Tiotropium improves walking endurance in COPD

Comparative measurement properties of constant work rate cycling and the endurance shuttle walking test in COPD: the TORRACTO® clinical trial

Background:

Exercise tolerance is an important endpoint in chronic obstructive pulmonary disease (COPD) clinical trials. Little is known about the comparative measurement properties of constant work rate cycle ergometry (CWRCE) and the endurance shuttle walking test (ESWT). The objective of this sub-analysis of the TORRACTO^® study was to directly compare the endurance measurement properties of CWRCE and ESWT in patients with COPD in a multicentre, multinational setting. We predicted that both tests would be similarly reliable, but that the ESWT would be more responsive to bronchodilation than CWRCE.

Methods:

This analysis included 151 patients who performed CWRCE and ESWT at baseline and week 6 after receiving once-daily placebo, tiotropium/olodaterol (T/O) 2.5/5 μg or T/O 5/5 μg. Reproducibility was assessed by comparing their respective performance at baseline and week 6 in the placebo group. Responsiveness to bronchodilation was assessed by comparing endurance time at week 6 with T/O with baseline values and placebo. The locus of symptom limitation and end-exercise Borg scales for breathing and leg discomfort for both tests were also analysed.

Results:

The intraclass correlation coefficients for CWRCE and ESWT were 0.56 [95% confidence interval (CI) 0.37–0.71] and 0.75 (95% CI 0.63–0.84). More patients were limited by breathing discomfort during the ESWT than during CWRCE, whereas more patients were limited by leg discomfort or breathing/leg discomfort during CWRCE than the ESWT (p <0.0001). Both tests were responsive to bronchodilator treatment: there was a 19% increase in endurance time from baseline at week 6 (p = 0.0006) assessed with CWRCE, and a 20% increase in endurance time assessed with ESWT (p = 0.0013).

Conclusions:

Both exercise tests performed well in a multicentre clinical trial. Although the locus of symptom limitation differed between the two tests, both were reliable and responsive to bronchodilation. For future clinical trials, the choice of test should depend on the study requirements.

ClinicalTrials.gov identifier:

NCT01525615.

The reviews of this paper are available via the supplemental material section.

Comparison of Vibrating Mesh and Jet Nebulizers During Noninvasive Ventilation in Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Background: Advances in aerosol technology have improved drug delivery efficiency during noninvasive ventilation (NIV). Clinical evaluation of the efficacy of aerosol therapy during NIV in the treatment of acute exacerbation of chronic obstructive pulmonary disease (COPD) is very limited. The aim of our study was to compare the efficacy of bronchodilators administered through a vibrating mesh nebulizer (VMN) and jet nebulizer (JN) during NIV in patients with acute exacerbation of COPD. Methods: Prospective randomized cross-over study included 30 patients treated with NIV for acute exacerbation of COPD in an acute care hospital. Patients were consented and enrolled after stabilization of acute exacerbation (3-5 days after admission). Subjects were randomly assigned into two treatment arms receiving salbutamol (2.5 mg): with VMN (Aerogen Solo) and JN (Sidestream) positioned between the leak port and the nonvented oronasal mask during bilevel ventilation with a single-limb circuit. Measurements (clinical data, pulmonary function tests [PFTs], and arterial blood gases) were performed at baseline, 1, and 2 hours after treatment. Results: All measured PFT parameters significantly increased in both groups, but numerically results were better after inhalation with VMN than with JN: for forced expiratory volume in 1 second (FEV₁) (mean increase from baseline to 120 minutes-165 ± 64 mL vs. 116 ± 46 mL, p = 0.001) and for forced vital capacity (FVC) (mean increase-394 ± 154 mL vs. 123 ± 57 mL, p < 0.001). There was also a statistically significant reduction in respiratory rate and in Borg dyspnea score after therapy with VMN in comparison with the conventional JN. In both groups, there were improvements in PaCO₂, but with VMN these changes were significantly higher. Conclusion: Bronchodilator administration in patients with acute exacerbation of COPD during NIV with VMN resulted in clinically significant improvements in FVC and in Borg dyspnea score. Additional studies required to determine the impact on clinical outcomes.

Bronchodilators for hyperinflation in COPD associated with biomass smoke: clinical trial

Introduction

The efficacy of long-acting bronchodilators for COPD associated with biomass (BE-COPD) has not been properly evaluated.

