1
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Iness AN, Shah KM, Kukreja RC. Physiological effects of ivabradine in heart failure and beyond. Mol Cell Biochem 2023:10.1007/s11010-023-04862-5. [PMID: 37768496 DOI: 10.1007/s11010-023-04862-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023]
Abstract
Ivabradine is a pharmacologic agent that inhibits the funny current responsible for determining heart rate in the sinoatrial node. Ivabradine's clinical potential has been investigated in the context of heart failure since it is associated with reduced myocardial oxygen demand, enhanced diastolic filling, stroke volume, and coronary perfusion time; however, it is yet to demonstrate definitive mortality benefit. Alternative effects of ivabradine include modulation of the renin-angiotensin-aldosterone system, sympathetic activation, and endothelial function. Here, we review key clinical trials informing the clinical use of ivabradine and explore opportunities for leveraging its potential pleiotropic effects in other diseases, including treatment of hyperadrenergic states and mitigating complications of COVID-19 infection.
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Affiliation(s)
- Audra N Iness
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Keyur M Shah
- Division of Cardiology, Pauley Heart Center, Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Rakesh C Kukreja
- Division of Cardiology, Pauley Heart Center, Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA.
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2
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Rizk M, Mowaka S, Mohamed M, Abou El-Alamin MM. Comparative HPTLC study for simultaneous determination of ivabradine and metoprolol using UV and fluorescence detectors. BMC Chem 2023; 17:113. [PMID: 37710300 PMCID: PMC10500752 DOI: 10.1186/s13065-023-01025-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 08/29/2023] [Indexed: 09/16/2023] Open
Abstract
New, simple, accurate, sensitive and validated high performance thin layer chromatographic (HPTLC) method coupled with UV absorbance mode and fluorescence (FL) detectors which were used for simultaneous determination of ivabradine (IVA) and metoprolol (MET) in their bulk and pharmaceutical dosage form using TLC silica 60 F254 plates and non-fluorescent TLC silica gel 60 plates. The developing system was chloroform: methanol: formic acid: ammonia (8.5:1.5:0.2:0.1, v/v). Desnitometric analysis in UV absorbance mode was set at λ = 275 nm. While, fluorescence mode was performed with excitation at 260 nm for quantitative simultaneous determination of IVA and MET using optical filter K320. The retention factors values were 0.45 ± 0.05 and 0.89 ± 0.01 of IVA and MET, respectively. UV absorbance mode, linearity was 50.0-600.0 ng/band for IVA and 50.0-900.0 ng/band for MET. For fluorescence mode, the linearity ranges were 18.0-400.0 ng/band and 50.0-550.0 ng/band for IVA and MET; respectively. ICH guidelines were followed in respect to linearity and range, accuracy, precision and selectivity, limit of detection (LOD), limit of quantitation (LOQ) and robustness. The analytical eco-scale, green analytical procedure index (GAPI) and analytical greenness metric tools were used to assess the suggested method. The quantitative proposed method results showed there was no statistically significant difference at 95% confidence when compared to the reported method of high performance liquid chromatography (HPLC).
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Affiliation(s)
- M Rizk
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Helwan University, 11795, Cairo, Egypt
| | - Shereen Mowaka
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Helwan University, 11795, Cairo, Egypt
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, The British University in Egypt, El-Sherouk City, 11837, Egypt
| | - Mariam Mohamed
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, The British University in Egypt, El-Sherouk City, 11837, Egypt.
| | - Maha M Abou El-Alamin
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Helwan University, 11795, Cairo, Egypt
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3
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Peters CH, Rickert C, Morotti S, Grandi E, Aronow KA, Beam KG, Proenza C. The funny current If is essential for the fight-or-flight response in cardiac pacemaker cells. J Gen Physiol 2022; 154:213619. [PMID: 36305844 PMCID: PMC9812006 DOI: 10.1085/jgp.202213193] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/22/2022] [Accepted: 10/04/2022] [Indexed: 01/07/2023] Open
Abstract
The sympathetic nervous system fight-or-flight response is characterized by a rapid increase in heart rate, which is mediated by an increase in the spontaneous action potential (AP) firing rate of pacemaker cells in the sinoatrial node. Sympathetic neurons stimulate sinoatrial myocytes (SAMs) by activating β adrenergic receptors (βARs) and increasing cAMP. The funny current (If) is among the cAMP-sensitive currents in SAMs. If is critical for pacemaker activity, however, its role in the fight-or-flight response remains controversial. In this study, we used AP waveform analysis, machine learning, and dynamic clamp experiments in acutely isolated SAMs from mice to quantitatively define the AP waveform changes and role of If in the fight-or-flight increase in AP firing rate. We found that while βAR stimulation significantly altered nearly all AP waveform parameters, the increase in firing rate was only correlated with changes in a subset of parameters (diastolic duration, late AP duration, and diastolic depolarization rate). Dynamic clamp injection of the βAR-sensitive component of If showed that it accounts for ∼41% of the fight-or-flight increase in AP firing rate and 60% of the decrease in the interval between APs. Thus, If is an essential contributor to the fight-or-flight increase in heart rate.
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Affiliation(s)
- Colin H. Peters
- Department of Physiology & Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Christian Rickert
- Department of Physiology & Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Stefano Morotti
- Department of Pharmacology, University of California, Davis, School of Medicine, Davis, CA
| | - Eleonora Grandi
- Department of Pharmacology, University of California, Davis, School of Medicine, Davis, CA
| | | | - Kurt G. Beam
- Department of Physiology & Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Catherine Proenza
- Department of Physiology & Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO,Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO,Correspondence to Catherine Proenza:
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Tan R, Cong T, Xu G, Hao Z, Liao J, Xie Y, Lin Y, Yang X, Li Q, Liu Y, Xia YL. Anthracycline-Induced Atrial Structural and Electrical Remodeling Characterizes Early Cardiotoxicity and Contributes to Atrial Conductive Instability and Dysfunction. Antioxid Redox Signal 2022; 37:19-39. [PMID: 35081742 DOI: 10.1089/ars.2021.0002] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Aims: Cancer patients treated with anthracyclines are susceptible to atrial fibrillation (AF), while the mechanisms remain unclear. Due to sudden and unpredictable features, prediction of anthracycline-induced AF at early phase is difficult. Clinically, we tested whether anthracycline-induced early atrial remodeling in patients could be detected by echocardiography. Experimentally, we investigated the mechanisms of doxorubicin-induced atrial remodeling and AF in mice, and the protective effects of dexrazoxane and antioxidants. Methods and Results: Postsurgery breast cancer patients with an anthracycline-containing or anthracycline exclusion regimen were recruited for echocardiography before chemotherapy, and 3 and 6 months after chemotherapy. Mice were injected with doxorubicin or vehicle (5 mg/kg/week, 4 weeks), and left atrial diameter, electrical transmission, and AF inducibility were measured. Meanwhile, the level of reactive oxygen species (ROS), activity of antioxidant enzymes, cardiomyocyte size, vacuolization, inflammation, and fibrosis were also measured in mouse atria. The therapeutic effects of dexrazoxane and antioxidants on doxorubicin-induced changes in the aforementioned parameters were also determined. While ventricular parameters and functions were unchanged in cancer patients receiving anthracyclines before and after chemotherapy, left atrial reservoir and conduit function were decreased at 3 months postchemotherapy versus prechemotherapy. Doxorubicin-induced susceptibility to AF occurred in mice before onset of ventricular dysfunction. Doxorubicin-induced AF was via inducing structural remodeling (cardiomyocyte death, hypotrophy, and vacuolization) and electrical remodeling (reduction and redistribution of connexin 43) in atria, which was effectively prevented by dexrazoxane or antioxidants through inhibiting ROS generation or enhancing ROS elimination. Innovation and Conclusion: AF inducibility was induced after doxorubicin injection, which can be inhibited by repressing the ROS level. Antioxid. Redox Signal. 37, 19-39. The Clinical Trial Registration number is PJ-KS-KY-2019-73.
