Risk of non-fatal cardiac failure and ischaemic heart disease with long acting beta 2 agonists

Evaluation of the Early Effects of Childhood Asthma and Its Treatment on Cardiac Function as Revealed by Two-Dimensional Speckle-Tracking Echocardiography

There is minimal information available regarding the early effects of bronchial asthma (BA) and its treatment on cardiac function in children. We used two-dimensional speckle-tracking echocardiography (2D-STE) to evaluate cardiac function before and after the treatment of childhood BA. We enrolled 44 children with moderate and severe BA who had not been treated over the preceding 3 months or who were newly diagnosed. All children received the same treatment (that recommended by the Global Initiative for Asthma [GINA] in 2017). All children also underwent transthoracic 2D-STE before treatment and 6 months later. Clinical data were compared before and after treatment. After treatment, significant increases were evident in right ventricular (RV) systolic and diastolic strain, as well as the systolic strain rate. Before and after treatment, the RV global longitudinal systolic strains were - 22.8 ± 3.6 and - 25.1 ± 4.5, respectively (p = 0.036); the RV global longitudinal diastolic strains were - 18.5 ± 6.0 and - 21.5 ± 5.2, respectively (p = 0.038); and the RV systolic strain rates were - 1.26 ± 0.4 and - 1.12 ± 0.3, respectively (p = 0.025). After treatment, significant increases were observed in the right atrial (RA) peak longitudinal strain and strain rate. Before and after treatment, the RA peak atrial longitudinal strains were 32.5 ± 10.8 and 44.7 ± 11.2, respectively (p = 0.042) and the RA longitudinal strain rates were - 1.6 ± 0.3 and - 2.0 ± 0.5, respectively (p = 0.041). RV and RA subclinical dysfunction may develop in children with early-stage BA. However, asthma treatment appears to improve such dysfunction. In children with BA, clinical and subclinical changes in cardiac functions can be easily detected via 2D-STE.

Asthma and COPD: A Focus on β-Agonists - Past, Present and Future

Asthma has been recognised as a respiratory disorder for millennia and the focus of targeted drug development for the last 120 years. Asthma is one of the most common chronic non-communicable diseases worldwide. Chronic obstructive pulmonary disease (COPD), a leading cause of morbidity and mortality worldwide, is caused by exposure to tobacco smoke and other noxious particles and exerts a substantial economic and social burden. This chapter reviews the development of the treatments of asthma and COPD particularly focussing on the β-agonists, from the isolation of adrenaline, through the development of generations of short- and long-acting β-agonists. It reviews asthma death epidemics, considers the intrinsic efficacy of clinical compounds, and charts the improvement in selectivity and duration of action that has led to our current medications. Important β2-agonist compounds no longer used are considered, including some with additional properties, and how the different pharmacological properties of current β2-agonists underpin their different places in treatment guidelines. Finally, it concludes with a look forward to future developments that could improve the β-agonists still further, including extending their availability to areas of the world with less readily accessible healthcare.

Association between Inhaled β2-agonists Initiation and Risk of Major Adverse Cardiovascular Events: A Population-based Nested Case-Control Study

Purpose

Despite ample evidence underpinning the efficacy of β₂-agonists in asthma and chronic obstructive pulmonary disease (COPD), the occurrence of β₁- and β₂-adrenoceptors in the heart suggests that β₂-agonists may have deleterious cardiac effects. We investigated the association between new users of long-or short-acting β₂-agonists (LABA or SABA) or ICS (inhaled corticosteroids)/LABA and major adverse cardiovascular events (MACE).

Methods

A nested case–control analysis was conducted using the UK Clinical Practice Research Datalink of patients with asthma, COPD or asthma–COPD overlap with initial treatment of LABA, SABA, ICS/LABA, ICS, long-or short-acting muscarinic antagonist (LAMA or SAMA) between 01 January 1998 and 31 July 2018. The primary outcome was MACE, defined as the first occurrence of stroke, heart failure, myocardial infarction, arrhythmia, or cardiovascular death. Each case was matched with up to 10 controls on age, sex, date of cohort-entry, and duration of follow-up. The risk of MACE associated with β₂-agonists was estimated using conditional logistic regression after controlling for potential confounders.

Results

The cohort included 180,567 new users of β₂-agonists, ICS, SAMA, or LAMA. Among asthmatics, β₂-agonists were not associated with the risk of MACE (SABA vs ICS: HR 1.29 [0.96–1.73]; ICS/LABA vs ICS, HR 0.75 [0.33–1.73]). In contrast, among COPD patients, LABA (HR, 2.38 [1.04–5.47]), SABA (HR, 2.02 [1.13–3.59]) and ICS/LABA (HR, 2.08 [1.04–4.16]) users had an increased risk of MACE compared with SAMA users. Among patients with asthma–COPD overlap, SABA (HR, 2.57 [1.26–5.24]) was associated with an increased risk of MACE compared with ICS.

Conclusion

In conclusion, initiation of LABA, SABA, or ICS/LABA in COPD or SABA in asthma–COPD overlap is associated with increased risk of MACE. No associations were observed among patients with asthma.

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.

[Cardiovascular complications of doping products]

Doping is the use of a substance that artificially increases an individual's physical ability for competition purpose. Products and methods used in doping are not without risk, especially at cardiovascular level. Here we review the most common doping substances in sport and their cardiovascular consequences.

Therapeutic effects of the combination of inhaled beta2-agonists and beta-blockers in COPD patients with cardiovascular disease

Chronic obstructive pulmonary disease (COPD) is a major health problem worldwide, with co-morbidities contributing to the overall severity and mortality of the disease. The incidence and prevalence of cardiovascular disease among COPD patients are high. Both disorders often co-exist, mainly due to smoking, but they also share common underlying risk factors, such as aging and low-grade systemic inflammation. The therapeutic approach is based on agents, whose pharmacological properties are completely opposed. Beta2-agonists remain the cornerstone of COPD treatment due to their limited cardiac adverse effects. On the other hand, beta-blockers are administered in COPD patients with cardiovascular disease, but despite their proven cardiac benefits, they remain underused. There is still a trend among physicians over underprescription of these drugs in patients with heart failure and COPD due to bronchoconstriction. Therefore, cardioselective beta-blockers are preferred, and recent meta-analyses have shown reduced rates in mortality and exacerbations in COPD patients treated with beta-blockers.

The effects of treatment in patients with childhood asthma on the elastic properties of the aorta

INTRODUCTION

The study aimed to investigate the effects of treatment in patients with childhood asthma on the elastic properties of the aorta and cardiovascular risk.

METHODS

The study was performed in 66 paediatric patients diagnosed with bronchial asthma (BA). All patients were administered the β2 agonist, salbutamol, for seven days, followed by one month of montelukast and six months of inhaled steroid treatment. All patients underwent conventional transthoracic echocardiographic imaging before and after treatment. Aortic elasticity parameters were considered to be the markers of aortic function.

RESULTS

Aortic elasticity parameters, including aortic strain (15.2 ± 4.8 and 18.8 ± 9.5%, p = 0.043), aortic distensibility (7.26 ± 4.71 and 9.53 ± 3.50 cm2/dyn, p = 0.010) and aortic stiffness index (3.2 ± 0.6 and 2.8 ± 0.5, p = 0.045 showed significant post-treatment improvement when compared to pre-treatment values. Tricuspid annular plane systolic excursion (TAPSE) was also observed to improve after treatment (1.81 ± 0.38 and 1.98 ± 0.43, p = 0.049).

CONCLUSION

The study demonstrated that when provided at appropriate doses, medications used in BA may result in an improvement in aortic stiffness.

A methodological comparison of two European primary care databases and replication in a US claims database: inhaled long-acting beta-2-agonists and the risk of acute myocardial infarction

PURPOSE

Results from observational studies on inhaled long-acting beta-2-agonists (LABA) and acute myocardial infarction (AMI) risk are conflicting, presumably due to variation in methodology. We aimed to evaluate the impact of applying a common study protocol on consistency of results in three databases.

