Should acute treatment with inhaled beta agonists be withheld from patients with dyspnea who may have heart failure?

Recent Advances in β2-Agonists for Treatment of Chronic Respiratory Diseases and Heart Failure

β₂-Adrenoceptor (β₂-AR) agonists are widely used as bronchodilators. The emerge of ultralong acting β₂-agonists is an important breakthrough in pulmonary medicine. In this review, we will provide mechanistic insights into the application of β₂-agonists in asthma, chronic obstructive pulmonary disease (COPD), and heart failure (HF). Recent studies in β-AR signal transduction have revealed opposing functions of the β₁-AR and the β₂-AR on cardiomyocyte survival. Thus, β₂-agonists and β-blockers in combination may represent a novel strategy for HF management. Allosteric modulation and biased agonism at the β₂-AR also provide a theoretical basis for developing drugs with novel mechanisms of action and pharmacological profiles. Overlap of COPD and HF presents a substantial clinical challenge but also a unique opportunity for evaluation of the cardiovascular safety of β₂-agonists. Further basic and clinical research along these lines can help us develop better drugs and innovative strategies for the management of these difficult-to-treat diseases.

A mini review of inhaled beta 2 agonists in acute decompensated heart failure requiring respiratory support

Acute decompensated heart failure (HF) results in over one million hospital admissions per year, many requiring invasive or noninvasive mechanical ventilation for respiratory/cardiovascular support. Inhaled beta-2 adrenergic receptor agonists have been shown to be effective at clearance of extravascular lung water in HF patients. However, studies done in the late 1990s and early 2000s, prior to standardization and wide adoption of guideline directed medical therapy for HF, suggested that inhaled beta-2 agonist use increased admissions for HF exacerbations as well as in-hospital mortality. One study even attempted to utilize intravenous Beta-2 agonists in Acute Respiratory Distress Syndrome patients, however the study was stopped prematurely due to an 11% increased mortality in the treatment group. More recently however, studies examining patients who have concurrent diagnoses of chronic obstructive pulmonary disease (COPD) and HF showed that beta-2 agonist therapy resulted in similar or better outcomes compared to controls. Likewise, in-vitro studies, animal models, and studies utilizing chronic heart failure patients treated with nebulized beta-2 agonists with no concurrent respiratory diagnosis had a therapeutic effect of treatment over controls. These studies have the advantage of being performed with the standardization of guideline directed HF medical therapy. In conclusion, while we continue to recommend the use of Beta-2 agonist therapy in patients with concurrent COPD and HF requiring respiratory support, further studies, preferably single or double blinded prospective trials, will need to be performed to determine whether Beta-2 agonist therapy offers morbidity and mortality benefits in patients with strictly acute decompensated heart failure requiring respiratory support.

Bronchodilators in subjects with asthma-related comorbidities

Asthma is often associated with different comorbidities such as cardiovascular diseases, depression, diabetes mellitus, dyslipidaemia, osteoporosis, rhinosinusitis and mainly gastro-oesophageal reflux disease and allergic rhinitis. Although bronchodilators play an important role in the treatment of asthma, there is no overall description of their impact on comorbid asthma, regardless of whether favourable or negative. This narrative review examines the potential effects of bronchodilators on comorbidities of asthma.

The impact of emergency medical services in acute heart failure

BACKGROUND

Real-life data on the role of emergency medical services (EMS) in acute heart failure (AHF) are scarce. Our aim was to describe prehospital treatment of AHF and to compare patients using EMS with self-presented, non-EMS patients.

METHODS

Data were collected retrospectively from three university hospitals in Helsinki metropolitan area between July 1, 2012 and July 31, 2013. According to the use of EMS, patients were divided into EMS and non-EMS groups.

RESULTS

The study included 873 AHF patients. One hundred were (11.5%) EMS and 773 (88.5%) non-EMS. EMS patients more often had comorbidities. Initial heart rate (HR) and peripheral oxygen saturation (SpO₂) differed between EMS and non-EMS patients; mean HR 89.2 (SD 22.5) vs. 83.7 (21.5)/min (p=0.02) and SpO₂ 90.3 (8.6) vs. 92.9 (6.6)% (p=0.01). However, on presentation to ED EMS patients' vital signs were similar to non-EMS patients'. On presentation to ED 46.0% were normotensive and 68.2% "warm and wet". Thirty-four percentage of EMS patients received prehospital medication. In-hospital mortality was 6.0% and 7.1% (p=0.84) and length of stay (LOS) 7.7 (7.0) and 8.5 (7.9) days (p=0.36) in EMS and non-EMS groups.

CONCLUSION

The use of EMS and administration of prehospital medication was low. EMS patients had initially worse HR and SpO₂ than non-EMS patients. However, EMS patients' signs improved and were similar on presentation to ED. There were no differences in in-hospital mortality and LOS. This underscores the need for equal attention to any AHF patient independent of the arrival mode.

