Concomitant beta-blocker therapy is associated with a lower occurrence of ventricular arrhythmias in patients with decompensated heart failure

Substrates and potential therapeutics of ventricular arrhythmias in heart failure

Heart failure (HF) is a clinical syndrome characterized by ventricular contractile dysfunction. About 50% of death in patients with HF are due to fetal ventricular arrhythmias including ventricular tachycardia and ventricular fibrillation. Understanding ventricular arrhythmic substrates and discovering effective antiarrhythmic interventions are extremely important for improving the prognosis of patients with HF and reducing its mortality. In this review, we discussed ventricular arrhythmic substrates and current clinical therapeutics for ventricular arrhythmias in HF. Base on the fact that classic antiarrhythmic drugs have the limited efficacy, side effects, and proarrhythmic potentials, we also updated some therapeutic strategies for the development of potential new antiarrhythmic interventions for patients with HF.

Effects of Traditional Chinese Medicine Shensong Yangxin Capsules on Heart Rhythm and Function in Congestive Heart Failure Patients with Frequent Ventricular Premature Complexes: A Randomized, Double-blind, Multicenter Clinical Trial

Background:

Pharmacological therapy for congestive heart failure (CHF) with ventricular arrhythmia is limited. In the study, our aim was to evaluate the effects of Chinese traditional medicine Shensong Yangxin capsules (SSYX) on heart rhythm and function in CHF patients with frequent ventricular premature complexes (VPCs).

Methods:

This double-blind, placebo-controlled, multicenter study randomized 465 CHF patients with frequent VPCs to the SSYX (n = 232) and placebo groups (n = 233) for 12 weeks of treatment. The primary endpoint was the VPCs monitored by a 24-h ambulatory electrocardiogram. The secondary endpoints included the left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter, N-terminal pro-brain natriuretic peptide (NT-proBNP), New York Heart Association (NYHA) classification, 6-min walking distance (6MWD), Minnesota Living with Heart Failure Questionnaire (MLHFQ) scores, and composite cardiac events (CCEs).

Results:

The clinical characteristics were similar at baseline. SSYX caused a significantly greater decline in the total number of VPCs than the placebo did (−2145 ± 2848 vs. −841 ± 3411, P < 0.05). The secondary endpoints of the LVEF, NYHA classification, NT-proBNP, 6MWD, and MLHFQ scores showed a greater improvements in the SSYX group than in the placebo group (ΔLVEF at 12^th week: 4.75 ± 7.13 vs. 3.30 ± 6.53; NYHA improvement rate at the 8^th and 12^th week: 32.6% vs. 21.8%, 40.5% vs. 25.7%; mean level of NT-proBNP in patients with NT-proBNP ≥125 pg/ml at 12^th week: −122 [Q1, Q3: −524, 0] vs. −75 [Q1, Q3: −245, 0]; Δ6MWD at 12^th week: 35.1 ± 38.6 vs. 17.2 ± 45.6; ΔMLHFQ at the 4^th, 8^th, and 12^th week: −4.24 ± 6.15 vs. −2.31 ± 6.96, −8.19 ± 8.41 vs. −3.25 ± 9.40, −10.60 ± 9.41 vs. −4.83 ± 11.23, all P < 0.05). CCEs were not different between the groups during the study period.

Conclusions:

In this 12-week pilot study, SSYX was demonstrated to have the benefits of VPCs suppression and cardiac function improvement with good compliance on a background of standard treatment for CHF.

Trial Registration:

www.chictr.org.cn, ChiCTR-TRC-12002061 (http://www.chictr.org.cn/showproj.aspx?proj=7487) and Clinicaltrials.gov, NCT01612260 (https://clinicaltrials.gov/ct2/show/NCT01612260).

