Systematic review of genuine versus spurious side-effects of beta-blockers in heart failure using placebo control: recommendations for patient information

Side effects and tolerability of combination blood pressure lowering according to blood pressure levels: an analysis of the PROGRESS and ADVANCE trials

OBJECTIVE

To measure the placebo-controlled effects of combination therapy on hypotension, treatment discontinuation, and major renal outcomes, according to baseline blood pressure.

METHODS

We conducted an analysis of the action in diabetes and vascular disease: preterax and diamicron-MR controlled evaluation ADVANCE and perindopril protection against recurrent stroke study PROGRESS trials, including 14 684 participants allocated combination therapy or placebo. The mean age was 65 years, 61% were men, and 64% were receiving background blood pressure lowering (BPL) therapy. Participants were stratified into five subgroups by baseline SBP less than 120, 120-129, 130-139, 140-159, and at least 160 mmHg. Discontinuation of study treatment during the active run-in phase and postrandomization follow-up was assessed for hypotension/dizziness and other causes. Major renal outcomes (sustained doubling in creatinine or renal death) were also assessed.

RESULTS

Discontinuation during the 4-6-week active run-in phase due to hypotension/dizziness ranged from 3.6% in those with SBP less than 120 mmHg to 1.3% in those with SBP at least 160 mmHg. Median follow-up in the randomized phase was 5.6 years, and discontinuation for hypotension was higher with combination therapy compared with placebo in the less than 120 mmHg group (4.7 vs. 1.2%). However, for each subgroup with baseline SBP 120-129, 130-139, and 140-159 mmHg, the absolute excess of discontinuation due to hypotension with combination therapy was 0.7%. Total discontinuations were only increased in the less than 120 mmHg group (18.4 vs. 12.5%) and the 120-129-mmHg subgroup (17.6 vs. 14.2%). There were no clear differences across the SBP subgroups for the combined renal outcome (overall, 0.8 vs. 0.6%).

CONCLUSION

Compared with those with baseline SBP 140-159 mmHg, side effects of dual combination BPL are essentially the same for people with SBP 130-139 mmHg and only modestly increased among patients with SBP 120-129 mmHg. During long-term therapy, side effects sufficient to stop treatment that are treatment related (i.e. occur in excess of rates seen with placebo) occur at less than 0.5%/year in patients with baseline SBP 120-139 mmHg. These results have important implications in assessing the likely balance of benefits and side effects of BPL with combination therapy among those with SBP 120-139 mmHg.

Ultrasound-promoted dispersive micro solid-phase extraction of trace anti-hypertensive drugs from biological matrices using a sonochemically synthesized conductive polymer nanocomposite

In this work, a rapid and efficient procedure named ultrasound meliorated dispersive micro solid-phase extraction followed by high performance liquid chromatography-ultra violet detection (US-D-μSPE-HPLC-UV) was developed for the pre-concentration of the main trace anti-hypertensive drugs in complex matrices. The basis of this procedure was a polypyrrole-sodium dodecylbenzenesulfonate/zinc oxide (PPy-DBSNa/ZnO) nanocomposite. It was readily synthesized by the impressive way of in situ sonochemical oxidative polymerization in the presence of some additives such as FeCl₃ and DBSNa, ultimately leading to the effective coating of PPy on the ZnO nanoparticle cores. Characterization of the proposed nanosorbent was performed by different techniques such as FESEM, XRD,EDX, and TGA, confirming the high quality and proper physico-chemical properties of the proposed sorbent. In order to better investigate the input variables, the central composite design (CCD) combined with the desirability function (DF) was utilized. The enriched optimum conditions consisted of the initial pH value of 11.8, 15mg of the PPy-DBSNa/ZnO nanocomposite, a sonication time of 4.6min, and 100μL of methanol, resulting in maximum responses at a relatively low extraction time with a logical DF. Under the optimum conditions, good linearity (5-5000, 2.5-3500, and 2.5-3000ngmL^-1 for metoprolol, propranolol, and carvedilol, respectively, with the correlation of determinations (R²s) higher than 0.99), low limits of detection (LODs) (0.8-1.5ngmL^-1), proper repeatabilities (relative standard deviation values (RSDs) below 6.3%, n=3), reasonable enrichment factors (EFs) (60-72), and good extraction recoveries (ERs) (higher than %75) were obtainable. These appropriate validations corroborated a good effectiveness of ultrasonic waves in the achievement of a supreme solid phase as well as a facile and efficient microextraction of the low therapeutic concentrations in human plasma and urine samples.