METHODS

In the primary analysis, we included patients from two GP databases (Dutch-Mondriaan, UK-CPRD GOLD) with a diagnosis of asthma and/or COPD and at least one inhaled LABA or a "non-LABA inhaled bronchodilator medication" (short-acting beta-2-agonist or short-/long-acting muscarinic antagonist) prescription between 2002 and 2009. A claims database (USA-Clinformatics) was used for replication. LABA use was divided into current, recent (first 91 days following the end of a treatment episode), and past use (after more than 91 days following the end of a treatment episode). Adjusted hazard ratios (AMI-aHR) and 95 % confidence intervals (95 % CI) were estimated using time-dependent multivariable Cox regression models stratified by recorded diagnoses (asthma, COPD, or both asthma and COPD).

RESULTS

For asthma or COPD patients, no statistically significant AMI-aHRs (age- and sex-adjusted) were found in the primary analysis. For patients with both diagnoses, a decreased AMI-aHR was found for current vs. recent LABA use in the CPRD GOLD (0.78; 95 % CI 0.68-0.90) and in Mondriaan (0.55; 95 % CI 0.28-1.08), too. The replication study yielded similar results. Adjusting for concomitant medication use and comorbidities, in addition to age and sex, had little impact on the results.

CONCLUSIONS

By using a common protocol, we observed similar results in the primary analysis performed in two GP databases and in the replication study in a claims database. Regarding differences between databases, a common protocol facilitates interpreting results due to minimized methodological variations. However, results of multinational comparative observational studies might be affected by bias not fully addressed by a common protocol.

Multimorbidity and COPD Medication Receipt Among Medicaid Beneficiaries With Newly Diagnosed COPD

BACKGROUND

Multimorbidity is highly prevalent among patients with COPD. The association between multimorbidity and COPD medication management is not well researched. The aim of this study was to examine the association between multimorbidity and COPD medication receipt among Medicaid beneficiaries with newly diagnosed COPD.

METHODS

A retrospective longitudinal dynamic cohort design was used, and data were extracted from Medicaid Analytic eXtract files from 2005 to 2008. Medicaid beneficiaries with newly diagnosed COPD (N = 19,060) were identified using the International Classification of Diseases, 9th Revision, Clinical Modification, for COPD. This code (for commonly co-occurring conditions with COPD) was used to create a multimorbidity variable. These conditions included anxiety, arthritis, bipolar disorder, cardiovascular diseases, depression, diabetes, hypertension, hyperlipidemia osteoporosis, and schizophrenia. Medicaid beneficiaries with newly diagnosed COPD were categorized as: (1) physical multimorbidity only, (2) psychiatric multimorbidity only, (3) both physical and psychiatric multimorbidity, and (4) no multimorbidity. Receipt of COPD medications (short- or long-acting bronchodilators, inhaled corticosteroids) was identified using National Drug Codes. Bivariate relationships between multimorbidity and COPD medication receipt were tested using the chi-square test of independence. The associations between multimorbidity and COPD medication receipt were analyzed with logistic and multinomial logistic regression analyses.

RESULTS

Among Medicaid beneficiaries with newly diagnosed COPD, 81.9% had at least one co-occurring chronic condition. After controlling for subject characteristics, adults with multimorbidity were less likely to receive COPD medications compared with those without any inflammation-related multimorbidity. For example, those with physical multimorbidity were less likely to receive short-acting bronchodilators (adjusted odds ratio [OR] 0.76, 95% CI 0.69-0.83), long-acting bronchodilators (adjusted OR 0.84, 95% CI 0.76-0.92), and inhaled corticosteroids (adjusted OR 0.75, 95% CI 0.68-0.82) compared with those with no inflammation-related multimorbidity.

CONCLUSIONS

The prevalence of multimorbidity is very high among Medicaid beneficiaries with newly diagnosed COPD. Our findings indicate poor COPD medication management among those with multimorbidity.

Heart failure, chronic obstructive pulmonary disease, and asthma: numbers, facts, and challenges

Heart failure (HF), chronic obstructive pulmonary disease (COPD), and asthma are considered as major health problems. They affect 1–3%, 4–10%, and 8–19% of population, respectively, and frequently coexist. Pulmonary function testing and echocardiography are needed for reliable diagnosis, but in clinical practice, diagnosis often is based on history and disease self‐reporting. Concomitant HF can be diagnosed in about 20% of patients with COPD, and at least 50% had systolic dysfunction. In patients with HF, prevalence of COPD is up to 35%, and less than 25% of patients have COPD GOLD stage III or IV. COPD is more severe in patients with HF with preserved ejection fraction. When HF and COPD coexist, hazard of death is increased for 39% but can even exceed the mortality in individual disease by threefold. In patients with acute deterioration, natriuretic peptides and lung ultrasound, along with other laboratory biomarkers and imaging, need to be implemented to differentiate underlying cause and to manage patients accordingly. COPD is not contraindication for beta‐blockers, and if used, the risk of death is reduced by 31%; if indicated, cardio‐selective agents can be used in asthma. Recent pan‐European registry reported that about 90% of patients with HF receive beta‐blockers, whereas dosing remains a large unmet need with only 17% being treated with target daily dose. Concurrent HF and COPD reduce the prescription of beta blockers threefold, which results in about 20% of patients actually being treated with beta‐blockers. In COPD/asthma, beta‐agonists are strongly associated with new HF (relative risk of 3.41) and HF hospitalizations (odds ratio of 1.74).

Inhaled bronchodilators and the risk of tachyarrhythmias

BACKGROUND/OBJECTIVES

There have been controversies about whether inhaled bronchodilators could increase the risk of clinically important tachyarrhythmias. We investigated the association between inhaled bronchodilators and the development of tachyarrhythmias, including atrial fibrillation and other paroxysmal tachyarrhythmias in real practice.

METHODS

We conducted a nested case-control study with the use of the nationwide insurance claims database of the Health Insurance Review and Assessment Service (Seoul, Republic of Korea). Overall, 3312 cases with newly developed tachyarrhythmias including atrial fibrillation and other paroxysmal tachyarrhythmias and 9732 matched (up to 1:5) controls were identified from 545,508 subjects without acute major cardiovascular events in the past year between January 1, 2011 and December 31, 2011. Conditional logistic regression analysis adjusted by comorbidities, cardiovascular drugs and healthcare utilization was performed.

RESULTS

In various multivariate models, the use of inhaled long-acting muscarinic antagonists (LAMAs) or long-acting inhaled β2 agonists (LABAs) was significantly associated with tachyarrhythmias. Statistically significant effects of LAMAs on tachyarrhythmias were found only in the non-users of β-blockers. We did not find a statistically significant difference in the impact of a LABA without a LAMA vs a LAMA without a LABA (aOR, 0.93; 95% CI, 0.74-1.18), or a multiplicative or additive interaction between a LABA and a LAMA.

CONCLUSIONS

Inhaled LAMAs and LABAs were significantly and comparably associated with an increased risk of tachyarrhythmias.

The Lipid-lowering Effects of R-bambuterol in Healthy Chinese Volunteers: A Randomized Phase I Clinical Study

Background

Existing treatments are inadequate for patients at high risk of coronary heart disease caused by elevated levels of plasma low-density lipoprotein cholesterol (LDL-C). Bambuterol is a prodrug of β2-agonist commonly used for the treatment of asthma and chronic obstructive pulmonary disease (COPD) with the advantage of once daily dosing and favorable side effect profile. The potential lipid-lowering effects of bambuterol were unclear, possibly due to the racemic bambuterol (rac-bambuterol) that was used in previous studies.

Methods

The lipid-lowering effects of R-bambuterol were examined in a randomized phase I trial in 48 healthy Chinese volunteers aged 18–45 years. Participants were randomly assigned to five groups to receive a single dose (2.5 mg, 5 mg or 10 mg) or multiple doses (5 mg) of oral medications of R-bambuterol, or a single dose of rac-bambuterol (10 mg). Plasma lipid levels were measured at baseline, time to peak concentration (T_max) and 24 h after the treatment.

