Comparison of effects of ivabradine versus carvedilol in murine model with the Coxsackievirus B3-induced viral myocarditis

Acute and Complicated Inflammatory Pericarditis: A Guide to Contemporary Practice

Inflammatory disease of the pericardium represents a relatively common presentation, especially among the young. For the most part, inflammatory pericardial disease can be expeditiously and effectively managed without significant sequelae. However, some individuals present with severe and recurrent illness, representing significant therapeutic challenges. During the past decade, there have been great strides made in developing an evidence-based approach to management of inflammatory pericardial disease, the result of which has been the development of (1) a systematic, protocoled approach to initial care; (2) targeted therapeutics; and (3) specialized, collaborative, and integrated care pathways. Herein we present a review of the current state of the art as it pertains to the diagnostic evaluation and therapeutic considerations in inflammatory pericardial disease with a focus on acute and complicated pericarditis.

Ivabradine in Septic Shock: A Narrative Review

In patients with septic shock, compensatory tachycardia initially serves to maintain adequate cardiac output and tissue oxygenation but may persist despite appropriate fluid and vasopressor resuscitation. This sustained elevation in heart rate and altered heart rate variability, indicative of autonomic dysfunction, is a well-established independent predictor of adverse outcomes in critical illness. Elevated heart rate exacerbates myocardial oxygen demand, reduces ventricular filling time, compromises coronary perfusion during diastole, and impairs the isovolumetric relaxation phase of the cardiac cycle, contributing to ventricular-arterial decoupling. This also leads to increased ventricular and atrial filling pressures, with a heightened risk of arrhythmias. Ivabradine, a highly selective inhibitor of the sinoatrial node's pacemaker current (If or "funny" current), mitigates heart rate by modulating diastolic depolarization slope without affecting contractility. By exerting a selective chronotropic effect devoid of negative inotropic properties, ivabradine shows potential for improving hemodynamics in septic shock patients with cardiac dysfunction. This review evaluates the plausible mechanisms and existing evidence regarding the utility of ivabradine in managing patients with septic shock.

The protective effect of LCZ696 in coxsackievirus B3-induced acute viral myocarditis mice

AIMS

Acute viral myocarditis (AVMC) is the aetiology of heart failure (HF) with few specific treatments. The improvement of left ventricular ejection fraction (LVEF) is a critical predictor for the prognosis of AVMC. LCZ696 is a drug used in HF to improve LVEF, with a few research on AVMC. In this research, we evaluated the effects and mechanism of LCZ696 in improving LVEF in AVMC.

METHODS

Eighty 4-week-old male BALB/c mice were randomly divided into four groups of 20: Sham; Sham + LCZ696 (60 mg/kg/d); AVMC; AVMC + LCZ696. The above experiments were repeated by CVB3-infected HL-1 and Mdivi-1 to down-regulated dynamin-related protein 1(Drp1). Adeno-associated virus 9 (AAV9) with enhanced green fluorescent proteins (GFP) was injected to produce Drp1-overexpression mice and set up four groups: AVMC group, AVMC + AAV group, AVMC + LCZ696 group, and AVMC + LCZ696 + AAV group (n = 20 in each group). LVEF was evaluated by echocardiography at a similar heart rate (HR) at d7, Drp1 (p-Drp1), inflammation and apoptosis by histology and Western blot (WB), and mitochondrial by electron microscopy.

RESULTS

Cardiac function were injured in AVMC that LCZ696 reversed (LVEF, %: Sham: 68.99 ± 9.67; Sham + LCZ696: 71.96 ± 6.20; AVMC: 30.95 ± 6.40*; AVMC + LCZ696: 68.99 ± 9.67*#, *P < 0.05 vs. Sham, #P < 0.05 vs. AVMC). LCZ696 attenuated p-Drp1 expression, inflammation, apoptosis, and mitochondrial fission (p-Drp1/Drp1: Sham: 1; Sham + LCZ696: 1.37 ± 0.22; AVMC: 2.29 ± 0.36*; AVMC+LCZ696: 1.43 ± 0.08*#, *P < 0.05 vs. Sham, #P < 0.05 vs. AVMC). Some of the above results were repeated in CVB3-infected HL-1 cells and Mdivi-1. AAV increased Drp1 expression and mitochondrial fission, inflammatory, and apoptosis. Compared with the AVMC + AAV group, the LVEF increased from 24.44 ± 0.03% to 32.33 ± 0.05% in the AVMC + LCZ696 + AAV group(P < 0.05), p-Drp1/Drp1 decreased from 0.54 ± 0.12 to 0.42 ± 0.09*, and IL-6, c-IL-1β, and c-caspase-3/caspase-3 decreased from 1.07 ± 0.22 to 0.72 ± 0.08*, from 1.03 ± 0.14 to 0.79 ± 0.09*, and from 4.69 ± 0.29 to 0.92 ± 0.13*, respectively (*P < 0.05).

CONCLUSIONS

LCZ696 has a protective effect on AVMC by improving LVEF and reducing inflammation and apoptosis, which may be due to the inhibition of Drp1-mediated mitochondrial fission.

Ivabradine in the management of COVID-19-related cardiovascular complications: A perspective

Abstract:

Besides acute respiratory distress syndrome, acute cardiac injury is a major complication in severe coronavirus disease 2019 (COVID-19) and associates with a poor clinical outcome. Acute cardiac injury with COVID-19 can be of various etiologies, including myocardial ischemia or infarction and myocarditis, and may compromise cardiac function, resulting in acute heart failure or cardiogenic shock. Systemic inflammatory response increases heart rate (HR), which disrupts the myocardial oxygen supply/demand balance and worsens cardiac energy efficiency, thus further deteriorating the cardiac performance of the injured myocardium. In fact, the combination of elevated resting HR and markers of inflammation synergistically predicts adverse cardiovascular prognosis. Thus, targeted HR reduction may potentially be of benefit in cardiovascular pathologies associated with COVID-19. Ivabradine is a drug that selectively reduces HR via If current inhibition in the sinoatrial node without a negative effect on inotropy. Besides selective HR reduction, ivabradine was found to exert various beneficial pleiotropic effects, either HR-dependent or HR-independent, including anti-inflammatory, anti-atherosclerotic, anti-oxidant and antiproliferative actions and the attenuation of endothelial dysfunction and neurohumoral activation. Cardioprotection by ivabradine has already been indicated in cardiovascular pathologies that are prevalent with COVID-19, including myocarditis, acute coronary syndrome, cardiogenic shock or cardiac dysautonomia. Here, we suggest that ivabradine may be beneficial in the management of COVID-19-related cardiovascular complications.