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Affiliation(s)
- Ruopeng Tan
- Institute of Cardiovascular Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Tao Cong
- Department of Cardiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Guiwen Xu
- Institute of Cardiovascular Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Zhujing Hao
- Institute of Cardiovascular Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Jiawei Liao
- Institute of Cardiovascular Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Yunpeng Xie
- Institute of Cardiovascular Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Yajuan Lin
- Institute of Cardiovascular Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Xiaolei Yang
- Institute of Cardiovascular Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Qingsong Li
- Department of Cardiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Yang Liu
- Institute of Cardiovascular Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Yun-Long Xia
- Institute of Cardiovascular Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, China.,Department of Cardiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
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Abstract
Major advances in biomedical imaging have occurred over the last 2 decades and now allow many physiological, cellular, and molecular processes to be imaged noninvasively in small animal models of cardiovascular disease. Many of these techniques can be also used in humans, providing pathophysiological context and helping to define the clinical relevance of the model. Ultrasound remains the most widely used approach, and dedicated high-frequency systems can obtain extremely detailed images in mice. Likewise, dedicated small animal tomographic systems have been developed for magnetic resonance, positron emission tomography, fluorescence imaging, and computed tomography in mice. In this article, we review the use of ultrasound and positron emission tomography in small animal models, as well as emerging contrast mechanisms in magnetic resonance such as diffusion tensor imaging, hyperpolarized magnetic resonance, chemical exchange saturation transfer imaging, magnetic resonance elastography and strain, arterial spin labeling, and molecular imaging.
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Affiliation(s)
- David E Sosnovik
- Cardiology Division, Cardiovascular Research Center (D.E.S.), Massachusetts General Hospital and Harvard Medical School, Boston.,A.A. Martinos Center for Biomedical Imaging (D.E.S.), Massachusetts General Hospital and Harvard Medical School, Boston.,Harvard-MIT Program in Health Sciences and Technology, Harvard Medical School and Massachusetts Institute of Technology, Cambridge (D.E.S.)
| | - Marielle Scherrer-Crosbie
- Cardiology Division, Hospital of the University of Pennsylvania and Perelman School of Medicine, Philadelphia (M.S.-C)
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The Inhibition of the Small-Conductance Ca2+-Activated Potassium Channels Decreases the Sinus Node Pacemaking during Beta-Adrenergic Activation. Pharmaceuticals (Basel) 2022; 15:ph15030313. [PMID: 35337111 PMCID: PMC8948633 DOI: 10.3390/ph15030313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 02/24/2022] [Accepted: 03/01/2022] [Indexed: 11/17/2022] Open
Abstract
Sinus pacemaking is based on tight cooperation of intracellular Ca2+ handling and surface membrane ion channels. An important player of this synergistic crosstalk could be the small-conductance Ca2+-activated K+-channel (ISK) that could contribute to the sinoatrial node (SAN) pacemaking driven by the intracellular Ca2+ changes under normal conditions and beta-adrenergic activation, however, the exact role is not fully clarified. SK2 channel expression was verified by immunoblot technique in rabbit SAN cells. Ionic currents and action potentials were measured by patch-clamp technique. The ECG R-R intervals were obtained by Langendorff-perfusion method on a rabbit heart. Apamin, a selective inhibitor of SK channels, was used during the experiments. Patch-clamp experiments revealed an apamin-sensitive current. When 100 nM apamin was applied, we found no change in the action potential nor in the ECG R-R interval. In experiments where isoproterenol was employed, apamin increased the cycle length of the SAN action potentials and enhanced the ECG R-R interval. Apamin did not amplify the cycle length variability or ECG R-R interval variability. Our data indicate that ISK has no role under normal condition, however, it moderately contributes to the SAN automaticity under beta-adrenergic activation.
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Ivabradine Ameliorates Cardiac Function in Heart Failure with Preserved and Reduced Ejection Fraction via Upregulation of miR-133a. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:1257283. [PMID: 34630844 PMCID: PMC8494584 DOI: 10.1155/2021/1257283] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 09/04/2021] [Indexed: 11/21/2022]
Abstract
Heart failure (HF) is a clinical syndrome caused by impairment of ventricular filling, ejection of blood, or both and is categorized as HF with reduced ejection fraction (HFrEF) or HF with preserved ejection fraction (HFpEF) based on left ventricular function. Cardiac fibrosis contributes to left ventricular dysfunction and leads to the development of HF. Ivabradine, an If current selective specific inhibitor, has been shown to improve the prognosis of patients with HF. However, the effects of ivabradine on cardiac function and fibrosis in HFpEF and HFrEF and the underlying mechanism remain unclear. In the present study, we utilized mouse models to mimic HFpEF and HFrEF and evaluated the therapeutic effects of ivabradine. By treating mice with different doses (10 mg/kg/d and 20 mg/kg/d) of ivabradine for 4 or 8 weeks, we found that a high dose of ivabradine improved cardiac diastolic function in HFpEF mice and ameliorated cardiac diastolic and systolic function and ventricular tachycardia incidence in HFrEF mice. Moreover, ivabradine significantly reduced the activation of cardiac fibroblasts and myocardial fibrosis in mice. Mechanistically, microRNA-133a, which was upregulated by ivabradine, targeted connective tissue growth factor and collagen 1 in cardiac fibroblasts and might contribute to the protective role of ivabradine. Together, our work utilized mouse models to study HFpEF and HFrEF, demonstrated the protective role of ivabradine in HFpEF and HFrEF, and elucidated the potential underlying mechanism, which provides an effective strategy for related diseases.
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8
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Wallman M, Scheuerer S, Martel E, Pairet N, Jirstrand M, Gabrielsson J. An Integrative Approach for Improved Assessment of Cardiovascular Safety Data. J Pharmacol Exp Ther 2021; 377:218-231. [PMID: 33648939 DOI: 10.1124/jpet.120.000348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 02/22/2021] [Indexed: 11/22/2022] Open
Abstract
Cardiovascular adverse effects in drug development are a major source of compound attrition. Characterization of blood pressure (BP), heart rate (HR), stroke volume (SV), and QT-interval prolongation are therefore necessary in early discovery. It is, however, common practice to analyze these effects independently of each other. High-resolution time courses are collected via telemetric techniques, but only low-resolution data are analyzed and reported. This ignores codependencies among responses (HR, BP, SV, and QT-interval) and separation of system (turnover properties) and drug-specific properties (potencies, efficacies). An analysis of drug exposure-time and high-resolution response-time data of HR and mean arterial blood pressure was performed after acute oral dosing of ivabradine, sildenafil, dofetilide, and pimobendan in Han-Wistar rats. All data were modeled jointly, including different compounds and exposure and response time courses, using a nonlinear mixed-effects approach. Estimated fractional turnover rates [h-1, relative standard error (%RSE) within parentheses] were 9.45 (15), 30.7 (7.8), 3.8 (13), and 0.115 (1.7) for QT, HR, total peripheral resistance, and SV, respectively. Potencies (nM, %RSE within parentheses) were IC 50 = 475 (11), IC 50 = 4.01 (5.4), EC 50 = 50.6 (93), and IC 50 = 47.8 (16), and efficacies (%RSE within parentheses) were I max = 0.944 (1.7), Imax = 1.00 (1.3), E max = 0.195 (9.9), and Imax = 0.745 (4.6) for ivabradine, sildenafil, dofetilide, and pimobendan. Hill parameters were estimated with good precision and below unity, indicating a shallow concentration-response relationship. An equilibrium concentration-biomarker response relationship was predicted and displayed graphically. This analysis demonstrates the utility of a model-based approach integrating data from different studies and compounds for refined preclinical safety margin assessment. SIGNIFICANCE STATEMENT: A model-based approach was proposed utilizing biomarker data on heart rate, blood pressure, and QT-interval. A pharmacodynamic model was developed to improve assessment of high-resolution telemetric cardiovascular safety data driven by different drugs (ivabradine, sildenafil, dofetilide, and pimobondan), wherein system- (turnover rates) and drug-specific parameters (e.g., potencies and efficacies) were sought. The model-predicted equilibrium concentration-biomarker response relationships and was used for safety assessment (predictions of 20% effective concentration, for example) of heart rate, blood pressure, and QT-interval.
