Heart rate: a forgotten link in coronary artery disease?

Ivabradine in Septic Shock: A Narrative Review

In patients with septic shock, compensatory tachycardia initially serves to maintain adequate cardiac output and tissue oxygenation but may persist despite appropriate fluid and vasopressor resuscitation. This sustained elevation in heart rate and altered heart rate variability, indicative of autonomic dysfunction, is a well-established independent predictor of adverse outcomes in critical illness. Elevated heart rate exacerbates myocardial oxygen demand, reduces ventricular filling time, compromises coronary perfusion during diastole, and impairs the isovolumetric relaxation phase of the cardiac cycle, contributing to ventricular-arterial decoupling. This also leads to increased ventricular and atrial filling pressures, with a heightened risk of arrhythmias. Ivabradine, a highly selective inhibitor of the sinoatrial node's pacemaker current (If or "funny" current), mitigates heart rate by modulating diastolic depolarization slope without affecting contractility. By exerting a selective chronotropic effect devoid of negative inotropic properties, ivabradine shows potential for improving hemodynamics in septic shock patients with cardiac dysfunction. This review evaluates the plausible mechanisms and existing evidence regarding the utility of ivabradine in managing patients with septic shock.

Integrative review of electrocardiographic characteristics in patients with reduced, mildly reduced, and preserved heart failure

INTRODUCTION

Electrocardiographic (ECG) changes in heart failure with reduced, mildly reduced, and preserved ejection fractions can be critical in clinical assessment while waiting to perform echocardiograms or when it is unavailable. This integrative review aimed to identify ECG characteristics among hospitalized patients demonstrating three types of heart failure during acute decompensation.

METHODS

We searched an electronic database of PubMed, Web of Science, EMBASE, Scopus, Google Scholar, and ClinicalTrials.gov using medical subject headings (MeSH) terms and keywords. Sixteen studies were synthesized and reported.

RESULTS

Heart failure with reduced ejection fraction (HFrEF) was more common in men, comorbid with coronary artery diseases and diabetes mellitus, higher BNP/Pro-BNP, wide QRS, and left bundle branch block on ECG. On average, clients with heart failure with preserved ejection fraction (HFpEF) were older and more likely to have a history of atrial fibrillation, valvular heart diseases, hypertension, chronic obstructive pulmonary, and atrial fibrillation (AF) on ECG. Patients with mildly reduced (HFmrEF) were more similar to HFpEF in older patients, comorbid with hypertension, AF and valvular diseases, and AF on ECG.

CONCLUSIONS

ECG characteristics might be related to left ventricular ejection fraction. Demographics, BNP/Pro-BNP, and ECG changes might help differentiate different heart failure types. Therefore, ECG might be a prognostic tool while caring for heart failure patients when highly skilled resources are unavailable. These identified ECG characteristics help generate research hypotheses and warrant validation in future research.

Validation of a predictive model for coronary artery disease in patients with diabetes

BACKGROUND

No reliable model can currently be used for predicting coronary artery disease (CAD) occurrence in patients with diabetes. We developed and validated a model predicting the occurrence of CAD in these patients.

METHODS

We retrospectively enrolled patients with diabetes at Henan Provincial People's Hospital between 1 January 2020 and 10 June 2020, and collected data including demographics, physical examination results, laboratory test results, and diagnostic information from their medical records. The training set included patients ( n  = 1152) enrolled before 15 May 2020, and the validation set included the remaining patients ( n  = 238). Univariate and multivariate logistic regression analyses were performed in the training set to develop a predictive model, which were visualized using a nomogram. The model's performance was assessed by area under the receiver-operating characteristic curve (AUC) and Brier scores for both data sets.

RESULTS

Sex, diabetes duration, low-density lipoprotein, creatinine, high-density lipoprotein, hypertension, and heart rate were CAD predictors in diabetes patients. The model's AUC and Brier score were 0.753 [95% confidence interval (CI) 0.727-0.778] and 0.152, respectively, and 0.738 (95% CI 0.678-0.793) and 0.172, respectively, in the training and validation sets, respectively.