Findings

Administration of a single-dose of R-bambuterol resulted in dose-dependent reductions in the levels of plasma LDL-C, high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), apolipoprotein B (ApoB) and apolipoprotein A1 (ApoA1) at T_max. Levels of LDL-C exhibited the most reductions, which were statistically significant in all three single-dose R-bambuterol groups (all P values < 0.05). R-bambuterol was more potent in LDL-C lowering compared to rac-bambuterol at T_max (P = 0.08). At 24 h after dosing, the significant lipid lowering effects of R-bambuterol sustained for LDL-C (P = 0.01), ApoB (P = 0.001) and ApoA1 (P = 0.03), but not for HDL-C. The ratio of ApoA1/ApoB was marginally increased (P = 0.06). In the multiple-dose group, LDL-C levels again were significantly reduced (all P values < 0.05), whereas the ratios of ApoA1/ApoB were marginally increased.

Interpretation

R-bambuterol can lower the plasma levels of LDL-C, and marginally raise the ratio of ApoA1/ApoB (indicator of HDL-C/LDL-C) with both a single dose and multiple doses. R-bambuterol was more potent in LDL-C lowering than rac-bambuterol.

•

Oral administration of R-bambuterol, a long-acting bronchodilator, can significantly lower LDL cholesterol in healthy Chinese volunteers.

•

R-bambuterol was more potent than rac-bambuterol in lowering LDL-C and raising the ratio of ApoA1/ApoB.

•

It may provide an alternative for treating high cholesterol, especially for those also suffering from COPD.

Biased β2-adrenoceptor signalling in heart failure: pathophysiology and drug discovery

The body is constantly faced with a dynamic requirement for blood flow. The heart is able to respond to these changing needs by adjusting cardiac output based on cues emitted by circulating catecholamine levels. Cardiac β-adrenoceptors transduce the signal produced by catecholamine stimulation via Gs proteins to their downstream effectors to increase heart contractility. During heart failure, cardiac output is insufficient to meet the needs of the body; catecholamine levels are high and β-adrenoceptors become hyperstimulated. The hyperstimulated β1-adrenoceptors induce a cardiotoxic effect, which could be counteracted by the cardioprotective effect of β2-adrenoceptor-mediated Gi signalling. However, β2-adrenoceptor-Gi signalling negates the stimulatory effect of the Gs signalling on cardiomyocyte contraction and further exacerbates cardiodepression. Here, further to the localization of β1- and β2-adrenoceptors and β2-adrenoceptor-mediated β-arrestin signalling in cardiomyocytes, we discuss features of the dysregulation of β-adrenoceptor subtype signalling in the failing heart, and conclude that Gi-biased β2-adrenoceptor signalling is a pathogenic pathway in heart failure that plays a crucial role in cardiac remodelling. In contrast, β2-adrenoceptor-Gs signalling increases cardiomyocyte contractility without causing cardiotoxicity. Finally, we discuss a novel therapeutic approach for heart failure using a Gs-biased β2-adrenoceptor agonist and a β1-adrenoceptor antagonist in combination. This combination treatment normalizes the β-adrenoceptor subtype signalling in the failing heart and produces therapeutic effects that outperform traditional heart failure therapies in animal models. The present review illustrates how the concept of biased signalling can be applied to increase our understanding of the pathophysiology of diseases and in the development of novel therapies.

Repeated use of albuterol inhaler as a potential cause of Takotsubo cardiomyopathy

Patient: Female, 78

Final Diagnosis: Takotsubo cardiomyopathy

Symptoms: Chest discomfort, chest pain, dyspnea, short of breath

Medication: —

Clinical Procedure: —

Specialty: Cardiology

Heart failure and chronic obstructive pulmonary disease: the challenges facing physicians and health services

Pulmonary disease is common in patients with heart failure, through shared risk factors and pathophysiological mechanisms. Adverse pulmonary vascular remodelling and chronic systemic inflammation characterize both diseases. Concurrent chronic obstructive pulmonary disease presents diagnostic and therapeutic challenges, and is associated with increased morbidity and mortality. The cornerstones of therapy are beta-blockers and beta-agonists, whose pharmacological properties are diametrically opposed. Each disease is implicated in exacerbations of the other condition, greatly increasing hospitalizations and associated health care costs. Such multimorbidity is a key challenge for health-care systems oriented towards the treatment of individual diseases. Early identification and treatment of cardiopulmonary disease may alleviate this burden. However, diagnostic and therapeutic strategies require further validation in patients with both conditions.

Prescription patterns in asthma patients initiating salmeterol in UK general practice: a retrospective cohort study using the General Practice Research Database (GPRD)

BACKGROUND

An association between salmeterol, a long-acting β(2)-agonist (LABA), use and rare serious asthma events or asthma mortality was observed in two large clinical trials. This has resulted in heightened scrutiny of LABAs and comprehensive reviews by regulatory agencies.

OBJECTIVE

The aim of this retrospective observational cohort study was to better characterize salmeterol medication use patterns in the UK. We describe asthma prescription patterns in a cohort of patients (n =17,745) in the General Practice Research Database who initiated treatment with salmeterol-containing prescriptions between 2003 and 2006, including salmeterol and salmeterol/fluticasone propionate in a single device.

METHODS

Prescriptions patterns by medication class, including concurrent prescription of salmeterol with inhaled corticosteroids (ICS), were described using 6-month intervals in the 1-year period before and after the salmeterol-containing index prescription.

RESULTS

In the 0- to 6-month and 7- to 12-month periods prior to initiation of the salmeterol-containing prescription, the cohort experienced worsening of asthma, measured by an increase in the proportion of patients with prescriptions for short-acting β-agonists [SABA] (73-89%), ICS (70-81%) and systemic corticosteroids (14-28%). Nearly all patients prescribed salmeterol were concurrently prescribed ICS (≥95% within 90 days). In the 12 months following initiation of the salmeterol-containing prescription, a decrease in asthma prescriptions was observed.

DISCUSSION

These results support the appropriate prescribing of salmeterol-containing medications, as per recommendations in asthma treatment guidelines in the UK.

CONCLUSION

Salmeterol was consistently prescribed as an add-on asthma-controller with an ICS for most patients, and was associated with improvements in asthma control, as indicated by decreases in SABA and systemic corticosteroid prescriptions following salmeterol introduction.

Protective effects of glycyrrhizin against β₂-adrenergic receptor agonist-induced receptor internalization and cell apoptosis

It has been reported that treatment with β₂ adrenergic receptor (β₂AR) agonist bronchodilators may result in airway β₂ARs internalization and cardiac muscle cells apoptosis. This could lead to the loss of pharmacological effect of β₂AR agonists and increase adverse cardiovascular events in asthma patients receiving β₂AR agonist therapy. Glycyrrhizin, the major bioactive component of licorice root extract, has been reported to exhibit protective effect on respiratory system. Here, we investigate the effects of glycyrrhizin against β₂AR agonist salbutamol-induced receptor internalization and cell apoptosis. In our study, the live cell confocal imaging and fixed-cell enzyme-linked immunosorbent assay (ELISA) assay revealed that glycyrrhizin significantly inhibited salbutamol-induced surface β₂AR internalization. The underlying mechanisms were then identified to be that glycyrrhizin could reduce the association of β₂ARs with β-arrestins and clathrin heavy chain as well as the level of G protein-coupled receptor kinase (GRK) mediated phosphorylation of β₂ARs. The inhibition of receptor internalization by glycyrrhizin further lead to stabilization of the β₂AR mRNA and protein expression, thus amplified the transmembrane signaling via the β₂ARs. We also proved that glycyrrhizin could profoundly attenuate salbutamol-induced early cellular apoptosis by regulating the expressions of B-cell lymphoma 2 (Bcl-2) family genes. Taken together, our results suggest that glycyrrhizin exhibits protective effects against β₂AR agonist-induced receptor internalization and cell apoptosis. These findings might have practical implications for future strategies of combined application of glycyrrhizin with β₂AR receptor agonists to improve the efficacy of bronchodilators in patients with asthma and chronic obstructive pulmonary disease (COPD).

