE:To determine whether initial 6 min walk distance (6MWD) or change in 6MWD following inpatient pulmonary rehabilitation (PR) predicted survival.METHODS:Patients referred for PR in 2010 were studied in a retrospective chart review. Measures of 6MWD before and following PR were recorded. Initial 6MWD was categorized as ≥250 m, 150 m to 249 m and ≤149 m. Government databases provided survival status up until December 2013 and survival analyses were performed. Initial 6MWD and a minimally important difference (MID) of ≥30 m were used for survival analysis.RESULTS:The cohort consisted of 237 patients (92 men, 145 women) with severe COPD. Mean (± SD) forced expiratory volume in 1 s (FEV₁) was 0.75±0.36 L, with a mean FEV₁/forced vital capacity (FVC) ratio of 0.57±0.16. Overall three-year survival was 58%. Mean survival for the study period as per predefined categories of 6MWD of ≥250 m, 150 m to 249 m and ≤149 m was 42.2, 37.0 and 27.8 months (P<0.001), respectively, with a three-year survival of 81%, 66% and 34% observed, respectively. Overall mean change in 6MWD was 62±57 m, and a minimal improvement of ≥30 m was observed in 72% of patients. In the lowest walking group, early mortality was significantly higher among those who did not achieve minimal improvement. Older age, male sex and shorter initial 6MWD were negative predictors of survival.CONCLUSION:In patients with severe COPD, initial 6MWD was predictive of survival. Overall survival at three years was only 58% and was especially poor (34%) in patients with low (<150 m) initial walk distance.     

Spirometric Thresholds for Diagnosing COPD: 0.70 or LLN,Pre- or Post-dilator Values?

Abstract

In absence of a gold standard for chronic obstructive pulmonary disease (COPD) it remains difficult to compare the true diagnostic characteristics of the forced expiratory volume in 1 second to the forced vital capacity (FEV₁/FVC) <0.70 and < lower limit of normal (LLN). COPD is a clinical diagnosis, based on symptoms signs and lung function results combined, and an expert panel assessment would be an adequate reference standard. We compared the diagnostic properties of FEV₁/FVC <LLN and <0.70 against this panel diagnosis: 342 participants, aged >50, consulting for persistent cough, but without physician-diagnosed COPD, were prospectively enrolled. All underwent extensive history taking, physical examination, spirometry and diffusion testing. An expert panel, including a board certified respiratory physician, assessed all diagnostic information to determine the presence or absence of COPD and served as reference standard. Then, 104 participants were diagnosed with COPD by the panel. The reproducibility of the panel diagnosis was high (kappa of 0.94). Sensitivity estimates of <0.70 were significantly higher than that of <LLN (0.73 and 0.47, respectively, p < 0.001). The fixed approach was less specific than the LLN (0.95 and 0.99, respectively, p < 0.001). There was no significant difference in diagnostic property when using pre- or post-bronchodilator FEV₁/FVC (p = 0.615). In a symptomatic primary care population, the FEV₁/FVC <0.70 was more accurate to detect COPD.     

Long-term safety of Prolastin®-C,an alpha1-proteinase inhibitor,in Japanese patients with alpha1-antitrypsin deficiency

BackgroundSafety and pharmacokinetics (PK) of alpha₁-proteinase inhibitor, modified process (Alpha-1 MP), was evaluated in a clinical trial of Japanese patients with alpha₁-antitrypsin deficiency (AATD). The present study aimed to evaluate the long-term safety of weekly intravenous infusions of 60 mg/kg Alpha-1 MP in Japanese patients with AATD.MethodsThis was a multi-center, open-label extension (OLE) study that enrolled adult patients with AATD, who had completed the preceding safety and PK clinical trial. Patients were administered with Alpha-1 MP (60 mg/kg) weekly, for 52 weeks, and this could be renewed annually. Alpha1-MP trough levels (C_min) were evaluated, and safety endpoints include: treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), TEAEs potentially related to Alpha-1 MP, chronic obstructive pulmonary disease (COPD) exacerbations, laboratory parameters, vital signs, and pulmonary function tests (forced expiration volume in 1 s [FEV₁] and forced vital capacity [FVC]).ResultsFour patients underwent Alpha-1 MP intravenous infusions at a mean (SD) of 210.8 (9.54) for 213 weeks (four years), with a C_min of 55.73 (4.99) mg/dL. A total of fifty-four TEAEs were reported in four patients, in which most of them were mild (n = 52, 96.3%). Two patients had five SAEs, and all were unrelated to treatment. Three mild TEAEs were potentially related to treatment with Alpha-1 MP. No clinically significant findings in laboratory parameters, COPD exacerbations, or vital signs were observed. There were no identifiable differences in FEV₁ and FVC throughout the study period.ConclusionsLong-term weekly intravenous infusions of 60 mg/kg Alpha-1 MP are generally safe and well-tolerated in Japanese patients with AATD.Clinicaltrials.govNCT02870348; JAPIC CTI: JapicCTI-163194.     

