Ivabradine in combination with Beta-blockers in patients with chronic stable angina after percutaneous coronary intervention

Short-Term Results of Ivabradine versus Metoprolol: The Effects on Atrial Fibrillation in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

INTRODUCTION

Classic coronary artery bypass grafting (CABG) surgery involves diastolic cardiac arrest under cardiopulmonary bypass, while off-pump CABG (OPCABG) has become widespread in recent years.

METHODS

174 patients who underwent OPCABG were included in the study. Patients were divided into two groups. Group I (n=90) received ivabradine and Group M (n=84) received metoprolol before surgery until postoperative day 10. Intraoperative arrhythmias and hypotension were recorded. Postoperative atrial fibrillation (AF) and arrhythmia, mortality and morbidity rates were assessed based on the 30-day postoperative follow-up.

RESULTS

There were no significant differences in the intraoperative amount of inotropic support and red blood cell transfusion between groups (P=0.87 and P=0.31). However, the rates of intraoperative arrhythmias and hypotension were not significantly higher in Group M (P=0.317 and P=0.47). Ventricular tachycardia/ventricular fibrillation (VT/VF) was observed in 2 patients in both groups. Postoperative AF occurred in 7 patients (7.7%) in Group I and in 10 patients (11.9%) in Group M. Although there was a trend towards a higher prevalence of AF in Group M patients, this did not reach statistical significance. In addition, mortality and morbidity rates were comparable between groups.

Ivabradine, the hyperpolarization-activated cyclic nucleotide-gated channel blocker, elicits relaxation of the human corpus cavernosum: a potential option for erectile dysfunction treatment

OBJECTIVE

To evaluate the effect of the I_f channel inhibitor, ivabradine on human corpus cavernosum (HCC) smooth muscle tone.

METHODS

HCC samples were obtained from erectile dysfunction(ED) patients (n = 12) undergoing penile prosthesis surgery. Concentration-response curves for ivabradine were exposed to various inhibitory and stimulatory agents. The relaxant and contractile responses to electrical field stimulation (EFS, 10 Hz and 80 Hz) were examined in the presence or absence of ivabradine (10 μM). HCN3 and HCN4 channel expression and localization were determined by Western blot and immunohistochemical analyses of HCC tissues.

RESULTS

Increasing ivabradine concentrations dependently reduced the maximal contractile responses of isolated HCC strips induced by KCl (59.5 ± 2.5%) and phenylephrine (84.0 ± 9.8%), which was not affected by nitric oxide synthase and soluble guanylyl cyclase inhibitors after phenylephrine-induced contraction. Nifedipine and tetraethylammonium inhibited the maximum relaxation to ivabradine by 75% and 39.3%, respectively. Fasudil and sildenafil increased the relaxation response to ivabradine without altering the maximum response. Pre-incubation with ivabradine significantly increased relaxant responses to EFS (p < 0.01) and reduced the contractile tension evoked by EFS (72.3%) (p < 0.001). Ivabradine incubation did not affect the expression and localization of HCN3 and HCN4 channels in the HCC smooth muscle cells.

CONCLUSIONS

Ivabradine exhibits a relaxant effect on HCC tissues, which is likely to be attributed to the blocking of L-type Ca²⁺ channels and the opening of K⁺ channels, independent of changes in the activation of the nitric oxide/cyclic guanosine monophosphate system. Inhibition of HCN channels localized in cavernosal smooth muscle cells may offer pharmacological benefits for patients with cardiovascular risk factors.

Effectiveness and Impact on Adherence of a New Fixed-Dose Combination of Ivabradine and Metoprolol in a Wide Range of Stable Angina Patients in Real-Life Practice

INTRODUCTION

The antianginal effectiveness of ivabradine administration in addition to beta-blockers has been shown in patients with stable angina. The first fixed-dose combination (FDC) of ivabradine and metoprolol is now available and its evaluation in various stable angina patient populations relevant to clinical practice would be useful.

METHODS

In this 4-month, prospective, multicenter, observational study, the effectiveness and tolerability of the metoprolol/ivabradine FDC was assessed in patient subgroups specified according to age, coronary artery disease (CAD) duration, Canadian Cardiovascular Society (CCS) class, co-morbidities, and previous myocardial infarction (MI) or revascularization. Heart rate (HR), angina attack frequency, short-acting nitrate (SAN) consumption, functional status, and medication adherence were documented at baseline and after 4 months of follow-up.

RESULTS

A total of 747 stable angina patients were included and divided into subgroups. At 4 months, a significant decrease in HR, angina attack frequency, and SAN consumption per week was consistently observed across all patient subgroups. The proportion of CCS class I patients increased significantly from baseline to month 4. In all patient subgroups, at 4 months, a significant increase was observed in the proportion of patients with self-reported complete adherence. Complete adherence at the final visit was found to decrease with an increasing number of medications. Physicians evaluated the effectiveness and tolerability of the FDC as 'very good' and 'good' for more than 96% of patients in all analyzed patient subgroups.