Differential regulation of β2 -adrenoceptor-mediated inotropic and lusitropic response by PDE3 and PDE4 in failing and non-failing rat cardiac ventricle

BACKGROUND AND PURPOSE

β-Adrenoceptors play a major role in regulating myocardial function through cAMP-dependent pathways. Different phosphodiesterases (PDEs) regulate intracellular cAMP-pools and thereby contribute to the compartmentalization of cAMP-dependent effects. We explored the involvement of PDEs in limiting the β(2) adrenoceptor-mediated positive inotropic (PIR) and lusitropic (LR) responses in sham-operated (Sham) and failing rat hearts.

EXPERIMENTAL APPROACH

Extensive myocardial infarctions were induced by coronary artery ligation in Wistar rats. Rats developing heart failure were studied 6 weeks after surgery. Contractility was measured in left ventricular strips from failing and Sham hearts. cAMP was quantified by RIA.

KEY RESULTS

In ventricular strips, stimulation of β(2) -adrenoceptors with (-)-adrenaline (300 nM CGP20712A present) exerted a small PIR and LR. In Sham hearts, β(2) -adrenoceptor-mediated as well as β(1) -adrenoceptor-mediated PIR and LR were increased by selective inhibition of either PDE3 (1 µM cilostamide) or PDE4 (10 µM rolipram). In failing rat hearts, PDE3 inhibition enhanced PIR and LR to both β(1) - and β(2) -adrenoceptor stimulation while PDE4 inhibition had no effect on these responses despite a significant increase in cAMP levels. Combined PDE3/4 inhibition further enhanced the PIR and LR of β(2) - and β(1) -adrenoceptor activation both in Sham and failing hearts, compared with PDE3 inhibition alone. PDE4 enzyme activity was reduced in failing hearts.

CONCLUSIONS AND IMPLICATIONS

Both PDE3 and PDE4 attenuated β(2) - and β(1) -adrenoceptor-mediated contractile responses in Sham hearts. In failing hearts, these responses are attenuated solely by PDE3 and thus even selective PDE3 inhibitors may provide a profound enhancement of β-adrenoceptor-mediated responses in heart failure.

Cardiovascular effects of chronic treatment with a β2-adrenoceptor agonist relieving neuropathic pain in mice

Neuropathic pain is often a chronic condition, disabling and difficult to treat. Using a murine model of neuropathic pain induced by placing a polyethylene cuff around the main branch of the sciatic nerve, we have shown that chronic treatment with β-AR agonists is effective against neuropathic allodynia. β-mimetics are widely used against asthma and chronic obstructive pulmonary disease and may offer an interesting option for neuropathic pain management. The most prominent adverse effects of chronic treatment with β-mimetics are cardiovascular. In this study, we compared the action of low doses of the selective β(2)-AR agonist terbutaline and of a high dose of the mixed β(1)/β(2)-AR agonist isoproterenol on cardiovascular parameters in a neuropathic pain context. Isoproterenol was used as a positive control for some heart-related changes. Cardiac functions were studied by echocardiography, hemodynamic measurements, histological analysis of fibrosis and cardiac hypertrophy, and by quantitative real time PCR analysis of atrial natriuretic peptide (Nppa), periostin (Postn), connective tissue growth factor (Ctgf) and β-myosin heavy chain (Myh7). Our data show that a chronic treatment with the β(2)-AR agonist terbutaline at low antiallodynic dose does not affect cardiovascular parameters, whereas the mixed β(1)/β(2)-AR agonist isoproterenol induces cardiac hypertrophy. These data suggest that low doses of β(2)-AR agonists may provide a suitable treatment with rare side effects in neuropathic pain management. This study conducted in an animal model requires clinical confirmation in humans.

β₂ AR agonists in treatment of chronic heart failure: long path to translation

The main clinical manifestations of advanced chronic heart failure (CHF), e.g. in dilated cardiomyopathy (DCM), are reduced systolic and diastolic functions, increased arterial elastance and arterio-ventricular uncoupling, accompanied and exacerbated by an excessive sympathetic activation and extensive abnormalities in the βAR signaling. Loss of cardiomyocytes due to apoptosis is one mechanism that undoubtedly contributes to cardiac remodeling and functional deterioration associated with dilated cardiomyopathy (DCM). Research during the last decade on the single cardiomyocyte level strongly suggested that selective stimulation of β(1) AR activates the proapoptotic signaling pathways, while selective stimulation of β(2) AR is antiapoptotic, but its precise mechanisms remain to be elucidated. Extensive research in the rat model of DCM following induction of myocardial infarction (MI) showed that prolonged treatment with of β(2) AR agonist, fenoterol, in combination with a β(1) AR blocker, metoprolol, is more effective than β(1) AR blocker alone and as effective as β(1) AR blocker with ACE inhibitor with respect to survival and cardiac remodeling. This combined regimen of β(2) AR agonists and a β(1) AR blocker might be considered for clinical testing as alternative or adjunct therapy to currently acceptable CHF arsenal. This article is part of a special issue entitled "Key Signaling Molecules in Hypertrophy and Heart Failure."

Therapeutic efficacy of a combination of a beta1-adrenoreceptor (AR) blocker and beta2-AR agonist in a rat model of postmyocardial infarction dilated heart failure exceeds that of a beta1-AR blocker plus angiotensin-converting enzyme inhibitor

We had proposed previously a novel combination of beta2-adrenoreceptor (AR) agonist and beta1-AR blocker that in the rat model of postmyocardial infarction (MI) dilated cardiomyopathy exceeds the therapeutic effectiveness of either monotherapy. In the present study, we compared that treatment with a combination of beta1-AR blocker and angiotensin-converting enzyme inhibitor (ACEi), a current standard chronic heart failure (CHF) therapy. Two weeks after coronary artery ligation, rats were divided into groups of similar average MI size, measured by echocardiography, and the following 12-month treatments were initiated: fenoterol (250 microg/kg/day), a beta2-AR agonist, plus metoprolol (100 mg/kg/day), a beta1-AR blocker (beta1-beta2+); metoprolol plus enalapril (20 mg/kg/day), an ACEi (beta1-ACEi); and a combination of all three drugs (beta1-beta2+ACEi). These treatment groups were compared with each other and with nontreated (nT) and sham groups. The 12-month mortality was significantly reduced in all treatment groups (44% in beta1-beta2+, 56% in beta1-beta2+ACEi, 59% in beta1-ACEi versus 81% in nT). Bimonthly echocardiography revealed significant attenuation of the left ventricular (LV) chamber remodeling, LV functional deterioration, and MI expansion in all three treatment groups, but effects were significantly more pronounced when treatment included a beta2-AR agonist. The results indicated that a combination of beta1-AR blocker and beta2-AR agonist is equipotent to a combination of beta1-AR blocker and ACEi in the treatment of CHF in rats, with the respect to mortality, and exceeds the latter with respect to cardiac remodeling and MI expansion. Thus, this novel therapeutic regimen for CHF warrants detailed clinical investigation.

Ecologic analysis of asthma-related events and dispensing of inhaled corticosteroid- and salmeterol-containing products

BACKGROUND

An association between salmeterol use and serious asthma episodes or asthma-related mortality has been noted in 2 clinical trials; however, a causal relationship has not been established. To date, observational studies have not replicated this finding.

OBJECTIVE

To examine the relationship between number of prescriptions dispensed of salmeterol-containing products and inhaled corticosteroid (ICS)-containing products and the rates of asthma-related hospitalizations and mortality in the United States.