Impact of chronic systolic heart failure on lung structure-function relationships in large airways

Heart failure (HF) is often associated with pulmonary congestion, reduced lung function, abnormal gas exchange, and dyspnea. We tested whether pulmonary congestion is associated with expanded vascular beds or an actual increase in extravascular lung water (EVLW) and how airway caliber is affected in stable HF. Subsequently we assessed the influence of an inhaled short acting beta agonist (SABA). Thirty‐one HF (7F; age, 62 ± 11 years; ht. 175 ± 9 cm; wt. 91 ± 17 kg; LVEF, 28 ± 15%) and 29 controls (11F; age; 56 ± 11 years; ht. 174 ± 8 cm; wt. 77 ± 14 kg) completed the study. Subjects performed PFTs and a chest computed tomography (CT) scan before and after SABA. CT measures of attenuation, skew, and kurtosis were obtained from areas of lung tissue to assess EVLW. Airway luminal areas and wall thicknesses were also measured. CT tissue density suggested increased EVLW in HF without differences in the ratio of airway wall thickness to luminal area or luminal area to TLC (skew: 2.85 ± 1.08 vs. 2.11 ± 0.79, P < 0.01; Kurtosis: 15.5 ± 9.5 vs. 9.3 ± 5.5 P < 0.01; control vs. HF). PFTs were decreased in HF at baseline (% predicted FVC:101 ± 15% vs. 83 ± 18%, P < 0.01;FEV1:103 ± 15% vs. 82 ± 19%, P < 0.01;FEF25–75: 118 ± 36% vs. 86 ± 36%, P < 0.01; control vs. HF). Airway luminal areas, but not CT measures, were correlated with PFTs at baseline. The SABA cleared EVLW and decreased airway wall thickness but did not change luminal area. Patients with HF had evidence of increased EVLW, but not an expanded bronchial circulation. Airway caliber was maintained relative to controls, despite reductions in lung volume and flow rates. SABA improved lung function, primarily by reducing EVLW.

Albuterol in the treatment of acute respiratory distress syndrome: A meta-analysis of randomized controlled trials

BACKGROUND

This meta-analysis of randomized controlled trials aimed to systematically evaluate the value of albuterol in the treatment of patients with acute respiratory distress syndrome (ARDS).

DATA SOURCES

Randomized controlled trials on albuterol treatment of ARDS from its inception to October 2014 were searched systematically. The databases searched included: PubMed, Ovid EMBASE, Ovid Cochrane, CNKI, WANFANG and VIP. The trials were screened according to the pre-designed inclusion and exclusion criteria. We performed a systematic review and meta-analysis of the randomized controlled trials (RCTs) on albuterol treatment, attempting to improve outcomes, i.e. lowering the 28-day mortality and ventilator-free days.

RESULTS

Three RCTs involving 646 patients met the inclusion criteria. There was no significant decrease in the 28-day mortality (risk difference=0.09; P=0.07, P for heterogeneity=0.22, I (2)=33%). The ventilator-free days and organ failure-free days were significantly lower in the patients who received albuterol (mean difference=-2.20; P<0.001, P for heterogeneity=0.49, I (2)=0% and mean difference=-1.71, P<0.001, P for heterogeneity=0.60, I (2)=0%).

CONCLUSIONS

Current evidences indicate that treatment with albuterol in the early course of ARDS was not effective in increasing the survival, but significantly decreasing the ventilator-free days and organ failure-free days. Owing to the limited number of included trails, strong recommendations cannot be made.

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.

Evaluating the safety of COPD medications: an evidence-based review

The goals of management of COPD include reducing exposure to risk factors; improving lung function, exercise tolerance, and quality of life; and decreasing exacerbations and mortality. Pharmacologic treatments, such as inhaled β2-agonists, anticholinergics, and inhaled corticosteroids, are widely used to help achieve these goals. In addition to efficacy, medication safety is an important consideration in selecting COPD treatments. Clinical trials conducted in support of the regulatory review and approval process establish the general efficacy and tolerability of pharmacologic treatments for COPD, and these data are reflected in product labeling. Following approval, further research continues to provide more data with longer follow-up and in broader settings than feasible in clinical trials. These data add to our knowledge of the efficacy of medications. Understanding medication safety requires assessment of the quality and appropriateness of study design, as well as knowledge of study findings, and is of paramount importance in making sound clinical judgments in the treatment of patients with COPD. In recent years, a wealth of data on COPD medications has been published from different sources, including randomized clinical trials, meta-analyses, systematic reviews, and observational studies. This review discusses important considerations in interpreting data from different types of studies, summarizes the tolerability profile of COPD medications established in preapproval studies, and discusses new findings from more recent postapproval data.

β-Blockers and chronic obstructive pulmonary disease: inappropriate avoidance?

