Long-term beta blockers for stable angina: systematic review and meta-analysis

The clinical value of β-blockers in patients with stable angina

Stable angina, one manifestation of chronic coronary syndrome (CCS), is characterised by intermittent episodes of insufficient blood supply to the myocardium, provoking symptoms of myocardial ischaemia, particularly chest pain. These attacks usually occur during exercise or stress. Anti-ischaemic drugs are the mainstay of pharmacologic management of CCS with symptoms of angina. β-blockers reduce heart rate and myocardial contractility, thus reducing myocardial oxygen consumption. These drugs have been shown to ameliorate the frequency of anginal attacks and to improve exercise capacity in these patients. Current management guidelines include β-blockers as a first-line management option for most patients with CCS and symptoms of myocardial ischaemia, alongside dihydropyridine calcium channel blockers (CCB). The presence of comorbid angina and heart failure is a strong indication for starting with a β-blocker. β-blockers are also useful in the management of angina symptoms accompanied by a high heart rate, hypertension (with or without a renin-angiotensin-aldosterone-system [RAS] blocker or CCB), or microvascular angina (with a RAS blocker and a statin). A β-blocker is not suitable for a patient with low heart rate (<50 bpm), although use of a β-blocker may be supported by a pacemaker if the β-blocker is strongly indicated) and should be used at a low dose only in patients with low blood pressure.

Angina in 2022: Current Perspectives

Angina is the main symptom of ischemic heart disease; mirroring a mismatch between oxygen supply and demand. Epicardial coronary stenoses are only responsible for nearly half of the patients presenting with angina; whereas in several cases; symptoms may underlie coronary vasomotor disorders; such as microvascular dysfunction or epicardial spasm. Various medications have been proven to improve the prognosis and quality of life; representing the treatment of choice in stable angina and leaving revascularization only in particular coronary anatomies or poorly controlled symptoms despite optimal medical therapy. Antianginal medications aim to reduce the oxygen supply-demand mismatch and are generally effective in improving symptoms; quality of life; effort tolerance and time to ischemia onset and may improve prognosis in selected populations. Since antianginal medications have different mechanisms of action and side effects; their use should be tailored according to patient history and potential drug-drug interactions. Angina with non-obstructed coronary arteries patients should be phenotyped with invasive assessment and treated accordingly. Patients with refractory angina represent a higher-risk population in which some therapeutic options are available to reduce symptoms and improve quality of life; but robust data from large randomized controlled trials are still lacking.

State of the art approach to managing angina and ischemia: tailoring treatment to the evidence

Stable angina represents a chronic and often debilitating condition that affects daily activities and quality of life in patients with chronic coronary syndromes (CCS). Current European Society of Cardiology guidelines recommend a four-step approach for the medical treatment of patients taking into consideration hemodynamic variables (heart rate and blood pressure) and the presence or absence of left ventricular dysfunction. However, CCS patients often have several comorbidities and risk factors. Thus, a tailored approach that takes into consideration patient risk factors and comorbidities may have additional benefits beyond angina relief. This is a state of the art review of stable angina treatment based on the currently available evidence.

β-blocker use and risk of all-cause mortality in patients with coronary heart disease: effect modification by serum vitamin A

AIMS 

Blockade of β-adrenoceptors reduces sympathetic nervous system activity and improves survival in patients with heart failure with reduced left ventricular ejection fraction (HFrEF); however, any improvement in longevity among patients with coronary heart disease (CHD) but without HFrEF remains uncertain. Vitamin A has been linked to the activation of tyrosine hydroxylase, the rate-limiting enzyme in the catecholamine synthesis pathway. We investigated if vitamin A status modified the association of β-blocker use with the risk of all-cause mortality.

METHODS AND RESULTS 

A total of 4118 patients undergoing elective coronary angiography for suspected stable angina pectoris, of whom the majority had normal left ventricular ejection fraction (LVEF) were studied. Hazard ratios (HRs) of all-cause mortality comparing treatment vs. non-treatment of β-blockers according to the tertiles of serum vitamin A were explored in Cox proportional hazards regression models. During a median follow-up of 10.3 years, 897 patients (21.8%) died. The overall LVEF was 65% and 283 (6.9%) had anamnestic HF. After multivariable adjustments for traditional risk factors, medical history, and drug therapies of cardiovascular disease, β-blocker treatment was inversely associated with the risk of all-cause mortality [HR : 0.84; 95% CI (confidence interval), 0.72-0.97]. However, the inverse association was generally stronger among patients in the upper serum vitamin A tertile (HR :0.66; 95% CI, 0.50-0.86; Pinteraction = 0.012), which remained present after excluding patients with LVEF < 40%.