Objective

To determine the acute effect of indacaterol (IND) 150 μg q.d and tiotropium (TIO) 18 μg q.d. on lung hyperinflation, walking distance (WD) and dyspnea during the six-minute walking test (6MWT) in moderate BE-COPD at 30, 60 and 240 mins post-drug administration.

Design

Randomized, controlled, open-level, crossover noninferiority clinical trial. Forty-two women with BE-COPD were randomly assigned to a bronchodilator sequence: IND–TIO or vice versa.

Results

There were statistically significant changes over time in inspiratory capacity (IC) (p<0.0001), FEV₁ (p<0.0001) and FVC (p<0.0001) when IND was used. When TIO was administered, an increase over all time periods was observed only for FEV₁ (p<0.0001) and FVC (p<0.0001), whereas for IC an increase was observed only at 30 mins and 24 hrs after TIO administration. We did not find clinically significant increases in WD and dyspnea after the administration of both bronchodilators.

Conclusion

Both IND and TIO showed significant and fast onset improvement in hyperinflation. Therefore, either of them may be recommended as a first line of treatment for COPD associated with BE-COPD.

Effect of 12 weeks of once-daily tiotropium/olodaterol on exercise endurance during constant work-rate cycling and endurance shuttle walking in chronic obstructive pulmonary disease

Background:

The TORRACTO^® study evaluated the effects of tiotropium/olodaterol versus placebo on endurance time during constant work-rate cycling and constant speed shuttle walking in patients with chronic obstructive pulmonary disease (COPD) after 12 weeks of treatment.

Methods:

The effects of once-daily tiotropium/olodaterol (2.5/5 and 5/5 μg) on endurance time during constant work-rate cycle ergometry (CWRCE) after 6 and 12 weeks of treatment were compared with placebo in patients with COPD in a randomized, double-blind, placebo-controlled, parallel-group clinical trial. Endurance time during the endurance shuttle walk test (ESWT) after 6 and 12 weeks of treatment was also evaluated in a subset of patients.

Results:

A total of 404 patients received treatment, with 165 participating in the ESWT substudy. A statistically significant improvement in endurance time during CWRCE was observed after 12 weeks (primary endpoint) with tiotropium/olodaterol 5/5 µg [14% (p = 0.02)] but not with tiotropium/olodaterol 2.5/5 µg [9% (p = 0.14)] versus placebo. In the ESWT substudy, a trend to improvement in endurance time during ESWT after 12 weeks (key secondary endpoint) was observed with tiotropium/olodaterol 5/5 µg [21% (p = 0.055)] and tiotropium/olodaterol 2.5/5 µg [21% (p = 0.056)] versus placebo.

Conclusion:

Tiotropium/olodaterol 5/5 µg improved endurance time during cycle ergometry versus placebo, with a strong tendency to also improve walking endurance time.

[ClinicalTrials.gov identifier: NCT01525615.]

The once-daily fixed-dose combination of olodaterol and tiotropium in the management of COPD: current evidence and future prospects

Long-acting bronchodilators are the cornerstone of pharmacologic treatment of chronic obstructive pulmonary disease (COPD). Spiolto® or Stiolto® is a fixed-dose combination (FDC) containing two long-acting bronchodilators, the long-acting muscarinic receptor antagonist tiotropium (TIO) and the long-acting β2-adrenoceptor agonist olodaterol (OLO), formulated in the Respimat® Soft Mist™ inhaler. A total of 13 large, multicentre studies of up to 52 weeks' duration have documented its efficacy in more than 15,000 patients with COPD. TIO/OLO 5/5 µg FDC significantly increases pulmonary function compared with placebo and its respective constituent mono-components TIO 5 µg and OLO 5 µg. TIO/OLO 5/5 µg also results in statistically and clinically significant improvements in patient-reported outcomes, such as dyspnoea, use of rescue medication, and health status. Addition of OLO 5 µg to TIO 5 µg reduces the rate of moderate-to-severe exacerbations by approximately 10%. Compared with placebo and TIO 5 µg, TIO/OLO 5/5 µg significantly improves exercise capacity (e.g. endurance time) and physical activity, the latter increase being reached by a unique combination behavioural modification intervention, dual bronchodilatation and exercise training. Overall, the likelihood for patients to experience a clinically significant benefit is higher with TIO/OLO 5/5 µg than with its constituent mono-components, which usually yield smaller improvements which do not always reach statistical significance, compared with baseline or placebo. This supports the early introduction of TIO/OLO 5/5 µg in the management of patients with symptomatic COPD.