CONCLUSIONS

Treatment with metoprolol/ivabradine FDC significantly improved angina symptoms and adherence, with an excellent tolerability profile, in stable angina patient subgroups relevant to real-life clinical practice, regardless of age, CAD duration, CCS class, comorbidities, previous MI, or history of revascularization.

TRIAL REGISTRATION

ISRCTN51906157.

FUNDING

This study was sponsored by Servier Deutschland GmbH. Editorial assistance and the Rapid Service Fee were funded by Servier, France. Plain language summary available for this article.

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

In chronic stable angina, elevated heart rate contributes to the development of symptoms and signs of myocardial ischaemia by increasing myocardial oxygen demand and reducing diastolic perfusion time. Accordingly, heart rate reduction is a well-known strategy for improving both symptoms of myocardial ischaemia and quality of life (QOL). The heart rate-reducing agent ivabradine, a direct and selective inhibitor of the I_f current, decreases myocardial oxygen consumption while increasing diastolic time, without affecting myocardial contractility or coronary vasomotor tone. Ivabradine is indicated for treatment of stable angina and chronic heart failure (HF). This review examines available evidence regarding the efficacy and safety of ivabradine in stable angina, when used as monotherapy or in combination with beta-blockers, in particular angina subgroups and in patients with stable angina with left ventricular systolic dysfunction (LVSD) or HF. Trials involving more than 45 000 patients receiving treatment with ivabradine have shown that this agent has antianginal and anti-ischaemic effects, regardless of age, sex, severity of angina, revascularisation status or comorbidities. This heart rate-lowering agent might also improve prognosis, reduce hospitalisation rates and improve QOL in angina patients with chronic HF and LVSD.

Management and clinical outcome of stable coronary artery disease in Austria : Results from 5 years of the CLARIFY registry

Background

The population of patients with established coronary artery disease (CAD) is growing because of an improvement in outcomes and survival from acute disease episodes. Nevertheless, these patients remain at high risk of cardiovascular events. Thus, CAD management is important in prevention of disease progression. The objective of this analysis was to describe disease management and clinical outcome of Austrian outpatients with stable CAD over 5 years by using data from the international CLARIFY registry.

Methods

CLARIFY was an international prospective observational registry of outpatients with stable CAD, defined as prior myocardial infarction or revascularization (CABG or PCI), coronary stenosis of more than 50% by coronary angiography or chest pain with myocardial ischemia. We analyzed demographic characteristics, risk factors, treatments and clinical outcomes of 424 Austrian outpatients with established CAD who were enrolled between November 2009 and July 2010 and observed until September 2015.

Results

The primary risk factors in Austrian outpatients with stable CAD were smoking (current smokers: 13.2%), overweight (77.1%), hypertension (78.5%), raised low-density lipoprotein (LDL) cholesterol plasma levels (81.4% ≥ 0.7 g/l or 1.8 mmol/l), elevated heart rate (≥70 bpm: 60.9% in patients with anginal symptoms) and poor physical activity (none or light activity: 63.4%). Patients received lipid-lowering drugs (predominantly statins), aspirin, beta-blockers and angiotensin-converting enzyme (ACE) inhibitors according to current recommendations. After 5 years a systolic blood pressure (SBP) < 140 mm Hg and diastolic blood pressure (DBP) < 90 mm Hg was reached in 58.5% of patients. Of the patients 70.4% had LDL cholesterol plasma levels below 1.0 g/l (2.6 mmol/l), 42.1% of smokers had stopped smoking, 42.9% of patients with anginal symptoms had a heart rate ≤60 bpm and 26.0% of diabetic patients had brought their HbA1c levels below 6.5%. Cardiovascular death, myocardial infarction or stroke occurred in 30 patients (7.1%), all-cause death in 25 cases (5.9%) and cardiovascular death in 15 cases (3.5%). Myocardial infarction was reported in 14 patients (fatal and non-fatal: 3.3%) and stroke in 8 patients (fatal and non-fatal: 1.9%), 39 patients (9.2%) underwent myocardial revascularization and 124 patients (29.2%) experienced cardiovascular hospitalization.

Conclusion

Characteristics of Austrian outpatients with stable CAD corresponded to those of patients with CAD in other developed countries. Medical treatments following the recommendations of the European guidelines were prescribed in the majority of patients; however, recommended goals of life style interventions including a heart rate less than 60 bpm and general risk factor management were not achieved by a high proportion of patients. Heart rate control and life style changes remain unmet needs of cardiovascular care in Austria.