Genetic predisposition to accelerated decline of lung function in COPD

Environmental exposures and genetic susceptibility can contribute to lung function decline in chronic obstructive pulmonary disease (COPD). The environmental factors are better known than the genetic factors. One of the commonest reasons of accelerated forced expiratory volume in one second (FEV₁) decline in COPD is the continuation of the smoking habit. In addition, COPD patients have frequent acute respiratory infections which can also accelerate the decline of FEV₁. All of the gene variants that have been reported in association with accelerated decline of lung function in COPD represent advancement because the findings generate plausible hypotheses about the possible mechanisms by which gene products could accelerate or avert FEV₁ decline. Unfortunately, the results have not been consistently replicated and, animal models required to functionally assess the genetic findings, have not yet yielded sufficient data. Genome-wide association studies should provide more definitive results in COPD and other multigenic conditions. Until these studies are reported, the data to date suggest that products encoded by the alpha-1 antitrypsin, some matrix metalloproteinases, and a number of antioxidant genes are associated with accelerated FEV₁ decline in COPD. Data on gene variants associated with acute exacerbations of COPD are now emerging.     

Effects of bronchoscopic lung volume reduction using transbronchial infusion of autologous blood and thrombin in patients with severe chronic obstructive pulmonary disease

Background

Existing medical treatments have limitations in the management of very severe chronic obstructive pulmonary disease (COPD).

Methods

We performed bronchoscopic lung volume reduction (BLVR) using transbronchial infusion of autologous blood and thrombin (BLVR with blood) in three patients with very severe COPD whose dyspnea could not be relieved by maximum medical management. Two patients underwent BLVR with blood in the left and right lungs at intervals of a half-year or a year, and one patient underwent this procedure in only the right lung. We assessed the changes in pulmonary function, exercise capacity and quality of life before and after BLVR with blood in a total of five procedures.

Results

The subjects were 58- to 74-year-old males. Their forced expiratory volume in one second (FEV₁) percent predicted ranged from 14.8% to 23.4%. BLVR with blood achieved significant improvements as follows (values before → after the procedure, mean ± standard deviation): FEV₁ 0.45r the L → 0.76r the L (P=0.004), inspiratory capacity 1.50cityo L → 2.05±.05c L (P=0.015), 3-minute walk test 46.8nuteo m → 89.6±34.5 m (P=0.004). Lung function peaked several months after BLVR with blood and returned to nearly the baseline level in 6 months, but exercise capacity was better than that at baseline for at least 12 months. St. George’s Respiratory Questionnaire (SGRQ), measured in two patients before and 12 months after the procedure, showed remarkable improvements (−15.6 and −11.9 units).

Conclusions

BLVR with blood is an effective palliative treatment for very severe COPD.     

Onset of Effect of Aclidinium,a Novel,Long-Acting Muscarinic Antagonist,in Patients with COPD

ABSTRACT

Aclidinium bromide is a novel, long-acting, inhaled muscarinic antagonist in development for the treatment of chronic obstructive pulmonary disease (COPD). The aim of this study was to assess the rate of onset of bronchodilation with aclidinium compared with placebo and tiotropium. This was a double-blind, double-dummy, multicenter, crossover study in COPD patients with a post-bronchodilator forced expiratory volume in 1 second (FEV₁) ≥30% and <60% predicted. On study days, patients received single doses of aclidinium 200 μg, tiotropium 18 μg, or placebo. Serial spirometry was conducted from 10 minutes to 3 hours post-dose. The primary variable was the percentage of patients with an increase in FEV₁ of ≥10% above baseline at 30 minutes post-dose. Other assessments included change from baseline in FEV₁ and dyspnea over 3 hours post-dose. A total of 115 patients entered the study. Significantly more patients had an increase in FEV₁ of ≥10% above baseline at 30 minutes with aclidinium and tiotropium versus placebo (49.5% and 51.8% versus 13.8%; p < 0.0001). At 30 minutes, the relative increase from baseline in FEV₁ was significantly higher for aclidinium and tiotropium versus placebo (12% and 11% versus 3%; p < 0.0001). Aclidinium and tiotropium also significantly increased FEV₁ (p < 0.01) and improved the perception of dyspnea compared with placebo at all measured time points from 10 minutes to 3 hours post-dose. In conclusion, aclidinium provided effective bronchodilation, similar to that seen with tiotropium, with significant improvements compared with placebo observed from 10 minutes post-dose.     

