Ivabradine restores tonic cardiovascular autonomic control and reduces tachycardia, hypertension and left ventricular inflammation in post-weaning protein malnourished rats.

Malnutrition results in autonomic imbalance and heart hypertrophy. Overexpression of hyperpolarization-activated cyclic nucleotide-gated channels (HCN) in the left ventricles (LV) is linked to hypertrophied hearts and abnormal myocardium automaticity. Given that ivabradine (IVA) has emerging pleiotropic effects, in addition to the widely known bradycardic response, this study evaluated if IVA treatment could repair the autonomic control and cardiac damages in malnourished rats. AIM: Assess the impact of IVA on tonic cardiovascular autonomic control and its relationship with hemodynamics regulation, LV inflammation, and HCN gene expression in post-weaning protein malnutrition condition. MAIN METHODS: After weaning, male rats were divided into control (CG; 22 % protein) and malnourished (MG; 6 % protein) groups. At 35 days, groups were subdivided into CG-PBS, CG-IVA, MG-PBS and MG-IVA (PBS 1 ml/kg or IVA 1 mg/kg) received during 8 days. We performed jugular vein cannulation and electrode implant for drug delivery and ECG registration to assess tonic cardiovascular autonomic control; femoral cannulation for blood pressure (BP) and heart rate (HR) assessment; and LV collection to evaluate ventricular remodeling and HCN gene expression investigation. KEY FINDINGS: Malnutrition induced BP and HR increases, sympathetic system dominance, and LV remodeling without affecting HCN gene expression. IVA reversed the cardiovascular autonomic imbalance; prevented hypertension and tachycardia; and inhibited the LV inflammatory process and fiber thickening caused by malnutrition. SIGNIFICANCE: Our findings suggest that ivabradine protects against malnutrition-mediated cardiovascular damage. Moreover, our results propose these effects were not attributed to HCN expression changes, but rather to IVA pleiotropic effects on autonomic control and inflammation.

Efficacy and Tolerability of Ivabradine for Cardiomyopathy in Patients with Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is an intractable X-linked myopathy caused by dystrophin gene mutations. Patients with DMD suffer from progressive muscle weakness, inevitable cardiomyopathy, increased heart rate (HR), and decreased blood pressure (BP). The aim of this study was to clarify the efficacy and tolerability of ivabradine treatment for DMD cardiomyopathy.A retrospective analysis was performed in 11 patients with DMD, who received ivabradine treatment for more than 1 year. Clinical results were analyzed before (baseline), 6 months after, and 12 months after the ivabradine administration.The initial ivabradine dose was 2.0 ± 1.2 mg/day and the final dose was 5.6 ± 4.0 mg/day. The baseline BP was 95/64 mmHg. A non-significant BP decrease to 90/57 mmHg was observed at 1 month but it recovered to 97/62 mmHg at 12 months after ivabradine administration. The baseline HR was 93 ± 6 bpm and it decreased to 74 ± 12 bpm at 6 months (P = 0.011), and to 77 ± 10 bpm at 12 months (P = 0.008). A linear correlation (y = 2.2x + 5.1) was also observed between the ivabradine dose (x mg/day) and HR decrease (y bpm). The baseline LVEF was 38 ± 12% and it significantly increased to 42 ± 9% at 6 months (P = 0.011) and to 41 ± 11% at 12 months (P = 0.038). Only 1 patient with the lowest BMI of 11.0 kg/m2 and BP of 79/58 mmHg discontinued ivabradine treatment at 6 months, while 1-year administration was well-tolerated in the other 10 patients.Ivabradine decreased HR and increased LVEF without lowering BP, suggesting it can be a treatment option for DMD cardiomyopathy.

Detection of retinal dysfunction induced by HCN channel inhibitors using multistep light stimulus and long-duration light stimulus ERG in rats.