The mortality risk of deferring optimal medical therapy in heart failure: a systematic comparison against norms for surgical consent and patient information leaflets

AIMS

The prescription of optimal medical therapy for heart failure is often delayed despite compelling evidence of a reduction in mortality. We calculated the absolute risk resulting from delayed prescription of therapy. For comparison, we established the threshold applied by clinicians when discussing the risk for death associated with an intervention, and the threshold used in official patient information leaflets.

METHODS AND RESULTS

We undertook a meta-analysis of randomized controlled trials to calculate the excess mortality caused by deferral of medical therapy for 1 year. Risk ratios for angiotensin-converting enzyme inhibitors, beta-blockers and aldosterone antagonists were 0.80, 0.73 and 0.77, respectively. In patients who might achieve a 1-year survival rate of 90% if treated, a 1-year deferral of treatment reduced survival to 78% (i.e. an annual absolute increase in mortality of 12 in 100 patients). This corresponds to an additional absolute mortality risk per month of 1%. A survey of clinicians carried out to establish the risk threshold at which they would obtain written consent showed the majority (85%) sought written consent for interventions associated with a 12-fold lower mortality risk: one in 100 patients. A systematic review of UK patient information leaflets to establish the magnitude of risk considered sufficient to be stated explicitly showed that leaflets begin to mention death at a ∼18 000-fold lower mortality risk of just 0.0007 in 100 patients.

CONCLUSIONS

Deferring heart failure treatment for 1 year carries far greater risk than the level at which most doctors seek written consent, and 18 000 times more risk than the level at which patient information leaflets begin to mention death.

True rate of mineralocorticoid receptor antagonists-related hyperkalemia in placebo-controlled trials: A meta-analysis

BACKGROUND

Mineralocorticoid receptor antagonists (MRA) improve survival in heart failure with reduced ejection fraction but are often underused, mostly due to concerns of hyperkalemia. Because hyperkalemia occurs also on placebo, we aimed to determine the truly MRA-related rate of hyperkalemia.

METHODS

We performed a meta-analysis including randomized, placebo-controlled trials reporting hyperkalemia on MRAs in patients after myocardial infarction or with chronic heart failure. We evaluated the truly MRA-related rate of hyperkalemia that represents hyperkalemia on MRA, corrected for hyperkalemia on placebo (Pla), according to the equation: True MRA (%)=(MRA (%) - Pla (%))/MRA (%).

RESULTS

A total number of 16,065 patients from 7 trials were analyzed. Hyperkalemia was more frequently observed on MRA (9.3%) vs placebo (4.3%) (risk ratio 2.17, 95% CI 1.92-2.45, P<.0001). Truly MRA-related hyperkalemia was 54%, whereas 46% were non-MRA related. In trials using eplerenone, hyperkalemia was documented in 5.0% on eplerenone and in 2.6% on placebo (P<.0001). In spironolactone trials, hyperkalemia was documented in 17.5% and in 7.5% of patients on placebo (P=.0001). Hypokalemia occurred less frequently in patients on MRA (9.3%) compared with placebo (14.8%) (risk ratio 0.58, CI 0.47-0.72, P<.0001).

CONCLUSION

This meta-analysis shows that in clinical trials, 54% of hyperkalemia cases were specifically related to the MRA treatment and 46% to other reasons. Therefore, non-MRA-related rises in potassium levels might be underestimated and should be rigorously explored before cessation of the evidence-based therapy with MRAs.

Association of β-Blockers With Functional Outcomes, Death, and Rehospitalization in Older Nursing Home Residents After Acute Myocardial Infarction

IMPORTANCE

Although β-blockers are a mainstay of treatment after acute myocardial infarction (AMI), these medications are commonly not prescribed for older nursing home residents after AMI, in part owing to concerns about potential functional harms and uncertainty of benefit.