CONCLUSIONS

Our model demonstrated favourable performance; thus, it can effectively predict CAD occurrence in diabetes patients.

The Effect of Antipsychotics and Their Combinations with Other Psychotropic Drugs on Electrocardiogram Intervals Other Than QTc among Jordanian Adult Outpatients

The ECG changes produced by antipsychotics and other psychotropic medications are studied mostly regarding QTc interval prolongation. This study aimed to investigate ECG changes beyond long QTc interval produced by psychotropic medications. A cross-sectional study was conducted to assess the effect of these agents on RR, PR, TpTe intervals and TpTe/QT ratio among Jordanian outpatients. The RR interval was significantly shorter among patients on TCAs versus those not receiving TCAs and among patients on polytherapy versus those on monotherapy (p < 0.05 for both comparisons), when adjusted for age, gender, BMI, caffeine intake, smoking, presence of diabetes mellitus, cardiovascular disease and medications known to produce heart rate changes. Positive correlations were found between the PR interval and age in patients treated with SGAs, SSRIs, citalopram, polytherapy and in the total sample (p < 0.01 for all). Inverse correlations were found between the RR interval and the number of psychotropic medications among patients treated with SSRIs and in the whole study sample (p < 0.01 for both). In conclusion, various ECG changes beyond QTc interval prolongation are observed in patients on antipsychotics and other psychotropic medications, in those on polytherapy. It is recommended to obtain an ECG before starting patients on psychotropic drugs known to produce electrocardiographic changes and their combinations.

Prediction of SYNTAX score II improvement by adding temporal heart rate changes between discharge and first outpatient visit in patients with acute myocardial infarction

Background

The prognostic ability of the temporal changes in resting heart rate (ΔHR) in patients with acute myocardial infarction (AMI) for cardiovascular (CV) mortality and clinical outcomes is rarely examined. This study investigated the predictive value of ΔHR using models with SYNTAX score II (SxS-II) for the long-term prognosis of patients with AMI.

Methods

Six hundred five AMI patients with vital signs recorded at the first outpatient visit (2–4 weeks after discharge) were retrospectively recruited into this study. The changes between discharge and outpatient resting heart rate (D-O ΔHR) were calculated by subtracting the HR at the first post-discharge visit from the value recorded at discharge. The major adverse cardiovascular and cerebrovascular events (MACCE) include cardiovascular death, recurrent myocardial infarction, revascularization, and nonfatal stroke. The predictive values and reclassification ability of the different models were assessed using a likelihood ratio test, Akaike’s information criteria (AIC), receiver operating characteristic (ROC) curves, net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

Results

During the follow-up period, a drop-in resting heart rate (RHR) from discharge to first outpatient visit was independently associated with less risk of CV mortality [D-O ΔHR: hazards ratio (HR) = 0.97, 95% CI = 0.96–0.99, P < 0.001] and MACCE (HR = 0.98, 95% CI = 0.97–0.99, p = 0.001). The likelihood test indicated that the combined model of SxS-II and D-O ΔHR yielded the lowest AIC for CV mortality and MACCE (P < 0.001). Moreover, D-O ΔHR alone significantly improved the net reclassification and integrated discrimination of the models containing SxS-II for CV mortality and MACCE (CV mortality: NRI = 0.5600, P = 0.001 and IDI = 0.0759, P = 0.03; MACCE: NRI = 0.2231, P < 0.05 and IDI = 0.0107, P < 0.05).

Conclusions

The change in D-O ΔHR was an independent predictor of long-term CV mortality and MACCE. The D-O ΔHR combined with SxS-II could significantly improve its predictive probability.

Resting heart rate and risk of left and right heart failure in 0.5 million Chinese adults

OBJECTIVES

To compare the shape and strength of the associations of resting heart rate (RHR) with incident heart failure (HF) and pulmonary heart disease (PHD) in Chinese adults.