CONCLUSION 

In patients with suspected CHD, β-blocker treatment was associated with improved survival primarily among patients with high serum vitamin A levels.

Treatment of stable ischaemic heart disease: the old and the new

Stable ischaemic heart disease is a frequent and very heterogeneous condition. Drug therapy is important, in these patients, for improving their prognosis and controlling their symptoms. The typical clinical manifestation of obstructive coronary disease is angina pectoris. This symptom can be improved by various classes of compounds, namely beta-blockers (BBs), calcium antagonist, and nitrates. More recently, ranolazine and ivabradine have been introduced. All these drugs have been proven to reduce significantly angina. On the other hand, there are no evidences supporting improvement in prognosis, besides for the use of BBs, in patients with previous myocardial infarction (MI) or systolic dysfunction. Besides drugs for symptoms control, these patients also receive antiplatelet drugs, specifically aspirin, and lipid lowering compounds such as statins. Furthermore, recent evidences supported the use of low doses direct anticoagulant, or a second antiplatelet agent in patients with previous MI. Similarly, a very low LDL cholesterol level, such as obtained with PCKS9 inhibitors, seems very beneficial in these patients. It is possible that in the near future a specific role for neo-angiogenesis factors and cellular therapies, could be proven, albeit, presently these treatments are not supported by solid evidences.

The New ESC Guidelines for the Diagnosis and Management of Chronic Coronary Syndromes: the Good and the Not So Good

During the annual meeting in Paris, the European Society of Cardiology released the new guidelines for the diagnosis and management of chronic coronary syndromes that will replace the 2013 guidelines on stable coronary artery disease. We intend to provide a brief commentary on what, in our opinion, is good and what is not as good. Our careful analysis shows that the 2019 guidelines contain a number of positive innovations, including a new definition, a central role of non-invasive testing for myocardial ischaemia, the most contemporary prevalence of the disease, the fact that medical therapy remains paramount despite the important advances in revascularisation and many other good issues as well as some limitations. The section on medical therapy of chronic coronary syndromes patients shows some inconsistency between text and the suggested scheme as well as contradictions with recommendations of regulatory agencies. It is not immediate to appreciate what is good and what is not so good in guidelines, which are often read in a hurry. We have provided a short commentary for the readers who usually concentrate more on the figures and flowcharts rather than on the text.

Evidence in Guidelines for Treatment of Coronary Artery Disease

In this chapter, we focus on evidences in current guidelines for treatment of coronary artery disease (CAD). In Part 1, diet and lifestyle management is discussed, which plays an important role in CAD risk control, including forming healthy dietary pattern, maintaining proper body weight, physical exercise, smoking cessation, and so on. Part 2 elaborated on revascularization strategies and medical treatments in patients presenting with acute coronary syndrome (ACS), including specific AHA and ESC guidelines on ST elevation myocardial infarction (STEMI) and non-ST elevation ACS (NSTE-ACS). Part 3 discussed chronic stable coronary artery disease (SCAD), the treatment objective of which is a combination of both symptomatic and prognostic improvement. Yet many of the recommendations for SCAD are expert-based rather than evidence-based. Initial medical treatment is safe and beneficial for most patients. While cumulating studies have focused on optimizing pharmacological therapy (referring to nitrates, beta-blockers, calcium channel blockers, antiplatelet agents, ACEI/ARB, statins, etc.), education, habitual modification, and social support matters a lot for reducing cardiac morbidity and mortality. Patients with moderate-to-severe symptoms and complex lesions should be considered for revascularization. But practical management of revascularization shall take individual characteristics, preference, and compliance into consideration as well.