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death in the United States and is often accompanied by one or more comorbid conditions. While there are established morbidity and mortality benefits of β-blocker (BB) use for certain cardiovascular conditions, data suggest that clinicians are often reluctant to prescribe them in the presence of COPD because of concerns for bronchoconstriction, despite evidence that they are typically well-tolerated among these patients. Treatment guidelines for COPD are consistent with those for cardiovascular disease management and support the role of BBs in management of particular cardiovascular conditions, even in the presence of severe COPD. Adherence to these guidelines could result in significant decreases in morbidity and mortality among patients with COPD. Additionally, current treatments for COPD are often linked to increased cardiovascular disease events. Further study is needed to clarify and guide therapeutic management in patients with COPD.

Cardiac asthma: new insights into an old disease

Cardiac asthma has been defined as wheezing, coughing and orthopnea due to congestive heart failure. The clinical distinction between bronchial asthma and cardiac asthma can be straight forward, except in patients with chronic lung disease coexisting with left heart disease. Pulmonary edema and pulmonary vascular congestion have been thought to be the primary causes of cardiac asthma but most patients have a poor response to diuretics. There appears to be limited effectiveness of classical asthma medications like bronchodilators or corticosteroids in treating cardiac asthma. Evidence suggests that circulating inflammatory factors and tissue growth factors also lead to airway obstruction suggesting the possibility of developing novel therapies.

Bronchodilator responsiveness in patients with chronic heart failure

OBJECTIVE

The aim of this study was to evaluate the effect of inhaled bronchodilators on pulmonary function and dyspnea in patients with chronic heart failure (HF).

BACKGROUND

Conflicting data exist on whether bronchodilators may improve pulmonary function and dyspnea in patients with chronic HF.

METHODS

In this retrospective observational study we analyzed data of 116 chronic HF outpatients with systolic dysfunction who underwent spirometry and Borg dyspnea measurements before and after inhalation of 400 μg salbutamol and 80 μg ipratropium. Patients with chronic obstructive pulmonary disease (COPD) or asthma were excluded.

RESULTS

Bronchodilators fully reversed airway obstruction (AO) in 25 of 64 (39.1%) patients with pre-bronchodilator AO. All spirometric measurements, except for forced vital and inspiratory capacities, improved significantly post-bronchodilation. Absolute and percent improvements in forced expiratory volume in 1 s (FEV1) were more pronounced in patients with persistent AO post-bronchodilation compared to those without AO (0.19 ± 0.18 L and 8.4 ± 7.3% versus 0.11 ± 0.12 L and 4.3 ± 4.0%, p < 0.05). Significant bronchodilator responsiveness of FEV1 (>200 mL and >12%) was noted in 12.1% and was more frequent in patients with persistent AO and fully reversible AO than in those without AO (23.1% and 16.0% versus 1.9%, p < 0.05). We measured a small, albeit significant improvement in dyspnea (0.7 ± 1.2 versus 0.9 ± 1.3, p = 0.002).

CONCLUSIONS

Inhaled bronchodilators may have an additional role in the management of patients with chronic HF because of their potential to improve pulmonary function, especially in those with AO. The clinical usefulness and possible adverse events of bronchodilators need to be further established.

Effect of intravenous β-2 agonist treatment on clinical outcomes in acute respiratory distress syndrome (BALTI-2): a multicentre, randomised controlled trial

BACKGROUND

In a previous randomised controlled phase 2 trial, intravenous infusion of salbutamol for up to 7 days in patients with acute respiratory distress syndrome (ARDS) reduced extravascular lung water and plateau airway pressure. We assessed the effects of this intervention on mortality in patients with ARDS.

METHODS

We did a multicentre, placebo-controlled, parallel-group, randomised trial at 46 UK intensive-care units between December, 2006, and March, 2010. Intubated and mechanically ventilated patients (aged ≥16 years) within 72 h of ARDS onset were randomly assigned to receive either salbutamol (15 μg/kg ideal bodyweight per h) or placebo for up to 7 days. Randomisation was done by a central telephone or web-based randomisation service with minmisation by centre, pressure of arterial oxygen to fractional inspired oxygen concentration (PaO(2)/F(I)O(2)) ratio, and age. All participants, caregivers, and investigators were masked to group allocation. The primary outcome was death within 28 days of randomisation. Analysis was by intention-to-treat. This trial is registered, ISRCTN38366450 and EudraCT number 2006-002647-86.

FINDINGS

We randomly assigned 162 patients to the salbutamol group and 164 to the placebo group. One patient in each group withdrew consent. Recruitment was stopped after the second interim analysis because of safety concerns. Salbutamol increased 28-day mortality (55 [34%] of 161 patients died in the salbutamol group vs 38 (23%) of 163 in the placebo group; risk ratio [RR] 1·47, 95% CI 1·03-2·08).

INTERPRETATION

Treatment with intravenous salbutamol early in the course of ARDS was poorly tolerated. Treatment is unlikely to be beneficial, and could worsen outcomes. Routine use of β-2 agonist treatment in ventilated patients with this disorder cannot be recommended.

FUNDING

UK Medical Research Council, UK Department of Health, UK Intensive Care Foundation.