METHODS

The prospective China Kadoorie Biobank recruited >0.5 million adults from 10 geographically diverse regions (5 urban, 5 rural) of China during 2004-2008. After an 11-year follow-up, 6082 incident cases of HF and 5572 cases of PHD, were recorded among 491 785 participants with no prior history of heart disease or use of beta-blockers at baseline. Cox regression yielded HRs for each disease associated with usual RHR after adjustment for confounding factors.

RESULTS

The mean (SD) baseline RHR was 79 (12) (men 78 (12); women 80 (11)) bpm, and these decreased with increasing age (by about 1 bpm per 10 years). Usual RHR showed J-shaped associations with HF and log-linear associations PHD. For HF, each 10 bpm higher usual RHR was associated with an adjusted HR of 1.25 (95% CI 1.17 to 1.34) for RHR>75 bpm. For PHD, each 10 bpm higher RHR was associated with HR of 1.74 (1.67-1.81) across the full range of usual RHR. For HF at RHR>75 bpm but not PHD, the HRs per 10 bpm higher RHR were approximately halved by further adjustment for diabetes and hypertension.

CONCLUSIONS

RHR was strongly positively associated with PHD throughout the range studied, but was only associated with HF at RHR>75 bpm, and the strength of the associations with HF were only one-third of those with PHD.

Association between heart rate and cardiovascular death in patients with coronary heart disease: A NHANES-based cohort study

BACKGROUND

Due to the lack of research, this study aimed to assess the association between the specific range of heart rate and cardiovascular (CV) death in coronary heart disease (CHD) patients.

HYPOTHESIS

Heart rate of 70-79 bpm may be associated with reduced risk of CV death in CHD patients.

METHODS

This retrospective cohort study collected the data of CHD patients from the eight cycles of the Health and Nutrition Examination Survey (NHANES). The included patients were divided into four groups: <60, 60-69, 70-79, and ≥80 bpm. The start of follow-up date was the mobile examination center date, the last follow-up date was December 31, 2015. The average follow-up time was 81.70 months, and the longest follow-up time was 200 months. Competing risk models were developed to evaluate the association between heart rate and CV death, with hazard ratios (HRs) and 95% confidence intervals (CIs) calculated.

RESULTS

A total of 1648 patients with CHD were included in this study. CHD patients at heart rate of <60 (HR, 1.35; 95% CI, 1.34-1.36), 60-69 (HR, 1.05; 95% CI, 1.04-1.06) or ≥80 (HR, 1.39; 95% CI, 1.38-1.41) bpm had a higher risk of CV death than those at heart rate of 70-79 bpm.

CONCLUSIONS

Heart rate of <70 or ≥80 bpm was associated with an elevated risk of CV death among CHD patients. Continuous monitoring of heart rate may help to screen for health risks and offer early interventions to corresponding patients.

Lycopene: A Natural Arsenal in the War against Oxidative Stress and Cardiovascular Diseases

Lycopene is a bioactive red pigment found in plants, especially in red fruits and vegetables, including tomato, pink guava, papaya, pink grapefruit, and watermelon. Several research reports have advocated its positive impact on human health and physiology. For humans, lycopene is an essential substance obtained from dietary sources to fulfil the body requirements. The production of reactive oxygen species (ROS) causing oxidative stress and downstream complications include one of the major health concerns worldwide. In recent years, oxidative stress and its counter strategies have attracted biomedical research in order to manage the emerging health issues. Lycopene has been reported to directly interact with ROS, which can help to prevent chronic diseases, including diabetes and neurodegenerative and cardiovascular diseases. In this context, the present review article was written to provide an accumulative account of protective and ameliorative effects of lycopene on coronary artery disease (CAD) and hypertension, which are the leading causes of death worldwide. Lycopene is a potent antioxidant that fights ROS and, subsequently, complications. It reduces blood pressure via inhibiting the angiotensin-converting enzyme and regulating nitrous oxide bioavailability. It plays an important role in lowering of LDL (low-density lipoproteins) and improving HDL (high-density lipoproteins) levels to minimize atherosclerosis, which protects the onset of coronary artery disease and hypertension. Various studies have advocated that lycopene exhibited a combating competence in the treatment of these diseases. Owing to all the antioxidant, anti-diabetic, and anti-hypertensive properties, lycopene provides a potential nutraceutical with a protective and curing ability against coronary artery disease and hypertension.