Ivabradine, a hyperpolarization-activated cyclic nucleotide-gated (HCN) channel inhibitor, has been reported to induce photosensitivity-related visual disturbances such as phosphene in humans. Ivabradine-induced visual disturbances are caused by inhibition of HCN channels in the retina, and the mechanisms have been verified using HCN channel knockout mice and electroretinography (ERG). However, in rats, classical ERG using single flash light stimulus with standard analyses of waveform amplitude and latency has not revealed abnormal retinal function after administration of ivabradine. To verify whether retinal dysfunction after ivabradine administration was detectable in rats, we performed ERG using multistep flash light stimulation at the time when plasma concentration of ivabradine was high. Furthermore, the mechanism of the change in the waveform that appeared after the b-wave was investigated. Ivabradine and cilobradine, a selective HCN channel inhibitor, were administered subcutaneously to rats at 4-40 mg/kg as a single dose, and flash or long-duration ERG recordings at each light stimulus luminance were conducted 1.5 h after administration. Plasma and retinal concentrations of both compounds were measured immediately after the ERG recordings. In the flash ERG, prolongation of a- and/or b-wave latencies were detected at each light stimulus, and dose-dependent waveform changes after the b-wave were recorded at the specific light stimulus luminance for both compounds. These ERG changes increased in response to increasing plasma and retinal concentrations for both ivabradine and cilobradine. In the long-duration light stimulus ERG, a change in the waveform of the b-wave trough and attenuation of the c-wave were recorded, suggesting that the feedback control in the photoreceptor cells may be inhibited. This study revealed that the retinal dysfunction by HCN channel inhibitors in rats can be detected by multistep light stimulus ERG. Additionally, we identified that the inhibition of feedback current and the sustained responses in the photoreceptor cells cause the retinal dysfunction of HCN channel inhibitors in rats.

Clinical Implications of Ivabradine in the Contemporary Era.

Ivabradine is a recently introduced inhibitor of the If ion channel, which exhibits the capacity to reduce heart rate while preserving hemodynamic stability. At present, ivabradine finds its clinical indication in patients suffering from heart failure with reduced ejection fraction and maintaining a relative sinus rhythm refractory to beta-blockers. To optimize heart rate control, it is recommended to pursue an aggressive up-titration of ivabradine. This approach may ameliorate tachycardia-induced hypotension by incrementally enhancing cardiac output and allow further up-titration of agents aimed at ameliorating heart failure, such as beta-blockers. Both the modulation of heart rate itself and the up-titration of agents targeting heart failure lead to cardiac reverse remodeling, consequently culminating in a subsequent reduction in mortality and morbidity. A novel overlap theory that our team proposed recently has emerged in recent times. Under trans-mitral Doppler echocardiography, the E-wave and A-wave closely juxtapose one another without any overlapping at the optimal heart rate. Employing echocardiography-guided ivabradine for heart-rate modulation to minimize the overlap between the E-wave and A-wave appears to confer substantial benefits to patients with heart failure. This approach facilitates superior cardiac reverse remodeling and yields more favorable clinical outcomes when compared to those patients who do not receive echocardiography-guided care. The next pertinent issue revolves around the potential expansion of ivabradine's clinical indications to encompass a broader spectrum of diseases. It is imperative to acknowledge that ivabradine may not yield clinically significant benefits in patients afflicted by heart failure with preserved ejection fraction, acute heart failure, sepsis, or stable angina. An important fact yet to be explored is the clinical applicability of ivabradine in patients with atrial fibrillation, a concern that beckons future investigation. In this review, the concept of overlap theory it introduced, along with its application to expand the indication of ivabradine and the overlap theory-guided optimal ivabradine therapy.

Effectiveness and safety of ivabradine in Chinese patients with chronic heart failure: an observational study.

AIMS: A therapeutic strategy for chronic heart failure (HF) is to lower resting heart rate (HR). Ivabradine is a well-known HR-lowering agent, but limited prospective data exist regarding its use in Chinese patients. This study aimed to evaluate the effectiveness and safety of ivabradine in Chinese patients with chronic HF. METHODS AND RESULTS: This multicentre, single-arm, prospective, observational study enrolled Chinese patients with chronic HF. The primary outcome was change from baseline in HR at 1 and 6 months, measured by pulse counting. Effectiveness was also evaluated using laboratory tests, the Kansas City Cardiomyopathy Questionnaire (KCCQ) clinical summary score (CSS) and overall summary score (OSS), and New York Heart Association (NYHA) class. Treatment-emergent adverse events (TEAEs) were assessed. A post hoc analysis examined the effectiveness and safety of ivabradine combined with an angiotensin receptor-neprilysin inhibitor (ARNI) or beta-blocker. A total of 1003 patients were enrolled [mean age 54.4 ± 15.0 years, 773 male (77.1%), mean baseline HR 88.5 ± 11.3 b.p.m., mean blood pressure 115.7/74.4 ± 17.2/12.3 mmHg, mean left ventricular ejection fraction 30.9 ± 7.6%, NYHA Classes III and IV in 48.8% and 22.0% of patients, respectively]. HR decreased by a mean of 12.9 and 16.1 b.p.m. after 1 and 6 months, respectively (both P < 0.001). At Month 6, improvements in the KCCQ CSS and OSS of ≥5 points were observed in 72.1% and 74.1% of patients, respectively (both P < 0.001). Left ventricular ejection fraction increased by 12.1 ± 11.6 (P < 0.001), and 66.7% of patients showed improvement in NYHA class (P < 0.001). At Month 6, the overall proportion of patients in NYHA Classes III and IV was reduced to 13.5% and 2.1%, respectively. Serum brain natriuretic peptide (BNP) and N-terminal pro-BNP changed by -331.9 ng/L (-1238.6, -134.0) and -1113.8 ng/L (-2202.0, -297.2), respectively (P < 0.001). HR reductions and improvements in NYHA and KCCQ scores with ivabradine were similar with and without use of ARNIs or beta-blockers. Of 498 TEAEs in 296 patients (29.5%), 73 TEAEs in 55 patients (5.5%) were considered related to ivabradine [most frequent sinus bradycardia (n = 7) and photopsia (n = 7)]. TEAEs were reported in a similar number of patients in ARNI and beta-blocker subgroups (21.9-35.6%). CONCLUSIONS: Ivabradine treatment reduced HR and improved cardiac function and health-related quality of life in Chinese patients with chronic HF. Benefits were seen irrespective of whether or not patients were also taking ARNIs or beta-blockers. Treatment was well tolerated with a similar profile to previous ivabradine studies.