ω-3 fatty acid alleviates virus-induced myocardial injury by regulating TLR4 and TLR3 expression

The specific pathogenesis of viral-induced myocardial injury is unclear. TLR regulation plays an important role in virus-induced myocardial injury. The therapeutic effect and possible mechanism of omega-3 fatty acids in patients with viral-induced myocardial injury must be investigated. The study population was randomly divided into three groups: a healthy control group (n = 50); general treatment group (n = 40); and general treatment with ω-3 polyunsaturated fatty acid group (n = 36). We detected the mRNA levels of TLR3 and TLR4, downstream signal pathway proteins, inflammatory factors, oxidative stress markers, and myocardial enzymes in patients and healthy controls. ω-3 fatty acid therapy in patients with virus-induced myocardial injury significantly regulates the expression of TLR3 and TLR4 and their downstream signal protein, increases antioxidant expression, reduces the secretion of inflammatory factors, alleviates myocardial injury, and improves cardiac function. This provides a new strategy to treat virus-induced myocardial injury.

Usefulness of Beta-Blockers to Control Symptoms in Patients With Pericarditis

Exercise restriction is a nonpharmacological treatment of pericarditis that could reduce symptoms by slowing heart rate (HR). Beta-blockers allow pharmacological control of HR. Aim of this paper is to explore the possible efficacy of beta-blockers to improve control of symptoms in patients with pericarditis. We analyzed consecutive cases with pericarditis referred to our center. Beta-blockers were prescribed on top of standard anti-inflammatory therapy in symptomatic patients (chest pain and palpitations) with rest HR>75 beats/min. The primary end point was the persistence of pericardial pain at 3 weeks. The secondary end point was the occurrence of recurrent pericarditis at 18 months. Propensity score matching was used to generate 2 cohorts of 101 patients with and without beta-blockers with balanced baseline features. A clinical and echocardiographic follow-up was performed at 3 weeks, 1, 3, 6 months and then every 12 months. A total of 347 patients (mean age 53 years, 58% females, 48% with a recurrence, 81% with idiopathic/viral etiology) were included. Among them, 128 patients (36.9%) were treated with beta-blockers. Peak C-reactive protein values were correlated with heart rate on first observation (r=0.48, p<0.001). Using propensity-score matched cohorts, patients treated with beta-blockers had a lower frequency of symptoms persistence at 3 weeks (respectively 4% vs. 14%; p = 0.024) and a trend towards a reduction of recurrences at 18 months (p = 0.069). In conclusion the use of beta-blockers on top of standard anti-inflammatory therapies was associated with improved symptom control.

Pathological and clinical effects of interleukin-6 on human myocarditis

BACKGROUND

Numerous basic studies have shown a relationship between interleukin-6 (IL-6) and the development or severity of myocarditis. However, there has been no study in which the effect of IL-6 levels in patients with myocarditis was evaluated.

METHODS

We enrolled control patients (n = 12) and consecutive patients with acute myocarditis (n = 13), including lymphocytic, eosinophilic, and giant cell myocarditis, and investigated the pathological and clinical effects of IL-6 on human myocarditis.

RESULTS

The serum IL-6 level in patients with myocarditis (16.7 [9.9, 103.8] pg/mL) was significantly higher than that in the control patients (1.4 [1.0, 1.9] pg/mL) (P<0.001). Immunohistochemical analysis showed that IL-6 was expressed in infiltrating inflammatory cells of endomyocardial biopsy samples from all patients with myocarditis. Moreover, the log-transformed value of serum IL-6 level showed significant positive correlations with serum creatine kinase (CK) level, CK-MB level, peak CK level, peak CK-MB level and C-reactive protein level (all P ≤ 0.005) and a negative correlation with the left ventricular (LV) ejection fraction (p = 0.014). We divided the patients with myocarditis into a low IL-6 group (9.9 [4.5, 14.2] pg/dL, n = 7) and a high IL-6 group (108.9 [51.1, 130.9] pg/dL, n = 6). The degree of infiltration of IL-6-expressing inflammatory cells in myocardial samples obtained from patients in the high IL-6 group was significantly more severe than that in samples obtained from patients in the low IL-6 group. Furthermore, patients in the high IL-6 group significantly more frequently received catecholamine therapy (P = 0.005), venoarterial extracorporeal membrane oxygenation (P = 0.029), and artificial respirator support (P = 0.021) in the acute phase of myocarditis.

CONCLUSION

The results suggest that there is a strong impact of IL-6 on cardiac injury and dysfunction in patients with myocarditis.

Ivabradine and endothelium: an update

Ivabradine is a pure heart-rate lowering drug that is nowadays used, accordingly to the last ESC Guidelines, to reduce mortality and heart failure (HF) hospitalization in patients with HF with reduced ejection fraction and in symptomatic patiens with inappropriate sinus tachycardia. Moreover, interesting effect of ivabradine on endothelial and myocardial function and on oxidative stress and inflamation pathways are progressively emerging. The aim of this paper is to highlight newer evidences about ivabradine effect (and consequently possible future application of the drug) in pathological settings different from guidelines-based clinical practice.

Therapies to limit myocardial injury in animal models of myocarditis: a systematic review and meta-analysis

Current myocarditis guidelines do not advocate treatment to prevent myocardial injury and scar deposition in patients with myocarditis and normal left ventricular ejection fraction. We aimed to ascertain the utility of beta blockers, calcium channel blockers and antagonists of the renin–angiotensin system in ameliorating myocardial injury, scar formation and calcification in animal in vivo models of myocarditis. The project was prospectively registered with the PROSPERO database of systematic reviews (CRD42018089336). Primary outcomes (necrosis, fibrosis and calcification) were meta-analysed with random-effects modelling. 52 studies were systematically reviewed. Meta-analysis was performed compared with untreated controls. In each study, we identified all independent comparisons of treatment versus control groups. The pooled weighted mean difference (WMD) indicated treatment reduced necrosis by 16.9% (71 controlled analyses, 95% CI 13.2–20.7%; P < 0.001), however there was less evidence of an effect after accounting for publication bias. Treatment led to a 12.8% reduction in fibrosis (73 controlled analyses, 95% CI 7.6–18.0%; P < 0.001). After accounting for publication bias this was attenuated to 7.8% but remained significant. Treatment reduced calcification by 4.1% (28 controlled analyses, 95% CI 0.2–8.0%; P < 0.0395). We observed significant heterogeneity in effect size in all primary endpoints, which was predominantly driven by differences between drug categories. Beta blockers and angiotensin-converting enzyme (ACE) inhibitors were the only agents that were effective for both necrosis and fibrosis, while only ACE inhibitors had a significant effect on calcification. This study provides evidence for a role for ACE inhibitors and beta blockers to prevent myocardial injury and scar deposition in in vivo models of myocarditis. There is a need for further well-designed studies to assess the translational application of these treatments.