Interaction between interleukin‑6 and angiotensin II receptor 1 in the hypothalamic paraventricular nucleus contributes to progression of heart failure

The association between interleukin‑6 (IL‑6) and angiotensin II receptor 1 (AT1‑R) in modulating the progression of heart failure (HF) remains to be fully elucidated. The aim of the present study was to investigate the mechanism of IL‑6 and AT1‑R in a model of HF induced by surgery. Male Sprague‑Dawley rats were randomly divided into five groups, including sham surgery and vehicle groups. The animals were treated for 4 weeks via paraventricular nucleus infusion with either vehicle, losartan (LOS; 200 µg/day), IL‑6 (1 µg/day) or LOS and IL‑6 together (LOS+IL‑6). The rats with HF had higher levels of IL‑6, corticotropin‑releasing hormone (CRH) and norepinephrine (NE), and a lower level of neuronal nitric oxide synthase (nNOS), compared with the rats in the sham surgery group. Treatment with LOS attenuated the decrease in nNOS and the increases in IL‑6, CRH and NE; whereas treatment with IL‑6 facilitated the lower expression of nNOS and higher expression levels of IL‑6, CRH and NE. No differences in the expression levels of nNOS, CRH or NE were found between the LOS group and LOS+IL‑6 group. The results of the study demonstrated that IL‑6 contributed to the progression of HF via the AT1‑R pathway.

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.

Cytokine blockade attenuates sympathoexcitation in heart failure: cross-talk between nNOS, AT-1R and cytokines in the hypothalamic paraventricular nucleus

OBJECTIVE

To investigate evidence for the interplay between cytokines, angiotensin II and nNOS in the paraventricular nucleus (PVN), for regulating sympathetic outflow in a rat model of CHF.

METHODS AND RESULTS

Heart failure was induced in Sprague-Dawley rats by coronary artery ligation. One group of rats was treated with pentoxifylline (PTX, 30 mg/kg IP), a cytokine blocker, or vehicle, for 5 weeks. Another group of rats was pre-treated with PTX before coronary ligation to study prior cytokine blocking effect on survival. Both groups were combined in the analysis. Echocardiography demonstrated an increase in LV end-diastolic pressure and Tei index after 5 weeks in CHF rats. ELISA revealed a significant increase in plasma TNF-alpha and IL-1beta in CHF rats. Inducible NOS (iNOS) and angiotensin receptor-type 1 (AT-1R) mRNA expressions were increased, while neuronal NOS (nNOS) was decreased in the PVN of CHF rats; these changes were reversed by PTX. PTX treatment also decreased plasma norepinephrine and epinephrine levels and improved baroreflex control of renal sympathoexcitation in CHF rats. Immunohistochemistry revealed elevated 3-nitrotyrosine formation in the heart and the PVN of CHF rats, but not in PTX treated rats.

CONCLUSION

PTX decreased both peripheral and central cytokine expression, alleviated nitric oxide dysregulation, and inhibited the formation of peroxynitrite in the PVN resulting in decreased sympathoexcitation in CHF rats.

Canadian Cardiovascular Society Consensus Conference recommendations on heart failure update 2007: Prevention, management during intercurrent illness or acute decompensation, and use of biomarkers

Heart failure is common, yet it is difficult to treat. It presents in many different guises and circumstances in which therapy needs to be individualized. The Canadian Cardiovascular Society published a comprehensive set of recommendations in January 2006 on the diagnosis and management of heart failure, and the present update builds on those core recommendations. Based on feedback obtained through a national program of heart failure workshops during 2006, several topics were identified as priorities because of the challenges they pose to health care professionals. New evidence-based recommendations were developed using the structured approach for the review and assessment of evidence adopted and previously described by the Society. Specific recommendations and practical tips were written for the prevention of heart failure, the management of heart failure during intercurrent illness, the treatment of acute heart failure, and the current and future roles of biomarkers in heart failure care. Specific clinical questions that are addressed include: which patients should be identified as being at high risk of developing heart failure and which interventions should be used? What complications can occur in heart failure patients during an intercurrent illness, how should these patients be monitored and which medications may require a dose adjustment or discontinuation? What are the best therapeutic, both drug and nondrug, strategies for patients with acute heart failure? How can new biomarkers help in the treatment of heart failure, and when and how should BNP be measured in heart failure patients? The goals of the present update are to translate best evidence into practice, to apply clinical wisdom where evidence for specific strategies is weaker, and to aid physicians and other health care providers to optimally treat heart failure patients to result in a measurable impact on patient health and clinical outcomes in Canada.