METHODS

In this ecologic study, annual age-adjusted rates of asthma-related hospitalization and asthma-related mortality from US population-based sources were graphed alongside annual number of prescriptions dispensed of salmeterol- and ICS-containing products by year from 1991 to 2004. We computed the Spearman rank correlations between number of prescriptions dispensed and serious events (asthma-related hospitalization rate, number of hospitalizations, asthma-related mortality rate, and number of asthma deaths).

RESULTS

During more than 14 years, while number of prescriptions dispensed of salmeterol-containing and ICS-containing products increased, age-adjusted asthma-related mortality rates declined and asthma-related hospitalization rates remained relatively stable. The number of asthma-related deaths has decreased steadily since the mid-1990s.

CONCLUSION

This study provides population-level evidence that asthma-related death rates declined and asthma-related hospitalization rates remained relatively constant for more than 14 years during a period of improvements in asthma management per treatment guidelines, including increased use of maintenance medications, such as ICSs and salmeterol.

Diagnostic and therapeutic challenges in patients with coexistent chronic obstructive pulmonary disease and chronic heart failure

Chronic obstructive pulmonary disease (COPD) and heart failure (CHF) are common conditions. The prevalence of COPD ranges from 20% to 30% in patients with CHF. The diagnosis of CHF can remain unsuspected in patients with COPD, because shortness of breath is attributed to COPD. Measurement of plasma B-type natriuretic peptide (BNP) levels helps to uncover unsuspected CHF in patients with COPD and clinical deterioration. Noninvasive assessment of cardiac function may be preferable to BNP to uncover unsuspected left ventricular (LV) systolic dysfunction in patients with stable COPD. Patients with COPD or CHF develop skeletal muscle alterations that are strikingly similar. Functional intolerance correlates with severity of skeletal muscle alterations but not with severity of pulmonary or cardiac impairment in COPD and CHF, respectively. Improvement of pulmonary or cardiac function does not translate into relief of functional intolerance in patients with COPD or CHF unless skeletal muscle alterations concomitantly regress. The mechanisms responsible for skeletal muscle alterations are incompletely understood in COPD and in CHF. Disuse and low-level systemic inflammation leading to protein synthesis/degradation imbalance are likely to contribute. The presence of COPD impacts on the treatment of CHF, as COPD is still viewed as a contraindication to beta-blockade. Therefore, COPD often deprives patients with CHF due to LV systolic dysfunction of the most beneficial pharmacologic intervention. A large body of data indicates that patients with COPD tolerate well selective beta-blockade that should not be denied to CHF patients with concomitant COPD.

Pharmacological Stimulation of β 2-adrenergic Receptors (β 2AR) Enhances Therapeutic Effectiveness of β 1AR Blockade in Rodent Dilated Ischemic Cardiomyopathy

BACKGROUND

We have reported that beta2 adrenoreceptor (beta2AR) stimulation is anti-apoptotic, and has strong beneficial effect on cardiac remodeling in an experimental model of post myocardial infarction chronic heart failure (CHF) in rats. Here we investigate whether the addition of chronic pharmacological beta2AR stimulation enhances the therapeutic effects of beta1AR blockade on cardiac remodeling in the same model.

METHODS AND RESULTS

Metoprolol, a beta1AR blocker, given alone (beta1) or in combination with beta2AR agonist, fenoterol (beta1beta2) were administered to rats via drinking water for 6 weeks, beginning 2 weeks following permanent coronary ligation. Progressive left ventricular (LV) remodeling of untreated animals, assessed by repeated echocardiography, occurred during the observation time, i.e., 42% and 25% increases in end-systolic and end-diastolic LV volumes respectively, 27% fall in ejection fraction, and 35% infarct expansion. Pressure-volume loop analyses at 2d and 8th post infarction weeks showed continuous deterioration of systolic and diastolic functions and arterio-ventricular mismatch. Histological evaluation at the end of 8 weeks revealed the MI expansion and hypertrophy of cardiomyocytes. beta1beta2 prevented LV remodeling, MI expansion and cardiomyocytes hypertrophy to a greater degree than beta1, due, in large part, to a vasodilatory effect of beta2AR stimulation and thus improvement of arterio-ventricular mismatch. The abnormal diastolic performance improved only in beta1beta2. beta1beta2 treatment reduced myocardial apoptosis throughout myocardium, but beta1 reduced apoptosis only in the areas remote from MI.

CONCLUSION

The therapeutic effects of chronic beta1AR blockade on cardiac remodeling of heart failure are enhanced and extended when supplemented with beta2AR stimulation.

Inhaled beta2-adrenoceptor agonists: cardiovascular safety in patients with obstructive lung disease

Although large surveys have documented the favourable safety profile of beta(2)-adrenoceptor agonists (beta(2)-agonists) and, above all, that of the long-acting agents, the presence in the literature of reports of adverse cardiovascular events in patients with obstructive airway disease must induce physicians to consider this eventuality. The coexistence of beta(1)- and beta(2)-adrenoceptors in the heart clearly indicates that beta(2)-agonists do have some effect on the heart, even when they are highly selective. It should also be taken into account that the beta(2)-agonists utilised in clinical practice have differing selectivities and potencies. beta(2)-agonist use has, in effect, been associated with an increased risk of myocardial infarction, congestive heart failure, cardiac arrest and sudden cardiac death. Moreover, patients who have either asthma or chronic obstructive pulmonary disease may be at increased risk of cardiovascular complications because these diseases amplify the impact of these agents on the heart and, unfortunately, are a confounding factor when the impact of beta(2)-agonists on the heart is evaluated. Whatever the case may be, this effect is of particular concern for those patients with underlying cardiac conditions. Therefore, beta(2)-agonists must always be used with caution in patients with cardiopathies because these agents may precipitate the concomitant cardiac disease.

Association between chronic heart failure and inhaled beta-2-adrenoceptor agonists

BACKGROUND

Recent reports suggest an association between beta-agonists and the risk of incident chronic heart failure (CHF). We sought to examine the association between inhaled beta-agonists and risk of incident and nonincident heart failure.

METHODS

We performed a nested case-control study within the Ambulatory Care Quality Improvement Project (ACQUIP). Case subjects were defined as having had a hospitalization with a primary discharge diagnosis of CHF. Controls were randomly selected from the ACQUIP cohort. The exposure was the number of beta-agonist canisters filled in the 90 days before an index date.

RESULTS

After adjusting for potentially confounding factors, there appeared to be no association between the use of inhaled beta-agonists and the risk of heart failure (1-2 canisters per month, OR 1.3 [95% CI 0.9, 1.8], > or =3 canisters per month, 1.1 [95% CI 0.8, 1.6]). However, among the cohort that had a history of CHF, there appeared to be a dose-response association between the number of inhaled beta-agonists and the risk of hospitalization for chronic heart failure (1-2 canisters per month, adjusted OR 1.8 [95% CI 1.1, 3.0], > or =3 canisters per month, adjusted OR 2.1 [95% CI 1.2, 3.8]).

CONCLUSION

beta-Agonists did not appear to be associated with incident heart failure but were associated with risk of CHF hospitalization among those subjects with a previous CHF diagnosis. Although a causal relationship cannot be inferred from these findings, further research is warranted to determine the safety and effectiveness of inhaled beta-agonists for patients with CHF.

Biofeedback treatment for asthma

STUDY OBJECTIVES

We evaluated the effectiveness of heart rate variability (HRV) biofeedback as a complementary treatment for asthma.

PATIENTS

Ninety-four adult outpatient paid volunteers with asthma.

SETTING

The psychophysiology laboratory at The University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, and the private outpatient offices of participating asthma physicians.

INTERVENTIONS

The interventions were as follows: (1) a full protocol (ie, HRV biofeedback and abdominal breathing through pursed lips and prolonged exhalation); (2) HRV biofeedback alone; (3) placebo EEG biofeedback; and (4) a waiting list control.

DESIGN

Subjects were first prestabilized using controller medication and then were randomly assigned to experimental groups. Medication was titrated biweekly by blinded asthma specialists according to a protocol based on National Heart, Lung, and Blood Institute guidelines, according to symptoms, spirometry, and home peak flows.

