Effects of beta receptor antagonists in patients with clinical evidence of heart failure after myocardial infarction: double blind comparison of metoprolol and xamoterol

β-Blockade for Patients with Hypertension, Ischemic Heart Disease or Heart Failure: Where are We Now?

β-blockers are a heterogeneous class of drugs, with varying selectivity/specificity for β₁ vs β₂ receptors, intrinsic sympathomimetic activity (ISA), and vasodilatory properties (through β₂ stimulation, α receptor blockade or nitric oxide release). These drugs are indicated for the management of arterial hypertension, heart failure or ischemic heart disease (IHD; eg angina pectoris or prior myocardial infarction). Most of the benefit of β-blockade in these conditions arises from blockade of the β₁ receptor, and, in practice, the addition of ISA appears to reduce the potential for improved clinical outcomes in people with heart failure or IHD. Aspects of the benefit/risk balance of β-blockers remain controversial, and recent meta-analyses have shed new light on this issue. We have reviewed the current place of cardioselective β-blockade in hypertension, IHD and heart failure, with special reference to the therapeutic profile of a highly selective β₁-adrenoceptor blocker, bisoprolol.

Adherence to beta-blockers and long-term risk of heart failure and mortality after a myocardial infarction

Aims

The aim of this study is to investigate the association between adherence to beta‐blocker treatment after a first acute myocardial infarction (AMI) and long‐term risk of heart failure (HF) and death.

Methods and results

All patients admitted for a first AMI included in the nationwide Swedish web‐system for enhancement and development of evidence‐based care in heart disease evaluated according to recommended therapies register between 2005 and 2010 were eligible (n = 71 638). After exclusion of patients who died in‐hospital, patients with previous HF, patients with unknown left ventricular ejection fraction (EF), and patients who died during the first year after the index event, 38 608 patients remained in the final analysis. Adherence to prescribed beta‐blockers was determined for 1 year after the index event using the national registry for prescribed drugs and was measured as proportion of days covered, the ratio between the numbers of days covered by the dispensed prescriptions and number of days in the period. As customary, a threshold level for proportion of days covered ≥80% was used to classify patients as adherent or non‐adherent. At discharge 90.6% (n = 36 869) of all patients were prescribed a beta‐blocker. Among 38 608 1 year survivors, 31.1% (n = 12 013) were non‐adherent to beta‐blockers. Patients with reduced EF with and without HF were more likely to remain adherent to beta‐blockers at 1‐year compared with patients with normal EF without HF (NEF). Being married/cohabiting and having higher income level, hypertension, ST‐elevation MI, and percutaneous coronary intervention were associated with better adherence. Adherence was independently associated with lower all‐cause mortality [hazard ratio (HR) 0.77, 95% confidence interval [CI] 0.71–0.84] and a lower risk for the composite of HF readmission/death, (HR 0.83, 95% CI 0.78–0.89, P value <0.001) during the subsequent 4 years of follow up. These associations were favourable but less apparent in patients with HFNEF and NEF.

Conclusions

Nearly one in three AMI patients was non‐adherent to beta‐blockers within the first year. Adherence was independently associated with improved long‐term outcomes; however, uncertainty remains for patients with HFNEF and NEF.

Peripheral vasoconstriction induced by β-adrenoceptor blockers: a systematic review and a network meta-analysis

AIM

Peripheral vasoconstriction has long been described as a vascular adverse effect of β-adrenoceptor blockers. Whether β-adrenoceptor blockers should be avoided in patients with peripheral vascular disease depends on pharmacological properties (e.g. preferential binding to β1 -adrenoreceptors or intrinsic sympathomimetic activity). However, this has not been confirmed in experimental studies. We performed a network meta-analysis in order to assess the comparative risk of peripheral vasoconstriction of different β-adrenoceptor blockers.

METHOD

We searched for randomized controlled trials (RCTs) including β-adrenoceptor blockers that were published in core clinical journals in the Pubmed database. All RCTs reporting peripheral vasoconstriction as an adverse effect of β-adrenoceptor blockers and controls were included. Sensitivity analyses were conducted including possibly confounding covariates (latitude, properties of the β-adrenoceptor blockers, e.g. intrinsic sympathomimetic activity, vasodilation, drug indication, drug doses). The protocol and the detailed search strategy are available online (PROSPERO registry CRD42014014374).

RESULTS

Among 2238 records screened, 38 studies including 57 026 patients were selected. Overall, peripheral vasoconstriction was reported in 7% of patients with β-adrenoceptor blockers and 4.6% in the control groups (P < 0.001), with heterogeneity among drugs. Atenolol and propranolol had a significantly higher risk than placebo, whereas pindolol, acebutolol and oxprenolol had not.