OBJECTIVE

To study the association of β-blockers after AMI with functional decline, mortality, and rehospitalization among long-stay nursing home residents 65 years or older.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study of nursing home residents with AMI from May 1, 2007, to March 31, 2010, used national data from the Minimum Data Set, version 2.0, and Medicare Parts A and D. Individuals with β-blocker use before AMI were excluded. Propensity score-based methods were used to compare outcomes in people who did vs did not initiate β-blocker therapy after AMI hospitalization.

MAIN OUTCOMES AND MEASURES

Functional decline, death, and rehospitalization in the first 90 days after AMI. Functional status was measured using the Morris scale of independence in activities of daily living.

RESULTS

The initial cohort of 15 720 patients (11 140 women [70.9%] and 4580 men [29.1%]; mean [SD] age, 83 [8] years) included 8953 new β-blocker users and 6767 nonusers. The propensity-matched cohort included 5496 new users of β-blockers and an equal number of nonusers for a total cohort of 10 992 participants (7788 women [70.9%]; 3204 men [29.1%]; mean [SD] age, 84 [8] years). Users of β-blockers were more likely than nonusers to experience functional decline (odds ratio [OR], 1.14; 95% CI, 1.02-1.28), with a number needed to harm of 52 (95% CI, 32-141). Conversely, β-blocker users were less likely than nonusers to die (hazard ratio [HR], 0.74; 95% CI, 0.67-0.83) and had similar rates of rehospitalization (HR, 1.06; 95% CI, 0.98-1.14). Nursing home residents with moderate or severe cognitive impairment or severe functional dependency were particularly likely to experience functional decline from β-blockers (OR, 1.34; 95% CI, 1.11-1.61 and OR, 1.32; 95% CI, 1.10-1.59, respectively). In contrast, little evidence of functional decline due to β-blockers was found in participants with intact cognition or mild dementia (OR, 1.03; 95% CI, 0.89-1.20; P = .03 for effect modification) or in those in the best (OR, 0.99; 95% CI, 0.77-1.26) and intermediate (OR, 1.05; 95% CI, 0.86-1.27) tertiles of functional independence (P = .06 for effect modification). Mortality benefits of β-blockers were similar across all subgroups.

CONCLUSIONS AND RELEVANCE

Use of β-blockers after AMI is associated with functional decline in older nursing home residents with substantial cognitive or functional impairment, but not in those with relatively preserved mental and functional abilities. Use of β-blockers yielded a considerable mortality benefit in all groups.

Are placebo and drug-specific effects additive? Questioning basic assumptions of double-blinded randomized clinical trials and presenting novel study designs

Double-blinded randomized clinical trials (RCTs) assume that pharmacological interventions have drug-specific and unspecific components. Traditional RCTs postulate an additivity of these two components. In this review, we provide evidence from both clinical trials and experimental studies that questions this 'additive model'. Given that the evaluation of drug treatments in RCTs is based on the assumption of additivity, its violation has far-reaching consequences. Therefore, we discuss an interactive model that, in contrast to the additive model, considers interactions between placebo and drug-specific effects. Moreover, we discuss implications for future clinical trials and present novel study designs enabling researchers to consider the complex interplay of drug-specific and unspecific effects.