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Affiliation(s)
- Mikael Wallman
- Systems and Data Analysis, Fraunhofer-Chalmers Centre, Gothenburg, Sweden (M.W., M.J.); Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany (S.S., E.M., N.P.); and Firma Biopharmacon, Gothenburg, Sweden (J.G.)
| | - Stefan Scheuerer
- Systems and Data Analysis, Fraunhofer-Chalmers Centre, Gothenburg, Sweden (M.W., M.J.); Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany (S.S., E.M., N.P.); and Firma Biopharmacon, Gothenburg, Sweden (J.G.)
| | - Eric Martel
- Systems and Data Analysis, Fraunhofer-Chalmers Centre, Gothenburg, Sweden (M.W., M.J.); Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany (S.S., E.M., N.P.); and Firma Biopharmacon, Gothenburg, Sweden (J.G.)
| | - Nicolas Pairet
- Systems and Data Analysis, Fraunhofer-Chalmers Centre, Gothenburg, Sweden (M.W., M.J.); Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany (S.S., E.M., N.P.); and Firma Biopharmacon, Gothenburg, Sweden (J.G.)
| | - Mats Jirstrand
- Systems and Data Analysis, Fraunhofer-Chalmers Centre, Gothenburg, Sweden (M.W., M.J.); Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany (S.S., E.M., N.P.); and Firma Biopharmacon, Gothenburg, Sweden (J.G.)
| | - Johan Gabrielsson
- Systems and Data Analysis, Fraunhofer-Chalmers Centre, Gothenburg, Sweden (M.W., M.J.); Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany (S.S., E.M., N.P.); and Firma Biopharmacon, Gothenburg, Sweden (J.G.)
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9
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Xing R, Moerman AM, Ridwan RY, Gaalen KV, Meester EJ, van der Steen AFW, Evans PC, Gijsen FJH, Van der Heiden K. The effect of the heart rate lowering drug Ivabradine on hemodynamics in atherosclerotic mice. Sci Rep 2018; 8:14014. [PMID: 30228313 PMCID: PMC6143553 DOI: 10.1038/s41598-018-32458-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 09/05/2018] [Indexed: 12/27/2022] Open
Abstract
The heart rate lowering drug Ivabradine was shown to improve cardiac outcome in patients with previous heart failure. However, in patients without heart failure, no beneficial effect of Ivabradine was observed. Animal studies suggested a preventive effect of Ivabradine on atherosclerosis which was due to an increase in wall shear stress (WSS), the blood flow-induced frictional force exerted on the endothelium, triggering anti-inflammatory responses. However, data on the effect of Ivabradine on WSS is sparse. We aim to study the effect of Ivabradine on (i) the 3D WSS distribution over a growing plaque and (ii) plaque composition. We induced atherosclerosis in ApoE-/- mice by placing a tapered cast around the right common carotid artery (RCCA). Five weeks after cast placement, Ivabradine was administered via drinking water (15 mg/kg/day) for 2 weeks, after which the RCCA was excised for histology analyses. Before and after Ivabradine treatment, animals were imaged with Doppler Ultrasound to measure blood velocity. Vessel geometry was obtained using contrast-enhanced micro-CT. Time-averaged WSS during systole, diastole and peak WSS was subsequently computed. Ivabradine significantly decreased heart rate (459 ± 28 bpm vs. 567 ± 32 bpm, p < 0.001). Normalized peak flow significantly increased in the Ivabradine group (124.2% ± 40.5% vs. 87.3% ± 25.4%, p < 0.05), reflected by an increased normalized WSS level during systole (110.7% ± 18.4% vs. 75.4% ± 24.6%, p < 0.05). However, plaque size or composition including plaque area, relative necrotic core area and macrophage content were not altered in mice treated with Ivabradine compared to controls. We conclude that increased WSS in response to Ivabradine treatment did not affect plaque progression in a murine model.
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Affiliation(s)
- R Xing
- Department of Biomedical Engineering, Thorax center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - A M Moerman
- Department of Biomedical Engineering, Thorax center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - R Y Ridwan
- Department of Molecular Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - K van Gaalen
- Department of Biomedical Engineering, Thorax center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - E J Meester
- Department of Biomedical Engineering, Thorax center, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - A F W van der Steen
- Department of Biomedical Engineering, Thorax center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - P C Evans
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - F J H Gijsen
- Department of Biomedical Engineering, Thorax center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - K Van der Heiden
- Department of Biomedical Engineering, Thorax center, Erasmus University Medical Center, Rotterdam, The Netherlands.
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10
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Badu-Boateng C, Jennings R, Hammersley D. The therapeutic role of ivabradine in heart failure. Ther Adv Chronic Dis 2018; 9:199-207. [PMID: 30364460 DOI: 10.1177/2040622318784556] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 05/30/2018] [Indexed: 12/18/2022] Open
Abstract
Heart failure represents a major global cause of morbidity and mortality. Ivabradine is a selective funny current (If) inhibitor, which acts on the sinoatrial node, resulting in a reduction in heart rate. Ivabradine is currently licensed for use in patients with symptomatic heart failure with reduced ejection fraction and a heart rate persistently at least 70 beats per minute in spite of otherwise optimal prognostic heart failure pharmacotherapy. In this review article, we examine the mechanism of action of ivabradine, evaluate the clinical trials underpinning its application in heart failure and discuss its current recommended clinical use in this capacity.
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Affiliation(s)
| | - Robert Jennings
- Department of Medicine, Frimley Park Hospital, Frimley, Camberley, UK
| | - Daniel Hammersley
- Department of Cardiology, Kings College Hospital NHS Foundation Trust, Denmark Hill, London SE5 9RS, UK
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11
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Giamouridis D, Gao MH, Lai NC, Tan Z, Kim YC, Guo T, Miyanohara A, Blankesteijn WM, Biessen E, Hammond HK. Effects of Urocortin 2 Versus Urocortin 3 Gene Transfer on Left Ventricular Function and Glucose Disposal. JACC Basic Transl Sci 2018; 3:249-264. [PMID: 30062211 PMCID: PMC6059348 DOI: 10.1016/j.jacbts.2017.12.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 12/13/2017] [Accepted: 12/21/2017] [Indexed: 12/20/2022]
Abstract
UCn2 and UCn3 peptides have recently been infused to treat patients with heart failure (HF) but are limited by their short half-lives. A 1-time intravenous injection of virus vectors encoding UCn2 or UCn3 provided sustained increases in plasma concentrations of the peptides. This was associated with increases in both systolic and diastolic left ventricular (LV) function, mediated by increased LV SERCA2a expression and Ca2+ handling. UCn2, but not UCn3, gene transfer reduced fasting glucose and increased glucose disposal. These findings support UCn2 and UCn3 gene transfer as potential treatments for HF and indicate that UCn2 may be an optimal selection in patients with diabetes and HF.
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Key Words
- AAV, adeno-associated virus
- CO, cardiac output
- CRF, corticotropin-releasing factor
- CRHR, corticotropin-releasing hormone receptor
- CaMKII, Ca2+/calmodulin-dependent protein kinase II
- EDD, end-diastolic diameter
- EF, ejection fraction
- ESD, end-systolic diameter
- ESPVR, end-systolic pressure-volume relationship
- HF, heart failure
- IP, intraperitoneal
- IV, intravenous
- LV, left ventricle/ventricular
- PKA, protein kinase A
- RYR2, ryanodine receptor 2
- SERCA2a, sarco/endoplasmic reticulum Ca2+-ATPase
- Tau, time constant of left ventricular pressure decline
- UCn2, urocortin 2
- UCn3, urocortin 3
- VCFc, velocity of circumferential fiber shortening corrected for heart rate
- adeno-associated virus
- cAMP, 3′,5′-cyclic adenosine monophosphate
- contractile function
- diastolic function
- gc, genome copies
- gene therapy
- insulin sensitivity
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Affiliation(s)
- Dimosthenis Giamouridis
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
- Department of Pharmacology and Toxicology, Cardiovascular Research Institute Maastricht University, Maastricht, the Netherlands
| | - Mei Hua Gao
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
| | - N. Chin Lai
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
| | - Zhen Tan
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
| | - Young Chul Kim
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
| | - Tracy Guo
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
| | - Atsushi Miyanohara
- Department of Medicine, University of California San Diego, San Diego, California
| | - W. Matthijs Blankesteijn
- Department of Pharmacology and Toxicology, Cardiovascular Research Institute Maastricht University, Maastricht, the Netherlands
| | - Erik Biessen
- Department of Pharmacology and Toxicology, Cardiovascular Research Institute Maastricht University, Maastricht, the Netherlands
| | - H. Kirk Hammond
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
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Bonadei I, Sciatti E, Vizzardi E, Fabbricatore D, Pagnoni M, Rossi L, Carubelli V, Lombardi CM, Metra M. Effects of ivabradine on endothelial function, aortic properties and ventricular-arterial coupling in chronic systolic heart failure patients. Cardiovasc Ther 2018; 36:e12323. [PMID: 29460403 DOI: 10.1111/1755-5922.12323] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 12/30/2017] [Accepted: 02/15/2018] [Indexed: 12/28/2022] Open
Abstract
AIM Heart rate (HR) is an important prognostic factor in patients affected by chronic heart failure (CHF); ivabradine has been demonstrated to significantly reduce nonfatal myocardial infarction and hospitalization rate for acute heart failure and to improve left ventricular (LV) reverse remodeling, quality of life, exercise capacity, and arterial elastance (Ea) in these patients. We aimed at evaluating the short-term effects of ivabradine on ventricular-arterial coupling (VAC), aortic stiffness, and endothelial function in stable patients with CHF. METHODS We evaluated 30 consecutive CHF patients (LVEF≤ 35%, NYHA class II) with sinus rhythm and HR ≥ 70 bpm on optimized pharmacological therapy. All of them underwent both transthoracic echocardiogram to assess aortic elastic properties (aortic distensibility, AD; aortic stiffness index, ASI; systolic aortic strain, SAS) and VAC, and peripheral arterial tonometry to measure endothelial function. Therapy with ivabradine 5 mg bid was added and each patient was evaluated with the same examinations after 4 months. RESULTS At the baseline, 73% of patients had impaired VAC and 63% endothelial dysfunction. After 4 months, there was a significant improvement in the VAC value (ΔVAC -0.10 ± 0.18, P = .021), mainly linked to Ea (ΔEa -0.40 ± 0.23 mm Hg/mL; P = .003). All the parameters of aortic elasticity underwent significant improvement (ΔAD 1.82 ± 1.43 cm² × dyn- ¹, P = .004; ΔASI -4.73 ± 6.07, P = .033; ΔSAS -7.98 ± 4.37%, P = .003). Lastly, we also noted a significant improvement of endothelial function (Δ RHI 0.35 ± 0.35; P < .001). At follow-up 40% of patients had impaired VAC (P = .018) and 33% endothelial dysfunction (P = .038). CONCLUSION In patients with CHF adding ivabradine on top to the standard optimized medical therapy, when indicated, seems to improve endothelial function, aortic properties, and VAC.
