Efficacy and Safety of Ivabradine in Combination with Beta-Blockers in Patients with Stable Angina Pectoris: A Systematic Review and Meta-analysis

INTRODUCTION

Beta-blockers are recommended by the European Society of Cardiology as first-line antianginal therapy for reducing heart rate (HR) and symptoms in patients with chronic coronary syndrome, despite a lack of data showing superiority to other antianginal agents. Most patients with angina pectoris require combination therapy to manage symptoms, with a second-line agent chosen to manage the predominant cardiovascular problem. Ivabradine, a selective sinus node If channel inhibitor shown to reduce HR and protect against anginal symptoms, has previously demonstrated noninferior anti-ischaemic and antianginal efficacy to beta-blockers.

METHODS

This systematic review and meta-analysis assessed the efficacy and safety of ivabradine in patients with stable angina pectoris who remained symptomatic despite receiving beta-blockers. Keyword searches of PubMed, The Cochrane Central Library Register, ClinicalTrials.gov, The World Health Organization International Clinical Trials Registry Platform (ICTRP) and Google Scholar identified studies comparing ivabradine plus beta-blockers with placebo or other first- or second-line antianginal agents in patients with stable angina pectoris. No date limits or language restrictions were applied. Outcomes were evaluated after 1 and 4 months of treatment, including changes in HR, angina attacks, use of short-acting nitrates, quality of life and safety. Risk of bias was evaluated on the basis of recommendations of the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

Seven relevant studies were identified (N = 6821). Ivabradine plus a beta-blocker consistently reduced HR, anginal symptoms and short-acting nitrate consumption within 1 month of initiating therapy, with continued reductions for up to 4 months. Furthermore, ivabradine plus beta-blocker therapy was well tolerated, with bradycardia rarely reported (0.1% of patients overall). This study is limited by the inclusion of only two randomised studies, which may lead to result interpretation bias.

CONCLUSIONS

Ivabradine may be valuable for tailoring early antianginal treatment when used in combination with beta-blockers for chronic stable angina inadequately controlled by beta-blockers.

A pathophysiological compass to personalize antianginal drug treatment

Myocardial ischaemia results from coronary macrovascular or microvascular dysfunction compromising the supply of oxygen and nutrients to the myocardium. The underlying pathophysiological processes are manifold and encompass atherosclerosis of epicardial coronary arteries, vasospasm of large or small vessels and microvascular dysfunction - the clinical relevance of which is increasingly being appreciated. Myocardial ischaemia can have a broad spectrum of clinical manifestations, together denoted as chronic coronary syndromes. The most common antianginal medications relieve symptoms by eliciting coronary vasodilatation and modulating the determinants of myocardial oxygen consumption, that is, heart rate, myocardial wall stress and ventricular contractility. In addition, cardiac substrate metabolism can be altered to alleviate ischaemia by modulating the efficiency of myocardial oxygen use. Although a universal agreement exists on the prognostic importance of lifestyle interventions and event prevention with aspirin and statin therapy, the optimal antianginal treatment for patients with chronic coronary syndromes is less well defined. The 2019 guidelines of the ESC recommend a personalized approach, in which antianginal medications are tailored towards an individual patient's comorbidities and haemodynamic profile. Although no antianginal medication improves survival, their efficacy for reducing symptoms profoundly depends on the underlying mechanism of the angina. In this Review, we provide clinicians with a rationale for when to use which compound or combination of drugs on the basis of the pathophysiology of the angina and the mode of action of antianginal medications.

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

Background and Objectives

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

Methods

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

Results

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

Conclusions

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

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.

Efficacy of Ivabradine in Combination with Beta-Blockers Versus Uptitration of Beta-Blockers in Patients with Stable Angina (CONTROL-2 Study)

Introduction

Heart rate (HR) reduction is an integral part of antianginal therapy, but many patients do not reach the guideline-recommended target of less than 60 bpm despite high use of beta-blockers (BB). Failure to uptitrate BB doses may be partly to blame. To explore other options for lowering HR and improving angina control, CONTROL-2 was initiated to compare the efficacy and tolerability of the combination of BBs with ivabradine versus uptitration of BBs to maximal tolerated dose, in patients with stable angina.

Methods

This multicenter, open, randomized study included 1104 patients with Canadian Cardiovascular Society (CCS) class II or III stable angina, in sinus rhythm, and on background stable treatment with non-maximal recommended doses of BBs. Consecutive patients were allocated to ivabradine + BB or BB uptitration in a 4:1 ratio.

Results

At the end of the study (week 16), addition of ivabradine to BB treatment and BB uptitration resulted in reduction in HR (61 ± 6 vs. 63 ± 8 bpm; p = 0.001). At week 16, significantly more patients on ivabradine + BB were in CCS class I than with BB uptitration (37.1% vs. 28%; p = 0.017) and significantly more patients were angina-free (50.6% vs. 34.2%; p < 0.001). Patient health status based on the visual analogue scale (VAS) was also better in the ivabradine + BB group. Adverse events (AEs) were significantly more common with BB uptitration than with the ivabradine + BB combination (18.4% vs. 9.4%, p < 0.001).