Interpretation of the evidence for the efficacy and safety of statin therapy

This Review is intended to help clinicians, patients, and the public make informed decisions about statin therapy for the prevention of heart attacks and strokes. It explains how the evidence that is available from randomised controlled trials yields reliable information about both the efficacy and safety of statin therapy. In addition, it discusses how claims that statins commonly cause adverse effects reflect a failure to recognise the limitations of other sources of evidence about the effects of treatment. Large-scale evidence from randomised trials shows that statin therapy reduces the risk of major vascular events (ie, coronary deaths or myocardial infarctions, strokes, and coronary revascularisation procedures) by about one-quarter for each mmol/L reduction in LDL cholesterol during each year (after the first) that it continues to be taken. The absolute benefits of statin therapy depend on an individual's absolute risk of occlusive vascular events and the absolute reduction in LDL cholesterol that is achieved. For example, lowering LDL cholesterol by 2 mmol/L (77 mg/dL) with an effective low-cost statin regimen (eg, atorvastatin 40 mg daily, costing about £2 per month) for 5 years in 10 000 patients would typically prevent major vascular events from occurring in about 1000 patients (ie, 10% absolute benefit) with pre-existing occlusive vascular disease (secondary prevention) and in 500 patients (ie, 5% absolute benefit) who are at increased risk but have not yet had a vascular event (primary prevention). Statin therapy has been shown to reduce vascular disease risk during each year it continues to be taken, so larger absolute benefits would accrue with more prolonged therapy, and these benefits persist long term. The only serious adverse events that have been shown to be caused by long-term statin therapy-ie, adverse effects of the statin-are myopathy (defined as muscle pain or weakness combined with large increases in blood concentrations of creatine kinase), new-onset diabetes mellitus, and, probably, haemorrhagic stroke. Typically, treatment of 10 000 patients for 5 years with an effective regimen (eg, atorvastatin 40 mg daily) would cause about 5 cases of myopathy (one of which might progress, if the statin therapy is not stopped, to the more severe condition of rhabdomyolysis), 50-100 new cases of diabetes, and 5-10 haemorrhagic strokes. However, any adverse impact of these side-effects on major vascular events has already been taken into account in the estimates of the absolute benefits. Statin therapy may cause symptomatic adverse events (eg, muscle pain or weakness) in up to about 50-100 patients (ie, 0·5-1·0% absolute harm) per 10 000 treated for 5 years. However, placebo-controlled randomised trials have shown definitively that almost all of the symptomatic adverse events that are attributed to statin therapy in routine practice are not actually caused by it (ie, they represent misattribution). The large-scale evidence available from randomised trials also indicates that it is unlikely that large absolute excesses in other serious adverse events still await discovery. Consequently, any further findings that emerge about the effects of statin therapy would not be expected to alter materially the balance of benefits and harms. It is, therefore, of concern that exaggerated claims about side-effect rates with statin therapy may be responsible for its under-use among individuals at increased risk of cardiovascular events. For, whereas the rare cases of myopathy and any muscle-related symptoms that are attributed to statin therapy generally resolve rapidly when treatment is stopped, the heart attacks or strokes that may occur if statin therapy is stopped unnecessarily can be devastating.

Beta-blocker use and risk of symptomatic bradyarrhythmias: a hospital-based case-control study

OBJECTIVE

To investigate the risk factors of symptomatic bradyarrhythmias in relation to β-blockers use.

METHODS

A hospital-based case-control study [228 patients: 108 with symptomatic bradyarrhythmias (cases) and 120 controls] was conducted in Sultanah Aminah Hospital, Malaysia between January 2011 and January 2014.

RESULTS

The mean age was 61.1 ± 13.3 years with a majority of men (68.9%). Cases were likely than control to be older, hypertensive, lower body mass index and concomitant use of rate-controlling drugs (such as digoxin, verapamil, diltiazem, ivabradine or amiodarone). Significantly higher level of serum potassium, urea, creatinine and lower level of estimated glomerular filtration rate (eGFR) were observed among cases as compared to controls. On univariate analysis among patients on β-blockers, older age (crude OR: 1.07; 95% CI: 1.03-1.11, P = 0.000), hypertension (crude OR: 5.6; 95% CI: 1.51-20.72, P = 0.010), lower sodium (crude OR: 0.04; 95% CI: 0.81-0.99, P = 0.036), higher potassium (crude OR: 2.36; 95% CI: 1.31-4.26, P = 0.004) and higher urea (crude OR: 1.23; 95% CI: 1.11-1.38, P = 0.000) were associated with increased risk of symptomatic bradyarrhythmias; eGFR was inversely and significantly associated with symptomatic bradyarrhythmias in both 'β-blockers' (crude OR: 0.97; 95% CI: 0.96-0.98, P = 0.000) and 'non-β-blockers' (crude OR: 0.99; 95% CI: 0.97-0.99, P = 0.023) arms. However, eGFR was not significantly associated with symptomatic bradyarrhythmias in the final model of both 'β-blockers' (adjusted OR: 0.98; 95% CI: 0.96-0.98, P = 0.103) and 'non-β-blockers' (adjusted OR: 0.99; 95% CI: 0.97-1.01, P = 0.328) arms. Importantly, older age was a significant predictor of symptomatic bradyarrhythmias in the 'β-blockers' as compared to the 'non-β-blockers' arms (adjusted OR: 1.09; 95% CI: 1.03-1.15, P = 0.003 vs. adjusted OR: 1.03; 95% CI: 0.98-1.09, P = 0.232, respectively).