Effects of Algorithmic Music on the Cardiovascular Neural Control

Music influences many physiological parameters, including some cardiovascular (CV) control indices. The complexity and heterogeneity of musical stimuli, the integrated response within the brain and the limited availability of quantitative methods for non-invasive assessment of the autonomic function are the main reasons for the scarcity of studies about the impact of music on CV control. This study aims to investigate the effects of listening to algorithmic music on the CV regulation of healthy subjects by means of the spectral analysis of heart period, approximated as the time distance between two consecutive R-wave peaks (RR), and systolic arterial pressure (SAP) variability. We studied 10 healthy volunteers (age 39 ± 6 years, 5 females) both while supine (REST) and during passive orthostatism (TILT). Activating and relaxing algorithmic music tracks were used to produce possible contrasting effects. At baseline, the group featured normal indices of CV sympathovagal modulation both at REST and during TILT. Compared to baseline, at REST, listening to both musical stimuli did not affect time and frequency domain markers of both SAP and RR, except for a significant increase in mean RR. A physiological TILT response was maintained while listening to both musical tracks in terms of time and frequency domain markers, compared to baseline, an increase in mean RR was again observed. In healthy subjects featuring a normal CV neural profile at baseline, algorithmic music reduced the heart rate, a potentially favorable effect. The innovative music approach of this study encourages further research, as in the presence of several diseases, such as ischemic heart disease, hypertension, and heart failure, a standardized musical stimulation could play a therapeutic role.

Prognostic impact of resting heart rate in patients with peripheral artery disease

OBJECTIVES

Resting heart rate has been increasingly identified as a marker of cardiovascular risk and has been extensively studied as a predictor of coronary artery disease progression. In peripheral artery disease, the prognostic impact of resting heart rate remains elusive.

METHODS

Consecutive patients undergoing invasive peripheral procedures were included. Data included resting heart rate determination by averaging manual radial pulse palpation measurements taken 24 h before and after an invasive peripheral procedure.

RESULTS

A total of 1720 patients were included (mean age 70±11 years, 38% were female, 39% had critical limb ischemia). During a median follow-up of 729 days, 364 (21.2%) patients died. Resting heart rate emerged as an independent predictor of mortality, even after adjusting for clinical characteristics, peripheral artery disease manifestation and anatomic extent, traditional risk factors, co-morbidities, and disease-modifying therapies: hazard ratio for heart rate >75 bpm was 1.010 (95% confidence interval 1.001-1.109), with each bpm increase in resting heart rate conferring a 1.1% increase in the risk of all-cause mortality (95% confidence interval 0.1-10.9%, adjusted p = 0.030).

CONCLUSIONS

Resting heart rate is an independent predictor of mortality in patients with peripheral artery disease; our findings extend heart rate as a possible marker of prognosis to non-coronary atherosclerotic vascular disease.

Effect of heart rate on hospital mortality in critically ill patients may be modified by age: a retrospective observational study from large database

BACKGROUND

Heart rate has been found associated with mortality in critically ill patients. However, whether the association differs between the elderly and non-elderly patients was unknown.

METHODS

We conducted a retrospective observational study of adult patients admitted to the intensive care unit (ICU) in the United States. Demographic, vital signs, laboratory tests, and interventions were extracted and compared between the elderly and non-elderly patients. The main exposure was heart rate, the proportion of time spent in heart rate (PTS-HR) was calculated. The primary outcome was hospital mortality. The multivariable logistic regression model was performed to assess the relationship between PTS-HR and hospital mortality, and interaction between PTS-HR and age categories was explored.