Effects of combined tiotropium/olodaterol on inspiratory capacity and exercise endurance in COPD

Two replicate, double-blind, 6-week, incomplete-crossover studies (MORACTO 1 and 2) assessed the effects of tiotropium/olodaterol on inspiratory capacity and exercise endurance time in patients with moderate to severe chronic obstructive pulmonary disease.For each patient, four of five treatments were administered once daily for 6 weeks, with a 21-day washout between treatments: tiotropium/olodaterol 2.5/5 µg or 5/5 µg, tiotropium 5 µg, olodaterol 5 µg or placebo, all via the Respimat inhaler. Primary outcomes were inspiratory capacity prior to exercise and exercise endurance time during constant work-rate cycle ergometry to symptom limitation at 75% of peak incremental work rate after 6 weeks (2 h post-dose).295 and 291 patients were treated in MORACTO 1 and 2, respectively. Tiotropium/olodaterol 2.5/5 and 5/5 µg provided significant improvements in inspiratory capacity versus placebo and monotherapies (p<0.0001), and significant improvements in exercise endurance time versus placebo (p<0.0001). Intensity of breathing discomfort was reduced following both doses of tiotropium/olodaterol versus placebo (p<0.0001).Once-daily tiotropium/olodaterol yielded improvements in lung hyperinflation versus placebo and statistically significant improvements versus monotherapies. Tiotropium/olodaterol also showed improvements in dyspnoea and exercise tolerance versus placebo but not consistently versus monotherapies.

Use of exercise testing in the evaluation of interventional efficacy: an official ERS statement

This document reviews 1) the measurement properties of commonly used exercise tests in patients with chronic respiratory diseases and 2) published studies on their utilty and/or evaluation obtained from MEDLINE and Cochrane Library searches between 1990 and March 2015.

Exercise tests are reliable and consistently responsive to rehabilitative and pharmacological interventions. Thresholds for clinically important changes in performance are available for several tests. In pulmonary arterial hypertension, the 6-min walk test (6MWT), peak oxygen uptake and ventilation/carbon dioxide output indices appear to be the variables most responsive to vasodilators. While bronchodilators do not always show clinically relevant effects in chronic obstructive pulmonary disease, high-intensity constant work-rate (endurance) tests (CWRET) are considerably more responsive than incremental exercise tests and 6MWTs. High-intensity CWRETs need to be standardised to reduce interindividual variability. Additional physiological information and responsiveness can be obtained from isotime measurements, particularly of inspiratory capacity and dyspnoea. Less evidence is available for the endurance shuttle walk test. Although the incremental shuttle walk test and 6MWT are reliable and less expensive than cardiopulmonary exercise testing, two repetitions are needed at baseline. All exercise tests are safe when recommended precautions are followed, with evidence suggesting that no test is safer than others.

Effects of a combination of umeclidinium/vilanterol on exercise endurance in patients with chronic obstructive pulmonary disease: two randomized, double-blind clinical trials

OBJECTIVE

Exercise intolerance is a hallmark of chronic obstructive pulmonary disease (COPD).

METHODS

Patients with COPD were randomized in two multicentre, double-blind, incomplete block crossover studies. Patients received two of six treatments in sequence (12 weeks each): placebo, umeclidinium (UMEC)/vilanterol (VI) (125/25 mcg or 62.5/25 mcg), VI (25 mcg) or UMEC (62.5 mcg or 125 mcg). Exercise endurance time (EET) and trough forced expiratory volume in 1 second (FEV1) (Week 12) were co-primary endpoints. Safety was monitored throughout.

RESULTS

Both studies showed similar 3-hour post-dose EET improvements from baseline for UMEC/VI (Week 12). Significant EET improvements were observed with both UMEC/VI doses versus placebo at Week 12 in Study 418 (UMEC/VI 125/25 mcg: 65.8 s; p = 0.005; UMEC/VI 62.5/25 mcg: 69.4 s; p = 0.003), but not in Study 417, where a placebo effect was evident. Post hoc integrated data analysis showed significant but smaller EET improvements for both UMEC/VI doses versus placebo at Week 12 (UMEC/VI 125/25 mcg: 47.5 s; p = 0.002; UMEC/VI 62.5/25 mcg: 43.7 s; p = 0.001). Both studies showed trough FEV1 improvements at Week 12 for both UMEC/VI doses. The incidence of adverse events was similar between treatment groups within each study.