Beta-blocker use in decompensated heart failure

Despite the current advances in treatment, acute decompensated heart failure accounts for more than 1 million hospital admissions annually. Many of the patients hospitalized are already receiving long-term treatment with beta-blockers. For patients who receive full dose beta-blocker therapy and suffer acute decompensated heart failure, clinicians face two key questions: what to do, if anything, with the dosage of beta-blocker and what is the best way to integrate inotropic and beta-blocker therapies for patients who require inotropes. This article discusses these issues and reviews the available literature. Because these topics have received little systematic evaluation, we also present our clinical approaches to these problems.

Effects of beta-blockers on implantable cardioverter defibrillator therapy and survival in the patients with ischemic cardiomyopathy (from the Multicenter Automatic Defibrillator Implantation Trial-II)

This study examined the effects of beta blockers on (1) appropriate implantable cardioverter defibrillator (ICD) therapy for ventricular tachycardia (VT) or ventricular fibrillation (VF), (2) inappropriate ICD therapy for atrial fibrillation or supraventricular tachycardia, and (3) survival in 691 patients who received ICDs in the Multicenter Automatic Defibrillator Implantation Trial-II. The study population involved 258 patients who were not receiving beta blockers and 433 who were receiving metoprolol (n = 192), atenolol (n = 58), or carvedilol (n = 182). Patients receiving beta blockers were divided into the upper quartile and lower 3 quartiles of the drug doses they were taking. Patients receiving the higher doses of beta blockers (those in the top quartile of doses) had a significant reduction in the risk for VT or VF requiring ICD therapy compared with patients not receiving beta blockers (hazard ratio 0.48, p = 0.02). The frequency of inappropriate ICD therapy for supraventricular tachyarrhythmias was not significantly different among the 3 treatment groups (p = 0.32). Beta-blocker use at the 2 dosage levels was associated with significant improvement in survival compared with the nonuse of beta blockers (hazard ratios 0.42 to 0.44, p <0.01). In conclusion, beta blockers reduce the risk for VT or VF and improve survival in ICD-treated patients with ischemic cardiomyopathy.

Effect of continuous positive airway pressure on ventricular ectopy in heart failure patients with obstructive sleep apnoea

BACKGROUND

Obstructive sleep apnoea (OSA) elicits a number of cardiovascular perturbations that could lead acutely or chronically to increased ventricular ectopy in patients with heart failure (HF). We tested the hypothesis that treatment of OSA with continuous positive airway pressure (CPAP) in patients with HF would reduce the frequency of ventricular premature beats (VPBs) during sleep in association with reduced sympathetic nervous system activity.

METHODS

Following optimisation of medical treatment, 18 HF patients with OSA and >10 VPBs per hour of sleep were randomised to a control group (n = 8) or a treatment group who received CPAP (n = 10). The frequency of VPBs and urinary norepinephrine (noradrenaline) concentrations during total sleep time were determined at baseline and after 1 month.

RESULTS

Control patients did not experience any significant changes in apnoea-hypopnoea index (AHI), mean nocturnal O(2) saturation, or the frequency of VPBs. In contrast, there was a significant reduction in AHI (p<0.001), an increase in minimum O(2) saturation (p = 0.05), a reduction in urinary norepinephrine concentrations (p = 0.009), and a 58% reduction in the frequency of VPBs during total sleep (from mean (SE) 170 (65) to 70 (28) per hour, p = 0.011) after 1 month of CPAP treatment.