Effects of yoga training in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

Introduction

Currently, several studies have assessed the effect of yoga training on the management of chronic obstructive pulmonary disease (COPD), but these studies involved a wide variation of sample and convey inconclusive results. Hence, the present study was performed a systematic review and meta-analysis to investigate the efficacy of yoga training in COPD patients.

Methods

PubMed, EMBASE, the Cochrane Library, Google Scholar, and ClinicalTrials.gov databases were searched for relevant studies. The primary outcomes were forced expiratory volume in one second (FEV₁), FEV₁% predicted (% pred). Secondary outcomes included 6-min walking distance (6 MWD), arterial oxygen tension (PaO₂), and arterial carbon dioxide tension (PaCO₂). Weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated, and heterogeneity was assessed with the I² test.

Results

Five randomized controlled trials (RCTs) involving 233 patients fulfilled the inclusion criteria. Yoga training significantly improved FEV₁ (WMD: 123.57 mL, 95% CI: 4.12-243, P=0.04), FEV₁% pred (WMD: 3.90%, 95% CI: 2.27-5.54, P<0.00001), and 6 MWD (WMD: 38.84 m, 95% CI: 15.52-62.16, P=0.001). However, yoga training had no significant effects on PaO₂ (WMD: 1.29 mmHg, 95% CI: –1.21-3.78, P=0.31) and PaCO₂ (WMD: –0.76 mmHg, 95% CI: –2.06-0.53, P=0.25).

Conclusions

The current limited evidence suggested that yoga training has a positive effect on improving lung function and exercise capacity and could be used as an adjunct pulmonary rehabilitation program in COPD patients. However, further studies are needed to substantiate our preliminary findings and to investigate the long-term effects of yoga training.     

Efficacy and safety of indacaterol and tiotropium in COPD patients according to dyspnoea severity

BackgroundGuidelines for chronic obstructive pulmonary disease (COPD) recommend that treatment choices be based partly on symptoms.MethodsA post-hoc analysis of pooled data from clinical studies compared the efficacy and safety of once-daily inhaled bronchodilators indacaterol (150 and 300 μg) and open-label tiotropium (18 μg) according to baseline dyspnoea severity on the modified Medical Research Council (mMRC) scale in patients with COPD (mMRC scores <2 = ‘less dyspnoea’; scores ≥2 = ‘more dyspnoea’). Outcomes were assessed after 26 weeks.ResultsThe analysis included 3177 patients. In patients with less dyspnoea: indacaterol (both doses) improved 24-h post-dose (‘trough’) forced expiratory volume in 1 s (FEV₁), transition dyspnoea index (TDI) and St George's Respiratory Questionnaire (SGRQ) total scores at week 26 and reduced the risk of COPD exacerbations vs placebo; and open-label tiotropium improved trough FEV₁ and TDI total score vs placebo at week 26. In patients with more dyspnoea: indacaterol (both doses) improved trough FEV₁, TDI and SGRQ total scores at week 26; indacaterol 300 μg was the only treatment to improve the TDI total score by more than the minimum clinically important difference (≥1 point) vs placebo; and open-label tiotropium improved trough FEV₁, TDI total score at week 26 and decreased the risk of COPD exacerbations vs placebo. In both subgroups, all treatments were well tolerated.ConclusionsIn patients with less dyspnoea, all treatments had similar effects. Indacaterol 300 μg may be a useful treatment option for patients with COPD who experience more severe breathlessness.     