CONCLUSION

Older age was a significant predictor of symptomatic bradyarrhythmias in patients on β-blockers than those without β-blockers.

Effect of age and sex on efficacy and tolerability of β blockers in patients with heart failure with reduced ejection fraction: individual patient data meta-analysis

OBJECTIVES

To determine the efficacy and tolerability of β blockers in a broad age range of women and men with heart failure with reduced ejection fraction (HFrEF) by pooling individual patient data from placebo controlled randomised trials.

DESIGN

Prospectively designed meta-analysis of individual patient data from patients aged 40-85 in sinus rhythm at baseline, with left ventricular ejection fraction <0.45.

PARTICIPANTS

13,833 patients from 11 trials; median age 64; 24% women.

MAIN OUTCOME MEASURES

The primary outcome was all cause mortality; the major secondary outcome was admission to hospital for heart failure. Analysis was by intention to treat with an adjusted one stage Cox proportional hazards model.

RESULTS

Compared with placebo, β blockers were effective in reducing mortality across all ages: hazard ratios were 0.66 (95% confidence interval 0.53 to 0.83) for the first quarter of age distribution (median age 50); 0.71 (0.58 to 0.87) for the second quarter (median age 60); 0.65 (0.53 to 0.78) for the third quarter (median age 68); and 0.77 (0.64 to 0.92) for the fourth quarter (median age 75). There was no significant interaction when age was modelled continuously (P=0.1), and the absolute reduction in mortality was 4.3% over a median follow-up of 1.3 years (number needed to treat 23). Admission to hospital for heart failure was significantly reduced by β blockers, although this effect was attenuated at older ages (interaction P=0.05). There was no evidence of an interaction between treatment effect and sex in any age group. Drug discontinuation was similar regardless of treatment allocation, age, or sex (14.4% in those give β blockers, 15.6% in those receiving placebo).

CONCLUSION

Irrespective of age or sex, patients with HFrEF in sinus rhythm should receive β blockers to reduce the risk of death and admission to hospital.Registration PROSPERO CRD42014010012; Clinicaltrials.gov NCT00832442.

Optimal Use of Beta-Blockers for Congestive Heart Failure

Beta-blockers are the cornerstone treatment for congestive heart failure (HF). Current HF guidelines commonly recommend β-blockers for the treatment of HF with reduced left ventricular ejection fraction (LVEF). The effect of β-blockers, however, is less clear for HF patients with preserved LVEF, unstable severe acute HF, or right ventricular failure. This review summarizes the effect of β-blockers in various clinical situations and suggests a strategy for optimal use. (Circ J 2016; 80: 565-571).

Quantifying the effects of diuretics and β-adrenoceptor blockers on glycaemic control in diabetes mellitus - a systematic review and meta-analysis

AIMS

Although there are reports that β-adrenoceptor antagonists (beta-blockers) and diuretics can affect glycaemic control in people with diabetes mellitus, there is no clear information on how blood glucose concentrations may change and by how much. We report results from a systematic review to quantify the effects of these antihypertensive drugs on glycaemic control in adults with established diabetes.

METHODS

We systematically reviewed the literature to identify randomized controlled trials in which glycaemic control was studied in adults with diabetes taking either beta-blockers or diuretics. We combined data on HbA1c and fasting blood glucose using fixed effects meta-analysis.

RESULTS

From 3864 papers retrieved, we found 10 studies of beta-blockers and 12 studies of diuretics to include in the meta-analysis. One study included both comparisons, totalling 21 included reports. Beta-blockers increased fasting blood glucose concentrations by 0.64 mmol l(-1) (95% CI 0.24, 1.03) and diuretics by 0.77 mmol l(-1) (95% CI 0.14, 1.39) compared with placebo. Effect sizes were largest in trials of non-selective beta-blockers (1.33, 95% CI 0.72, 1.95) and thiazide diuretics (1.69, 95% CI 0.60, 2.69). Beta-blockers increased HbA1c concentrations by 0.75% (95% CI 0.30, 1.20) and diuretics by 0.24% (95% CI -0.17, 0.65) compared with placebo. There was no significant difference in the number of hypoglycaemic events between beta-blockers and placebo in three trials.

