Single Dose of Tiotropium Improves the 6-Minute Walk Distance in Chronic Obstructive Pulmonary Disease

Predicting treatable traits for long-acting bronchodilators in patients with stable COPD

Purpose

There is currently no measure to predict a treatability of long-acting β-2 agonist (LABA) or long-acting muscarinic antagonist (LAMA) in patients with chronic obstructive pulmonary disease (COPD). We aimed to build prediction models for the treatment response to these bronchodilators, in order to determine the most responsive medication for patients with COPD.

Methods

We performed a prospective open-label crossover study, in which each long-acting bronchodilator was given in a random order to 65 patients with stable COPD for 4 weeks, with a 4-week washout period in between. We analyzed 14 baseline clinical traits, expression profiles of 31,426 gene transcripts, and damaged-gene scores of 6,464 genes acquired from leukocytes. The gene expression profiles were measured by RNA microarray and the damaged-gene scores were obtained after DNA exome sequencing. Linear regression analyses were performed to build prediction models after using factor and correlation analyses.

Results

Using a prediction model for a LABA, traits found associated with the treatment response were post-bronchodilator forced expiratory volume in 1 second, bronchodilator reversibility (BDR) to salbutamol, expression of three genes (CLN8, PCSK5, and SKP2), and damage scores of four genes (EPG5, FNBP4, SCN10A, and SPTBN5) (R²=0.512, p<0.001). Traits associated with the treatment response to a LAMA were COPD assessment test score, BDR, expression of four genes (C1orf115, KIAA1618, PRKX, and RHOQ) and damage scores of three genes (FBN3, FDFT1, and ZBED6) (R²=0.575, p<0.001). The prediction models consisting only of clinical traits appeared too weak to predict the treatment response, with R²=0.231 for the LABA model and R²=0.121 for the LAMA model.

Conclusion

Adding the expressions of genes and damaged-gene scores to the clinical traits may improve the predictability of treatment response to long-acting bronchodilators.

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.

Once-daily indacaterol 75 μg in moderate- to-severe COPD: results of a Phase IV study assessing time until patients' perceived onset of effect

Background

Indacaterol 75 μg once daily is a long-acting β₂ agonist approved for maintenance bronchodilator treatment in patients with chronic obstructive pulmonary disease (COPD). The purpose of this study was to evaluate patients’ perception of onset of effect with a single dose.

Methods

In this double-blind, crossover, Phase IV study, 40 patients were randomized to receive a single dose of indacaterol 75 μg or placebo via a dry powder inhaler device. The primary variable was time until patient’s perception of onset of effect, using a simple self-administered (nonvalidated) questionnaire that patients answered at nine protocol-specified time points. Exploratory variables included change in forced expiratory volume in 1 second (FEV₁) and change in percent predicted FEV₁ from predose to postdose (determined 60–75 minutes postdose).

Results

The least-squares mean time to patient’s perception of onset of effect was 25.4 minutes and 23.9 minutes for indacaterol and placebo, respectively. There was no significant effect for treatment, period, or sequence on the time to patient’s perception. In addition, no statistically significant differences between treatments were observed for patient’s global satisfaction with onset of effect and global expectation of treatment adherence. For the exploratory variable change in FEV₁ from predose to postdose, indacaterol showed superiority over placebo with a clinically relevant least-squares mean treatment difference of 0.12 L (P<0.0001). There was little or no association between patient’s perception of time to onset of effect and change in FEV₁, or change in percent predicted FEV₁. Both treatments were well tolerated.

Conclusion

A single dose of indacaterol 75 μg did not separate from placebo in terms of patient perception of onset, although there was an improvement in FEV₁ for indacaterol compared with placebo. Development and use of a validated questionnaire may be needed to address the inconsistency in evaluating this patient-related outcome.

Combined therapy with tiotropium and formoterol in chronic obstructive pulmonary disease: effect on the 6-minute walk test

Combined therapy with tiotropium and long-acting beta 2 agonists confers additional improvement in symptoms, lung function and aspects of health-related quality of life (QOL) compared with each drug alone in patients with COPD. However, the efficacy of combined therapy on walking distance, a surrogate measure of daily functional activity and morbidity remains unclear. The aim was, therefore, to quantify the benefit of this therapy on the six minute walk test. Secondary outcomes included change in lung function, symptoms, the BODE index and QOL. In a double-blind, crossover study, 38 participants with moderate to severe COPD on tiotropium were randomised to receive either formoterol or placebo for 6 weeks. Following a 2-week washout period, participants crossed over to the alternate arm of therapy for a further 6 weeks. Thirty-six participants, with an average age of 64.3 years and FEV1 predicted of 53%, completed the study. Combined therapy improved walking distance by a mean of 36 metres [95% CI: 2.4, 70.1; p = 0.04] compared with tiotropium. FEV1 increased in both groups (160 mL combination therapy versus 30 mL tiotropium) with a mean difference of 110 mL (95% CI: -100, 320; p = 0.07) between groups, These findings further support the emerging advantages of combined therapy in COPD. Australian New Zealand Clinical Trials.

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.

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.