Evaluating the applicability of ivabradine in acute heart failure.

BACKGROUND: While ivabradine has demonstrated benefits in heart rate control and prognosis for chronic heart failure patients, its application in acute decompensated heart failure remains underexplored. HYPOTHESIS: For patients with acute decompensated heart failure with reduced ejection fraction (HFrEF) who are intolerant to ß-blockers or unable to further titrate their dosage, the use of ivabradine is hypothesized to be effective and safe is improving outcomes. METHODS: This retrospective, multicenter database analysis included patients with hospitalized decompensated heart failure with a left ventricular ejection fraction of ≤40% from June 1, 2015 to December 31, 2020. The exclusion criteria were a baseline heart rate of <70 bpm, previous use of ivabradine, mortality during admission, existing atrial fibrillation, or atrial flutter. The primary outcome was the composite of cardiovascular death and hospitalization for heart failure. RESULTS: Of the 4163 HFrEF patients analyzed, 684 (16.4%) were administered ivabradine during their index admission. After matching, there were 617 patients in either group. The results indicated that ivabradine use was not significantly associated with the risk of the primary composite outcome (hazard ratio: 1.10; 95% confidence interval: 0.94-1.29). Similarly, the risk of secondary outcomes and adverse renal events did not significantly differ between the ivabradine and non-ivabradine cohorts (all p > .05). CONCLUSION: For hospitalized acute decompensated heart failure patients who are intolerant to ß-blockers or cannot further titrate them, ivabradine offers a consistent therapeutic effect. No significant disparities were noted between the ivabradine and non-ivabradine groups in heart failure hospitalization and cardiovascular death.

Successful treatment with ivabradine for haemodynamically unstable junctional ectopic tachycardia occurring early after ST-elevation myocardial infarction.

Junctional ectopic tachycardia (JET) is a relatively uncommon arrhythmia predominantly observed in infancy, often occurring after congenital heart surgery. Although JET is rare in adults, it can occur in the presence of myocardial ischaemia. We describe a woman in her early 70s who presented with multivessel ST-segment elevation myocardial infarction and underwent percutaneous coronary intervention on left anterior descending artery and right coronary artery. She developed JET on the second day, resulting in haemodynamic compromise. Despite initial treatment attempts including amiodarone and beta-blocking agents proving insufficient in controlling JET, we successfully managed by administering ivabradine. Subsequently, she was discharged with recovered cardiac function without recurrence of JET. JET often proves refractory to multiple antiarrhythmic agents and can lead to unfavourable outcomes. Several case reports have demonstrated the effectiveness of ivabradine in treating JET during infancy, which can also be an effective therapeutic option for adult without adversely affecting haemodynamics.

Ivabradine Alleviates Experimental Autoimmune Myocarditis-Mediated Myocardial Injury.