Effects of Ivabradine on Residual Myocardial Ischemia after PCI Evaluated by Stress Echocardiography

Background

Residual angina after PCI is a frequently occurring disease. Ivabradine improves symptoms but its role in patients without left ventricular systolic dysfunction is still unclear. The aim was to quantify the effects of ivabradine in terms of MVO₂ indicators and diastolic function.

Methods

Twenty-eight consecutive patients with residual angina after PCI were randomized to ivabradine 5 mg twice/day (IG) or standard therapy (CG). All patients performed a stress echocardiography at the enrollment and after 30 days. MVO₂ was estimated from double product (DP) and triple product (TP) integrating DP with ejection time (ET). Diastolic function was evaluated determining E and A waves, E' measurements, and E/E' ratio both at rest and at the peak of exercise.

Results

The exercise time was longer in IG 9'49″ ± 48″ vs 8'09″ ± 59″ in CG (p=0.0001), reaching a greater workload (IG 139.3 ± 13.4 vs CG 118.7 ± 19.6 Watts; p=0.003). MVO₂ expressed with DP and TP was significantly higher in IG (DP: IG 24194 ± 2697 vs CG 20358 ± 4671.8, p=0.01; TP: IG 17239 ± 4710 vs CG 12206 ± 4413, p=0.007). At peak exercise, the ET was diminished in IG than CG. The analysis of diastolic function after the exercise revealed an increase of E and A waves, without difference in the E/A ratio. The E' wave was higher in IG than CG, and in the same group, the differences between baseline and peak exercise were greater (∆E'3.14 ± 0.7 vs 2.4 ± 1.13, p=0.047). The E/E' ratio was reduced in patients treated with ivabradine (IG 10.2 ± 2.0 vs CG 7.9 ± 1.6, p=0.002).

Conclusions

Ivabradine seems to produce a significant improvement of ischemic threshold, chronotropic reserve, and diastolic function.

Ivabradine: Evidence and current role in cardiovascular diseases and other emerging indications

Increased heart rate (HR) is associated with deleterious effects on several disease conditions. Chronic heart failure (CHF) is one of the cardiovascular diseases with recurrent hospitalization burden and an ongoing drain on health-care expenditure. Despite advancement in medicine, management of CHF remains a challenge to health-care providers. Ivabradine selectively and specifically inhibits the pacemaker I(f) ionic current which reduces the cardiac pacemaker activity. The main effect of ivabradine therapy is the substantial lowering of HR. It does not influence intracardiac conduction, contractility, or ventricular repolarization. As shown in numerous clinical studies, ivabradine improves clinical outcomes and quality of life and reduces the risk of death from heart failure (HF) or other cardiovascular causes. Recently updated HF guidelines recommend ivabradine as a class II indication for reduction of HF hospitalizations. Based on the principle of benefits of reduced HR, the ivabradine in patients with ischemic heart disease, sepsis, and multiple organ dysfunction syndrome has also been studied. It can also be a useful agent for HR reduction in patients with contraindications to use beta-blockers or those who cannot tolerate them. In this review, we provide an overview of efficacy and safety of ivabradine and its combination with currently recommended pharmacological therapy in different conditions.

Safety profile and efficacy of ivabradine in heart failure due to Chagas heart disease: a post hoc analysis of the SHIFT trial

AIMS

The SHIFT trial showed that ivabradine reduced heart rate (HR) and the risk of cardiovascular outcomes. Concerns remain over the efficacy and safety of ivabradine on heart failure (HF) due to Chagas disease (ChD). We therefore conducted a post hoc analysis of the SHIFT trial to investigate the effect of ivabradine in these patients.

METHODS AND RESULTS

SHIFT was a randomized, double-blind, placebo-controlled trial in symptomatic systolic stable HF, HR ≥ 70 b.p.m., and in sinus rhythm. The ChD HF subgroup included 38 patients, 20 on ivabradine, and 18 on placebo. The ChD HF subgroup showed high prevalence of bundle branch right block and, compared with the overall SHIFT population, lower systolic blood pressure; higher use of diuretics, cardiac glycosides, and antialdosterone agents; and lower use of angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker or target daily dose of beta-blocker. ChD HF presented a poor prognosis (all-cause mortality at 2 years was ~60%). The mean twice-daily dose of ivabradine was 6.26 ± 1.15 mg and placebo 6.43 ± 1.55 mg. Ivabradine reduced HR from 77.9 ± 3.8 to 62.3 ± 10.1 b.p.m. (P = 0.005) and improved functional class (P = 0.02). A trend towards reduction in all-cause death was observed in ivabradine arm vs. placebo (P = 0.07). Ivabradine was not associated with serious bradycardia, atrioventricular block, hypotension, or syncope.

CONCLUSIONS

ChD HF is an advanced form of HF with poor prognosis. Ivabradine was effective in reducing HR in these patients and improving functional class. Although our results are based on a very limited sample and should be interpreted with caution, they suggest that ivabradine may have a favourable benefit-risk profile in ChD HF patients.