RESULTS

104,276 patients were included, of which 52,378 (50.2%) were elderly patients and 51,898 (49.8%) were non-elderly patients. The median age was 66 (IQR 54-76) years. After adjusting for confounders, PTS-HR < 60 beats per minute (bpm) (OR 0.972, 95% CI [0.945, 0.998], p = 0.031, P_interaction = 0.001) and 60-80 bpm (OR 0.925, 95% CI [0.912, 0.938], p < 0.001, P_interaction = 0.553) were associated with decreased risk of mortality; PTS-HR 80-100 bpm was associated with decreased mortality in the non-elderly patients (OR 0.955, 95% CI [0.941,0.975], p < 0.001) but was associated with increased mortality in the very elderly patients (OR 1.018, 95% CI [1.003,1.029], p = 0.017, P_interaction < 0.001). PTS-HR > 100 bpm (OR 1.093, 95% CI [1.081,1.105], p < 0.001, P_interaction = 0.004) was associated with increased mortality.

CONCLUSIONS

The effect of heart rate on hospital mortality differs between the elderly and non-elderly critically ill patients.

Temporal Changes in Resting Heart Rate, Left Ventricular Dysfunction, Heart Failure and Cardiovascular Disease: CARDIA Study

BACKGROUND

The prognostic significance of temporal changes in resting heart rate in young adults for premature heart failure and cardiovascular disease is unclear. We investigated the association between temporal changes in resting heart rate in young adults and early adult risk factors, subsequent cardiac function, and the risk of heart failure and cardiovascular by middle age.

METHODS

We examined 4343 Coronary Artery Risk Development in Young Adults (CARDIA) study participants (mean [SD] age was 29.9 [3.6] years at the CARDIA Year-5 examination [1990-1991], 49% of participants were men, and 45% were African-American). Adjusted linear regression models were used to assess the association between temporal changes in resting heart rate, early life cardiovascular disease risk factors, and midlife cardiac function. Cox proportional hazard regression models were used to relate temporal changes in resting heart rate to heart failure and cardiovascular disease. Outcomes were followed up until August 31, 2017.

RESULTS

Higher alcohol consumption (β = 0.03, P <0.001), lower physical activity (β = 0.002, P = 001), smoking (β = 1.58, P <0.001), men (P <0.001), African Americans (P <0.001), impaired left ventricular relaxation (e´,β = -0.13, P = 0.002), and worse diastolic function (E/e´, β = 0.1, P = 0.01) were associated with longitudinal increases in resting heart rate. We observed 268 cardiovascular disease and 74 heart failure events over a median of 26 years. In Cox models, baseline and temporal changes in resting heart rate were associated with higher risk of heart failure (hazard ratio [HR] =1.37 95% confidence interval [CI] [1.05-1.79] and HR = 1.38 95% CI [1.02-1.86]) and a higher risk cardiovascular disease (HR = 1.23 95% CI [1.07-1.42] and HR = 1.23 95% CI [1.05-1.44]).

CONCLUSIONS

Baseline and temporal changes in resting heart rate in young adults were associated with incident heart failure and cardiovascular disease by midlife. Contributory factors were associations between temporal increases in resting heart rate and early adult risk factors and subsequent cardiac dysfunction.

Ivabradine and endothelium: an update

Ivabradine is a pure heart-rate lowering drug that is nowadays used, accordingly to the last ESC Guidelines, to reduce mortality and heart failure (HF) hospitalization in patients with HF with reduced ejection fraction and in symptomatic patiens with inappropriate sinus tachycardia. Moreover, interesting effect of ivabradine on endothelial and myocardial function and on oxidative stress and inflamation pathways are progressively emerging. The aim of this paper is to highlight newer evidences about ivabradine effect (and consequently possible future application of the drug) in pathological settings different from guidelines-based clinical practice.

Possibilities of Combination of Beta-blockers and Ivabradine in Patients with Stable Angina Pectoris

Aim. To evaluate the therapeutic efficacy of a combination of ivabradine and beta-blockers (BAB) in patients with stable angina, initially taking only BAB and not reaching the target heart rate (HR) due to the risk of hypotension.

