Role of ivabradine in management of stable angina in patients with different clinical profiles

Effects of Ivabradine on Myocardial Perfusion in Chronic Angina: A Prospective, Preliminary, Open-Label, Single-Arm Study

INTRODUCTION

Ivabradine reduces heart rate (HR), episodes of angina, and nitrate consumption, and increases exercise capacity in patients with chronic angina (CA). In this exploratory study, myocardial perfusion scintigraphy (MPS) was used to evaluate changes in the percentage of myocardial ischemia after ivabradine therapy in patients with CA.

METHODS

This prospective, open-label, single-arm study included patients with CA receiving maximum tolerated doses of beta blockers, who had a resting HR ≥ 70 bpm and had experienced ischemia according to MPS during an exercise test at baseline. Participants received ivabradine 5 mg twice daily (titrated according to HR) concomitant with beta blockers. A second MPS was performed after 3 months, without interruption of treatment with beta blockers or ivabradine. The primary outcome was change in the percentage of myocardial ischemia from baseline to 3 months. Time to ischemia during the exercise test, the proportion of patients presenting angina during the exercise test, and health status, assessed using the seven-item Seattle Angina Questionnaire-7 (SAQ-7), were also evaluated.

RESULTS

Twenty patients (3 females) with a mean (± standard deviation [SD]) age of 62.2 ± 6.5 years were included in the study, of whom 55% had diabetes, 70% had previous myocardial revascularization, and 45% had previous myocardial infarction. The percentage of patients with myocardial ischemia significantly decreased from baseline to 3 months after initiation of treatment with ivabradine (- 2.9%; 95% confidence interval [CI] - 0.3 to - 5.5; p = 0.031). Mean time to appearance of ischemia increased from 403 ± 176 s at baseline to 466 ± 136 s at 3 months after initiation of ivabradine (Δ62 s; 95% CI 18-106 s; p = 0.008), and the proportion of patients experiencing angina during the exercise test decreased from 40% at baseline to 5% also at 3 months (p = 0.016). Mean resting HR decreased from 76 ± 7 bpm at baseline to 55 ± 8 bpm at 3 months (p < 0.001). The mean SAQ-7 summary score improved from 69 ± 21 at baseline to 83 ± 12 at 3 months (p = 0.001). No serious adverse effects were reported.

CONCLUSION

Ivabradine added to beta blockers was associated with a reduction in detectable myocardial ischemia by MPS in patients with CA. Infographic available for this article.

TRIAL REGISTRATION

The trial has been retrospectively registered with the Brazilian Registry of Clinical Trials (REBEC) under the following number RBR-5fysqrh (date of registration: 30 November 2023).

Label-free green estimation of atenolol and ivabradine hydrochloride in pharmaceutical and biological matrices by synchronous spectrofluorimetry

In this work, a label-free, rapid, and sensitive synchronous spectrofluorometric method was implemented to assay atenolol (ATL) and ivabradine hydrochloride (IVB) in pharmaceutical and biological matrices. Simultaneous determination of ATL and IVB by conventional spectrofluorometry cannot be implemented because of the clear overlap of the emmision spectra of ATL and IVB. To overcome this problem, synchronous fluorescence measurements at a constant wavelength difference (Δλ) combined with mathematical derivatization of the zero order spectra were perforemed. The results indicated a good resolution between emission spectra of the studied drugs when the first-order derivative of the synchronous fluorescence scans at Δλ = 40 nm was conducted using ethanol as the optimum solvent which is less hazardous than other organic solvents such as methanol and acetonitrile, keeping the method safe and green. The amplitudes of the first derivative synchronous fluorescent scans of ATL and IVB in ethanol were monitored at 286 and 270 nm to simultaneously estimate ATL and IVB, respectively. Method optimisation was conducted by assessing different solvents, buffer pHs, and surfactants. The optimum results were obtained when ethanol was utilized as a solvent without using any other additives. The developed method was linear over concentration ranges of 10.0-250.0 ng mL^-1 for IVB and 100.0-800.0 ng mL^-1 for ATL with detection limits of 3.07 and 26.49 ng mL^-1 for IVB and ATL, respectively. The method was utilized to assay the studied drugs in their dosages and in human urine samples with acceptable % recoveries and RSD values. The greenness of the method was implemented by three approaches involving the recently reported metric (AGREE) which ensured the eco-freindship and safety of the method.