Ivabradine Treatment Reduces Cardiomyocyte Apoptosis in a Murine Model of Chronic Viral Myocarditis

This study was designed to explore the effects of ivabradine on cardiomyocyte apoptosis in a murine model of chronic viral myocarditis (CVMC). Mice were inoculated intraperitoneally with Coxsackievirus B3 at days 1, 14, and 28, respectively. On day 42, the mice were gavaged with ivabradine for 30 days until the 72nd day. The heart of infected mice was dilated and a large number of interstitial fibroblasts infiltrated into the myocardium on day 42. Compared with the untreated CVMC mice, mice treated with ivabradine showed a significant reduction in heart rate and less impairment of left ventricular function on day 72. The positive apoptosis of myocardial cells in the untreated CVMC group was significantly higher than that of the normal group and was significantly reduced after treatment with ivabradine. The expression levels of Bax and Caspase-3 in the untreated CVMC group were significantly higher than those of the normal group and were apparently reduced in the ivabradine-treated group versus the untreated CVMC group. Bcl-2 showed a high expression in the normal group and low expression in the untreated CVMC group, but its expression level in the ivabradine-treated group were higher than that of the untreated CVMC group. These results indicate that ivabradine could attenuate the expression of Caspase-3 by downregulation of Bax and upregulation of Bcl-2 to prevent the deterioration of cardiac function resulting from ventricular myocyte loss by cardiomyocyte apoptosis.

Combination Therapy With Coenzyme Q10 and Trimetazidine in Patients With Acute Viral Myocarditis

BACKGROUND

Acute viral myocarditis is an inflammatory disease with global impact. Although it may resolve spontaneously, its course is not easily predicted, and there is a paucity of specific treatment options available with proven efficacy. Coenzyme Q10 (CQ10) and trimetazidine possess antioxidant and antiinflammatory effects.

METHODS

We examined the therapeutic efficacy of these agents in acute viral myocarditis both individually and in combination. Patients were blinded and randomized to receive CQ10 (n = 42), trimetazidine (n = 39), or CQ10 + trimetazidine (n = 43) treatment.

RESULTS

Serum inflammatory and oxidative stress marker and myocardial enzyme levels, and heart function were measured. Both CQ10 and trimetazidine decreased inflammatory and oxidative stress biomarker levels compared with baseline measurements. However, combination therapy with CQ10 and trimetazidine showed a significantly more powerful effect not only on markers of inflammation and oxidative stress, but also on left ventricular systolic function and troponin, compared with either treatment alone.

CONCLUSION

This study confirmed the beneficial effect of CQ10 and trimetazidine individually, but demonstrated a superior effect of combining the therapies on cardiac left ventricular ejection fraction, and biochemical markers of myocardial damage in acute viral myocarditis.

Carvedilol Inhibits Matrix Metalloproteinase-2 Activation in Experimental Autoimmune Myocarditis: Possibilities of Cardioprotective Application

AIMS

Acute myocarditis is a potentially lethal inflammatory heart disease that frequently precedes the development of dilated cardiomyopathy and subsequent heart failure. At present, there is no effective standardized therapy for acute myocarditis, besides the optimal care of heart failure and arrhythmias in accordance with evidence-based guidelines and specific etiology-driven therapy for infectious myocarditis. Carvedilol has been shown to be cardioprotective by reducing cardiac pro-inflammatory cytokines present in oxidative stress in certain heart diseases. However, effects of carvedilol administration in acute myocarditis with its impact on matrix metalloproteinases' (MMPs) activation have not been elucidated.

METHODS AND RESULTS

Carvedilol in 3 doses (2, 10, and 30 mg/kg) was given daily to 3 study groups of rats (n = 8) with experimental autoimmune myocarditis by gastric gavage for 3 weeks. In comparison to untreated rats (n = 8) with induced myocarditis, carvedilol significantly prevented the left ventricle enlargement and/or systolic dysfunction depending on the dose in study groups. Performed zymography showed enhanced MMP-2 activity in untreated rats, while carvedilol administration reduced alterations. This was accompanied by prevention of troponin I release and myofilaments degradation in cardiac muscle tissue. Additionally, severe inflammatory cell infiltration was detected in the nontreated group. Carvedilol in all doses tested, had no impact on severity of inflammation. The severity of inflammation did not differ between study groups and in relation to the untreated group.

CONCLUSIONS

The protective effects of carvedilol on heart function observed in the acute phase of experimental autoimmune myocarditis seem to be associated with its ability to decrease MMP-2 activity and subsequently prevent degradation of myofilaments and release of troponin I while not related to suppression of inflammation.

Carvedilol can attenuate histamine-induced paw edema and formaldehyde-induced arthritis in rats without risk of gastric irritation

BACKGROUND AND AIM

Rheumatoid arthritis treatment aims to control joint damage and any associated complications such as cardiovascular disease. Most anti-inflammatory drugs have a high tendency to cause gastro-intestinal irritation. The present study is designed to investigate the anti-inflammatory effect of carvedilol and to study its effect on gastric mucosa.

EXPERIMENTAL APPROACH

Lornoxicam (1.3mg/kg) or carvedilol (10mg/kg) was administrated orally 1h before histamine injection into animals of a histamine-induced paw edema model and orally daily for 11days into animals of a formaldehyde-induced arthritis model. Tumor necrosis factor-α and prostaglandin E₂ were measured in animals of the formaldehyde-induced arthritis model. The effect of lornoxicam and carvedilol on gastric mucosa was assessed in normal rats and after induction of cold stress ulcer.

RESULTS

Carvedilol succeeded in reducing hind paw edema in both histamine-induced paw edema and formaldehyde-induced arthritis and in reducing the elevated level of tumor necrosis factor-α and prostaglandin E₂ nearly with near equal efficacy compared with lornoxicam. Carvedilol did not show any ulcerative effect on the gastric mucosa of normal rats, and its use was associated with an improvement of both the gross and histopathological pictures of gastric ulcers in animals of the cold stress ulcer model compared with lornoxicam treated rats.

CONCLUSION

The current findings support the use of carvedilol both in the management of inflammation as well as the prevention of cardiovascular complications in rheumatoid arthritis patients. The use of carvedilol was not associated with any gastro-intestinal tract irritation.

Granisetron and carvedilol can protect experimental rats againstadjuvant-induced arthritis

CONTEXT

Rheumatoid arthritis (RA), a disabling autoimmune disorder of the joints as well as other organs, affects about 1% of population. Unfortunately, all current treatments of RA cause severe gastrointestinal, renal and other complications.

OBJECTIVE

We aimed to evaluate the possible antiarthritic effects of a serotonin 5-HT₃ receptor blocker, granisetron, and a nonselective adrenergic receptor blocker, carvedilol, on complete Freund's adjuvant-induced RA in adult female albino rats.