MEASUREMENTS

Subjects recorded daily asthma symptoms and twice-daily peak expiratory flows. Spirometry was performed before and after each weekly treatment session under the HRV and placebo biofeedback conditions, and at triweekly assessment sessions under the waiting list condition. Oscillation resistance was measured approximately triweekly.

RESULTS

Compared with the two control groups, subjects in both of the two HRV biofeedback groups were prescribed less medication, with minimal differences between the two active treatments. Improvements averaged one full level of asthma severity. Measures from forced oscillation pneumography similarly showed improvement in pulmonary function. A placebo effect influenced an improvement in asthma symptoms, but not in pulmonary function. Groups did not differ in the occurrence of severe asthma flares.

CONCLUSIONS

The results suggest that HRV biofeedback may prove to be a useful adjunct to asthma treatment and may help to reduce dependence on steroid medications. Further evaluation of this method is warranted.

Cardiovascular safety of beta(2)-adrenoceptor agonist use in patients with obstructive airway disease: a systematic review

BACKGROUND

beta(2)-Adrenoceptor agonists have been used as bronchodilators in the management of asthma and chronic obstructive pulmonary disease (COPD); however, there is evidence suggesting that beta(2)-adrenoceptor agonist use may increase morbidity and mortality.

METHODS

A systematic review of case-control studies and randomised controlled trials was performed to evaluate the cardiovascular safety of beta(2)-adrenoceptor agonist use in patients with obstructive airway disease, defined as asthma or COPD.

RESULTS

Case-control studies have shown that beta(2)-adrenoceptor agonist use is associated with an increased risk of myocardial infarction, congestive heart failure, cardiac arrest and sudden cardiac death. The degree of risk appears to be dose-dependent, and may be highest for new users and those with concomitant cardiac conditions. Pooled data from randomised placebo-controlled trials indicate that beta(2)-adrenoceptor agonist use increases the risk of adverse cardiovascular events by more than 2-fold compared with placebo, thus providing evidence that the association seen in case-control studies is a causal one. Single doses of beta(2)-adrenoceptor agonists significantly increase heart rate and decrease potassium concentrations compared with placebo.

CONCLUSIONS

Initiation of beta(2)-adrenoceptor agonist treatment increases heart rate and decreases potassium concentrations, while continued use may increase the risk of adverse cardiovascular events. It could be through these effects of beta-adrenergic stimulation that beta(2)-adrenoceptor agonists may induce ischaemia, congestive heart failure, arrhythmias and sudden cardiac death. In addition to increasing adverse cardiovascular events, beta(2)-adrenoceptor agonist use may induce respiratory tolerance and increase the risk of asthma attacks. It is not clear whether beta(2)-adrenoceptor agonists should be used regularly in the treatment of obstructive airway disease, with or without concomitant cardiovascular disease.

A design for prescription-event monitoring in Japan (J-PEM)

OBJECTIVES

To present a design for Prescription-Event Monitoring in Japan (J-PEM).

METHODS

In J-PEM, pharmacists are asked to register patients who are prescribed the 'test drug' or a 'control drug' for the first time ever, the drug, and prescribing physician. Although J-PEM does not identify all users of a drug, this method provides concurrent controls. In J-PEM, a questionnaire for the pharmacist and one for the prescribing physician are mailed 6 months after the drug to be monitored is first prescribed to a patient. Doctors and pharmacists are asked to report events that occurred in the patient after the drug was prescribed. The questionnaire for the physician includes questions that are specific to the class of drug that was prescribed, to obtain information on possible confounding variables. Pharmacists are requested to give information on all concomitant drugs used by the patient during or for a part of the period that the patient was taking the drug to be monitored.

RESULTS AND CONCLUSIONS

Compared with the UK PEM, the weakness of J-PEM is its inability to identify all users of a drug, and its strengths are the availability of concurrent controls and a relatively large amount of information per patient.

Cardiovascular Effects of β-Agonists in Patients With Asthma and COPD

BACKGROUND

beta-Adrenergic agonists exert physiologic effects that are the opposite of those of beta-blockers. beta-Blockers are known to reduce morbidity and mortality in patients with cardiac disease. beta(2)-Agonist use in patients with obstructive airway disease has been associated with an increased risk for myocardial infarction, congestive heart failure, cardiac arrest, and acute cardiac death.

OBJECTIVES

To assess the cardiovascular safety of beta(2)-agonist use in patients with obstructive airway disease, defined as asthma or COPD.

METHODS

A meta-analysis of randomized placebo-controlled trials of beta(2)-agonist treatment in patients with obstructive airway disease was performed, to evaluate the short-term effect on heart rate and potassium concentrations, and the long-term effect on adverse cardiovascular events. Longer duration trials were included in the analysis if they reported at least one adverse event. Adverse events included sinus and ventricular tachycardia, syncope, atrial fibrillation, congestive heart failure, myocardial infarction, cardiac arrest, or sudden death.

RESULTS

Thirteen single-dose trials and 20 longer duration trials were included in the study. A single dose of beta(2)-agonist increased the heart rate by 9.12 beats/min (95% confidence interval [CI], 5.32 to 12.92) and reduced the potassium concentration by 0.36 mmol/L (95% CI, 0.18 to 0.54), compared to placebo. For trials lasting from 3 days to 1 year, beta(2)-agonist treatment significantly increased the risk for a cardiovascular event (relative risk [RR], 2.54; 95% CI, 1.59 to 4.05) compared to placebo. The RR for sinus tachycardia alone was 3.06 (95% CI, 1.70 to 5.50), and for all other events it was 1.66 (95% CI, 0.76 to 3.6).

CONCLUSION

beta(2)-Agonist use in patients with obstructive airway disease increases the risk for adverse cardiovascular events. The initiation of treatment increases heart rate and reduces potassium concentrations compared to placebo. It could be through these mechanisms, and other effects of beta-adrenergic stimulation, that beta(2)-agonists may precipitate ischemia, congestive heart failure, arrhythmias, and sudden death.

Adverse effects of beta-agonists: are they clinically relevant?

Inhaled beta(2)-adrenoceptor agonists (beta(2)-agonists) are the most commonly used asthma medications in many Western countries. Minor adverse effects such as palpitations, tremor, headache and metabolic effects are predictable and dose related. Time series studies suggested an association between the relatively nonselective beta-agonist fenoterol and asthma deaths. Three case-control studies confirmed that among patients prescribed fenoterol, the risk of death was significantly elevated even after controlling for the severity of asthma. The Saskatchewan study not only found an increased risk of death among patients dispensed fenoterol, but also suggested this might be a class effect of beta(2)-agonists. However, in subsequent studies, the long-acting beta(2)-agonist salmeterol was not associated with increased asthma mortality. In a case-control study blood albuterol (salbutamol) concentrations were found to be 2.5 times higher among patients who died of asthma compared with controls. It is speculated that such toxic concentrations could cause tachyarrhythmias under conditions of hypoxia and hypokalemia. The risk of asthma exacerbations and near-fatal attacks may also be increased among patients dispensed fenoterol, but this association may be largely due to confounding by severity. Although salmeterol does not appear to increase the risk of near-fatal attacks, there is a consistent association with the use of nebulized beta(2)-agonists. Nebulized and oral beta(2)-agonists are also associated with an increased risk of cardiovascular death, ischemic heart disease and cardiac failure. Caution should be exercised when first prescribing a beta-agonist for patients with cardiovascular disease. A potential mechanism for adverse effects with regular use of beta(2)-agonists is tachyphylaxis. Tachyphylaxis to the bronchodilator effects of long-acting beta(2)-agonists can occur, but has been consistently demonstrated only for formoterol (eformoterol) a full agonist, rather than salmeterol, a partial agonist. Tachyphylaxis to protection against induced bronchospasm occurs with both full and partial beta(2)-agonists, and probably within a matter of days at most. Underlying airway responsiveness to directly acting bronchoconstricting agents is not increased when the bronchodilator effect of the regular beta(2)-agonist has been allowed to wear off, although there may be an increase in responsiveness to indirectly acting agents. While there has been speculation that underlying airway inflammation in asthma may be made worse by regular use of short-acting beta(2)-agonists, in contradistinction, a number of studies have shown that long-acting beta(2)-agonists have positive anti-inflammatory effects. An Australian Cochrane Airways Group systematic review of the randomized, controlled trials of short-acting beta-agonists found only minimal and clinically unimportant differences between regular use and use as needed. Regular short-acting treatment was better than placebo. However, a subsequent systematic review has found that regular use of long-acting beta-agonists had significant advantages over regular use of short-acting beta-agonists. More studies and data are needed on the regular use of beta(2)-agonists in patients not taking inhaled corticosteroids, and in potentially vulnerable groups, such as the elderly and those with particular genotypes for the beta-receptor, who might be more prone to adverse effects.