CONCLUSIONS

In patients with HF, treatment of co-existing OSA by CPAP reduces the frequency of VPBs during sleep. These data suggest that reductions in VPBs and other ventricular arrhythmias through treatment of OSA might improve the prognosis in patients with HF.

Ventricular Dysrhythmias in Heart Failure

Left-ventricular systolic dysfunction, or heart failure (HF), is a chronic, progressive condition with a poor prognosis. Approximately 50% of deaths, especially in mild to moderate cases, are sudden. Most sudden deaths are thought to be due to ventricular tachycardia; however, premature ventricular contractions and couplets parallel severity of HF and have been associated with increased mortality risk as opposed to dysrhythmic death. Ventricular arrhythmogenesis results from many mechanisms (afterdepolarizations, reentry, and enhanced automaticity) and preconditions (electrophysiologic abnormalities, neuroendocrine activation, electrolyte imbalances, scar from an ischemic event in ischemic cardiomyopathy, fibrosis in dilated cardiomyopathy, hemodynamic abnormalities, and HF medical management). Nurses are key caregivers in optimally managing HF, either by direct actions or by using advocacy, communication, and collaboration skills to promote positive outcomes. Ventricular dysrhythmia management consists of facilitating core HF pharmacologic and nonpharmacologic medical therapies, using amiodarone to improve symptoms, as needed, and utilizing implantable cardioverter-defibrillator therapy to reduce the risk of sudden cardiac death.

Medical therapy for sudden death

Drug therapy can reduce the incidence of sudden death in many subgroups of patients. Patients who have long QT syndrome, in particular, benefit significantly from the use of beta-blockers and other antiarrhythmic agents. Although less useful, drug therapy has an important adjunctive role in patients who have conditions, such as hypertrophic cardiomyopathy and congestive heart failure. Proarrhythmia, which is a potentially dangerous side effect of drug therapy, needs to be watched for with special care in this group of high-risk patients.

Risk stratification of in-hospital mortality in patients hospitalized for chronic congestive heart failure secondary to non-ischemic cardiomyopathy

The study population consisted of 234 consecutive patients hospitalized for acute exacerbation of congestive heart failure secondary to non-ischemic cardiomyopathy. Of the 234 patients, there were 55 in-hospital deaths. Their medical records were deliberatively reviewed and the association of 38 clinical, hemodynamic and biochemical variables with in-hospital mortality was evaluated by multiple stepwise logistic regression analysis. The following variables were statistically associated with in-hospital mortality: profound cardiogenic shock, severe hyponatremia, the presence of ventricular arrhythmias, history of stroke, the presence of acute renal failure, and requirement of dobutamine therapy. In stratified analyses, the rates of in-hospital mortality rose rapidly as the number of risk factors increased: 0 risk factors, 2.5%; 1 risk factor, 5.1%; 2 risk factors, 36.4%; 3 risk factors, 75%, and no less than 4 risk factors, 100%. In conclusion, our study identified 6 variables that correlated with in-hospital death in patients with heart failure secondary to non-ischemic cardiomyopathy. The identification of these variables may allow more accurate risk stratification of individuals at risk of in-hospital mortality in this clinical setting.

Beta-adrenergic receptor blockers in heart failure

Congestive heart failure is a progressive disease with high morbidity and mortality if left untreated. Standard therapy for patients with systolic left ventricular dysfunction now includes angiotensin-converting enzyme inhibitors and beta blockers. beta Blockers have been demonstrated to decrease mortality, reduce hospitalizations, improve functional class, decrease left ventricular dimensions, and improve ejection fraction in several large-scale, randomized, placebo-controlled trials. In addition to reducing deaths due to progressive heart failure, beta blockers also reduce the incidence of sudden death. Therapy with beta blockers can successfully be initiated in most patients with heart failure if recommended titration schedules are followed. beta Blockers are an important component of medical therapy for all stages of heart failure.