CONCLUSIONS

UMEC/VI improved lung function and EET.

Does Improving Exercise Capacity and Daily Activity Represent the Holistic Perspective of a New COPD Approach?

In COPD patients a reduced daily activity has been well documented, resulting from both respiratory and non-respiratory manifestations of the disease. An evaluation by multisensory armband has confirmed that daily physical activity is mainly associated with dynamic hyperinflation, regardless of COPD severity. This aspect is crucial, since exercise capacity is closely correlated to life expectancy. Notwithstanding the causal key role of lung impairment in the patient's symptoms, some authors have suggested that other factors, such as systemic inflammation and co-morbidities, have an important role, particularly as mortality risk factors. Many studies suggest the efficacy of bronchodilators and rehabilitation in improving exercise capacity, and, speaking in terms of daily life, in increasing the number of days in which patients are able to perform their usual activities. On this evidence, the first aim in the management of COPD should be to improve exercise capacity and daily activity since these outcomes have direct effects on patients' quality of life, co-morbidities (heart and metabolic diseases), and prognosis. Thus, improving physical activity represents a modern approach aimed at dealing with both pulmonary and systemic manifestations of the disease. It is however worth of notice to remember that in patients affected by COPD the relationship between the improvement of "potential" exercise capacity and daily physical activity has been found to be only moderate to weak. Obtaining a significant behavior modification with regard to daily physical activity, together with the optimization of therapy thus represents currently the true challenge.

Effects of pharmacologic treatment based on airflow limitation and breathlessness on daily physical activity in patients with chronic obstructive pulmonary disease

BACKGROUND

Improvement in the daily physical activity (PA) is important for the management of chronic obstructive pulmonary disease (COPD). However, the effects of pharmacologic treatment on PA are not well understood. We evaluated the effects of additional medications, including bronchodilator with or without inhaled corticosteroid, based on airflow limitation and breathlessness on the PA in COPD patients and the factors that could predict or affect the improvement in PA.

METHODS

A prospective non-randomized observational study was employed. Twenty-one COPD subjects without any other diseases that might reduce PA were recruited. The PA was measured with a triaxial accelerometer for 2 weeks, and pulmonary function tests and incremental shuttle walking tests were administered before and after 4-week treatment with an additional medication.

RESULTS

Bronchodilation was obtained by additional medication. The mean values of PA evaluated by metabolic equivalents (METs) at ≥3.0 METs and the duration of PA at ≥3.0 METs and ≥3.5 METs were improved by medication. The % change in the duration of PA at ≥3.5 METs was significantly correlated with the baseline functional residual capacity (FRC), residual volume, and inspiratory capacity/total lung capacity. However, the % change in the duration of PA at any intensity was not correlated with the % changes of any values of the pulmonary function tests or incremental shuttle walking test except the PA at ≥2.5 METs with FRC.

CONCLUSION

Medication could improve the PA in patients with COPD, especially at a relatively high intensity of activity when medication was administered based on airflow limitation and breathlessness. The improvement was seen in the patients with better baseline lung volume, but was not correlated with the improvements in the pulmonary function tests or exercise capacity.

Patient-reported outcomes and considerations in the management of COPD: focus on aclidinium

Chronic obstructive pulmonary disease (COPD) is a complex heterogeneous disease, in which several factors combine to give the final clinical expression. Both early and more recent studies have shown that forced expiratory volume in one second (FEV1), despite being an extremely important parameter to predict the progression of the disease, is a poor surrogate marker for symptoms perception. Accordingly, patient-reported outcomes (PROs) have gained popularity as a measure of the impact of treatment from the patients' perspective, since they represent the individuals' perception of their health status, beyond any physiological limitations. Several such PROs, therefore, are currently included in multidimensional COPD evaluation. This multidimensional approach helps identify different patient types and individualize, up to a certain point, pharmacological treatment. In this multidimensional approach it is important to highlight the importance of long-acting bronchodilators in COPD treatment strategies. Long-acting bronchodilators are cost-effective and have been shown to achieve the greatest functional and clinical improvements in COPD. As a result, long-acting bronchodilators are now the main pharmacological treatment for COPD at all stages of the disease. Until recently, tiotropium was the leading bronchodilator for the treatment of COPD. The clinical development of this medication, unprecedented in inhaled therapy, involved tens of thousands of patients and yielded consistent outcomes in terms of lung function, symptoms, quality of life, exacerbations, and prognosis. However, new long-acting bronchodilators have recently been developed or are currently under development. In this review, we evaluate the effects of aclidinium bromide, a novel long-acting bronchodilator, on PROs in COPD. Aclidinium is a novel long-acting muscarinic antagonist with a good safety profile for the treatment of COPD, and has proven efficacy in both objective functional measurements and PROs. Comparison studies with tiotropium have shown it to have similar lung function improvement and a similar impact on PROs, including quality of life or symptom perception.