Role of Beta-blockers in Cardiovascular Disease in 2019

Beta-blockers are the cornerstone of treatment for various cardiovascular conditions. Although their effects have classically been considered to be driven by their antagonistic and competitive action on beta-adrenergic receptors, nowadays it is known that their effect goes beyond that of mere competition with catecholamines on these receptors. Beta-blockers were discovered as antianginal drugs in the 1960s and are currently widely used in heart failure, arrhythmias, and ischemic heart disease. In this article, we review the evidence for the beneficial effects of beta-blockers in these conditions, as well as the current recommendations in clinical practice guidelines for their use. Surprisingly, despite having been prescribed for more than 4 decades, new, previously unnoticed mechanisms of action on cellular compartments are still being discovered, which continues to open up new horizons for their use. All in all, beta-blockers are one of the most fascinating drug groups in our therapeutic armamentarium.

Esmolol acutely alters oxygen supply-demand balance in exercising muscles of healthy humans

Beta‐adrenoreceptor antagonists (β blockers) reduce systemic O₂ delivery and blood pressure (BP) during exercise, but the subsequent effects on O₂ extraction within the active limb muscles are unknown. In this study, we examined the effects of the fast‐acting, β₁ selective blocker esmolol on systemic hemodynamics and leg muscle O₂ saturation (near infrared spectroscopy, NIRS) during submaximal leg ergometry. Our main hypothesis was that esmolol would augment exercise‐induced reductions in leg muscle O₂ saturation. Eight healthy adults (6 men, 2 women; 23–67 year) performed light and moderate intensity bouts of recumbent leg cycling before (PRE), during (β₁‐blocked), and 45 min following (POST) intravenous infusion of esmolol. Oxygen uptake, heart rate (HR), BP, and O₂ saturation (SmO₂) of the vastus lateralis (VL) and medial gastrocnemius (MG) muscles were measured continuously. Esmolol attenuated the increases in HR and systolic BP during light (−12 ± 9 bpm and −26 ± 12 mmHg vs. PRE) and moderate intensity (−20 ± 10 bpm and −40 ± 18 mmHg vs. PRE) cycling (all P < 0.01). Exercise‐induced reductions in SmO₂ occurred to a greater extent during the β₁‐blockade trial in both the VL (P = 0.001 vs. PRE) and MG muscles (P = 0.022 vs. PRE). HR, SBP and SmO₂ were restored during POST (all P < 0.01 vs. β₁‐blocked). In conclusion, esmolol rapidly and reversibly increases O₂ extraction within exercising muscles of healthy humans.

Long-term effectiveness of bisoprolol in patients with angina: A real-world evidence study

A cohort analysis using UK Clinical Practice Research Datalink (CPRD) was performed to compare the effects of bisoprolol, other β-blockers, and drugs other than β-blockers on the long-term risk of mortality and cardiovascular events in patients with angina. Adult patients first diagnosed with angina from 2000 to 2014, with ≥365 days of registration to first angina diagnosis and initiating monotherapies of bisoprolol, other β-blockers, or drugs other than β-blockers within 6 months of angina diagnosis were included. Incidence rates for each treatment cohort were compared using adjusted hazard ratio (HR) and 95% confidence intervals (CI) obtained from Cox regression analyses. Overall, 987 patients were treated with bisoprolol, 1348 with other β-blockers and 5272 with drugs other than β-blockers. Over the total follow-up (≤14 years), the HR of bisoprolol versus other β-blockers and drugs other than β-blockers for mortality was 0.45 (95% CI: 0.34-0.61) and 0.50 (95% CI: 0.38-0.66), respectively. The HR of bisoprolol versus other β-blockers for angina was 0.58 (95% CI: 0.50-0.68) and versus drugs other than β-blockers was 0.77 (95% CI: 0.68-0.88), respectively. For myocardial infarction, the HR of bisoprolol versus drugs other than β-blockers up to 14 years was 0.34 (95% CI: 0.23-0.52) and versus other β-blockers up to 5 years was 0.45 (95% CI: 0.27-0.75). At 5 years, the HR of bisoprolol versus other β-blockers, and drugs other than β-blockers, for arrhythmia was 0.60 (95% CI: 0.35-1.0) and 0.61 (95% CI: 0.40-0.93), respectively. In conclusion, long-term significant reduction in the risk of mortality and various cardiovascular events with bisoprolol versus other β-blockers, and drugs other than β-blockers, confirm treatment guidelines recommendation that bisoprolol is particularly well suited as the first-line treatment of angina in primary care.