CONCLUSIONS

Randomized trials suggest that thiazide diuretics and non-selective beta-blockers increase fasting blood glucose and HbA1c concentrations in patients with diabetes by moderate amounts. These data will inform prescribing and monitoring of beta-blockers and diuretics in patients with diabetes.

Vagus Nerve Stimulation Improves Cardiac Function by Preventing Mitochondrial Dysfunction in Obese-Insulin Resistant Rats

Long-term high-fat diet (HFD) consumption leads to not only obese-insulin resistance, but also impaired left ventricular (LV) function. Vagus nerve stimulation (VNS) has been shown to exert cardioprotection. However, its effects on the heart and metabolic parameters under obese-insulin resistant condition is not known. We determined the effects of VNS on metabolic parameters, heart rate variability (HRV) and LV function in obese-insulin resistant rats. Male Wistar rats were fed with HFD for 12 weeks, and were randomly divided into sham and VNS groups. VNS was applied for the next 12 weeks. Echocardiography, blood pressure and HRV were examined. Blood samples were collected for metabolic parameters. At the end, the heart was removed for determination of apoptosis, inflammation, oxidative stress, and cardiac mitochondrial function. VNS for 12 weeks significantly decreased plasma insulin, HOMA index, total cholesterol, triglyceride, LDL and visceral fat. Serum adiponectin was significantly increased in the VNS group. VNS also significantly decreased blood pressure, improved HRV and LV function, decreased cardiac MDA, TNF-α and Bax levels, and improved cardiac mitochondrial function. VNS improves metabolic and hemodynamic parameters, and the LV function via its ability against apoptosis, inflammation and oxidative stress, and preserved cardiac mitochondrial function in obese-insulin resistant rats.

Understanding adverse drug reactions in package leaflets - an exploratory survey among health care professionals

Background

Current German or UK package leaflets do not contain an explicit notice that the listing of side effects does not imply that they are caused by the drug. Causal interpretations by patients and lay people are frequently observed. The authors examined whether health professionals understand that there is not necessarily a causal relation between drug intake and the frequency of side effects and whether adding placebo comparison improves understanding.

Methods

Exploratory survey consisting of eight assessments, each containing 2–6 survey items, and focus groups with one survey sample using questionnaires on adverse reactions in standard package leaflets and modified package leaflets supplemented with placebo comparison. Participants were convenience samples of 379 health professionals including 153 physicians (80 gynaecologists, 124 diabetes experts - physicians, nurses, and others, 39 medical students in their last year at university, 49 first year health science and education students with completed vocational training and professional experience in various health care professions and 87 pharmacists/pharmacy students). They were asked to rate how often the different adverse reactions listed were caused by drug intake.

All surveys were carried out within university seminars and postgraduate lectures from April 2014 to June 2015 in Germany. Response rate was 86 % or higher.

Results

Without placebo comparison, the majority of participants responded that the drug causes adverse reactions with the frequency given in the package leaflet or even more often (95 % of health science students, 100 % of medical students, 60 to 80 % of physicians and 66 % of pharmacists/pharmacy students). Simply adding placebo comparison in a table did not prevent misunderstanding. Analysis of focus groups with health science students supported the lack of understanding.

Conclusions

In the present surveys, health professionals had major difficulties understanding frequency information on side effects in package leaflets. The great majority erroneously implied a causal relation between drug intake and the frequency of side effects, even though most side effects listed are symptoms commonly experienced in daily life.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-015-1160-1) contains supplementary material, which is available to authorized users.

"Triple therapy" of heart failure with angiotensin-converting enzyme inhibitor, beta-blocker, and aldosterone antagonist may triple survival time: shouldn't we tell patients?

Prescription and adherence to medical therapy for heart failure are disappointing despite convincing randomized controlled trial (RCT) evidence for angiotensin-converting enzyme inhibition, beta-blockade, and aldosterone antagonism. In this study, we report an imbalanced approach amongst clinicians, who describe focusing during patient consultations on perceived risks of therapy rather than survival benefits. Only one-half of clinicians mention increased lifespan, and very few suggest to the patient how large this gain might be. We calculate from the available RCT data that, for patients whose lifespan is limited by heart failure, triple therapy triples lifespan.