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Affiliation(s)
- Ivano Bonadei
- Cardiology Unit, University and ASST Spedali Civili, Brescia, Italy
| | - Edoardo Sciatti
- Cardiology Unit, University and ASST Spedali Civili, Brescia, Italy
| | - Enrico Vizzardi
- Cardiology Unit, University and ASST Spedali Civili, Brescia, Italy
| | | | - Mattia Pagnoni
- Cardiology Unit, University and ASST Spedali Civili, Brescia, Italy
| | - Laura Rossi
- Cardiology Unit, University and ASST Spedali Civili, Brescia, Italy
| | | | - Carlo M Lombardi
- Cardiology Unit, University and ASST Spedali Civili, Brescia, Italy
| | - Marco Metra
- Cardiology Unit, University and ASST Spedali Civili, Brescia, Italy
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If Channel Inhibition With Ivabradine Does Not Improve Cardiac and Vascular Function in Experimental Septic Shock. Shock 2018; 46:297-303. [PMID: 26909707 DOI: 10.1097/shk.0000000000000593] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Previous studies have suggested that lowering heart rate (HR) by selective β1-blockers improves sepsis-induced cardiac and vascular dysfunction primarily by decreasing proinflammatory pathways. However, the impact of isolated heart rate reduction (HRR) on hemodynamics and inflammatory pathways remains unknown. The present study was designed to assess the effects of HRR by ivabradine, an If channel inhibitor, on cardiovascular function and inflammatory pathways in peritonitis-induced septic shock in rats. DESIGN Randomized animal study. SETTING University research laboratory. INTERVENTIONS Four hours after cecal ligation and puncture (CLP), Wistar rats were randomly allocated to the following groups: CLP (n = 8) and CLP + ivabradine (n = 8, administered per os 4 h after the surgery). Another eight Wistar male rats underwent sham operation. All rats received a continuous infusion of saline (10 mL kg h), analgesic (nalbuphine: 0.2 mg kg h), and antibiotics (imipenem and cilastatin sodium: 10 mg kg) 4 h after the surgery. Assessment at 18 h included hemodynamics, in vivo cardiac function by echocardiography, and ex vivo vasoreactivity by myography. Circulating cytokine levels (TNF-α, IL-6, and IL-10) were measured by ELISA, whereas cardiac and vascular protein expressions of NF-κB/IκBα/iNOS and Akt/eNOS were assessed by Western blotting. RESULTS Compared with sham animals, CLP induced tachycardia, hypotension, decreased cardiac output, hyperlactatemia, and vascular hyporesponsiveness to vasopressors. Compared with the CLP group, adjunction of ivabradine decreased the HR without any impact on blood pressure, lactatemia, or vascular responsiveness to vasopressors. Adjunction of ivabradine to CLP rats had no impact on TNF-α, IL-6, and IL-10 cytokines, or on the protein expression levels of phosphorylated forms of NF-κB, Akt, eNOS, and degradation of IκBα in cardiac and vascular tissues. CONCLUSION Isolated HRR by ivabradine in an experimental model of septic shock does not appear to be associated with any effect on the tested parameters of cardiac function or on vascular responsiveness to vasopressors. Moreover, in this setting, ivabradine does not alter the circulating levels of selected pro/anti-inflammatory cytokines or cardiac and vascular NF-κB/IκBα protein expression levels.
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Abstract
Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias.
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Affiliation(s)
- Christopher L-H Huang
- Physiological Laboratory and the Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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15
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Godino C, Colombo A, Margonato A. Ivabradine in Patients with Stable Coronary Artery Disease: A Rationale for Use in Addition to and Beyond Percutaneous Coronary Intervention. Clin Drug Investig 2016; 37:105-120. [PMID: 27766510 DOI: 10.1007/s40261-016-0472-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Heart rate is an established prognostic marker for longevity and is an important contributor in the pathophysiology of various cardiovascular diseases, including ischemic heart disease and heart failure. Most ischemic episodes are triggered by an increase in heart rate, which causes an imbalance between myocardial oxygen delivery and consumption. In addition, increased heart rate is a modifiable risk factor for chronic heart failure. Ivabradine, an inhibitor of If ion channels, is an approved second-line anti-ischemic drug for the treatment of angina. Ivabradine has been shown to decrease the risk of hospitalization in patients with chronic heart failure who were previously treated with β-blockers, renin-angiotensin system blockers or mineralocorticoid receptor antagonists. This review describes the rationale for the pathophysiological and clinical use of ivabradine as an anti-ischemic agent in patients with stable coronary disease and highlights its benefits and drawbacks compared with other first- and second-line anti-anginal drugs. The review also highlights the role of ivabradine as a treatment for patients with high-risk coronary artery disease in whom first-line anti-anginal drugs are insufficient or inadequate and percutaneous coronary intervention is contraindicated or revascularization is incomplete or unsuitable.
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Affiliation(s)
- Cosmo Godino
- Cardio-Thoracic-Vascular Department, San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy.