Risk of All-Cause Mortality in Diabetic Patients Taking β-Blockers

OBJECTIVE

To assess the relationship between use of β-blockers and all-cause mortality in patients with and without diabetes.

PATIENTS AND METHODS

Using data from the US National Health and Nutrition Examination Survey 1999-2010, we conducted a prospective cohort study. The study participants were followed-up from the survey participation date until December 31, 2011. We used a Cox proportional hazards model for all-cause mortality analysis. The multivariate-adjusted hazard ratios (HRs) of the participants taking β-blockers were compared with those of the participants not taking β-blockers.

RESULTS

This study included 2840 diabetic participants and 14,684 nondiabetic participants. Compared with diabetic participants not taking a β-blocker, all-cause mortality was significantly higher in diabetic participants taking any β-blocker (HR, 1.49; 95% CI, 1.09-2.04; P=.01), taking a β₁-selective β-blocker (HR, 1.60; 95% CI, 1.13-2.24; P=.007), or taking a specific β-blocker (bisoprolol, metoprolol, and carvedilol) (HR, 1.55; 95% CI, 1.09-2.21; P=.01). In addition, all-cause mortality in diabetic participants with coronary heart disease (CHD) was significantly higher in those taking beta-blockers, compared with those not taking beta-blockers (HR, 1.64; 95% CI, 1.08-2.48; P=.02), whereas that in non-diabetic participants with CHD was significantly lower in those taking beta-blockers (HR, 0.68; 95% CI, 0.50-0.94; P=.02). A propensity score-matched Cox proportional hazards model yielded similar results.

CONCLUSION

Use of β-blockers may be associated with an increased risk of mortality for patients with diabetes and among the subset who have CHD.

Beta-1 vs. beta-2 adrenergic control of coronary blood flow during isometric handgrip exercise in humans

During exercise, β-adrenergic receptors are activated throughout the body. In healthy humans, the net effect of β-adrenergic stimulation is an increase in coronary blood flow. However, the role of vascular β1 vs. β2 receptors in coronary exercise hyperemia is not clear. In this study, we simultaneously measured noninvasive indexes of myocardial oxygen supply (i.e., blood velocity in the left anterior descending coronary artery; Doppler echocardiography) and demand [i.e., rate pressure product (RPP) = heart rate × systolic blood pressure) and tested the hypothesis that β1 blockade with esmolol improves coronary exercise hyperemia compared with nonselective β-blockade with propranolol. Eight healthy young men received intravenous infusions of esmolol, propranolol, and saline on three separate days in a single-blind, randomized, crossover design. During each infusion, subjects performed isometric handgrip exercise until fatigue. Blood pressure, heart rate, and coronary blood velocity (CBV) were measured continuously, and RPP was calculated. Changes in parameters from baseline were compared with paired t-tests. Esmolol (Δ = 3296 ± 1204) and propranolol (Δ = 2997 ± 699) caused similar reductions in peak RPP compared with saline (Δ = 5384 ± 1865). In support of our hypothesis, ΔCBV with esmolol was significantly greater than with propranolol (7.3 ± 2.4 vs. 4.5 ± 1.6 cm/s; P = 0.002). This effect was also evident when normalizing ΔCBV to ΔRPP. In summary, not only does selective β1 blockade reduce myocardial oxygen demand during exercise, but it also unveils β2-receptor-mediated coronary exercise hyperemia.NEW & NOTEWORTHY In this study, we evaluated the role of vascular β1 vs. β2 receptors in coronary exercise hyperemia in a single-blind, randomized, crossover study in healthy men. In response to isometric handgrip exercise, blood flow velocity in the left anterior descending coronary artery was significantly greater with esmolol compared with propranolol. These findings increase our understanding of the individual and combined roles of coronary β1 and β2 adrenergic receptors in humans.