MATERIALS AND METHODS

Rats were allocated into a normal control group, an arthritis control group, two reference treatment groups receiving dexamethasone (1.5 mg/kg/day) and methotrexate (1 mg/kg/day), and two treatment groups receiving granisetron (2.5 mg/kg/day) and carvedilol (10 mg/kg/day). Serum-specific rheumatoid, immunological, inflammatory and oxidative stress biomarkers were assessed. A confirmatory histopathological study on joints and spleens was performed.

RESULTS

Granisetron administration significantly improved all the measured biomarkers, with the values of rheumatoid factor, matrix metalloproteinase-3, cartilage oligomeric matrix protein, immunoglobulin G, antinuclear antibody and myeloperoxidase being restored back to normal levels. Carvedilol administration significantly improved all biomarkers, with serum MPO value restored back to normal levels.

DISCUSSION AND CONCLUSIONS

Serotonin 5-HT₃ receptor blockers and adrenergic receptor blockers, represented by granisetron and carvedilol, may represent new promising protective strategies against RA, at least owing to immune-modulator, anti-inflammatory and antioxidant potentials.

Right Cervical Vagotomy Aggravates Viral Myocarditis in Mice Via the Cholinergic Anti-inflammatory Pathway

The autonomic nervous system dysfunction with increased sympathetic activity and withdrawal of vagal activity may play an important role in the pathogenesis of viral myocarditis. The vagus nerve can modulate the immune response and control inflammation through a ‘cholinergic anti-inflammatory pathway’ dependent on the α7-nicotinic acetylcholine receptor (α7nAChR). Although the role of β-adrenergic stimulation on viral myocarditis has been investigated in our pervious studies, the direct effect of vagal tone in this setting has not been yet studied. Therefore, in the present study, we investigated the effects of cervical vagotomy in a murine model of viral myocarditis. In a coxsackievirus B3 murine myocarditis model (Balb/c), effects of right cervical vagotomy and nAChR agonist nicotine on echocardiography, myocardial histopathology, viral RNA, and proinflammatory cytokine levels were studied. We found that right cervical vagotomy inhibited the cholinergic anti-inflammatory pathway, aggravated myocardial lesions, up-regulated the expression of TNF-α, IL-1β, and IL-6, and worsened the impaired left ventricular function in murine viral myocarditis, and these changes were reversed by co-treatment with nicotine by activating the cholinergic anti-inflammatory pathway. These results indicate that vagal nerve plays an important role in mediating the anti-inflammatory effect in viral myocarditis, and that cholinergic stimulation with nicotine also plays its peripheral anti-inflammatory role relying on α7nAChR, without requirement for the integrity of vagal nerve in the model. The findings suggest that vagus nerve stimulation mediated inhibition of the inflammatory processes likely provide important benefits in myocarditis treatment.

The role of Ivabradine in Diastolic Heart Failure with preserved Ejection Fraction. A Doppler-Echocardiographic study

Background:

Ivabradine (IVA) is effective in patients with coronary artery disease (CAD) or systolic heart failure in sinus rhythm. Its action consists in reducing heart rate (HR) and improving the time of left ventricular (LV) diastolic filling. The aim of this study was to evaluate the effects of IVA added to conventional therapy on patients with diastolic heart failure (DHF) and preserved ejection fraction (HFpEF).

Methods:

We evaluated 25 patients with DHF in the New York Heart Association (NYHA) Class II-III and sinus rhythm. In these, IVA per os (5 mg/twice a day) was added to the conventional medical therapy and given for 12 weeks. Immediately before the beginning of IVA therapy and 3 months later, patients underwent echocardiographic evaluation by two-dimensional (2D) ultrasound and tissue Doppler imaging (TDI). The patterns of diastolic mitral inflow and pulmonary venous flow were recorded using 2D echocardiography, while the diastolic phase of mitral flow was recorded by TDI, from the lateral mitral annulus.

Results:

Three months after the addition of IVA to conventional treatment, HR significantly decreased in comparison to the baseline values. On the contrary, the echocardiographic indexes of LV diastolic dysfunction improved.

Conclusions:

These results testify that the addition of IVA to conventional therapy in patients with HFpEF can improve LV diastolic function evaluated by 2D and tissue Doppler-echocardiographic patterns. These Doppler-echocardiographic results match with the clinical improvement of patients evaluated.

The Protective Effects of Ivabradine in Preventing Progression from Viral Myocarditis to Dilated Cardiomyopathy

To study the beneficial effects of ivabradine in dilated cardiomyopathy (DCM) mice, which evolved from coxsackievirus B3-induced chronic viral myocarditis. Four-to-five-week-old male balb/c mice were inoculated intraperitoneally with coxsackievirus B3 (Strain Nancy) on days 1, 14, and 28. The day of the first virus inoculation was defined as day 1. Thirty-five days later, the surviving chronic viral myocarditis mice were divided randomly into two groups, a treatment group and an untreated group. Ivabradine was administered by gavage for 30 consecutive days in the treatment group, and the untreated group was administered normal saline. Masson’s trichrome stain was used to evaluate the fibrosis degree in myocardial tissue. The expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), collagen I, collagen III and p38-MAPK signaling pathway proteins were detected by Western blot. Electrocardiogram was used to investigate the heart rate and rhythm. The thickness of the ventricular septum and left ventricular posterior wall, left ventricular end diastolic dimension, left ventricular end systolic dimension, left ventricular ejection fractions and fractional shortening were studied by echocardiography. Compared with the untreated chronic viral myocarditis mice, ivabradine significantly increased the survival rate, attenuated the myocardial lesions and fibrosis, improved the impairment of the left ventricular function, diminished the heart dimension, decreased the production of collagen I and collagen III, reduced the expression of the proinflammatory cytokines TNF-α, IL-1β, and IL-6, and lowered the production of phospho-p38 MAPK. The findings indicate the therapeutic effect of ivabradine in preventing the progression from viral myocarditis to DCM in mice with chronic viral myocarditis induced by coxsackievirus B3, is associated with inhibition of the p38 MAPK pathway, downregulated inflammatory responses and decreased collagen expression. Ivabradine appears a promising approach for the treatment of patients with viral myocarditis.