The safety and tolerability of beta blockers in heart failure with reduced ejection fraction: is the current underutilization of this evidence-based therapy justified?

INTRODUCTION

Beta blockers are one of the cornerstones for treatment of Heart Failure with Reduced Ejection fraction (HFRef), yet their use is often limited by adverse effects, either perceived or real. We performed a review of available data using PubMed.gov utilizing beta blocker, heart failure, reduced ejection fraction and safety as key words.

AREAS COVERED

Several well designed, large scale randomized clinical trials including CIBS-II (bisoprolol), MERIT-HF (metoprolol succinate), and Copernicus (carvedilol) among others, have been conducted in patients with HFRef and demonstrated an improvement in cardiac mortality and morbidity. Despite the preponderance of data supporting the use of beta blockers for patients HFRef, these medications remain underutilized and/or are often prescribed at lower than recommended dosages. Some of the reluctance to embrace beta blockade may be attributed to concern on the part of both the patient and prescriber about the non-cardiac adverse effects of this class of drugs. We have reviewed several recent reviews and meta-analyses of trials of beta blocker in heart failure which have conclusively demonstrated their tolerability in the populations studied.

EXPERT OPINION

In the final section of this paper we provide our opinions regarding initiating and optimizing beta blocker therapy for patients with HFRef.

Must every child with long QT syndrome take a beta blocker?

Long QT syndrome is the most commonly recognised cause of sudden cardiac death in children. With a prevalence of 1 in 2000, family screening is identifying large numbers of hitherto asymptomatic gene carriers in the community, about a third of whom have a normal QT interval. The mainstay of treatment is long term uninterrupted beta blocker therapy, a treatment with many potential side effects. This article reviews the evidence and suggests a cohort who may, after assessment in a specialised cardiac-genetic clinic, be spared this treatment because of very low baseline risk. These are asymptomatic boys and prepubertal girls with a heart rate corrected QT interval persistently less than 470 ms who do not indulge in high risk activities (especially swimming) and do not have a missense mutation in the c-loop region of the KCNQ1 (long QT 1) gene.

The use of medications in the secondary prevention of coronary artery disease in the Asian region

BACKGROUND

Cardiovascular diseases, to which coronary artery disease (CAD) is a significant contributor, are a leading cause of long-term morbidity and mortality worldwide. In the years ahead, it is estimated that approximately half of the world's cardiovascular burden will occur in the Asian region. Currently there is a large gap in secondary prevention, with unrealized health gains resulting from underuse of evidence-based medications, including beta-blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), aspirin and other antiplatelet agents, and lipid-lowering drugs. Despite the almost universal recommendation for these drugs in unstable CAD, their under-prescription is well documented for patients with acute heart failure, non-obstructive CAD, and for secondary prevention of CAD.

OBJECTIVE

This article reviews the burden of CAD in Asian countries together with guidelines supporting evidence-based medication use from a secondary prevention perspective.

METHODS

The MEDLINE database was searched from 2000 to 2013, inclusive, for country-specific data related to CAD and supplemented with unpublished registry data.

RESULTS

In the post-discharge setting following hospital admission for acute coronary syndromes, medication prescription rates were low. Beta-blocker prescription rates ranged from 49% in China to 99% in Singapore, ACE-inhibitor/ARB prescription rates ranged from 28% in China to 96% in Singapore, and lipid-lowering therapy rates ranged from 47% in China to 97% in Singapore. Aspirin/antiplatelet drug prescription rates ranged from 86% in Indonesia to 99.5% in Singapore. Recommendations are provided to improve patient outcomes and reduce the disease burden in Asia.

CONCLUSIONS

Despite recommendations issued in international and national guidelines, use of CAD medications in Asia remains suboptimal. In the absence of clear contraindications, all patients with unstable CAD should receive these agents as secondary prevention. This averts the need to target drug use according to risk, with high-risk features paradoxically associated with under-prescribing of such drugs.

Review article: depression and the use of antidepressants in patients with chronic liver disease or liver transplantation

BACKGROUND

The scale of depression in patients with chronic liver disease (CLD) and those who have received orthotopic liver transplantation (OLT) is poorly characterised. Clinicians are uncertain of how best to manage depression within these patients.