Material and methods. A prospective observational post-registration study was performed at the Research Institute for Complex Issues of Cardiovascular Diseases. The study included 50 patients with stable angina pectoris (diagnosed by coronary angiography in combination with clinical manifestations of angina of functional class II-III according to the Canadian classification) and an initial sinus rhythm with a heart rate of more than 70 beats per minute. These patients have already taken BAB. Heart rate, the number of angina attacks, nitrate intake and quality of life indicators according to the questionnaire were evaluated as criteria for therapeutic efficacy.

Results. Taking the study drug in combination with BAB led to a significant decrease the average heart rate at rest by 20%, as well as after a six-minute walk test (TLC) in most patients (p<0.050), and a decrease in the total number of angina attacks per week from 5 to less than 1 (p<0.050) and the frequency of nitrate intake for the relief of angina attacks from 58% to 20% (p=0.001). Therapy with ivabradine (Bravadin) was well tolerated by patients: there were no adverse events in the observed sample of patients, patients had a high adherence to treatment (100% of the contents of handed out blisters were used). During the 3 months of follow-up, according to the EQ-5D-5L quality of life questionnaire, patients improved their perception of their own health level (p<0.050), the number of patients experiencing mild (p=0.034) and strong (p=0.041) mobility limitations decreased; strong (p=0.024) restriction in self-care, mild (p=0.041) and strong (p=0.024) restriction of daily activities, mild manifestation of pain (p=0.009) and mild anxiety (p=0.027) also were reduced compared with the initial questionnaires.

Conclusion. Ivabradine (Bravadin) in addition to BAB is an effective and safe antianginal therapy for the prevention of angina attacks by reducing the initially high heart rate in patients with angina pectoris of functional class II-III.

Resting heart rate is associated with metabolic syndrome and predicted 10-year risk of cardiovascular disease: a cross-sectional study

BACKGROUND

This study examined whether resting heart rate (RHR) was associated with metabolic syndrome (MetS) and the 10-year predicted risk of cardiovascular disease in a Chinese population.

METHODS

The associations of RHR with MetS and 10-year risk of atherosclerotic cardiovascular diseases (ASCVD) was examined in a cross-sectional study conducted in Shanghai, China (n = 9486).

RESULTS

Compared with individuals in the lowest RHR quintile (≤71 b.p.m.), those in the highest quintile (≥91 b.p.m.) had a higher prevalence of MetS (21.2% vs 32.6%, respectively; P < 0.001). Logistic regression analyses showed that the multivariate-adjusted odds ratio (OR) and 95% confidence interval (CI) for MetS was 1.13 (1.08-1.18) for each 10-b.p.m. increment of RHR (P < 0.0001). Furthermore, RHR was strongly associated with the prevalence of hypertension, high blood glucose, and dyslipidemia, but not with central obesity. A stronger association of RHR with MetS was observed among individuals aged <65 years, male, with a body mass index <24 kg/m² , without diabetes, hypertension, abnormal lipids, and insulin resistance than among their counterparts (P < 0.05 for all). A significantly higher 10-year risk for ASCVD was observed with each 10-b.p.m. increment in RHR in both men and women (ORs [95% CIs] 1.20 [1.07-1.33] and 1.28 [1.17-1.39], respectively; P_trend  = 0.002 and < 0.0001, respectively).

CONCLUSIONS

In this study, RHR was associated with a higher prevalence of MetS and elevated 10-year predicted risk of ASCVD in both Chinese men and women. Whether RHR may serve as an indicator for MetS among relatively healthy individuals requires further investigation.

Ivabradine and metoprolol in fixed dose combination: When, why and how to use it

Heart rate is an important factor in coronary artery disease and its manifestations, and as such has been considered as a possible target for therapy. Although in epidemiological, and in less degree, in clinical studies derived indications of a possible pathogenetic role of heart rate in major cardiac diseases, clinical trials did not provided any strong evidence. However, even as a simple risk marker, remains important in the treatment of coronary artery disease and heart failure. Beta-blockers are the drugs most frequently used for heart rate control. However, recent studies constantly find insufficient effectiveness of beta-blockers in heart rate control and go further to question their efficacy on outcomes, making clear the need for an additional therapy. Ivabradine, a pure heart rate inhibitor, added to classic beta-blocker treatment represent the new therapeutic option in stable coronary disease and heart failure.