Osthole inhibits intimal hyperplasia by regulating the NF-κB and TGF-β1/Smad2 signalling pathways in the rat carotid artery after balloon injury

Osthole (7-methoxy-8-isopentenoxy-coumarin), a compound extracted from Cnidiummonnieri (L.) Cusson seeds, has been found to exhibit potent therapeutic effects in cancer due to its ability to inhibit inflammation and cell proliferation. However, its effects on arterial wall hypertrophy-related diseases remain unclear. Therefore, in this study, we aimed to investigate the effects of Osthole on intimal hyperplasia in a rat model of carotid artery balloon injury. We established the balloon-induced carotid artery injury rat model in male Sprague-Dawley rats, after which we administered Osthole (20mg/kg/day or 40mg/kg/day) or volume-matched normal saline orally by gavage for 14 consecutive days. Intimal hyperplasia and the degree of vascular smooth muscle cell proliferation were then evaluated by histopathological examination of the changes in the carotid artery, as well as by examination of proliferating cell nuclear antigen (PCNA) expression. Tumour necrosis factor-ɑ (TNF-α), interleukin-1β (IL-1β), transforming growth factor-beta (TGF-β1) and PCNA mRNA expression levels were examined by real-time RT-PCR, while nuclear factor-κB (NF-κB (p65)), IκB-α, TGF-β1 and phospho-Smad2 (p-Smad2) protein expression levels were analysed by immunohistochemistry or western blot analysis. We found that Osthole significantly attenuated neointimal thickness and decreased the elevations in PCNA protein expression induced by balloon injury. Moreover, Osthole down-regulated the pro-inflammatory factors TNF-α and IL-1β and NF-κB (p65), whose expression had been upregulated after balloon injury. Moreover, IκB-α protein expression levels increased following Osthole treatment. In addition, the elevations in TGF-β1 and p-Smad2 protein expression induced by balloon injury were both significantly attenuated by Osthole administration. We concluded that Osthole significantly inhibited neointimal hyperplasia in balloon-induced rat carotid artery injury and that the mechanism by which this occurs may involve NF-κB, IL-1β and TNF-ɑ down-regulation, which alleviates the inflammatory response, and TGF-β1/Smad2 signalling pathway inhibition.

Ivabradine in Patients with Stable Coronary Artery Disease: A Rationale for Use in Addition to and Beyond Percutaneous Coronary Intervention

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 I_f 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.

Effectiveness of Ivabradine Treatment in Different Subpopulations with Stable Angina in Clinical Practice: A Pooled Analysis of Observational Studies

Objectives: The efficacy of ivabradine has been demonstrated in different subpopulations of stable angina patients in randomized clinical trials. This study explored its effectiveness in subpopulations seen in clinical practice as they often differ from those of randomized trials. Methods: Data were pooled from three German observational studies with similar inclusion criteria (stable angina and heart rate ≥60 bpm). All patients received 2.5, 5, or 7.5 mg b.i.d. of ivabradine for 4 months, with or without concomitant beta-blocker. Antianginal effectiveness was analyzed in subpopulations defined by gender, age, heart rate, angina severity, use of concomitant beta-blocker, previous percutaneous coronary intervention procedure, and comorbidities (including previous myocardial infarction and diabetes). Results: Treatment data were available on 8,555 patients, where therapy with ivabradine was associated with a significant reduction in the frequency of angina attacks and consumption of short-acting nitrates of 87%. Effectiveness was maintained in all investigated subpopulations, with a reduction in antianginal parameters of 82-90%. Clinical status (Canadian Cardiovascular Society class) and quality of life were also improved. Ivabradine was well tolerated in all subgroups. Conclusions: Ivabradine is effective and safe in all subpopulations of angina patients seen in clinical practice, independent of age, comorbidities, and use of beta-blocker.

Ivabradine: A Unique and Intriguing Medication for Treating Cardiovascular Disease

There has been much research linking elevated resting heart rate to cardiovascular morbidity and mortality. Based on these findings, a lower resting heart rate would be of theoretical benefit in patients with cardiovascular disease. From a pathophysiologic perspective, a lower resting heart rate would be of particular benefit in patients with ischemic heart disease and/or heart failure. Although β-blockers and nondihydropyridine calcium channel blockers are effective at lowering heart rate, they have many other pharmacologic effects that may not be desirable in some patients, such as negative inotropy. Ivabradine is a drug designed to lower heart rate without any other demonstrable pharmacologic effects; in other words, a pure heart rate-lowering drug. It functions by blocking the hyperpolarization-activated cyclic nucleotide gated channels (f-channels) specific for the sinoatrial node and disrupting If ion current flow. This effectively prolongs diastolic depolarization and slows firing in the sinoatrial node, which lowers heart rate. The effects of ivabradine are most pronounced at higher heart rates (use-dependence), which is important in minimizing the development of symptomatic bradycardia. Clinical trials have demonstrated ivabradine to be an effective antianginal drug both alone and in combination with β-blocker therapy, although it has not been shown to produce a demonstrable effect on reducing major adverse cardiovascular events. In patients with heart failure, ivabradine has demonstrated many hemodynamic benefits, but its effect on clinical outcomes have been mixed and dependent on baseline heart rate, ie, the drug may be of benefit with higher baseline heart rates, but detrimental with low baseline heart rates. The adverse effects of ivabradine are not uncommon, but are rarely severe and include visual disturbances, bradycardia, and atrial fibrillation. Although ivabradine is a very interesting new agent, its variable benefits in large-scale clinical trials leave its exact place in therapy still somewhat nebulous. Unanswered questions include which patient populations would benefit most from this drug, and which concomitant medications would produce the best clinical outcomes when used with ivabradine.