| | - Antonio Colombo
- Cardio-Thoracic-Vascular Department, San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy.,EMO-GVM Centro Cuore Columbus, Milan, Italy
| | - Alberto Margonato
- Cardio-Thoracic-Vascular Department, San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy
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16
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Silva FC, Paiva FA, Müller-Ribeiro FC, Caldeira HMA, Fontes MAP, de Menezes RCA, Casali KR, Fortes GH, Tobaldini E, Solbiati M, Montano N, Dias Da Silva VJ, Chianca DA. Chronic Treatment with Ivabradine Does Not Affect Cardiovascular Autonomic Control in Rats. Front Physiol 2016; 7:305. [PMID: 27507948 PMCID: PMC4960883 DOI: 10.3389/fphys.2016.00305] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/06/2016] [Indexed: 12/05/2022] Open
Abstract
A low resting heart rate (HR) would be of great benefit in cardiovascular diseases. Ivabradine—a novel selective inhibitor of hyperpolarization-activated cyclic nucleotide gated (HCN) channels- has emerged as a promising HR lowering drug. Its effects on the autonomic HR control are little known. This study assessed the effects of chronic treatment with ivabradine on the modulatory, reflex and tonic cardiovascular autonomic control and on the renal sympathetic nerve activity (RSNA). Male Wistar rats were divided in 2 groups, receiving intraperitoneal injections of vehicle (VEH) or ivabradine (IVA) during 7 or 8 consecutive days. Rats were submitted to vessels cannulation to perform arterial blood pressure (AP) and HR recordings in freely moving rats. Time series of resting pulse interval and systolic AP were used to measure cardiovascular variability parameters. We also assessed the baroreflex, chemoreflex and the Bezold-Jarish reflex sensitivities. To better evaluate the effects of ivabradine on the autonomic control of the heart, we performed sympathetic and vagal autonomic blockade. As expected, ivabradine-treated rats showed a lower resting (VEH: 362 ± 16 bpm vs. IVA: 260 ± 14 bpm, p = 0.0005) and intrinsic HR (VEH: 369 ± 9 bpm vs. IVA: 326 ± 11 bpm, p = 0.0146). However, the chronic treatment with ivabradine did not change normalized HR spectral parameters LF (nu) (VEH: 24.2 ± 4.6 vs. IVA: 29.8 ± 6.4; p > 0.05); HF (nu) (VEH: 75.1 ± 3.7 vs. IVA: 69.2 ± 5.8; p > 0.05), any cardiovascular reflexes, neither the tonic autonomic control of the HR (tonic sympathovagal index; VEH: 0.91± 0.02 vs. IVA: 0.88 ± 0.03, p = 0.3494). We performed the AP, HR and RSNA recordings in urethane-anesthetized rats. The chronic treatment with ivabradine reduced the resting HR (VEH: 364 ± 12 bpm vs. IVA: 207 ± 11 bpm, p < 0.0001), without affecting RSNA (VEH: 117 ± 16 vs. IVA: 120 ± 9 spikes/s, p = 0.9100) and mean arterial pressure (VEH: 70 ± 4 vs. IVA: 77 ± 6 mmHg, p = 0.3293). Our results suggest that, in health rats, the long-term treatment with ivabradine directly reduces the HR without changing the RSNA modulation and the reflex and tonic autonomic control of the heart.
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Affiliation(s)
- Fernanda C Silva
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
| | - Franciny A Paiva
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
| | - Flávia C Müller-Ribeiro
- Laboratory of Hypertension, Institute of Biological Sciences, Department of Physiology and Biophysics, Federal University of Minas Gerais Belo Horizonte, Brazil
| | - Henrique M A Caldeira
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto Ouro Preto, Brazil
| | - Marco A P Fontes
- Laboratory of Hypertension, Institute of Biological Sciences, Department of Physiology and Biophysics, Federal University of Minas Gerais Belo Horizonte, Brazil
| | - Rodrigo C A de Menezes
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
| | - Karina R Casali
- Laboratory of Biomedical Engineering, Institute of Science and Technology, Federal University of São Paulo São José dos Campos, Brazil
| | | | - Eleonora Tobaldini
- Department of Clinical Sciences and Community Health, IRCCS Ca' Granda Foundation, Ospedale Maggiore Policlinico, University of Milan Milan, Italy
| | - Monica Solbiati
- Department of Clinical Sciences and Community Health, IRCCS Ca' Granda Foundation, Ospedale Maggiore Policlinico, University of Milan Milan, Italy
| | - Nicola Montano
- Department of Clinical Sciences and Community Health, IRCCS Ca' Granda Foundation, Ospedale Maggiore Policlinico, University of Milan Milan, Italy
| | - Valdo J Dias Da Silva
- Department of Physiology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro Uberaba, Brazil
| | - Deoclécio A Chianca
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
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O'Connor DM, Smith RS, Piras BA, Beyers RJ, Lin D, Hossack JA, French BA. Heart Rate Reduction With Ivabradine Protects Against Left Ventricular Remodeling by Attenuating Infarct Expansion and Preserving Remote-Zone Contractile Function and Synchrony in a Mouse Model of Reperfused Myocardial Infarction. J Am Heart Assoc 2016; 5:e002989. [PMID: 27107133 PMCID: PMC4843531 DOI: 10.1161/jaha.115.002989] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/28/2016] [Indexed: 01/24/2023]
Abstract
BACKGROUND Ivabradine selectively inhibits the pacemaker current of the sinoatrial node, slowing heart rate. Few studies have examined the effects of ivabradine on the mechanical properties of the heart after reperfused myocardial infarction (MI). Advances in ultrasound speckle-tracking allow strain analyses to be performed in small-animal models, enabling the assessment of regional mechanical function. METHODS AND RESULTS After 1 hour of coronary occlusion followed by reperfusion, mice received 10 mg/kg per day of ivabradine dissolved in drinking water (n=10), or were treated as infarcted controls (n=9). Three-dimensional high-frequency echocardiography was performed at baseline and at days 2, 7, 14, and 28 post-MI. Speckle-tracking software was used to calculate intramural longitudinal myocardial strain (Ell) and strain rate. Standard deviation time to peak radial strain (SD Tpeak Err) and temporal uniformity of strain were calculated from short-axis cines acquired in the left ventricular remote zone. Ivabradine reduced heart rate by 8% to 16% over the course of 28 days compared to controls (P<0.001). On day 28 post-MI, the ivabradine group was found to have significantly smaller end-systolic volumes, greater ejection fraction, reduced wall thinning, and greater peak Ell and Ell rate in the remote zone, as well as globally. Temporal uniformity of strain and SD Tpeak Err were significantly smaller in the ivabradine-treated group by day 28 (P<0.05). CONCLUSIONS High-frequency ultrasound speckle-tracking demonstrated decreased left ventricular remodeling and dyssynchrony, as well as improved mechanical performance in remote myocardium after heart rate reduction with ivabradine.
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Affiliation(s)
- Daniel M O'Connor
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - Robert S Smith
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA Department of Surgery, University of Virginia, Charlottesville, VA
| | - Bryan A Piras
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - Ronald J Beyers
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - Dan Lin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - John A Hossack
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA
| | - Brent A French
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA Department of Radiology, University of Virginia, Charlottesville, VA Department of Medicine, University of Virginia, Charlottesville, VA
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Capel RA, Herring N, Kalla M, Yavari A, Mirams GR, Douglas G, Bub G, Channon K, Paterson DJ, Terrar DA, Burton RAB. Hydroxychloroquine reduces heart rate by modulating the hyperpolarization-activated current If: Novel electrophysiological insights and therapeutic potential. Heart Rhythm 2015; 12:2186-94. [PMID: 26025323 PMCID: PMC4689153 DOI: 10.1016/j.hrthm.2015.05.027] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Indexed: 01/01/2023]
Abstract
BACKGROUND Bradycardic agents are of interest for the treatment of ischemic heart disease and heart failure, as heart rate is an important determinant of myocardial oxygen consumption. OBJECTIVES The purpose of this study was to investigate the propensity of hydroxychloroquine (HCQ) to cause bradycardia. METHODS We assessed the effects of HCQ on (1) cardiac beating rate in vitro (mice); (2) the "funny" current (If) in isolated guinea pig sinoatrial node (SAN) myocytes (1, 3, 10 µM); (3) heart rate and blood pressure in vivo by acute bolus injection (rat, dose range 1-30 mg/kg), (4) blood pressure and ventricular function during feeding (mouse, 100 mg/kg/d for 2 wk, tail cuff plethysmography, anesthetized echocardiography). RESULTS In mouse atria, spontaneous beating rate was significantly (P < .05) reduced (by 9% ± 3% and 15% ± 2% at 3 and 10 µM HCQ, n = 7). In guinea pig isolated SAN cells, HCQ conferred a significant reduction in spontaneous action potential firing rate (17% ± 6%, 1 μM dose) and a dose-dependent reduction in If (13% ± 3% at 1 µM; 19% ± 2% at 3 µM). Effects were also observed on L-type calcium ion current (ICaL) (12% ± 4% reduction) and rapid delayed rectifier potassium current (IKr) (35% ± 4%) at 3 µM. Intravenous HCQ decreased heart rate in anesthetized rats (14.3% ± 1.1% at 15mg/kg; n = 6) without significantly reducing mean arterial blood pressure. In vivo feeding studies in mice showed no significant change in systolic blood pressure nor left ventricular function. CONCLUSIONS We have shown that HCQ acts as a bradycardic agent in SAN cells, in atrial preparations, and in vivo. HCQ slows the rate of spontaneous action potential firing in the SAN through multichannel inhibition, including that of If.
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Affiliation(s)
- Rebecca A Capel
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Neil Herring
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Manish Kalla
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Arash Yavari
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Gary R Mirams
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Gillian Douglas
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Gil Bub
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Keith Channon
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - David J Paterson
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Derek A Terrar
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Rebecca-Ann B Burton
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.