Impact of Ivabradine on Inflammatory Markers in Chronic Heart Failure

Background. Inflammation plays a crucial role in the progression of chronic heart failure (CHF). Ivabradine is known to reduce the morbidity and mortality of patients with CHF under certain conditions. Beyond the reduction of heart rate, only limited knowledge exists about potential anti-inflammatory effects of ivabradine that might contribute to its benefit in CHF. Thus, the present study aimed to investigate the effect of ivabradine on systemic inflammation. Methods. In the present study, 33 patients with CHF due to dilated, ischemic, and hypertensive cardiomyopathy were treated with ivabradine according to the guidelines of the European Society of Cardiology (ESC). A number of circulating dendritic cells as well as inflammatory mediators were investigated using FACS analysis and ELISA, respectively, before and during ivabradine therapy. Results. Treatment with ivabradine resulted in a significant improvement of CHF symptoms as well as an increase in left ventricular ejection fraction. Moreover, ivabradine treatment led to a significant reduction of TNF-alpha (TNF-α) serum levels and a reconstitution of circulating dendritic cells which are known to be reduced in patients with CHF. Conclusion. We show that treatment with ivabradine in patients with CHF resulted in an improvement of HF symptoms and ejection fraction as well as a normalization of inflammatory mediators.

Nicotine inhibits the production of proinflammatory cytokines of mice infected with coxsackievirus B3

AIMS

Although excessive sympathetic activation in viral myocarditis and the protective effects of sympathetic inhibition with β-blockers are clear, the effects of enhancing vagal tone on viral myocarditis remain unclear. In several models, vagus nerve activation with the α7 nicotinic acetylcholine receptor (α7-nAChR) agonists has been demonstrated to ameliorate inflammation. This study was therefore designed to examine the effects of cholinergic stimulation with α7-nAChR agonist nicotine in a murine model of acute viral myocarditis.

MATERIALS AND METHODS

BALB/C mice were infected by an intraperitoneally injection with coxsackievirus B3. Nicotine and methyllycaconitine (an α7-nAChR antagonist) were administered at doses of 0.4mg/kg and 0.8mg/kg three times per day for 7 or 14 consecutive days, respectively. The effects of nicotine and methyllycaconitine on survival rate, myocardial histopathological changes, cardiac function, cytokine levels, viral RNA, malondialdehyde, and superoxide dismutase contents were investigated.

KEY FINDINGS

Nicotine significantly increased survival rate of the infected mice, decreased myocardial inflammation, and improved the impairment of left ventricular function in murine coxsackievirus B3-induced myocarditis compared with methyllycaconitine. The proinflammatory cytokines TNF-α, IL-1β, IL-6 and IL-17A were significantly decreased in the infected mice treated with nicotine compared with methyllycaconitine. Nicotine had no significant anti-oxidative and antiviral effects in coxsackievirus B3-infected mice.

SIGNIFICANCE

The results indicate that cholinergic stimulation with nicotine significantly reduced the severity of viral myocarditis in mice. The findings suggest that alpha7 nAChR agonists may be a promising new strategy for patients with myocarditis.

Ivabradine in Management of Heart Failure: a Critical Appraisal

Elevated resting heart rate has been linked to poor outcomes in patients with chronic systolic heart failure. Blockade of funny current channel with ivabradine reduces heart rate without inotropic effects. Ivabradine was recently approved by US Food and Drug Administration for patients with stable, symptomatic chronic heart failure (HF) with left ventricular ejection fraction (LVEF) ≤35 %, who are in sinus rhythm with resting heart rate (HR) ≥ 70 bpm and either are on maximally tolerated doses of beta-blockers, or have a contraindication to beta-blockers. This article will review and evaluate the data supporting the use of ivabradine in patients with HF and explore its mechanisms and physiologic effects.

Methods for Testing Immunological Factors

Hypersensitivity reactions can be elicited by various factors: either immunologically induced, i.e., allergic reactions to natural or synthetic compounds mediated by IgE, or non-immunologically induced, i.e., activation of mediator release from cells through direct contact, without the induction of, or the mediation through immune responses. Mediators responsible for hypersensitivity reactions are released from mast cells. An important preformed mediator of allergic reactions found in these cells is histamine. Specific allergens or the calcium ionophore 48/80 induce release of histamine from mast cells. The histamine concentration can be determined with the o-phthalaldehyde reaction.

β-Blockers and ivabradine differentially affect cardiopulmonary function and left ventricular filling index

OBJECTIVE

Patients with left ventricular (LV) diastolic dysfunction are characterized by exertional dyspnoea. Heart rate (HR) reduction by β-blockers can improve exercise tolerance by prolonging LV filling, but their negative inotropic and lusitropic properties can be detrimental in this disease. We tested the effects of administering ivabradine, a HR-lowering drug without impact on cardiac kinetics that may favorably affect diastolic function.

METHODS

Twenty-four patients with coronary artery disease (CAD) and normal LV ejection fraction on chronic β-blocker therapy were included. NT-proBNP serum levels were determined prior to and after cardiopulmonary exercise. β-Blockers were then replaced by ivabradine and patients were re-tested after 6 weeks. Patients were initially classified as having a low (E/e' ≤ 8; n = 11) or high (E/e' > 8; n = 13) LV filling index.

RESULTS

E/e' significantly decreased during ivabradine therapy in patients with high E/e' (10.7 ± 2.9 vs. 8.9 ± 1.7; p < 0.01), whereas no difference occurred in patients with low E/e' (6.4 ± 0.7 vs. 6.5 ± 1.1; p = ns). With ivabradine, patients with high E/e' had an increased oxygen uptake at the anaerobic threshold (from 10.8 ± 1.4 to 11.8 ± 1.9 ml/min/kg; p < 0.05) and a steeper slope of the initial oxygen pulse curve (from 293 ± 109 to 359 ± 117 µl/beat/kg/W; p < 0.05). Moreover, patients with high E/e' had lower NT-proBNP serum levels at rest (169 ± 207 vs. 126 ± 146 pg/ml; p < 0.05) and after exercise (190 ± 256 vs. 136 ± 162 pg/ml; p < 0.05) during ivabradine therapy.

CONCLUSIONS

In patients with CAD and elevated E/e', switching therapy from β-blockers to ivabradine may cause a reduction in LV filling pressures and an improved stroke volume response to exercise.

Ventricular myocarditis coincides with atrial myocarditis in patients

INTRODUCTION

Atrial fibrillation (AF) is a common complication in myocarditis. Atrial inflammation has been suggested to play an important role in the pathophysiology of AF. However, little is known about the occurrence of atrial inflammation in myocarditis patients. Here, we analyzed inflammatory cell numbers in the atria of myocarditis patients without symptomatic AF.