The six-minute walk test: a useful metric for the cardiopulmonary patient

Measurement of exercise capacity is an integral element in assessment of patients with cardiopulmonary disease. The 6-min walk test (6MWT) provides information regarding functional capacity, response to therapy and prognosis across a range of chronic cardiopulmonary conditions. A distance less than 350 m is associated with increased mortality in chronic obstructive pulmonary disease, chronic heart failure and pulmonary arterial hypertension. Desaturation during a 6MWT is an important prognostic indicator for patients with interstitial lung disease. The 6MWT is sensitive to commonly used therapies in chronic obstructive pulmonary disease such as pulmonary rehabilitation, oxygen, long-term use of inhaled corticosteroids and lung volume reduction surgery. However, it appears less reliable to detect changes in clinical status associated with medical therapies for heart failure. A change in walking distance of more than 50 m is clinically significant in most disease states. When interpreting the results of a 6MWT, consideration should be given to choice of predictive values and the methods by which the test was carried out.

Impact of bronchodilator therapy on exercise tolerance in COPD

Exercise tolerance is an important parameter in patients with COPD and a primary goal of treatment is to reduce dyspnea to facilitate physical activities and improve health-related quality of life. This review examines the link between expiratory flow limitation and dyspnea to explain the rationale for the use of bronchodilators and review the characteristics of different types of exercise tests, with specific focus on which tests are likely to show a response to bronchodilators. An earlier literature search of studies published up to 1999 assessed the effects of bronchodilatort therapy on dypsnea and exercise tolerance among patients with COPD. This current review examines the clinical evidence published since 1999. Thirty-one randomized studies of exercise tolerance associated with short- and long-acting beta(2)-agonists and anticholinergics were identified. Evidence for the efficacy of bronchodilators in enhancing exercise capacity is often contradictory and possibly depends on the exercise test and study methodology. However, further studies should confirm the benefit of long-acting bronchodilators in improving spontaneous everyday physical activities.

Updating the minimal important difference for six-minute walk distance in patients with chronic obstructive pulmonary disease

OBJECTIVE

To establish the minimal important difference (MID) for the six-minute walk distance (6MWD) in persons with chronic obstructive pulmonary disease (COPD).

DESIGN

Analysis of data from an observational study using distribution- and anchor-based methods to determine the MID in 6MWD.

SETTING

Outpatient pulmonary rehabilitation program at 2 teaching hospitals.

PARTICIPANTS

Seventy-five patients with COPD (44 men) in a stable clinical state with mean age 70 years (SD 9 y), forced expiratory volume in one second 52% (SD 21%) predicted and baseline walking distance 359 meters (SD 104 m).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Participants completed the six-minute walk test before and after a 7-week pulmonary rehabilitation program. Participants and clinicians completed a global rating of change score while blinded to the change in 6MWD.

RESULTS

The mean change in 6MWD in participants who reported themselves to be unchanged was 17.7 meters, compared with 60.2 meters in those who reported small change and 78.4 meters in those who reported substantial change (P=.004). Anchor-based methods identified an MID of 25 meters (95% confidence interval 20-61 m). There was excellent agreement with distribution-based methods (25.5-26.5m, kappa=.95). A change in 6MWD of 14% compared with baseline also represented a clinically important effect; this threshold was less sensitive than for absolute change (sensitivity .70 vs .85).

CONCLUSIONS

The MID for 6MWD in COPD is 25 meters. Absolute change in 6MWD is a more sensitive indicator than percentage change from baseline. These data support the use of 6MWD as a patient-important outcome in research and clinical practice.

The efficacy of tiotropium administered via Respimat Soft Mist Inhaler or HandiHaler in COPD patients

BACKGROUND

Tiotropium, a once daily inhaled anticholinergic delivered via HandiHaler, provides bronchodilation for >24h and improves patient-centred outcomes. The Respimat Soft Mist Inhaler (SMI), a novel, propellant-free inhaler, has been developed and proposed as an alternative delivery device for use with tiotropium.

METHODS

In a pre-specified, pooled analysis of two 30-week, double-blind, double-dummy, crossover studies, 207 patients with Chronic Obstructive Pulmonary Disease (COPD) were randomised to receive once daily tiotropium 5 microg or 10 microg (aqueous solution delivered via Respimat SMI), tiotropium 18 microg (inhalation powder via HandiHaler) or placebo. The primary endpoint was trough forced expiratory volume in 1s (FEV(1)) response. Forced vital capacity (FVC), peak expiratory flow rate (PEFR), rescue medication use, safety and pharmacokinetics (in a subgroup of patients) were also assessed.

RESULTS

Both tiotropium doses delivered by Respimat SMI were significantly superior to placebo and non-inferior to tiotropium 18 microg HandiHaler on the primary endpoint (all p<0.0001). All active treatments were significantly superior to placebo (all p<0.0001) and both doses of tiotropium Respimat SMI were non-inferior to tiotropium 18 microg HandiHaler on the secondary spirometry variables and rescue medication use. The systemic exposure was similar between tiotropium 5 microg Respimat SMI and tiotropium 18 microg HandiHaler but was higher for tiotropium 10 microg Respimat SMI. All active treatments were well tolerated.

CONCLUSIONS

Tiotropium 5 microg Respimat SMI is comparable with tiotropium 18 microg HandiHaler in terms of efficacy, pharmacokinetics and safety. Respimat SMI is an effective alternative, multi-dose delivery device for tiotropium.

Update on the pharmacologic therapy for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease is a treatable disease characterized by progressive airflow limitation. Prevention of disease progression; improvement of symptoms, exercise tolerance, and health status; and decrease in exacerbations and mortality are the goals of management. Inhaled short-acting bronchodilators are recommended for symptoms in mild disease, whereas inhaled long-acting bronchodilators are recommended for maintenance therapy of daily symptoms. When symptoms are not controlled using one bronchodilator, combining bronchodilators may be more effective. Combining a long-acting beta-agonist with an inhaled corticosteroid is more effective than either agent alone. Several novel therapies are in different stages of development.