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Merino B, Quesada I, Hernández-Cascales J. Glucagon Increases Beating Rate but Not Contractility in Rat Right Atrium. Comparison with Isoproterenol. PLoS One 2015. [PMID: 26222156 PMCID: PMC4519109 DOI: 10.1371/journal.pone.0132884] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This study evaluated the chronotropic and inotropic responses to glucagon in spontaneously beating isolated right atria of rat heart. For comparison, we also investigated the effects resulting from stimulating β-adrenoceptors with isoproterenol in this tissue. Isoproterenol increased both atrial frequency and contractility but glucagon only enhanced atrial rate. The transcript levels of glucagon receptors were about three times higher in sinoatrial node than in the atrial myocardium. Chronotropic responses to glucagon and isoproterenol were blunted by the funny current (If) inhibitor ZD 7288. Inhibitors of protein kinase A, H-89 and KT-5720 reduced the chronotropic response to glucagon but not to isoproterenol. Inhibition of ryanodine receptors and calcium/calmodulin dependent protein kinase II (important regulators of sarcoplasmic reticulum Ca2+ release), with ruthenium red and KN-62 respectively, failed to alter chronotropic responses of either glucagon or isoproterenol. Non selective inhibition of phosphodiesterase (PDE) with 3-isobutylmethylxantine or selective inhibition of PDE3 or PDE4 with cilostamide or rolipram respectively did not affect chronotropic effects of glucagon or isoproterenol. Our results indicate that glucagon increases beating rate but not contractility in rat right atria which could be a consequence of lower levels of glucagon receptors in atrial myocardium than in sinoatrial node. Chronotropic responses to glucagon or isoproterenol are mediated by If current but not by sarcoplasmic reticulum Ca2+ release, neither are regulated by PDE activity.
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Affiliation(s)
- Beatriz Merino
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Elche, Spain
| | - Ivan Quesada
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Elche, Spain
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Nguyen MN, Kiriazis H, Ruggiero D, Gao XM, Su Y, Jian A, Han LP, McMullen JR, Du XJ. Spontaneous ventricular tachyarrhythmias in β2-adrenoceptor transgenic mice in relation to cardiac interstitial fibrosis. Am J Physiol Heart Circ Physiol 2015; 309:H946-57. [PMID: 26116714 DOI: 10.1152/ajpheart.00405.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 06/26/2015] [Indexed: 12/21/2022]
Abstract
Myocardial fibrosis is regarded as a pivotal proarrhythmic substrate, but there have been no comprehensive studies showing a correlation between the severity of fibrosis and ventricular tachyarrhythmias (VTAs). Our purpose was to document this relationship in a transgenic (TG) strain of mice with fibrotic cardiomyopathy. TG mice with cardiac overexpression of β2-adrenoceptors (β2-AR mice) and non-TG (NTG) littermates were studied at 4-12 mo of age. VTA was quantified by ECG telemetry. The effect of pharmacological blockade of β2-ARs on VTA was examined. Myocardial collagen content was determined by hydroxyproline assay. NTG and TG mice displayed circadian variation in heart rate, which was higher in TG mice than in NTG mice (P <0.05). Frequent spontaneous ventricular ectopic beats (VEBs) and ventricular tachycardia (VT) were prominent in TG mice but not present in NTG mice. The frequency of VEB and VT episodes in TG mice increased with age (P < 0.01). Ventricular collagen content was greater in TG mice than in NTG mice (P <0.001) and correlated with age (r = 0.71, P < 0.01). The number of VEBs or VT episodes correlated with age (r = 0.83 and r = 0.73) and the content of total or cross-linked collagen (r = 0.62∼0.66, all P <0.01). While having no effect in younger β2-TG mice, β2-AR blockade reduced the frequency of VTA in old β2-TG mice with more severe fibrosis. In conclusion, β2-TG mice exhibit interstitial fibrosis and spontaneous onset of VTA, becoming more severe with aging. The extent of cardiac fibrosis is a major determinant for both the frequency of VTA and proarrhythmic action of β2-AR activation.
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Affiliation(s)
- My-Nhan Nguyen
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Helen Kiriazis
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Diego Ruggiero
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; University of Milan, Milan, Italy
| | - Xiao-Ming Gao
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Yidan Su
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Anne Jian
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Li-Ping Han
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; WenZhou Medical University, WenZhou, China; and
| | - Julie R McMullen
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Central Clinical School, Monash University, Melbourne, Victoria, Australia; Department of Physiology, Monash University, Melbourne, Australia
| | - Xiao-Jun Du
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Central Clinical School, Monash University, Melbourne, Victoria, Australia;
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Heart rate reduction and longevity in mice. Basic Res Cardiol 2015; 110:2. [PMID: 25589054 DOI: 10.1007/s00395-014-0460-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 12/03/2014] [Accepted: 12/19/2014] [Indexed: 12/19/2022]
Abstract
Heart rate correlates inversely with life span across all species, including humans. In patients with cardiovascular disease, higher heart rate is associated with increased mortality, and such patients benefit from pharmacological heart rate reduction. However, cause-and-effect relationships between heart rate and longevity, notably in healthy individuals, are not established. We therefore prospectively studied the effects of a life-long pharmacological heart rate reduction on longevity in mice. We hypothesized, that the total number of cardiac cycles is constant, and that a 15% heart rate reduction might translate into a 15% increase in life span. C57BL6/J mice received either placebo or ivabradine at a dose of 50 mg/kg/day in drinking water from 12 weeks to death. Heart rate and body weight were monitored. Autopsy was performed on all non-autolytic cadavers, and parenchymal organs were evaluated macroscopically. Ivabradine reduced heart rate by 14% (median, interquartile range 12-15%) throughout life, and median life span was increased by 6.2% (p = 0.01). Body weight and macroscopic findings were not different between placebo and ivabradine. Life span was not increased to the same extent as heart rate was reduced, but nevertheless significantly prolonged by 6.2%.
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Verrier RL, Bonatti R, Silva AF, Batatinha JA, Nearing BD, Liu G, Rajamani S, Zeng D, Belardinelli L. If inhibition in the atrioventricular node by ivabradine causes rate-dependent slowing of conduction and reduces ventricular rate during atrial fibrillation. Heart Rhythm 2014; 11:2288-96. [DOI: 10.1016/j.hrthm.2014.08.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Indexed: 01/09/2023]
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Kuwabara Y, Kuwahara K, Takano M, Kinoshita H, Arai Y, Yasuno S, Nakagawa Y, Igata S, Usami S, Minami T, Yamada Y, Nakao K, Yamada C, Shibata J, Nishikimi T, Ueshima K, Nakao K. Increased expression of HCN channels in the ventricular myocardium contributes to enhanced arrhythmicity in mouse failing hearts. J Am Heart Assoc 2013; 2:e000150. [PMID: 23709563 PMCID: PMC3698776 DOI: 10.1161/jaha.113.000150] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 04/30/2013] [Indexed: 01/08/2023]
Abstract
BACKGROUND The efficacy of pharmacological interventions to prevent sudden arrhythmic death in patients with chronic heart failure remains limited. Evidence now suggests increased ventricular expression of hyperpolarization-activated cation (HCN) channels in hypertrophied and failing hearts contributes to their arrythmicity. Still, the role of induced HCN channel expression in the enhanced arrhythmicity associated with heart failure and the capacity of HCN channel blockade to prevent lethal arrhythmias remains undetermined. METHODS AND RESULTS We examined the effects of ivabradine, a specific HCN channel blocker, on survival and arrhythmicity in transgenic mice (dnNRSF-Tg) expressing a cardiac-specific dominant-negative form of neuron-restrictive silencer factor, a useful mouse model of dilated cardiomyopathy leading to sudden death. Ivabradine (7 mg/kg per day orally) significantly reduced ventricular tachyarrhythmias and improved survival among dnNRSF-Tg mice while having no significant effect on heart rate or cardiac structure or function. Ivabradine most likely prevented the increase in automaticity otherwise seen in dnNRSF-Tg ventricular myocytes. Moreover, cardiac-specific overexpression of HCN2 in mice (HCN2-Tg) made hearts highly susceptible to arrhythmias induced by chronic β-adrenergic stimulation. Indeed, ventricular myocytes isolated from HCN2-Tg mice were highly susceptible to β-adrenergic stimulation-induced abnormal automaticity, which was inhibited by ivabradine. CONCLUSIONS HCN channel blockade by ivabradine reduces lethal arrhythmias associated with dilated cardiomyopathy in mice. Conversely, cardiac-specific overexpression of HCN2 channels increases arrhythmogenicity of β-adrenergic stimulation. Our findings demonstrate the contribution of HCN channels to the increased arrhythmicity seen in failing hearts and suggest HCN channel blockade is a potentially useful approach to preventing sudden death in patients with heart failure.