Redefining Treatment in COPD

COPD is a growing international health concern and it is estimated that by the year 2020 it will rank fifth as a cause of disability worldwide. In response to this problem, the World Health Organization and the US National Institutes of Health convened a panel of experts to draft a consensus strategy to treat patients with COPD. Called the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines, they are designed to define and stage the severity of COPD, make recommendations for treatment, and to expand global awareness of the disease. The GOLD guidelines describe a multimodality approach to provide optimal care for the COPD patient population. This includes respiratory and rehabilitative therapy, nutrition services, psychosocial counseling, and surgical care. Bronchodilators form the cornerstone of pharmacologic treatment for COPD. These medications can significantly lessen dyspnea, enhance quality of life, increase airflow, and improve exercise performance. While bronchodilators decrease airway resistance and lessen hyperinflation in patients with COPD, they have not been shown to influence the decline in FEV1 over time or improve survival in this patient population. Recently, long-acting beta2-adrenoceptor agonists (beta2-agonists) such as formoterol and salmeterol and anticholinergic medications including tiotropium bromide have been developed which may further improve symptom management in COPD patients. This article discusses bronchodilator pharmacologic therapy for patients with COPD focusing on beta2-agonists, anticholinergics, and methylxanthines in the light of the recent GOLD consensus statements.

Insuffisances cardiaques d’origine médicamenteuse (en dehors des anthracyclines)

The principal drugs implicated in or disclosing cardiac insufficiency are drawn from a review of the literature and observations by the French national pharmacovigilance database, from 1984 to April 2003. Several pharmacological classes are identified: in addition to antimitotic drugs, such as anthracyclines, many drugs are implicated in cardiac insufficiency, e.g. immunomodulators, anti-inflammatory drugs (including coxibs), antiarrhythmic drugs, anaesthetic drugs, antipsychotic drugs, and antidiabetic drugs (including glitazones). It is usual to classify these drugs according to three categories: (i) drugs likely to cause cardiac insufficiency de novo (such as cyclophosphamide, paclitaxel, mitoxantrone, interferons, interleukin-2 etc.); (ii) drugs likely to worsen preexisting cardiac insufficiency (such as antiarrhythmics, beta-blockers, calcium antagonists, nonsteroidal and steroidal anti-inflammatory drugs, sympathomimetic drugs etc.); and (iii) drugs only occasionally causing cardiac insufficiency. This review shows that this classification is, in fact, artificial. If cardiac toxicity is a constant concern when using antimitotic drugs or some immunomodulator drugs, it is advisable to exercise caution in the use of many other drugs when treating patients with cardiac insufficiency, even if the clinical situation is well controlled. In particular, drug-drug interactions and patient medical history must be taken into account.

Pharmacology of airway inflammation in asthma and COPD

The current asthma therapies are not cures and symptoms return soon after treatment is stopped even after long term treatment. Although inhaled glucocorticoids are highly effective in controlling airway inflammation in asthma, they are ineffective in the small group of patients with glucocorticoid-dependent and -resistant asthma. With very few exceptions, COPD is caused by tobacco smoking, and smoking cessation is the only truly effective treatment of COPD available. Current pharmacological treatment of COPD is unsatisfactory, as it does not significantly influence the severity of the disease or its natural course. Glucocorticoids are scarcely effective in COPD patients without concomitant asthma. Bronchodilators improves symptoms and quality of life, in COPD patients, but, with the exception of tiotropium, they do not significantly influence the natural course of the disease. Theophylline is the only drug which has been demonstrated to have a significant effect on airway inflammation in patients with COPD. Here we review the pharmacology of currently used antiinflammatory therapies for asthma and COPD and their proposed mechanisms of action. Recent understanding of disease mechanisms in severe steroid-dependent and -resistant asthma and in COPD, has lead to the development of novel compounds, which are in various stages of clinical development. We review the current status of some of these new potential drugs.

Risk of mortality and heart failure exacerbations associated with inhaled beta-adrenoceptor agonists among patients with known left ventricular systolic dysfunction

OBJECTIVES

Recent studies suggest that myocardial beta(2)-adrenoceptors may be important in chronic heart failure. We sought to determine if use of selective beta(2)-agonists was associated with hospitalization for heart failure and all-cause mortality.

METHODS

We studied a cohort of patients with left ventricular systolic dysfunction (LVSD). The outcome was the first hospitalization with a primary diagnosis of chronic heart failure or death from any cause. The exposure was the average number of beta-agonist canisters filled per month in the 90 days prior to and 15 days after enrollment.

RESULTS

Among 1,529 subjects, the relative risk (RR) of chronic heart failure hospital admission associated with inhaled beta-agonists followed a dose-response relationship: RR for one canister per month, 1.4 (95% confidence interval [CI], 0.9 to 2.0), RR for two canisters per month, 1.7 (95% CI, 1.2 to 2.5), and RR for three canisters per month, 2.1 (95% CI, 1.4 to 3.1). The RR of death demonstrated a similar finding: RR for one canister per month, 0.9 (95% CI, 0.5 to 1.5), RR for two canisters per month, 1.3 (95% CI, 0.9 to 2.1), and RR for three canisters per month, 2.0 (95% CI, 1.3 to 3.1). Adjusting for potential confounding factors did not affect the estimates.

CONCLUSION

Among subjects with LVSD, inhaled beta-agonists were associated with an increased risk of heart failure hospitalization, and all-cause mortality. Clinicians should carefully consider the etiology of dyspnea when prescribing beta-agonists to patients with LVSD.

Left ventricular diastolic dysfunction in patients with bronchial asthma with long-term oral beta2-adrenoceptor agonists

BACKGROUND

Long-term administration of oral beta(2)-adrenergic receptor agonists (beta(2)-AG) in patients with bronchial asthma (BA) causes disastrous events such as sudden death and heart attack. However, long-term effects of beta(2)-AG on cardiac function have not been previously quantified.

METHODS

Seventy-four patients with BA with regular long-term use of oral beta(2)-AG (group A) and 69 patients with BA without beta(2)- AG (group B) were examined in medical records of outpatient clinics from 1985 to 1999. In the prospective study, echocardiography was performed in 48 consecutive patients from January to April 1999. There were 26 patients with regular oral use of beta(2)-AG (group a) and 22 patients without beta(2)-AG (group b). Twenty-one age-matched normal volunteers without heart or pulmonary diseases were used as control subjects (group c). Oral beta(2)-AG was withdrawn from remedies in 11 patients of group a, and echocardiographic studies were repeated 2 weeks after its cessation.

RESULTS

Events related to heart failure were more frequently seen in group A than in group B (14% vs 1%, P <.01). The echocardiographic study showed that indexes of left ventricular diastolic but not systolic function were significantly deteriorated in group a, along with a markedly reduced level of plasma norepinephrine concentration (P <.05 vs groups b and c). When heart rate was adjusted to 90 beats/min during isoproterenol infusion, left ventricular diastolic function remained deteriorated in group a (P <.05 vs groups b and c). In 11 patients of group a, the cessation of beta(2)-AG for 2 weeks resulted in an improvement of left ventricular diastolic function and in an increase of plasma norepinephrine level (P <.01).