AIMS

To review the literature evaluating both the prevalence and impact of depression in patients with CLD and post-OLT, and to assess the safety and efficacy of antidepressant use within this context.

METHODS

A PubMed search using the phrases 'chronic liver disease', 'cirrhosis', 'liver transplantation', 'depression', 'antidepressant' and the names of specific causes of liver disease and individual antidepressants.

RESULTS

Over 30% of cirrhotic patients have depressive features, and they experience worse clinical outcomes than nondepressed cirrhotic patients. CLD patients with chronic hepatitis C are particularly prone to depression, partly related to the use of interferon therapy. OLT patients with depression have higher mortality rates than nondepressed patients; appropriate antidepressant use reverses this effect. Selective serotonin reuptake inhibitors (SSRIs) and selective noradrenaline reuptake inhibitors (SNRIs) are effective and generally safe in both CLD and OLT patients.

CONCLUSIONS

Depression is much more prevalent in CLD or OLT patients than is generally recognised, and it adversely affects clinical outcomes. The reasons for this relationship are complex and multifactorial. Antidepressants are effective in both CLD and post-OLT, although lower doses or a reduced dosing frequency may be required to minimise side effects, e.g. exacerbation of hepatic encephalopathy. Further research is needed to establish optimal management of depression in these patients, including the potential role of nonpharmacological treatments.

Inconsistencies and misleading information in officially approved prescribing information from three major drug markets

The summary of product characteristics (SPC) should provide information for the safe prescription and use of a drug. We evaluated the consistency of critical interaction warnings, the quality of presentation of undesirable effects as well as concordance of critical information of representative drugs marketed in the United States, the UK, and Germany. Reciprocal warnings regarding drug-drug interactions that constitute contraindications were frequently missing in the SPCs of the drugs concerned (all countries >40%). Most SPCs did not explicitly exclude adverse reactions considered not reasonably attributable to the use of the drug. Comparing SPCs of different generic brands of the same drug, only 60, 10, and 20% of the US, UK, and German SPCs, respectively, provided identical contraindications. Current SPCs contain inconsistencies and misleading data that are not compatible with the purpose of SPCs, which is to provide a basis for the safe prescription and use of drugs.

Cardiac resynchronization therapy and AV optimization increase myocardial oxygen consumption, but increase cardiac function more than proportionally

BACKGROUND

The mechanoenergetic effects of atrioventricular delay optimization during biventricular pacing ("cardiac resynchronization therapy", CRT) are unknown.

METHODS

Eleven patients with heart failure and left bundle branch block (LBBB) underwent invasive measurements of left ventricular (LV) developed pressure, aortic flow velocity-time-integral (VTI) and myocardial oxygen consumption (MVO2) at 4 pacing states: biventricular pacing (with VV 0 ms) at AVD 40 ms (AV-40), AVD 120 ms (AV-120, a common nominal AV delay), at their pre-identified individualised haemodynamic optimum (AV-Opt); and intrinsic conduction (LBBB).

RESULTS

AV-120, relative to LBBB, increased LV developed pressure by a mean of 11(SEM 2)%, p=0.001, and aortic VTI by 11(SEM 3)%, p=0.002, but also increased MVO2 by 11(SEM 5)%, p=0.04. AV-Opt further increased LV developed pressure by a mean of 2(SEM 1)%, p=0.035 and aortic VTI by 4(SEM 1)%, p=0.017. MVO2 trended further up by 7(SEM 5)%, p=0.22. Mechanoenergetics at AV-40 were no different from LBBB. The 4 states lay on a straight line for Δexternal work (ΔLV developed pressure × Δaortic VTI) against ΔMVO2, with slope 1.80, significantly >1 (p=0.02).

CONCLUSIONS

Biventricular pacing and atrioventricular delay optimization increased external cardiac work done but also myocardial oxygen consumption. Nevertheless, the increase in cardiac work was ~80% greater than the increase in oxygen consumption, signifying an improvement in cardiac mechanoenergetics. Finally, the incremental effect of optimization on external work was approximately one-third beyond that of nominal AV pacing, along the same favourable efficiency trajectory, suggesting that AV delay dominates the biventricular pacing effect - which may therefore not be mainly "resynchronization".