Ivabradine (IVA) reduces heart rate by inhibiting hyperpolarization-activated cyclic nucleotide-gated channels (HCNs), which play a role in the promotion of pacemaker activity in cardiac sinoatrial node cells. HCNs are highly expressed in neural and myocardial tissues and are involved in the modulation of inflammatory neuropathic pain. However, whether IVA exerts any effect on myocardial inflammation in the pathogenesis of heart failure is unclear. We employed single-cell RNA sequencing (scRNA-seq) in porcine cardiac myosin-induced experimental autoimmune myocarditis rat model to determine the effects and mechanisms of IVA. Lewis rats (n = 32) were randomly divided into the normal, control, high-dose-IVA, and low-dose-IVA groups. Heart rate and blood pressure were measured on days 0 and 21, respectively. Echocardiography was performed on day 22, and inflammation of the myocardium was evaluated via histopathological examination. Western blot was employed to detect the expression of HCN1-4, MinK-related protein 1 (MiRP1), matrix metalloproteinase 2 (MMP-2), MMP-9, and transforming growth factor-ß (TGF-ß). Furthermore, enzyme-linked immunosorbent assay was performed to measure serum IL-1, IL-6, and TNF-α. The relative mRNA levels of collagen I, collagen III, and α-smooth muscle actin (α-SMA) were determined via qRT-PCR. We found that IVA reduced the total number of cells infiltrated into the myocardium, particularly in the subset of fibroblasts, endocardia, and monocytes. IVA administration ameliorated cardiac inflammation and reduced collagen production. Results of the echocardiography indicated that left ventricular internal diameter at end-systole LVIDs increased whereas left ventricular ejection fraction and left ventricular fractional shortening decreased in the control group. IVA improved cardiac performance. The expression of HCN4 and MiRP1 protein and the level of serum IL-1, IL-6, and TNF-α were decreased by IVA treatment. In conclusion, HCNs and the helper proteins were increased in the profile of myocardial inflammation. HCNs may be involved in the regulation of myocardial inflammation by inhibiting immune cell infiltration. Our findings can contribute to the development of IVA-based combination therapies for the future treatment of cardiac inflammation and heart failure.

The efficacy and safety of ivabradine hydrochloride in hemodialysis patients with chronic heart failure.

INTRODUCTION: There is little evidence for ivabradine hydrochloride in patients undergoing hemodialysis. METHODS: In this open-label prospective interventional trial of hemodialysis patients with chronic heart failure, during 12 weeks of treatment, changes in Heart rate (HR), frequency of dialysis-related hypotension were examined, and we investigated health-related quality of life (HR-QOL) and adverse effects. RESULTS: 18 patients from 6 facilities were enrolled in the study. HR significantly decreased over time, from 87 ± 12.61/min at baseline to 75.85 ± 8.91/min (p = 0.0003), and systolic blood pressure also increased significantly (p < 0.0001). The frequency of dialysis-related hypotension was markedly reduced (p = 0.0001). The HR-QOL survey showed significant improvements in Social Functioning among others (p = 0.0178). No specific adverse events occurred. CONCLUSION: Ivabradine hydrochloride improved dialysis-related hypotension. Furthermore, the HR-QOL improvement effect were suggested. These results demonstrated the safety and effectiveness of ivabradine hydrochloride.

Hyperpolarization-activated cyclic nucleotide-gated channel inhibitor in myocardial infarction: Potential benefits beyond heart rate modulation.

Myocardial infarction (MI) and its associated complications including ventricular arrhythmias and heart failure are responsible for a significant incidence of morbidity and mortality worldwide. The ensuing cardiomyocyte loss results in neurohormone-driven cardiac remodeling, which leads to chronic heart failure in MI survivors. Ivabradine is a heart rate modulation agent currently used in treatment of chronic heart failure with reduced ejection fraction. The canonical target of ivabradine is the hyperpolarization-activated cyclic nucleotide-gated channels (HCN) in cardiac pacemaker cells. However, in post-MI hearts, HCN can also be expressed ectopically in non-pacemaker cardiomyocytes. There is an accumulation of intriguing evidence to suggest that ivabradine also possesses cardioprotective effects that are independent of heart rate reduction. This review aims to summarize and discuss the reported cardioprotective mechanisms of ivabradine beyond heart rate modulation in myocardial infarction through various molecular mechanisms including the prevention of reactive oxygen species-induced mitochondrial damage, improvement of autophagy system, modulation of intracellular calcium cycling, modification of ventricular electrophysiology, and regulation of matrix metalloproteinases.

Anti-ischemic and pleiotropic effects of ranolazine in chronic coronary syndromes.

The vast majority of antianginal drugs decrease heart rate and or blood pressure levels or the inotropic status of the left ventricle to decrease myocardial oxygen consumption (MVO2) and thus anginal symptoms. Ranolazine presents a completely different mechanism of action, which reduces the sodium-dependent calcium overload inhibiting the late sodium current. Current European Society of Cardiology (ESC) guidelines for the management of angina in patients with chronic coronary symptoms recommend the use of several drugs such as ranolazine, b-blockers, calcium channel blockers, long-acting nitrates, ivabradine, nicorandil and trimetazidine for angina relief. However, ranolazine, in addition to symptom relief properties, is an antianginal drug showing favorable effects in decreasing the arrhythmic burden and in ameliorating the glycemic profile of these patients. In this review, we summarize the available data regarding the antianginal and pleiotropic effects of this drug.