Expert Consensus on Ivabradine-based Therapy for Heart Rate Management in Chronic Coronary Syndrome and Heart Failure with Reduced Ejection Fraction in India

Heart rate is an important indicator of health and disease and the modulation of heart rate can help to improve cardiovascular outcomes. Besides β-blockers, Ivabradine is a wellestablished heart rate modulating drug that reduces heart rate without any hemodynamic effects. This consensus document was developed with the help of expert opinions from cardiologists across India on effective heart rate management in routine clinical practice and choosing an appropriate Ivabradine-based therapy considering the available scientific data and guideline recommendations. Based on the discussion during the meetings, increased heart rate was recognized as a significant predictor of adverse cardiovascular outcomes among patients with chronic coronary syndromes and heart failure with reduced ejection fraction making heart rate modulation important in these subsets. Ivabradine is indicated in the management of chronic coronary syndromes and heart failure with reduced ejection fraction for patients in whom heart rate targets cannot be achieved despite guideline-directed β-blocker dosing or having contraindication/intolerance to β-blockers. A prolonged release once-daily dosage of Ivabradine can be considered in patients already stabilized on Ivabradine twice-daily. Ivabradine/β-blocker fixed-dose combination can also be considered to reduce pill burden. Two consensus algorithms have been developed for further guidance on the appropriate usage of Ivabradine-based therapies. Ivabradine and β-blockers can provide more pronounced clinical improvement in most chronic coronary syndromes and heart failure with reduced ejection fraction patients with a fixed-dose combination providing an opportunity to improve adherence.

Clinical use of ivabradine in the acute coronary syndrome: A systematic review and narrative synthesis of current evidence

Heart rate (HR) lowering during acute coronary syndrome (ACS) is beneficial as it reduces myocardial oxygen consumption. However, the role of ivabradine as an HR-lowering agent in the setting of ACS is not clear. We aimed to systematically review and synthesize the current evidence on the role of ivabradine use in the ACS. A systematic review was conducted for eligible randomized clinical trials and quasi-experimental studies, between 2009 and 2020, that investigated the use of ivabradine in ACS. Various clinical endpoints were evaluated such as major adverse cardiovascular events, efficacy in HR control, impact on left ventricular (LV) dimensions and function, and overall safety. Eleven publications were included encompassing a total of 1833 patients. The mean age of the examined cohort was 57 ± 11 years and 80 % were men. Seven studies were in the setting of ST-segment elevation myocardial infarction (MI) while the remaining studies also included patients with unstable angina and non-ST-segment elevation MI. Ivabradine was administered as a peroral drug with dosing from 2.5 to 7.5 mg b.i.d. Overall, the addition of ivabradine was superior to the control arm concerning HR control with a good safety profile. Beneficial effects on LV function and potential impact on infarct size reduction were observed as well. The use of ivabradine appeared to not affect short-term mortality. In conclusion, the use of ivabradine for HR control is safe, feasible, and efficacious for HR control in the ACS. Further studies are required to elucidate other potentially beneficial effects of ivabradine.

Photochemical and Electrochemical Applications of Proton-Coupled Electron Transfer in Organic Synthesis

We present here a review of the photochemical and electrochemical applications of multi-site proton-coupled electron transfer (MS-PCET) in organic synthesis. MS-PCETs are redox mechanisms in which both an electron and a proton are exchanged together, often in a concerted elementary step. As such, MS-PCET can function as a non-classical mechanism for homolytic bond activation, providing opportunities to generate synthetically useful free radical intermediates directly from a wide variety of common organic functional groups. We present an introduction to MS-PCET and a practitioner's guide to reaction design, with an emphasis on the unique energetic and selectivity features that are characteristic of this reaction class. We then present chapters on oxidative N-H, O-H, S-H, and C-H bond homolysis methods, for the generation of the corresponding neutral radical species. Then, chapters for reductive PCET activations involving carbonyl, imine, other X═Y π-systems, and heteroarenes, where neutral ketyl, α-amino, and heteroarene-derived radicals can be generated. Finally, we present chapters on the applications of MS-PCET in asymmetric catalysis and in materials and device applications. Within each chapter, we subdivide by the functional group undergoing homolysis, and thereafter by the type of transformation being promoted. Methods published prior to the end of December 2020 are presented.

[New opportunities to improve the treatment effectiveness of patients with stable angina]