CONCLUSION

Our results suggest that β-adrenoceptor blockers have variable propensity to enhance peripheral vasoconstriction and that it is not related to preferential binding to β1 -adrenoceptors. These findings challenge FDA and European recommendations regarding precautions and contra-indications of use of β-adrenoceptor blockers and suggest that β-adrenoceptor blockers with intrinsic sympathomimetic activity could be safely used in patients with peripheral vascular disease.

Carvedilol in the treatment of elderly patients with chronic heart failure

Chronic heart failure (CHF) is common, and increases in incidence and prevalence with age. There are compelling data demonstrating reduced mortality and hospitalizations with adrenergic blockade in older patients with CHF. Despite this, many older patients remain under-treated. The aim of the present article is to review the potential mechanisms of the benefits of adrenergic blockade in CHF and the clinical data available from the large randomized studies, focusing particularly on older patients.

Left Ventricular Remodeling and Systolic Deterioration in Acute Myocardial Infarction: Findings from the Stent-PAMI Study

BACKGROUND

Left ventricular systolic deterioration (LVSD) develops in some patients despite successful percutaneous intervention and medical therapy for myocardial infarction (MI). We sought to determine predictors of LVSD by comparing demographic, procedural, angiographic variables, and 6-month major adverse cardiac events (MACE) in patients with and without LVSD after MI.

METHODS

We performed a posthoc analysis of patients prospectively enrolled in the Stent-PAMI trial if they had successful percutaneous intervention for MI (<50% residual stenosis and TIMI-3 grade flow), normal left ventricular systolic function on index ventriculogram, and protocol driven coronary angiography with ventriculography at 6 months. We defined LVSD as an absolute decrease in ejection fraction > or =15% compared to baseline value.

RESULTS

Of the 900 patients enrolled in Stent-PAMI, 187 patients met the inclusion criteria. LVSD developed in 30 patients (16%) and occurred independent of demographic, procedural, angiographic variables, and 6-month MACE. Multivariate predictors of LVSD were higher baseline ejection fraction (P = 0.0065, OR 1.09; 95% CI = 1.02-1.16) and peak creatine phosphokinase (CPK) level (P = 0.0022, OR 1.04; 95% CI = 1.02-1.07).

CONCLUSIONS

LVSD occurs in a minority of patients despite successful mechanical reperfusion and occurred independent of procedural, angiographic variables, target vessel revascularization, reinfarction, and combined MACE. Infarct size (determined by peak CPK) and high baseline ejection fraction predicted development of LVSD at 6 months. LVSD in this population likely occurred by negative left ventricular remodeling.

Role of brain natriuretic peptide in the diagnosis and management of heart failure: current concepts

BACKGROUND

Progression of heart failure is related to ventricular remodeling, a process associated to neurohormonal activation. Brain natriuretic peptide (BNP), a member of the natriuretic peptide family, has recently emerged as an important neurohormone in the pathophysiology of heart failure.

METHODS

In this update, some of the recent advances on the role of BNP in heart failure are summarized. In particular, the role of BNP in diagnosis of heart disease, as a prognostic marker of cardiovascular events and as a possible guide to optimize heart failure therapy is discussed.

RESULTS

Recent results from 4,300 patients enrolled in the Valsartan Heart Failure Trial (Val-HeFT) confirmed that BNP is the strongest predictor of outcome in heart failure, when compared to other neurohormones and clinical markers. The current use of BNP in the screening and diagnosis of heart failure and its possible future roles are presented.

CONCLUSION

In recent years, there has been an impressive accumulation of data supporting an important role of BNP as a diagnostic and prognostic marker of heart failure. Development of rapid, accurate and affordable diagnostic methods will allow the routine monitoring of BNP in a wide spectrum of settings, from general practice to controlled clinical trials.

Neurohormonal activation in heart failure after acute myocardial infarction treated with beta-receptor antagonists

BACKGROUND

Few studies have described how neurohormonal activation is influenced by treatment with beta-receptor antagonists in patients with heart failure after acute myocardial infarction. The aims were to describe neurohormonal activity in relation to other variables and to investigate treatment effects of a beta(1) receptor-antagonist compared to a partial beta(1) receptor-agonist.

METHODS

Double-blind, randomized comparison of metoprolol 50-100 mg b.i.d. (n=74), and xamoterol 100-200 mg b.i.d (n=67). Catecholamines, neuropeptide Y-like immunoreactivity (NPY-LI), renin activity, and N-terminal pro-atrial natriuretic factor (N-ANF) were measured in venous plasma before discharge and after 3 months. Clinical and echocardiographic variables were assessed.