Prospective validation of the endurance shuttle walking test in the context of bronchodilation in COPD

This study focused on repeatability data and minimal important difference (MID) estimates of the endurance shuttle walking test (ESWT). 255 chronic obstructive pulmonary disease patients (forced expiratory volume in 1 s 54.7±13.2% predicted) completed four ESWTs at different times during the 8-week study: two under baseline conditions with tiotropium (1 week apart), one after a single dose and one after 4 weeks of either fluticasone propionate/salmeterol combination or placebo in addition to tiotropium. 97 patients performed all the tests with a portable metabolic system. Reproducibility of test performance and cardiorespiratory response was investigated with the data obtained on the first two ESWTs. The mean differences between the first two ESWT performances (-6.7±72.2 s and -7.3±113.1 m for endurance time and walking distance, respectively) were not statistically significant. The between-test end-exercise and isotime values for each cardiorespiratory parameter were not significantly different from each other. With the exception of arterial oxygen saturation by pulse oximetry, the repeatability of cardiorespiratory adaptations to ESWT was also confirmed with strong Pearson and intraclass correlation coefficients. Finally, changes of 56-61 s and 70-82 m in endurance time and distance walked, respectively, were perceived by patients. This study provides methodological information supporting the reliability of the ESWT and suggests MID estimates for this test.

Minimal clinically important differences in pharmacological trials

The concept of a minimal clinically important difference (MCID) is well established. Here, we review the evidence base and methods used to define MCIDs as well as their strengths and limitations. Most MCIDs in chronic obstructive pulmonary disease (COPD) are empirically derived estimates applying to populations of patients. Validated MCIDs are available for many commonly used outcomes in COPD, including lung function (100 ml for trough FEV1), dyspnea (improvement of ≥ 1 unit in the Transition Dyspnea Index total score or 5 units in the University of California, San Diego Shortness of Breath Questionnaire), health status (reduction of 4 units in the St George's Respiratory Questionnaire total score), and exercise capacity (47.5 m for the incremental shuttle walking test, 45-85 s for the endurance shuttle walking test, and 46-105 s for constant-load cycling endurance tests), but there is currently no validated MCID for exacerbations. In a clinical trial setting, many factors, including study duration, withdrawal rate, baseline severity, and Hawthorne effects, can influence the measured treatment effect and determine whether it reaches the MCID. We also address recent challenges presented by clinical trials that compare active treatments and suggest that MCIDs should be used to identify the additional proportion of patients who benefit, for example, when one drug is replaced by another or when a second drug is added to a first. We propose the term "minimum worthwhile incremental advantage" to describe this parameter.

Validation of the i-BODE index as a predictor of hospitalization and mortality in patients with COPD participating in pulmonary rehabilitation

Abstract The aim of this study was to examine the value of the i-BODE index to predict hospital admission and to confirm its usefulness to predict mortality in a Danish population. The incremental shuttle walking test (ISWT) is widely used in the UK and Europe and previous work has examined the replacement of the 6MWT with the ISWT within the BODE index for predicting the prognosis of COPD (i-BODE). The 674 patients included in the analysis participated in a 7-week pulmonary rehabilitation program from 2002 to 2011. The National Health Services Central Register ascertained vital status and provided information on all hospital admissions. The mean follow-up period was 66 months (range 11-118 months). Cox proportional hazards model was used to identify factors that significantly predicted mortality and time to first hospital admission. The i-BODE index as well as body mass index, MRC dyspnea grade, and exercise capacity (ISWT) were significantly associated with all-cause mortality. The adjusted hazard ratio for death per one point increase in the i-BODE score was 1.28 (95% confidence interval 1.20 to 1.37). The i-BODE index was also a significant predictor of hospitalization, both for all causes and COPD exacerbation. Patients in the highest i-BODE quartile had a median time to first hospitalization of 17 months compared to 51 months for patients in the lowest quartile. The i-BODE index is a significant predictor of hospital admission and thus health care utilization, and also mortality.