CONCLUSIONS

Long-term use of oral beta(2)-AG impaired left ventricular diastolic function in patients with BA, and the cessation of beta(2)-AG reversed diastolic pump performance to the normal level.

Age- and gender-specific asthma death rates in patients taking long-acting beta2-agonists: prescription event monitoring pharmacosurveillance studies

OBJECTIVE

Prescription event monitoring is a national drug safety surveillance scheme in which prescribers are prompted to report events and deaths following prescription of newly marketed drugs. This paper presents age- and gender-specific asthma death rates in patients prescribed the long-acting beta2-agonists salmeterol and bambuterol.

DESIGN AND SETTING

Pharmacosurveillance cohort study of general practice patients in England.

PATIENTS AND PARTICIPANTS

15 406 patients prescribed salmeterol between December 1990 and May 1991, and 8098 patients prescribed bambuterol between February 1993 and December 1995.

METHODS

Patients prescribed these drugs by general practitioners in England were identified using the national pharmacovigilance system of prescription event monitoring, in which details of all dispensed prescriptions were provided in confidence by the Prescription Pricing Authority. Questionnaires were sent to the prescriber asking for details of events occurring after the first prescription. In each study an attempt was made to establish the cause of all deaths reported on the questionnaires, via retrieval of the patients' medical notes or examination of death certificates.

OUTCOME MEASURES AND RESULTS

There was little evidence of heterogeneity in the drug-specific death rates and we therefore present the combined age- and gender-specific death rates for the 2 cohorts. Overall, there were 85 asthma deaths among people taking the long-acting beta2-agonists studied (bambuterol and salmeterol cohorts combined). The overall death rate was 2.33 [95% confidence interval (CI) 1.84 to 2.84] per 10000 months of observation. There were 37 asthma deaths among male patients (rate 2.40 per 10000 months of observation; 95% CI 1.74 to 3.40) and 48 asthma deaths among female patients (rate 3.08 per 10000 months of observation; 95% CI 2.21 to 3.98). There was no difference in death rates when male and female patients were compared (rate ratio 0.78; 95% CI 0.49 to 1.22; p = 0.26).

CONCLUSION

Prescription event monitoring is a form of prompted surveillance allowing rapid, uniform, national and practical assessment of newly marketed drugs on large cohorts of patients in England. These data provide benchmark rates from which to assess the performance of newly prescribed anti-asthma drugs and generate hypotheses for later analytical investigation in which confounding by indication and asthma severity can be controlled for. Any differences in these rates should be considered as a source of signal generation within the context of a surveillance programme, rather than as robust evidence of any mortality differential between drugs.

Long-acting beta-agonist treatment in patients with persistent asthma already receiving inhaled corticosteroids

International guidelines recommend that long-acting beta-agonists should be considered in patients who are symptomatic despite moderate doses of inhaled corticosteroids. When combined with inhaled corticosteroids they improve asthma symptoms and lung function and reduce exacerbations. The evidence suggests that they are well tolerated. However, they are less effective than inhaled corticosteroids as monotherapy and should not be used alone, although the addition of a long-acting beta-agonist may permit a small reduction in the corticosteroid dose. Both salmeterol and formoterol appear equally effective in improving asthma control. Formoterol, however, has a rapid onset of action and is now being promoted for the relief of acute asthma symptoms. Both drugs provide prolonged protection against exercise-induced bronchospasm. However, this effect rapidly diminishes with continuous therapy and if this is the main aim of treatment, intermittent use may be preferable. When compared with alternative treatments, inhaled long-acting beta-agonists are more effective in controlling asthma symptoms than either theophylline or antileukotriene agents. Bambuterol, an oral prodrug of terbutaline, appears to be as effective as the inhaled long-acting beta-agonists and has the advantage of once daily oral administration. However, the inhaled long-acting beta-agonists are less likely to have systemic adverse effects. There are theoretical concerns that regular beta-agonist treatment may lead to tolerance and a failure to respond to emergency asthma treatment. While there is no doubt that tolerance occurs, there is currently little evidence that this is a clinical problem. Insights into pharmacological as well as therapeutic interactions between inhaled corticosteroids and beta-agonists are providing justification for their use in combination. Guidelines for the management of patients with chronic persistent asthma are likely to require modification to reflect these developments.

Risk of myocardial ischaemia and beta-adrenoceptor agonists

Modern therapy for both cardiovascular disease and obstructive lung disease involves diametrically opposed manipulations of the beta-adrenoceptor. Beta-agonists reduce airflow limitation and improve symptoms among patients with obstructive lung disease while beta-blockers reduce symptoms, recurrent myocardial ischaemia and all-cause mortality among patients with ischaemic heart disease. There is biological plausibility for beta-agonists leading to adverse cardiovascular outcomes, and observational trials have raised concern about the safety of beta-agonists among patients with cardiovascular disease. Although there are many potential causal and noncausal explanations for these observational findings, the implications from these studies are the same. Physicians should be careful when prescribing beta-agonists for patients at risk for ischaemic heart disease. Furthermore, careful consideration should be given to distinguish symptoms caused by cardiovascular versus respiratory aetiologies.

Prospective cohort study of adverse events monitored by hospital pharmacists. Hospital Adverse Event Monitoring Study (HAEMS) Group

PURPOSE

To examine the feasibility of pharmacist-led intensive hospital monitoring of adverse events (AEs) associated with newly marketed drugs.

SUBJECTS/SETTING

303 patients admitted to Southampton Hospitals who were prescribed selected newly marketed drugs during their inpatient stay in 1998.

METHODS

Prospective observational study. Patients were identified from computerized pharmacy records, clinical pharmacist ward rounds, dispensary records or via nursing staff. The pharmacist reviewed medical notes and recorded AEs, suspected adverse drug reactions (ADRs) and reasons for stopping drugs.

OUTCOMES

Incidence of AEs, ADRs; proportionate agreement between the physician's and pharmacist's event recording.

RESULTS

303 patients were monitored. Of the patients taking newly marketed drugs 92% were identifiable using pharmacy computer systems and pharmacist ward visits. There were 21 (7%) suspected ADRs detected during this pilot study. The types of adverse events detected were broadly similar to those identified by general practice-based prescription event monitoring. However, biochemical changes featured more frequently than in general practice. Differences between adverse events recorded by pharmacist and physician were systematic and attributed to differences in event coding.

CONCLUSION

Pharmacist-led monitoring in a typical NHS hospital setting was effective at detecting ADRs in newly marketed drugs. However, this effort might have been substantially less time-consuming and more effective were electronic patient records (EPRs) available. Pharmacy computer systems are not designed to be patient focused and are therefore unable to identify patients taking newly marketed drugs. It is argued that future EPR and computerised patient-specific prescribing systems should be designed to capture this data in the same way as some US systems are currently able to do.

Post-marketing studies: the work of the Drug Safety Research Unit

The Drug Safety Research Unit (DSRU) is the centre for prescription-event monitoring (PEM) in England. PEM studies are noninterventional observational cohort studies which monitor the safety of newly marketed drugs. The need for post-marketing surveillance is well recognised in the UK and general practice is an ideal source of data. PEM studies are general practitioner (community)-based and exposure is based on dispensed prescription data in England. To date, 65 PEM studies have been completed with a mean cohort size of 10 979 patients and the DSRU database has clinical information on over 700000 patients prescribed new drugs. Unlike spontaneous reporting schemes, PEM produces incidence rates for events reported during treatment. Comparative studies can be conducted for drugs in the same class. The DSRU aggregates outcome data for pregnancies exposed to new drugs. Data for children and the elderly can also be specifically examined. PEM data have a number of advantages over data from computerised general practice databases in the UK. PEM is the only technique within the UK capable of monitoring newly marketed drugs in such a comprehensive and systematic way.