RESULTS

N-ANF showed the closest correlations to clinical and echocardiographic measures of heart failure severity, e.g. NYHA functional class, furosemide dose, exercise tolerance, systolic and diastolic function. Plasma norepinephrine, dopamine and renin activity decreased after 3 months on both treatments, in contrast to a small increase in NPY-LI which was greater (by 3.9 pmol/l, 95% CI 1.2-6.6) in the metoprolol group. N-ANF increased on metoprolol, and decreased on xamoterol (difference: 408 pmol/l, 95% CI 209-607). Increase above median of NPY-LI (>25.2 pmol/l, odds ratio 2.8, P=0.0050) and N-ANF (>1043 pmol/l, odds ratio 2.8, P=0.0055) were related to long term (mean follow-up 6.8 years) cardiovascular mortality.

CONCLUSIONS

Decreased neurohormonal activity, reflecting both the sympathetic nervous system and the renin-angiotensin system, was found 3 months after an acute myocardial infarction with heart failure treated with beta-receptor antagonists. The small increase in NPY-LI may suggest increased sympathetic activity or reduced clearance from plasma. The observed changes of N-ANF may be explained by changes in cardiac preload, renal function, and differences in beta-receptor mediated inhibition of atrial release of N-ANF. NPY-LI, and N-ANF at discharge were related to long term cardiovascular mortality.

The underreporting of results and possible mechanisms of 'negative' drug trials in patients with chronic heart failure

Large drug trials have become very important to determine which drugs should be used in the treatment of patients with chronic heart failure (CHF). When these trials showed "positive" results, publication of the data soon followed, leading to a substantial impact on prescription patterns. In the case of "negative" results, many times they were not published, or were reported as an abstract or as short paper disclosing only the main findings. In this article we will discuss some of these trials that were conducted in the last 10 years, since we believe they may provide insight into the pathophysiology and treatment options in CHF.

Psychosocial variables in relation to various risk factors in patients with stable angina pectoris

OBJECTIVES

To evaluate relationships between psychosocial variables and common risk factors such as age, concomitant diseases (hypertension, diabetes mellitus, myocardial infarction, heart failure) and smoking habits in patients with stable angina pectoris.

SETTING

University Hospital.

SUBJECTS

Participants in the Angina Prognosis Study in Stockholm (APSIS), which comprised 809 patients (248 females) <70 years of age, with chronic stable angina pectoris, of whom 767 (236 females) participated in the present report. Patients with angina pectoris occurring only at rest constituted one group, patients with angina pectoris on effort with or without angina at rest were stratified according to signs of marked ischaemia on exercise and/or clinical signs of heart failure.

METHODS

Psychosomatic symptoms, job strain, Type-A behaviour, sleep disturbances and overall life satisfaction were evaluated by a structured interview, which also included questions regarding how the patients usually felt, and health related problems, according to a standardized check-list.

RESULTS

Age correlated with several psychosomatic symptoms and tendency to worry. When adjusted for age and sex, patients with previous myocardial infarction and heart failure described more psychosomatic symptoms, but worried less about the future than patients without these diseases. In the group with angina pectoris at rest only there were fewer smokers than amongst other groups, regardless of risk stratification.

CONCLUSIONS

Smoking habits and concomitant diseases influence psychosocial variables in patients with stable angina pectoris. The severity of angina pectoris does not seem to relate to life satisfaction and attitudes towards the future.

Effect of beta-blocker therapy in patients with coronary artery disease in New York Heart Association classes II and III. The Bezafibrate Infarction Prevention (BIP) Study Group

The aim of the study was to investigate the effect of beta-blocker treatment on a large cohort of patients with coronary artery disease in functional classes II and III according to the New York Heart Association (NYHA) classification. Among 11,575 patients with coronary artery disease screened for participation, but not included in the Bezafibrate Infarction Prevention (BIP) study, 3,225 (28%) were in NYHA classes II and III. In the latter group of patients we compared the prognosis of 1,109 (34%) treated with beta blockers with 2,116 counterparts not receiving beta-blocker therapy. After a mean follow-up of 4 years, all-cause and cardiac mortality rates were significantly lower among beta-blocker users, 9% and 5%, respectively, than among beta-blocker nonusers, 17% and 11%, respectively (p <0.01 for both). After multivariate adjustment, treatment with beta blockers was associated with a lower all-cause mortality risk (hazards ratio [HR] 0.62, 95% confidence interval [CI] 0.49 to 0.78), and a lower cardiac mortality risk (HR = 0.61, 95% CI 0.45 to 0.83) than was no treatment with a beta blocker. Lower total mortality risk was noted among patients in NYHA class II (HR 0.63, 95% CI 0.48 to 0.82) and in NYHA class III (HR 0.57, 95% CI 0.37 to 0.87) as well as in patients with (HR 0.62, 95% CI 0.48 to 0.81) or without (HR 0.70, 95% CI 0.45 to 1.09) a previous myocardial infarction. We conclude that beta-blocker therapy in coronary patients in NYHA classes II or III is safe and associated with a lower risk for all-cause and cardiac mortality.