METHODS

Cardiac tissue was obtained postmortem from lymphocytic myocarditis patients (n=6), catecholamine-induced myocarditis patients (n=5), and control patients without pathological evidence of heart disease (n=5). Tissue sections of left and right ventricle and left and right atrium were stained for myeloperoxidase (neutrophilic granulocytes), CD45 (lymphocytes), and CD68 (macrophages). These cells were subsequently quantified in atrial and ventricular myocardium and atrial adipose tissue.

RESULTS

In lymphocytic myocarditis patients, a significant increase was observed for lymphocytes in the left atrial adipose tissue. In catecholamine-induced myocarditis patients, significant increases were found in the atria for all three inflammatory cell types. Infiltrating inflammatory cell numbers in the atrial myocardium correlated positively with those in the ventricles, especially in catecholamine-induced myocarditis patients.

CONCLUSIONS

To a varying extent, atrial myocarditis occurs concurrently with ventricular myocarditis in patients diagnosed with myocarditis of different etiology. This provides a substrate that potentially predisposes myocarditis patients to the development of AF and subsequent complications such as sudden cardiac death and heart failure.

Dose-dependent protective effect of nicotine in a murine model of viral myocarditis induced by coxsackievirus B3

The alpha 7 nicotinic acetylcholine receptor (alpha7 nAChR) was recently described as an anti-inflammatory target in various inflammatory diseases. The aim of this study was to investigate the dose-related effects of nicotine, an alpha7 nAChR agonist, in murine model of viral myocarditis. BALB/C mice were infected by an intraperitoneally injection with coxsackievirus B3. Nicotine was administered at doses of 0.1, 0.2 or 0.4 mg/kg three times per day for 7 or 14 consecutive days. The effects of nicotine on survival, myocardial histopathological changes, cardiac function, and cytokine levels were studied. The survival rate on day 14 increased in a dose-dependent fashion and was markedly higher in the 0.2 and 0.4 mg/kg nicotine groups than in the infected untreated group. Treatment with high-dose nicotine reduced the myocardial inflammation and improved the impaired left ventricular function in infected mice. The mRNA expressions and protein levels of TNF-α, IL-1β, IL-6, and IL-17A were significantly downregulated in dose-dependent manners in the nicotine treatment groups compared to the infected untreated group. Nicotine dose-dependently reduced the severity of viral myocarditis through inhibiting the production of proinflammatory cytokines. The findings suggest that alpha7 nAChR agonists may be a promising new strategy for patients with viral myocarditis.

Ivabradine Versus Beta-Blockers in Patients with Conduction Abnormalities or Left Ventricular Dysfunction Undergoing Cardiac Surgery

INTRODUCTION

In patients with conduction abnormalities or left ventricle (LV) dysfunction the use of β-blockers for post cardiac surgery rhythm control is difficult and controversial, with a paucity of information about other drugs such ivabradine used postoperatively. The objective of this study was to compare the efficacy and safety of ivabradine versus metoprolol used perioperatively in cardiac surgery patients with conduction abnormalities or LV systolic dysfunction.

METHODS

This was an open-label, randomized clinical trial enrolling 527 patients with conduction abnormalities or LV systolic dysfunction undergoing coronary artery bypass grafting or valvular replacement, randomized to take ivabradine or metoprolol, or metoprolol plus ivabradine. The primary endpoints were the composites of 30-day mortality, in-hospital atrial fibrillation (AF), in-hospital three-degree atrioventricular block and need for pacing, in-hospital worsening heart failure (HF; safety endpoints), duration of hospital stay and immobilization and the above endpoint plus in-hospital bradycardia, gastrointestinal symptoms, sleep disturbances, cold extremities (efficacy plus safety endpoint).

RESULTS

Heart rate reduction and prevention of postoperative AF or tachyarrhythmia with combined therapy was more effective than with metoprolol or ivabradine alone during the immediate postoperative management of cardiac surgery patients. In the Ivabradine group, the frequency of early postoperative pacing and HF worsening was smaller than in the Metoprolol group and in combined therapy group. The frequency of primary combined endpoint was lower in the combined Ivabradine + Metoprolol group compared with the monotherapy groups.

CONCLUSION

Considering efficacy and safety, the cardiac rhythm reduction after open heart surgery in patients with conduction abnormalities or LV dysfunction with ivabradine plus metoprolol emerged as the best treatment in this trial.

Ivabradine improves left ventricular function during chronic hypertension in conscious pigs

During chronic hypertension, increases in heart rate (HR) or adrenergic stimulation are associated with maladaptive left ventricular responses as isovolumic contraction and relaxation durations failed to reduce, impeding filling. We, therefore, investigated the effects of acute selective HR reduction with ivabradine on left ventricular dysfunction during chronic hypertension. Accordingly, chronically instrumented pigs received angiotensin II infusion during 4 weeks to induce chronic hypertension. Left ventricular function was investigated while angiotensin II infusion was stopped. A single intravenous dose of ivabradine was administered at days 0 and 28. Dobutamine infusion was also performed. HR was increased at day 28 versus day 0. Paradoxically, both isovolumic contraction and relaxation times failed to reduce and remained unchanged (57±3 versus 58±3 ms and 74±3 versus 70±3 at day 28 versus day 0, respectively). At day 28, ivabradine significantly reduced HR by 27%. Concomitantly, abnormal ventricular responses were corrected because both isovolumic contraction and relaxation times were significantly reduced while filling time was improved. Similarly at day 28, maladaptive responses of isovolumic contraction and relaxation to dobutamine were no longer observed during HR reduction with ivabradine. Correction of HR reduction with pacing showed that non-HR-related mechanisms also participated to these beneficial effects. In this model of chronic hypertension and left ventricular hypertrophy, acute HR reduction with ivabradine corrects the maladaptive responses of cardiac cycle phases by restoring a normal profile for isovolumic contraction and relaxation both at rest and under adrenergic stimuli, ultimately favoring filling.

Ivabradine therapy to unmask heart rate-independent effects of β-blockers on pulse wave reflections

BACKGROUND

Prior studies suggest that β-blockers lead to increased pulse wave reflections, thereby negating the blood pressure lowering effects on cardiovascular mortality. Parts of these effects may be induced by the heart rate reduction under β-blockade. The aim of this study was to unmask heart rate-independent effects of β-blockade on pulse wave reflections by switching therapy from β-blockers to ivabradine, an I f channel inhibitor without impact on systemic hemodynamics.