Aim To study the antianginal and heart rate slowing effects in patients with stable angina (SA) who failed to achieve the heart rate (HR) goal and were switched from the beta-blocker (BB) metoprolol tartrate to a combination of metoprolol tartrate and ivabradine.Materials and methods The study included 54 patients with SA not higher than functional class (FC) III (35 (64.8 %) men and 19 (35.2 %) women) aged 59 [48; 77] years. Prior to the study start and at 4 and 8 weeks of follow-up, electrocardiography (ECG) and 24-h ECG monitoring (24h-ECGM) were performed for all patients. The follow-up period duration was 8 weeks. The antianginal and heart rate slowing effects of therapy were clinically evaluated by a decrease in frequency of anginal attacks and patients' requirement for nitrates, a decrease in HR, and the effect on 24h-ECGM indexes characterizing myocardial ischemia. At the first stage, all patients were prescribed metoprolol tartrate (Egilok®, Egis, Hungary) 25 mg twice a day. Patients with resting HR still higher than 70 bpm after 4 weeks of treatment were switched from metoprolol tartrate to a fixed ivabradine/metoprolol combination (Implicor®, Servier, France) 5 / 25 mg twice a day. Thus, based on achieving/ non-achieving the HR goal, two groups of patients were formed. Statistical analysis was performed with a STATISTICA 10,0 software package.Results After 4 weeks of therapy with metoprolol tartrate 25 mg twice a day, 18 (33.3%) patients of group 1 achieved the HR goal of 70 bpm, while  36 (66.7%) patients of group 2 did not achieve the goal. For further correction of HR, patients of group 2 were switched from metoprolol tartrate to ivabradine/metoprolol 5 / 25 mg twice a day. After 4 weeks of the ivabradine/metoprolol treatment, 31 (86.1 %) patients achieved the HR goal with median resting HR of 62 [56; 70] bpm. The number of angina attacks decreased from 6 [3; 8] to 2 [1; 3] per week (р&lt;0.001). 24hECGM showed that the mean diurnal HR decreased from 81 [76; 96] to 66 [56; 76] bpm (р&lt;0.001); mean night HR decreased from 69 [73; 80] to 52 [43; 60] bpm (р=0.012); and the ischemic ST segment depression was absent.Conclusion Only 33.3% of patients with stable angina achieved the HR goal on metoprolol tartrate 25 mg twice a day. Supplementing the beta-blocker metoprolol tartrate at the same dose with ivabradine allowed 86.1% of patients to achieve the HR goal and exerted a pronounced anti-anginal effect.

Ivabradine for the Therapy of Chronic Stable Angina Pectoris: a Systematic Review and Meta-Analysis

Background and Objectives

Coronary artery disease (CAD) is the number one cause of death worldwide. The I_f channel inhibitor ivabradine serves as second line medication for the CAD leading symptom angina pectoris. This systematic review and meta-analysis assess the existing evidence of ivabradine in angina pectoris.

Methods

We systematically searched MEDLINE, Embase, CENTRAL, and Web of Science (September 2019) for randomized controlled trials (RCTs) that compared ivabradine versus placebo, standard therapy (ST) or other anti-anginal drugs. Two review authors independently assessed trials for inclusion and performed data extraction. We completed a ‘risk of bias’ assessment for all studies and assessed quality of the trial evidence using the Grading of Recommendations Assessment, Development and Evaluation methodology. We meta-analysed data were applicable and calculated mean differences (MDs) and risk ratios using a random-effects model.

Results

A total of 11 RCTs (n=16,039) were included. Compared to placebo/ST, we found significant effects on the frequency of hospitalisation in a small cohort (n=90; hazard ratio [HR], 0.19; 95% confidence interval [CI], 0.04, −0.92; p=0.04), but no effects on cardiovascular mortality (n=19,102; HR, 1.10; 95% CI, 0.94, 1.28; p=0.25) or the frequency of angina pectoris episodes (n=167; weighted MD, −1.06; 95% CI, −2.74, −0.61; p=0.21).

Conclusions

The present work makes an important contribution to optimal patient care in angina pectoris by complementing the current European Society of Cardiology guideline—recommending class IIa with evidence level B—decisively with 8 further studies.

Metabolic remodeling induced by mitokines in heart failure

The prevalence rates of heart failure (HF) are greater than 10% in individuals aged >75 years, indicating an intrinsic link between aging and HF. It has been recognized that mitochondrial dysfunction contributes to the pathology of HF. Mitokines are a type of cytokines, peptides, or signaling pathways produced or activated by the nucleus or the mitochondria through cell non-autonomous responses during cellular stress. In addition to promoting the communication between the mitochondria and the nucleus, mitokines also exert a systemic regulatory effect by circulating to distant tissues. It is noteworthy that increasing evidence has demonstrated that mitokines are capable of reducing the metabolic-related HF risk factors and are associated with HF severity. Consequently, mitokines might represent a potential therapy target for HF.

Pharmacology of Ivabradine and the Effect on Chronic Heart Failure

Chronic Heart Failure (CHF) is a complex clinical syndrome with a high incidence worldwide. Although various types of pharmacological and device therapies are available for CHF, the prognosis is not ideal, for which, the control of increased Heart Rate (HR) is critical. Recently, a bradycardic agent, ivabradine, is found to reduce HR by inhibiting the funny current (If). The underlying mechanism states that ivabradine can enter the Hyperpolarization-activated Cyclic Nucleotide-gated (HCN) channels and bind to the intracellular side, subsequently inhibiting the If. This phenomenon can prolong the slow spontaneous phase in the diastolic depolarization, and thus, reduce HR. The clinical trials demonstrated the significant effects of the drug on reducing HR and improving the symptoms of CHF with fewer adverse effects. This review primarily introduces the chemical features and pharmacological characteristics of ivabradine and the mechanism of treating CHF. Also, some expected therapeutic effects on different diseases were also concluded. However, ivabradine, as a typical If channel inhibitor, necessitates additional research to verify its pharmacological functions.