Exercise for patients with COPD: an integral yet underutilized intervention

Chronic obstructive pulmonary disease (COPD) was the third leading cause of mortality in the United States in 2009 and accounts for millions of dollars in health care expenses annually. It is characterized by slow declines in functional ability and exercise tolerance, which are strongly predictive of poor health-related quality of life and survival. The cycle of physical, social, and psychosocial consequences of COPD is more easily prevented than remedied; therefore, maintaining baseline respiratory function is a key goal of early treatment. Although medical management of COPD is generally well understood and implemented by most primary care physicians, multidisciplinary approaches that include nonpharmacologic modalities (eg, exercise training) are not often used. Exercise training can alleviate dyspnea and improve exercise tolerance and health-related quality of life in patients with mild-to-severe COPD. Pulmonary rehabilitation, which includes exercise training, nutritional and psychological counseling, and patient education, is an important component of COPD treatment and management programs, and is currently underutilized in the United States. This article addresses the role of exercise as part of a multidisciplinary approach to the management of COPD, especially with regard to pulmonary rehabilitation.

Exercise and COPD: therapeutic responses, disease-related outcomes, and activity-promotion strategies

Chronic obstructive pulmonary disease (COPD) reduces patients' exercise capacities and their abilities to perform daily physical activities, thereby increasing morbidity and mortality rates. The cycle of dyspnea, deconditioning, and declining physical activity not only accelerates the progression of COPD but also increases the risk for developing or aggravating metabolic and cardiovascular diseases. Cardiovascular and metabolic comorbidities also limit physical function, and their disabling effects in combination with COPD may be greater than the effects of each disease alone. The impact of COPD and its treatment on the ability to exercise, and the degree of physical activity in daily life, can be measured by field-based tests (eg, the 6-minute walk test or incremental and endurance shuttle-walk test), laboratory-based tests (eg, incremental or constant work-rate treadmill and cycle-ergometer tests), and physical activity assessments (eg, questionnaires and accelerometers). Walking tests increase oxygen consumption and desaturation in patients with COPD more than cycling tests with similar work-rate profiles and may more closely resemble patients' normal activities. Despite the questionable relevance of exercise testing to patients' daily functionality, exercise parameters remain important predictors of survival in patients with COPD. Treatment of COPD (pharmacotherapy, pulmonary rehabilitation, or both) can increase exercise capacity and physical activity in daily life, which potentially slows the decline of lung function, reduces the frequencies of exacerbations and hospitalizations, decreases mortality, slows the progression of comorbidities, improves health-related quality of life, and increases the activity reserve for routine function. This article examines the interactions of reduced physical activity and decreased exercise capacity with the progression of COPD, comorbidities, and mortality. The article also describes the available exercise tests for patients with COPD and reviews the evidence indicating that treating COPD improves exercise capacity. Notably, it appears that even mild COPD reduces exercise capacity and daily physical activity, indicating the need for early intervention.

Responsiveness of Various Exercise-Testing Protocols to Therapeutic Interventions in COPD

Exercise intolerance is a key element in the pathophysiology and course of Chronic Obstructive Pulmonary Disease (COPD). As such, evaluating exercise tolerance has become an important part of the management of COPD. A wide variety of exercise-testing protocols is currently available, each protocol having its own strengths and weaknesses relative to their discriminative, methodological, and evaluative characteristics. This paper aims to review the responsiveness of several exercise-testing protocols used to evaluate the efficacy of pharmacological and nonpharmacological interventions to improve exercise tolerance in COPD. This will be done taking into account the minimally important difference, an important concept in the interpretation of the findings about responsiveness of exercise testing protocols. Among the currently available exercise-testing protocols (incremental, constant work rate, or self-paced), constant work rate exercise tests (cycle endurance test and endurance shuttle walking test) emerge as the most responsive ones for detecting and quantifying changes in exercise capacity after an intervention in COPD.