METHODS

14 male patients (age 61 ± 3 years, LVEF 62 ± 1 %) with arterial hypertension and coronary artery disease (CAD) under chronic β-blocker therapy at moderate dosage and additional renin-angiotensin system-blocking therapy were included. We determined radial augmentation index (rAI) by radial applanation tonometry in patients under β-blockade both at rest and during early recovery after exercise. β-Blockers were then replaced by ivabradine. Six weeks later, patients were re-tested at rest and after exercise under ivabradine therapy.

RESULTS

Mean heart rate (68 ± 3 vs. 63 ± 3 bpm; p = ns) and resting mean arterial pressure (98 ± 2 vs. 98 ± 2 mmHg; p = ns) were not different between β-blocker or ivabradine therapy, respectively. The rAI remained unchanged after switching therapy from β-blocker to ivabradine (86 ± 2 vs. 84 ± 4 %; p = ns). Post exercise, the rAI revealed an identical decrease in both groups (-7.2 ± 2.4 vs. -5.4 ± 2.5 %, p = ns). The increase in heart rate between resting conditions and early recovery post exercise was inversely correlated with the decrease of rAI under β-blockade (r = -0.70; p < 0.01) and showed a trend towards correlation under ivabradine (r = -0.52; p = 0.07).

CONCLUSION

In men at the age of 60 years and CAD, β-blockade does not exert heart rate-independent, pleiotropic effects on peripheral pulse wave reflections, both at rest or after exercise. Our results fit well within recent studies, demonstrating the fundamental influence of heart rate on rAI.

Effects of carvedilol treatment on cardiac cAMP response element binding protein expression and phosphorylation in acute coxsackievirus B3-induced myocarditis

Background

The role of β-adrenergic stimulation on viral myocarditis has been investigated in animal models of viral myocarditis. Excess stimulation of β-adrenergic receptors by catecholamines causes phosphorylation/activation of cAMP response element binding protein (CREB) by the cAMP signaling pathway. CREB as an important regulator of gene expression mediates the cardiovascular remodeling process and promotes anti-inflammatory immune responses. However, the CREB expression and phosphorylation have not been studied, and the effects of carvedilol (a nonselective β-adrenoceptor antagonist) on the CREB has not been investigated in the setting of acute viral myocarditis.

Methods

This study was therefore designed to examine the effects of carvedilol on the transcriptional factor CREB in a murine model of acute viral myocarditis. In a coxsackievirus B3 murine myocarditis model (Balb/c), effects of carvedilol on plasma noradrenaline, heart rate and blood pressure, myocardial histopathological changes and fibrosis, cardiomyocyte apoptosis, cardiac CREB and phosphorylated CREB, cytokine levels, and viral RNA were studied.

Results

The expression and phosphorylation of CREB were decreased with concomitant increase of IL-6 and TNF-α in murine coxsackievirus-induced acute viral myocarditis. The levels of IL-6 and TNF-α were correlated with the expression of CREB or phosphorylated CREB. Carvedilol increased the cardiac CREB expression and phosphorylation and decreased the plasma catecholamine levels and the production of IL-6 and TNF-α with amelioration of acute viral myocarditis.

Conclusion

These results show that CREB may be involved in the pathophysiology of viral myocarditis and carvedilol exerts some of its beneficial effects by increasing the CREB expression and phosphorylation.

Management of pericarditis and myocarditis: could heart-rate-reducing drugs hold a promise?

Rest is usually recommended in acute pericarditis and acute myocarditis. Given that myocarditis often leads to hospitalization, this task seems easy to carry out in hospital practice; however, it could be a real challenge at home in daily life. Heart rate-lowering treatments (mainly beta-blockers) are usually recommended in case of acute myocarditis, especially in case of heart failure or arrhythmias, but level of proof remains weak. Calcium channel inhibitors and digoxin are sometimes proposed, albeit in limited situations. It is possible that rest or even heart rate-lowering treatments could help to manage these patients by preventing heart failure as well as by limiting "mechanical inflammation" and controlling arrhythmias, especially life-threatening ones. Whether heart rate has an effect on inflammation remains unclear. Several questions remain unsolved, such as the duration of such treatments, especially in light of new heart rate-lowering treatments, such as ivabradine. In this review, we discuss rest and heart-rate lowering medications for the treatment of pericarditis and myocarditis. We also highlight some work in experimental models that indicates the beneficial effects of such treatments for these conditions. Finally, we suggest certain experimental avenues, through the use of animal models and clinical studies, which could lead to improved management of these patients.

Carvedilol alleviates adjuvant-induced arthritis and subcutaneous air pouch edema: modulation of oxidative stress and inflammatory mediators

Rheumatoid arthritis (RA) is a systemic inflammatory disease with cardiovascular complications as the leading cause of morbidity. Carvedilol is an adrenergic antagonist which has been safely used in treatment of several cardiovascular disorders. Given that carvedilol has powerful antioxidant/anti-inflammatory properties, we aimed to investigate its protective potential against arthritis that may add further benefits for its clinical usefulness especially in RA patients with concomitant cardiovascular disorders. Two models were studied in the same rat; adjuvant arthritis and subcutaneous air pouch edema. Carvedilol (10mg/kg/day p.o. for 21days) effectively suppressed inflammation in both models with comparable efficacy to the standard anti-inflammatory diclofenac (5mg/kg/day p.o.). Notably, carvedilol inhibited paw edema and abrogated the leukocyte invasion to air pouch exudates. The latter observation was confirmed by the histopathological assessment of the pouch lining that revealed mitigation of immuno-inflammatory cell influx. Carvedilol reduced/normalized oxidative stress markers (lipid peroxides, nitric oxide and protein thiols) and lowered the release of inflammatory cytokines (TNF-α & IL-6), and eicosanoids (PGE2 & LTB4) in sera and exudates of arthritic rats. Interestingly, carvedilol, per se, didn't present any effect on assessed biochemical parameters in normal rats. Together, the current study highlights evidences for the promising anti-arthritic effects of carvedilol that could be mediated through attenuation of leukocyte migration, alleviation of oxidative stress and suppression of proinflammatory cytokines and eicosanoids.