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Affiliation(s)
- Yoshihiro Kuwabara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
| | - Koichiro Kuwahara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
| | - Makoto Takano
- Department of Physiology, Kurume University School of Medicine, Japan (M.T., S.I.)
| | - Hideyuki Kinoshita
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
| | - Yuji Arai
- Department of Bioscience, National Cerebral and Cardiovascular Center Research Institute, Japan (Y.A.)
| | - Shinji Yasuno
- EBM Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan (S.Y., K.U.)
| | - Yasuaki Nakagawa
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
| | - Sachiyo Igata
- Department of Physiology, Kurume University School of Medicine, Japan (M.T., S.I.)
| | - Satoru Usami
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
| | - Takeya Minami
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
| | - Yuko Yamada
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
| | - Kazuhiro Nakao
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
| | - Chinatsu Yamada
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
| | - Junko Shibata
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
| | - Toshio Nishikimi
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
| | - Kenji Ueshima
- EBM Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan (S.Y., K.U.)
| | - Kazuwa Nakao
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan (Y.K., K.K., H.K., Y.N., S.U., T.M., Y.Y., K.N., C.Y., J.S., T.N., K.N.)
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Custodis F, Fries P, Müller A, Stamm C, Grube M, Kroemer HK, Böhm M, Laufs U. Heart rate reduction by ivabradine improves aortic compliance in apolipoprotein E-deficient mice. J Vasc Res 2012; 49:432-40. [PMID: 22759927 DOI: 10.1159/000339547] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 05/14/2012] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Impaired vascular compliance is associated with cardiovascular mortality. The effects of heart rate on vascular compliance are unclear. Therefore, we characterized effects of heart rate reduction (HRR) by I(f) current inhibition on aortic compliance and underlying molecular mechanisms in apolipoprotein E-deficient (ApoE(-)/(-)) mice. METHODS ApoE(-)/(-) mice fed a high-cholesterol diet and wild-type (WT) mice were treated with ivabradine (20 mg/kg/d) or vehicle for 6 weeks. Compliance of the ascending aorta was evaluated by MRI. RESULTS Ivabradine reduced heart rate by 113 ± 31 bpm (~19%) in WT mice and by 133 ± 6 bpm (~23%) in ApoE(-)/(-) mice. Compared to WT controls, ApoE(-)/(-) mice exhibited reduced distensibility and circumferential strain. HRR by ivabradine increased distensibility and circumferential strain in ApoE(-)/(-) mice but did not affect both parameters in WT mice. Ivabradine reduced aortic protein and mRNA expression of the angiotensin II type 1 (AT1) receptor and reduced rac1-GTPase activity in ApoE(-)/(-) mice. Moreover, membrane translocation of p47(phox) was inhibited. In ApoE(-)/(-) mice, HRR induced anti-inflammatory effects by reduction of aortic mRNA expression of IL-6, TNF-alpha and TGF-beta. CONCLUSION HRR by ivabradine improves vascular compliance in ApoE(-)/(-) mice. Contributing mechanisms include downregulation of the AT1 receptor, attenuation of oxidative stress and modulation of inflammatory cytokine expression.
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Affiliation(s)
- Florian Custodis
- Kliniken für Innere Medizin III, Kardiologie, Angiologie und Internistische Intensivmedizin, Universitätsklinikum des Saarlandes, Homburg/Saar, Germany.
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Thollon C, Vilaine JP. I(f) inhibition in cardiovascular diseases. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2010; 59:53-92. [PMID: 20933199 DOI: 10.1016/s1054-3589(10)59003-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Heart rate (HR) is determined by the pacemaker activity of cells from the sinoatrial node (SAN), located in the right atria. Spontaneous electrical activity of SAN cells results from a diastolic depolarization (DD). Despite controversy in the exact contribution of funny current (I(f)) in pacemaking, it is a major contributor of DD. I(f) is an inward Na(+)/K(+) current, activated upon hyperpolarization and directly modulated by cyclic adenosine monophosphate. The f-proteins are hyperpolarization-activated cyclic nucleotide-gated channels, HCN4 being the main isoform of SAN. Ivabradine (IVA) decreases DD and inhibits I(f) in a use-dependent manner. Under normal conditions IVA selectively reduces HR and limits exercise-induced tachycardia, in animals and young volunteers. Reduction in HR with IVA both decreases myocardial oxygen consumption and increases its supply due to prolongation of diastolic perfusion time. In animal models and in human with coronary artery disease (CAD), IVA has anti-anginal and anti-ischemic efficacy, equipotent to classical treatments, β-blockers, or calcium channel blockers. As expected from its selectivity for I(f), the drug is safe and well tolerated with minor visual side effects. As a consequence, IVA is the first inhibitor of I(f) approved for the treatment of stable angina. Available clinical data indicate that IVA could improve the management of stable angina in all patients including those treated with β-blockers. As chronic elevation of resting HR is an independent predictor of mortality, pure HR reduction by inhibition of I(f) could, beyond the control of anti-anginal symptoms, improve the prognosis of CAD and heart failure; this therapeutic potential is currently under evaluation with IVA.
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Affiliation(s)
- Catherine Thollon
- Cardiovascular Department, Institut de Recherches Servier, Suresnes, France
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Prasad UK, Gray D, Purcell H. Review of the If selective channel inhibitor ivabradine in the treatment of chronic stable angina. Adv Ther 2009; 26:127-37. [PMID: 19259630 DOI: 10.1007/s12325-009-0005-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Indexed: 10/21/2022]
Abstract
Coronary heart disease is the major cause of morbidity and mortality in industrialized countries, and its prevalence is predicted to grow as the population ages. Current drugs for chronic stable angina (such as beta-blockers, calcium-channel blockers, long- and short-acting nitrates, and potassium-channel activators) are often effective, either as monotherapy or in combination, but side effects and contraindications may limit their use. The "I(f)" (for "funny") channel, discovered in 1979, is expressed mainly in the membrane of pacemaker cells present in the sinus node, the atrioventricular node, the ventricular conduction pathways, and ventricular myocytes. By determining the slope of diastolic depolarization, which in turn controls action potential frequency, it is a key determinant of heart rate and so provides a new therapeutic target for controlling angina symptoms. A new antiangina drug, ivabradine, has been developed and licensed for clinical use. It exclusively reduces the heart rate by selectively blocking the I(f) channel of the sino-atrial node. As clinical trials have shown it to be remarkably well-tolerated, ivabradine offers an alternative for patients who cannot take, or are intolerant of, beta blockade. This review provides an insight into this new agent, its historical background, mechanism of action, and pathophysiologic basis, and provides up-to-date evidence-based information on its optimum use in stable angina.
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Characterization of the Heart Rate-Lowering Action of Ivabradine, a Selective I f Current Inhibitor. Am J Ther 2008; 15:461-73. [PMID: 18806523 DOI: 10.1097/mjt.0b013e3181758855] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
The heart automaticity is a fundamental physiological function in higher organisms. The spontaneous activity is initiated by specialized populations of cardiac cells generating periodical electrical oscillations. The exact cascade of steps initiating the pacemaker cycle in automatic cells has not yet been entirely elucidated. Nevertheless, ion channels and intracellular Ca(2+) signaling are necessary for the proper setting of the pacemaker mechanism. Here, we review the current knowledge on the cellular mechanisms underlying the generation and regulation of cardiac automaticity. We discuss evidence on the functional role of different families of ion channels in cardiac pacemaking and review recent results obtained on genetically engineered mouse strains displaying dysfunction in heart automaticity. Beside ion channels, intracellular Ca(2+) release has been indicated as an important mechanism for promoting automaticity at rest as well as for acceleration of the heart rate under sympathetic nerve input. The potential links between the activity of ion channels and Ca(2+) release will be discussed with the aim to propose an integrated framework of the mechanism of automaticity.