Advancements in pharmacotherapy for angina

INTRODUCTION

Angina pectoris is the most prevalent symptomatic manifestation of ischemic heart disease, frequently leads to a poor quality of life, and is a major cause of medical resource consumption. Since the early descriptions of nitrite and nitrate in the 19th century, there has been considerable advancement in the pharmacologic management of angina. Areas covered: Management of chronic angina is often challenging for clinicians. Despite introduction of several pharmacological agents in last few decades, a significant proportion of patients continue to experience symptoms (i.e., refractory angina) with subsequent disability. For the purpose of this review, we searched PubMed and Cochrane databases from inception to August 2016 for the most clinically relevant publications that guide current practice in angina therapy and its development. In this article, we briefly review the pathophysiology of angina and mechanism-based classification of current therapy. This is followed by evidence-based insight into the traditional and novel pharmacotherapeutic agents, highlighting their clinical usefulness. Expert opinion: Considering the wide array of available therapies with different mechanism efficacy and limiting factors, a personalized approach is essential, particularly for patients with refractory angina. Ongoing research with novel pharmacologic modalities is likely to provide new options for management of angina.

β-adrenoceptor blockers valuable but higher doses not necessary

β-adrenoceptor blockers have an important role in the treatment of heart disease and are useful as an adjunct in systemic hypertension. They are often prescribed at unnecessarily high doses, near the top of the dose-response curve. Higher doses are associated with more adverse events, have not been shown to improve clinical outcomes in cardiac failure and may worsen outcome in hypertension. β-adrenoceptor blockers can be very effective in lower doses, guided by close monitoring of heart rate and blood pressure and, when used in combination with low dose vasodilators and diuretics, give a better risk benefit profile.

Usefulness of Beta blockade in contemporary management of patients with stable coronary heart disease

Considerable progress has been made over the last few decades in the management of clinically stable coronary heart disease (SCHD), including improvements in interventions (e.g., percutaneous revascularization), pharmacological management, and risk factor control (e.g., smoking, diet, activity level, hypercholesterolemia, hypertension). Although β blockers have long been used for the treatment of SCHD, their efficacy was established in the era before widespread use of reperfusion interventions, modern medical therapy (e.g., angiotensin-converting enzyme inhibitors, angiotensin receptor blockers), or preventive treatments (e.g., aspirin, statins). On the basis of these older data, β blockers are assumed beneficial, and their use has been extrapolated beyond patients with heart failure and previous myocardial infarction, which provided the best evidence for efficacy. However, there are no randomized clinical trials demonstrating that β blockers decrease clinical events in patients with SCHD in the modern era. Furthermore, these agents are associated with weight gain, problems with glycemic control, fatigue, and bronchospasm, underscoring the fact that their use is not without risk. In conclusion, data are currently lacking to support the widespread use of β blockers for all SCHD patients, but contemporary data suggest that they be reserved for a well-defined high-risk group of patients with evidence of ongoing ischemia, left ventricular dysfunction, heart failure, and perhaps some arrhythmias.

β-blockers and cardiovascular events in patients with and without myocardial infarction: post hoc analysis from the CHARISMA trial

BACKGROUND

The long-term efficacy of β-blockers in patients with and without myocardial infarction (MI) is controversial.

METHODS AND RESULTS

This is post hoc analysis from the Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance (CHARISMA) trial of 4772 patients with prior MI, 7804 patients with known atherothrombosis, and 2101 patients with risk factors alone but without heart failure. Primary outcome was a composite of nonfatal MI, stroke, or cardiovascular mortality. The cohorts were divided into 2 groups based on baseline β-blocker use. In the propensity score-matched prior MI cohort, after 28 months of follow-up, β-blocker use was associated with a 31% lower risk of the primary outcome (70 [7.1%] versus 100 [10.2%]; hazards ratio, 0.69; 95% confidence interval, 0.50-0.94; P=0.021), driven by a lower risk of recurrent MI (33 [3.4%] versus 48 [4.9%]; hazards ratio, 0.62; 95% confidence interval, 0.39-1.00; P=0.049) with no difference in mortality (52 [5.3%] versus 66 [6.7%]; P=0.20). In the known atherothrombotic disease and the risk factors alone cohorts, β-blocker use was not associated with lower ischemic outcomes, whereas a trend toward a higher risk of stroke (3.5% versus 1.5%; hazards ratio, 2.13; 95% confidence interval, 0.92-4.92; P=0.079) was observed in the risk factors alone cohort. This higher stroke risk was significant in the regression model adjusted to the propensity score (hazards ratio, 2.69; 95% confidence interval, 1.33-5.44; P=0.006) and in the multivariable models.