Indacaterol 75 μg once daily for the treatment of patients with chronic obstructive pulmonary disease: a North American perspective

Chronic obstructive pulmonary disease (COPD) is a progressive disease in which patients become increasingly disabled by their symptoms and limited in their activities. Health-related quality of life may be profoundly impaired even in the early stages of the disease. Treatment with long-acting inhaled bronchodilators can improve lung function, symptoms and health status and reduce exacerbations of COPD. This review profiles the efficacy, safety and tolerability of indacaterol, an inhaled β(2)-agonist bronchodilator for once-daily maintenance treatment of patients with COPD. After 12 weeks of treatment with a once-daily dose of 75 µg (the dose approved in the USA and Canada) in patients with moderate to severe COPD, compared with placebo, indacaterol provided significant and clinically relevant levels of bronchodilation [difference in trough forced expiratory volume in 1 s: 131 ml; 95% confidence interval (CI) 104-159; p < 0.001], together with significant reductions in symptom scores (difference in transition dyspnea index total score: 0.84 points; 95% CI 0.37-1.31; p < 0.001) and improvements in health status (difference in St George's Respiratory Questionnaire total score: -3.8 units; 95% CI -5.6 to -2.0; p < 0.001). The overall safety and tolerability of once-daily treatment with indacaterol 75 µg for 12 weeks did not differ in any substantial aspect from placebo treatment. Indirect comparisons analyzing pooled clinical data and meta-analyses suggest that treatment with indacaterol 75 µg once daily may be effective in reducing exacerbations of COPD, and that its effects on lung function and health status will be comparable with other currently available inhaled long-acting bronchodilators used for COPD. Treatment with indacaterol 75 µg once daily provides effective bronchodilation, improves dyspnea and health status, and has a well characterized profile of safety and tolerability.

Modifying the course of chronic obstructive pulmonary disease: looking beyond the FEV1

COPD is defined by airflow limitation that is not fully reversible and is usually progressive. Thus, airflow obstruction (measured as FEV(1)) has traditionally been used as the benchmark defining disease modification with therapy. However, COPD exacerbations and extrapulmonary effects are common and burdensome and generally become more prominent as the disease progresses. Therefore, disease progression should be broader than FEV(1) alone. Interventions that reduce the frequency or severity of exacerbations or ameliorate extrapulmonary effects should also be considered disease modifiers. A narrow focus on FEV(1) will fail to capture all the beneficial effects of therapy on disease modification. Although smoking cessation has been unequivocally demonstrated to slow the rate of FEV(1) decline, inhaled corticosteroid-long-acting bronchodilator therapy may also have modest effects according to post hoc analysis. Maintenance pharmacotherapy with inhaled long-acting anti-muscarinic or β-adrenergic agents or combined β-adrenergic--inhaled corticosteroid reduces symptoms, improves lung function, reduces the frequency of exacerbations, and improves exercise capacity and HRQL. Pulmonary rehabilitation reduces symptom burden, increases exercise capacity, improves HRQL, and reduces health care utilization, probably through reducing the severity of exacerbations. Smoking cessation, lung volume reduction surgery, inhaled maintenance pharmacotherapy, and pulmonary rehabilitation administered in the post-exacerbation period may reduce mortality in COPD. These improvements over multiple outcome areas and over relatively long durations suggest that disease modification is indeed possible with existing therapies for COPD. Therefore, therapeutic nihilism in COPD is no longer warranted.

Role of exercise in testing and in therapy of COPD

The stair-climbing test, 6MWT, and shuttle test are exercise tests that requires less technical support than the CPET and are more available to any physician. The 6MWT is the simplest and most likely to be cost effective, as it provides useful information regarding prognosis, ADLs, and health care use at a very low cost. In addition, the 6MWT can be used to evaluate response to several interventions, including physical rehabilitation, medications, lung volume reduction interventions, and transplantation. The 6MWT has also been useful in and has become an integral part of the evaluation and response to treatment in other medical conditions, including congestive heart failure, pulmonary hypertension, and pulmonary fibrosis. The stair-climbing test seems to be most useful for preoperative evaluations when a CPET is not available. We have also used it on patients unable to perform a good CPET because of lack of familiarity with bicycle pedaling. The shuttle walk test may be used to better determine a maximal exercise capacity when a CPET is not available and to measure the effects of pulmonary rehabilitation in patients unfamiliar with a CPET. The role of exercise as a therapeutic tool is central to the concept of pulmonary rehabilitation. Exercise training improves not only functional dyspnea and health-related quality of life, but also has been shown to decrease health care resource use. As part of a comprehensive pulmonary rehabilitation initiated after a hospitalization for exacerbation, it has been shown to decrease readmission rates.