Small airways ventilation heterogeneity and hyperinflation in COPD: Response to tiotropium bromide

In chronic obstructive pulmonary disease (COPD) patients tiotropium bromide has been shown to improve forced expiratory volume in one second (FEV₁) and inspiratory capacity (IC). We investigated whether the mechanism leading to these improvements is related to small airways ventilation heterogeneity, assessed by multiple breath washout tests. Forty stable tiotropium-free COPD patients (FEV₁: 27%–78% predicted) were studied before and 90 min after administration of tiotropium bromide on visit₀, and following 3 and 6 weeks of tiotropium bromide treatment (visit_3wks, visit_6wks). After study completion, COPD patients were classified into two subgroups according to degree of hyperinflation at visit₀ (Hyp−, Hyp+). The Hyp+ group showed significant increases in trough (ie, pre-dose) FEV₁ and IC after 3 and 6 weeks of tiotropium bromide, and the 90 min tiotropium bromide responses of FEV₁ and IC were significant at visit₀ (p ≤ 0.001 for both) but not during subsequent visits. The Hyp- group showed significant FEV₁ increases 90 min after tiotropium bromide on all three visits (all p < 0.005) but no sustained increase in trough values. In both COPD subgroups, the grossly abnormal ventilation heterogeneity barely showed any significant improvements with tiotropium bromide in the conductive airways (without changes in trough value) and no changes at all in the acinar airways. We conclude that the sustained improvements in trough IC and FEV₁ with tiotropium bromide predominantly observed in COPD patients with considerable hyperinflation, are unrelated to small airways ventilation heterogeneity.     

Acute Effect of Bronchodilator on Intrathoracic Airway Wall Compliance in COPD Patients

Purpose

In patients with chronic obstructive pulmonary disease (COPD), bronchial responsiveness after acute administration of short acting bronchodilators is conventionally assessed by measuring the improvement of forced expiratory volume in the first second (FEV₁) during a maximal forced expiratory maneuver. This study aimed to measure the variation of intrathoracic airway wall compliance (AWC) after acute administration of short acting beta-2 agonist in COPD patients since this might influence the final modification of airway caliber during maximal expiratory effort and the resulting bronchodilation as inferred by FEV₁ changes.

Methods

In a group of 10 patients suffering from COPD, intrathoracic AWC was measured at middle (50% of Forced Vital Capacity (FVC) and low (75% of FVC) lung volumes using the interrupter method during forced expiratory maneuver in basal conditions and after acute inhalation of albuterol (salbutamol) (400 mcg by MDI). Ten healthy subjects were examined similarly as a control group.

Results

Lower values of baseline intrathoracic AWC at both lung volumes were found in COPD patients (1.72?±?0.20 ml/cmH₂O and 1.08?±?0.20 ml/cmH₂O, respectively) as compared to controls (2.28?±?0.27 ml/cmH₂O and 1.44?±?0.22 ml/cmH₂O, respectively) (p?<?0.001). In COPD patients, AWC increased significantly at both lung volumes after salbutamol, amounting to 1.81?±?0.38 ml/cmH₂O and 1.31?±?0.39 ml/cmH₂O, respectively (p?<?0.01), but the relative change was not different from that observed in controls.

Conclusion

In COPD patients, AWC is reduced compared to controls, but after bronchodilator, the intrathoracic airways become more compliant. The consequent increased collapsibility under high positive pleural pressure could limit the airway caliber improvement seen after bronchodilator, as assessed by the FEV₁ changes during the forced expiratory maneuver, underestimating the effective bronchodilation achieved in these patients.

     

A new staging strategy for chronic obstructive pulmonary disease

Background:

The best method for expressing lung function impairment is undecided. We tested in a population of patients with chronic obstructive pulmonary disease (COPD) whether forced expiratory volume in 1 second (FEV₁) or FEV₁ divided by height squared (FEV₁/ht²) was better than FEV₁ percent predicted (FEV₁PP) for predicting survival.

Method:

FEV₁, FEV₁PP, and FEV₁/ht² recorded post bronchodilator were compared as predictors of survival in 1095 COPD patients followed for 15 years. A staging system for severity of COPD was defined from FEV₁/ht² and compared with the Global Initiative for Obstructive Lung Disease (GOLD) staging system.

Result:

FEV₁/ht² was a better univariate predictor of survival in COPD than FEV₁ and both were better than FEV₁PP. The best multivariate model for predicting survival included FEV₁/ht², age and sex. Comparing the GOLD stages with the FEV₁/ht² groups found that survival was more coherent within each FEV₁/ht group than it was within each GOLD stage. FEV₁/ht² had 60% more people in its most severe group than the severest GOLD stage with these extra subjects having equivalently poor survival and had 155% more in the least severe group with equivalent survival. GOLD staging misclassified 51% of subjects with regard to survival.

Conclusion:

We conclude that GOLD criteria using FEV₁PP do not optimally stage COPD with regard to survival. An alternative strategy using FEV₁/ht² improves the staging of this disease. Studies which stratify COPD patients to determine the effect of interventions such as drug trials, rehabilitation, or management guidelines should consider alternatives to the GOLD classification.