Conclusion

In patients with stable angina, combination therapy with ivabradine + BB demonstrated good tolerability, safety, and more pronounced clinical improvement, compared to BB uptitration.

Trial Registration

ISRCTN30654443.

Funding

Servier.

Treatment of Stable Angina with a New Fixed-Dose Combination of Ivabradine and Metoprolol: Effectiveness and Tolerability in Routine Clinical Practice

Introduction

In this prospective, multicenter, observational cohort study, the effectiveness and tolerability of the first fixed-dose combination (FDC) formulation of the selective heart rate reducing agent ivabradine and the beta-blocker metoprolol was evaluated in stable angina pectoris (AP) patients in a clinical practice setting.

Methods

Stable AP outpatients received a FDC of ivabradine and metoprolol (b.i.d.) for 4 months, in addition to cardiovascular standard therapy. Resting heart rate (HR), number of angina attacks, short-acting nitrate consumption, severity of symptoms (assessed by patient judgment and documented by CCS score) and tolerability were documented. Medication adherence was assessed by a modified four-item Morisky questionnaire. Descriptive statistics were performed on all data.

Results

A total of 747 stable AP patients (mean age, 66.4 years, 62% male, 50% and 31% with previous PCI and myocardial infarction, respectively) were included. Apart from ivabradine and beta-blockers as free combination, most frequently used concomitant standard medications at baseline were aspirin (68%), statins (71%), ACEI/AT1-blockers (76%), diuretics (35%), and calcium antagonists (15%). Highly prevalent comorbidities were hypertension (86%), hyperlipidemia (65%), and diabetes (35%). After 4 months, switch to treatment with the FDC was associated with a significant reduction in mean HR by 10 bpm. Proportion of patients with ≥ 1 angina attacks/week decreased from 38 to 7%. Patients in CCS class 1 increased (25 to 63%), while they decreased in CCS class 3 (19 to 5%). Medication adherence was also significantly improved (p < 0.001 for all changes from baseline). Mostly mild adverse events were documented in 5.4% of patients.

Conclusions

In these stable AP patients in a real-life setting, treatment with a FDC of ivabradine and metoprolol was associated with reduced HR and angina symptoms, while exercise capacity (CCS score) was improved. These effects may be mainly mediated by the increased medication adherence of patients observed with use of the FDC formulation.

Funding

Servier

Trial registration number

ISRCTN51906157

Practical Applications for Single Pill Combinations in the Cardiovascular Continuum

Despite the availability of new drugs and devices, the treatment of cardiovascular disease remains suboptimal. Single-pill combination therapy offers a number of potential advantages. It can combine different classes of drugs to increase efficacy while mitigating the risks of treatment-related adverse events, reduce pill burden, lower medical cost, and improve patient adherence. Furthermore, in hypertension, single pill combinations include standard to lower doses of each drug than would be necessary to achieve goals with monotherapy, which may explain their better tolerability compared with higher dose monotherapy. Combination therapy is now established in the treatment of hypertension. In ischaemic heart disease, the concept of a preventative polypill has been studied, but its benefits have not been established conclusively. However, the combination of ivabradine and beta-blockers has proven efficacy in patients with stable angina pectoris. This combination has also demonstrated benefits in patients with chronic heart failure.

[National disease management guidelines (NVL) for chronic CAD : What is new, what is particularly important?]

Coronary heart disease (CAD) is widespread and affects 1 in 10 of the population in the age group 40-79 years in Germany. The German national management guidelines on chronic CAD comprise evidence and expert-based recommendations for the diagnostics of chronic stable CAD as well as for interdisciplinary/multidisciplinary therapy and care of patients with stable CAD. The focus is on the diagnostics, prevention, medication therapy, revascularization, rehabilitation, general practitioner care and coordination of care. Recommendations for optimizing cooperation between all medical specialties involved as well as the definition of mandatory and appropriate measures are essential aims of the guidelines both to improve the quality of care and to strengthen the position of the patient.

Alpha-crystallin: an ATP-independent complete molecular chaperone toward sorbitol dehydrogenase

alpha-Crystallin, the major component of the vertebrate lens, is known to interact with proteins undergoing denaturation and to protect them from aggregation phenomena. Bovine lens sorbitol dehydrogenase (SDH) was previously shown to be completely protected by alpha-crystallin from thermally induced aggregation and inactivation. Here we report that alpha-crystallin, in the presence of the SDH pyridine cofactor NAD(H), can exert a remarkable chaperone action by favoring the recovery of the enzyme activity from chemically denaturated SDH up to 77%. Indeed, even in the absence of the cofactor, alpha-crystallin present at a ratio with SDH of 20:1 (w:w) allows a recovery of 35% of the enzyme activity. The effect of ATP in enhancing alpha-crystallin-promoted SDH renaturation appears to be both nonspecific and to not involve hydrolysis phenomena, thus confirming that the chaperone action of alpha-crystallin is not dependent on ATP as energy donor.