CONCLUSIONS

β-blocker use in patients with prior MI but no heart failure was associated with a lower composite cardiovascular outcome driven by lower risk of recurrent MI with no difference in mortality. However, β-blocker use was not associated with lower cardiovascular events in those without MI, with a suggestion of inferior outcome with regard to stroke risk.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00050817.

Drug efficacy in treating stable angina pectoris: a protocol for network meta-analysis of randomised controlled trials

INTRODUCTION

There were 11 pairwise meta-analysis on the efficacy of β-blockers (including atenolol, propranolol, bisoprolol, metoprolol and nadolol), calcium channel blockers (including amlodipine, diltiazem, felodipine, nifedipine and verapamil), and nitrates (including isosorbide dinitrate, isosorbide mononitrate and nitroglycerin) in treating stable angina pectoris. No network meta-analytic study has been published to evaluate the efficacies of these antianginal drugs. Current clinical guidelines (eg, National Institute of Health and Care Excellence (NICE) clinical guideline 126) are only based on the findings of limited clinical trials and pairwise meta-analysis. This study aims to fill this gap of research by conducting a Bayesian network meta-analysis to compare all these antianginal drugs.

METHODS AND ANALYSES

Randomised controlled trials (RCT) on the drug therapy of stable angina pectoris with multiple outcome measures, selected from symptomatic relief, ECG tests, exercise tests, heart rates and blood pressures, etc, will be included. Overall effect sizes will be represented as mean differences with 95% credible intervals (CrI) for continuous outcome data and as ORs with 95% CrI for dichotomous outcome data. Bayesian network meta-analysis by WinBUGS will be conducted to compare the efficacies of these drugs. Sensitivity analysis on the quality of RCTs and subgroup analysis on the category of included drugs will be performed.

ETHICS AND DISSEMINATION

Ethical approval is not required because this study includes no confidential personal data and interventions on the patients. Network meta-analysis is based on the RCT reports of eligible drugs in treating stable angina pectoris. The results of this study will be disseminated by an open access and peer-reviewed publication.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42014007113.

Ivabradine in combination with beta-blocker improves symptoms and quality of life in patients with stable angina pectoris: results from the ADDITIONS study

AIM

Several clinical trials have demonstrated the antianginal and anti-ischemic efficacy of ivabradine in combination with beta-blocker in patients with stable angina pectoris. The ADDITIONS (PrActical Daily efficacy anD safety of Procoralan(®) In combinaTION with betablockerS) study evaluated the efficacy, safety, and tolerability of ivabradine added to beta-blocker, and its effect on angina symptoms and quality of life in routine clinical practice.

METHODS

This non-interventional, multicenter, prospective study included 2,330 patients with stable angina pectoris treated with a flexible dose of ivabradine twice daily in addition to beta-blocker for 4 months. The parameters recorded included heart rate, number of angina attacks, nitrate consumption, tolerance, and quality of life.

RESULTS

After 4 months ivabradine (mean dose 12.37 ± 2.95 mg/day) reduced heart rate by 19.4 ± 11.4 to 65.6 ± 8.2 bpm (p < 0.0001). The number of angina attacks was reduced by 1.4 ± 1.9 per week (p < 0.0001), and nitrate consumption by 1.9 ± 2.9 U per week (p < 0.0001). At baseline (i.e., on beta-blocker), half of the patients (51%) were classified as Canadian Cardiovascular Society (CCS) grade II; 29% were CCS grade I. After 4 months' treatment with ivabradine, most of the patients were CCS grade I (68%). The EQ-5D index improved by 0.17 ± 0.23 (p < 0.0001). The overall efficacy of ivabradine was considered by the physicians as "very good" (61%) or "good" (36%) in most patients. Suspected adverse drug reactions were documented in 14 patients; none were severe.

CONCLUSION

In daily clinical practice, combining ivabradine with beta-blocker not only reduces heart rate, number of angina attacks, and nitrate consumption, but also improves the quality of life in patients with stable angina pectoris.