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Affiliation(s)
- Matteo E Mangoni
- Institute of Functional Genomics, Department of Physiology, Centre National de la Recherche Scientifique UMR5203, INSERM U661, University of Montpellier I and II, Montpellier, France.
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Drouin A, Gendron ME, Thorin E, Gillis MA, Mahlberg-Gaudin F, Tardif JC. Chronic heart rate reduction by ivabradine prevents endothelial dysfunction in dyslipidaemic mice. Br J Pharmacol 2008; 154:749-57. [PMID: 18414390 DOI: 10.1038/bjp.2008.116] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE High resting heart rate is a predictor for total and cardiovascular mortality independent of other risk factors in patients with coronary artery disease. We tested the hypothesis that a reduction of resting heart rate with the cardiac pacemaker I(f) current inhibitor ivabradine prevents the endothelial dysfunction associated with dyslipidaemia. EXPERIMENTAL APPROACH Three-month-old dyslipidaemic (DL) male mice expressing the human ApoB-100 were assigned or not (DL, n=16), to treatment for 3 months with ivabradine (10 mg kg(-1) d(-1), n=17). Wild-type C57Bl/6 mice (WT, n=15) were used as controls. Heart rate was measured at 3, 4.5 and 6 months. Dilatation to acetylcholine (ACh) of isolated cerebral and renal arteries was investigated at 6 months. KEY RESULTS Heart rate remained stable in anaesthetized WT mice, increased (25%, P<0.05) with age in DL mice but was limited (11%, P<0.05) by ivabradine. At 6 months, left ventricular maximal pressure was similar in all groups. The minimal and end-diastolic left ventricular pressures were increased (P<0.05) in DL (10.2+/-1.0 and 18.7+/-1.4 mm Hg) compared to WT (-0.4+/-0.7 and 6.3+/-1.0 mm Hg) and reduced (P<0.05) by ivabradine (4.2+/-1.3 and 11.5+/-1.5 mm Hg). ACh-induced maximal dilatation was impaired (P<0.05) in renal and cerebral arteries isolated from DL compared to WT (56+/-7 versus 83+/-3% in renal arteries; 22+/-2 versus 42+/-2% in cerebral arteries). Ivabradine completely prevented (P<0.05) this dysfunction in renal and cerebral arteries. CONCLUSIONS AND IMPLICATIONS Selective heart rate reduction with ivabradine limits cardiac dysfunction and prevents the renovascular and cerebrovascular endothelial dysfunction associated with dyslipidaemia.
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Affiliation(s)
- A Drouin
- Montreal Heart Institute, Research Center, Faculty of Medicine, Department of Surgery, Université de Montréal, Montréal, Québec, Canada
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Heusch G. Heart rate in the pathophysiology of coronary blood flow and myocardial ischaemia: benefit from selective bradycardic agents. Br J Pharmacol 2008; 153:1589-601. [PMID: 18223669 DOI: 10.1038/sj.bjp.0707673] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Starting out from a brief description of the determinants of coronary blood flow (perfusion, pressure, extravascular compression, autoregulation, metabolic regulation, endothelium-mediated regulation and neurohumoral regulation) the present review highlights the overwhelming importance of metabolic regulation such that coronary blood flow is increased at increased heart rate under physiological circumstances and the overwhelming importance of extravascular compression such that coronary blood flow is decreased at increased heart rate through reduction of diastolic duration in the presence of severe coronary stenoses. The review goes on to characterize the role of heart rate in the redistribution of regional myocardial blood flow between a normal coronary vascular tree with preserved autoregulation and a poststenotic vasculature with exhausted coronary reserve. When flow is normalized by heart rate, there is a consistent close relationship of regional myocardial blood flow and contractile function for each single cardiac cycle no matter whether or not there is a coronary stenosis and what the actual blood flow is. beta-Blockade improves both flow and function along this relationship. When the heart rate reduction associated with beta-blockade is prevented by pacing, alpha-adrenergic coronary vasoconstriction is unmasked and both flow and function are deteriorated. Selective heart rate reduction, however, improves both flow and function without any residual negative effect such as unmasked alpha-adrenergic coronary vasoconstriction or negative inotropic action.
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Affiliation(s)
- G Heusch
- Institute for Pathophysiology, University of Essen Medical School, Essen, Germany.
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Stieber J, Wieland K, Stöckl G, Ludwig A, Hofmann F. Bradycardic and proarrhythmic properties of sinus node inhibitors. Mol Pharmacol 2005; 69:1328-37. [PMID: 16387796 DOI: 10.1124/mol.105.020701] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Sinus node inhibitors reduce the heart rate presumably by blocking the pacemaker current If in the cardiac conduction system. This pacemaker current is carried by four hyperpolarization-activated, cyclic nucleotide-gated cation (HCN) channels. We tested the potential subtype-specificity of the sinus node inhibitors cilobradine, ivabradine, and zatebradine using cloned HCN channels. All three substances blocked the slow inward current through human HCN1, HCN2, HCN3, and HCN4 channels. There was no subtype-specificity for the steady-state block, with mean IC50 values of 0.99, 2.25, and 1.96 microM for cilobradine, ivabradine, and zatebradine, respectively. Native If, recorded from mouse sinoatrial node cells, was slightly more efficiently blocked by cilobradine (IC50 value of 0.62 microM) than were the HCN currents. The block of I(f) in sinoatrial node cells resulted in slower and dysrhythmic spontaneous action potentials. The in vivo action of these blockers was analyzed using telemetric ECG recordings in mice. Each compound reduced the heart rate dose-dependently from 600 to 200 bpm with ED50 values of 1.2, 4.7, and 1.8 mg/kg for cilobradine, ivabradine, and zatebradine, respectively. beta-Adrenergic stimulation or forced physical activity only partly reversed this bradycardia. In addition to bradycardia, all three drugs induced increasing arrhythmia at concentrations greater than 5 mg/kg for cilobradine, greater than 10 mg/kg for zatebradine, or greater than 15 mg/kg for ivabradine. This dysrhythmic heart rate is characterized by periodic fluctuations of the duration between the T and P wave, resembling a form of sick sinus syndrome in humans. Hence, all available sinus node inhibitors possess an as-yet-unrecognized proarrhythmic potential.
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Affiliation(s)
- Juliane Stieber
- Institut für Pharmakologie und Toxikologie, TU München, Biedersteiner Str. 29, 80802 München, Germany.
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Leoni AL, Marionneau C, Demolombe S, Le Bouter S, Mangoni ME, Escande D, Charpentier F. Chronic heart rate reduction remodels ion channel transcripts in the mouse sinoatrial node but not in the ventricle. Physiol Genomics 2005; 24:4-12. [PMID: 16219869 DOI: 10.1152/physiolgenomics.00161.2005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We investigated the effects of chronic and moderate heart rate (HR) reduction on ion channel expression in the mouse sinoatrial node (SAN) and ventricle. Ten-week-old male C57BL/6 mice were treated twice daily with either vehicle or ivabradine at 5 mg/kg given orally during 3 wk. The effects of HR reduction on cardiac electrical activity were investigated in anesthetized mice with serial ECGs and in freely moving mice with telemetric recordings. With the use of high-throughput real-time RT-PCR, the expression of 68 ion channel subunits was evaluated in the SAN and ventricle at the end of the treatment period. In conscious mice, ivabradine induced a mean 16% HR reduction over a 24-h period that was sustained over the 3-wk administration. Other ECG parameters were not modified. Two-way hierarchical clustering analysis of gene expression revealed a separation of ventricles from SANs but no discrimination between treated and untreated ventricles, indicating that HR reduction per se induced limited remodeling in this tissue. In contrast, SAN samples clustered in two groups depending on the treatment. In the SAN from ivabradine-treated mice, the expression of nine ion channel subunits, including Navbeta1 (-25%), Cav3.1 (-29%), Kir6.1 (-28%), Kvbeta2 (-41%), and Kvbeta3 (-30%), was significantly decreased. Eight genes were significantly upregulated, including K+ channel alpha-subunits (Kv1.1, +30%; Kir2.1, +29%; Kir3.1, +41%), hyperpolarization-activated cation channels (HCN2, +24%; HCN4, +52%), and connexin 43 (+26%). We conclude that reducing HR induces a complex remodeling of ion channel expression in the SAN but has little impact on ion channel transcripts in the ventricle.
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Affiliation(s)
- Anne-Laure Leoni
- Institut National de la Santé et de la Recherche Médicale (INSERM), U533, l'Institut du Thorax, Nantes, France
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