Acute Tachycardia Increases Aortic Distensibility, but Reduces Total Arterial Compliance Up to a Moderate Heart Rate

Background: The differential effects of rapid cardiac pacing on small and large vessels have not been well-established. The objective of this study was to investigate the effect of pacing-induced acute tachycardia on hemodynamics and arterial stiffness.

Methods: The pressure and flow waves in ascending aorta and femoral artery of six domestic swine were recorded simultaneously at baseline and heart rates (HR) of 135 and 155 beats per minutes (bpm) and analyzed by the models of Windkessel and Womersley types. Accordingly, the flow waves were simultaneously measured at carotid and femoral arteries to quantify aortic pulse wave velocity (PWV). The arterial distensibility was identified in small branches of coronary, carotid and femoral arteries with diameters of 300–600 μm by ex vivo experiments.

Results: The rapid pacing in HR up to 135 bpm reduced the total arterial compliance, stroke volume, systemic pulse pressure, and central systolic pressure by 36 ± 17, 38 ± 26, 29 ± 16, and 23 ± 12%, respectively, despite no statistical difference of mean aortic pressure, cardiac output, peripheral resistance, and vascular flow patterns. The pacing also resulted in a decrease of distensibility of small muscular arteries, but an increase of aortic distensibility. Pacing from 135 to 155 bpm had negligible effects on systemic and local hemodynamics and arterial stiffness.

Conclusions: There is an acute mismatch in the response of aorta and small arteries to pacing from basal HR to 135 bpm, which may have important pathological implications under chronic tachycardia conditions.

Incidence of cardiovascular events in patients with stabilized coronary heart disease: the EUROASPIRE IV follow-up study

The EUROASPIRE surveys (EUROpean Action on Secondary Prevention through Intervention to Reduce Events) demonstrated that most European coronary patients fail to achieve lifestyle, risk factor and therapeutic targets. Here we report on the 2-year incidence of hard cardiovascular (CV) endpoints in the EUROASPIRE IV cohort. EUROASPIRE IV (2012-2013) was a large cross-sectional study undertaken at 78 centres from selected geographical areas in 24 European countries. Patients were interviewed and examined at least 6 months following hospitalization for a coronary event or procedure. Fatal and non-fatal CV events occurring at least 1 year after this baseline screening were registered. The primary outcome in our analyses was the incidence of CV death or non-fatal myocardial infarction, stroke or heart failure. Cox regression models, stratified for country, were fitted to relate baseline characteristics to outcome. Our analyses included 7471 predominantly male patients. Overall, 222 deaths were registered of whom 58% were cardiovascular. The incidence of the primary outcome was 42 per 1000 person-years. Comorbidities were strongly and significantly associated with the primary outcome (multivariately adjusted hazard ratio HR, 95% confidence interval): severe chronic kidney disease (HR 2.36, 1.44-3.85), uncontrolled diabetes (HR 1.89, 1.50-2.38), resting heart rate ≥ 75 bpm (HR 1.74, 1.30-2.32), history of stroke (HR 1.70, 1.27-2.29), peripheral artery disease (HR 1.48, 1.09-2.01), history of heart failure (HR 1.47, 1.08-2.01) and history of acute myocardial infarction (HR 1.27, 1.05-1.53). Low education and feelings of depression were significantly associated with increased risk. Lifestyle factors such as persistent smoking, insufficient physical activity and central obesity were not significantly related to adverse outcome. Blood pressure and LDL-C levels appeared to be unrelated to cardiovascular events irrespective of treatment. In patients with stabilized CHD, comorbid conditions that may reflect the ubiquitous nature of atherosclerosis, dominate lifestyle-related and other modifiable risk factors in terms of prognosis, at least over a 2-year follow-up period.

Radial Pulse Spectrum Analysis as Risk Markers to Improve the Risk Stratification of Silent Myocardial Ischemia in Type 2 Diabetic Patients

Diabetic patients with silent myocardial ischemia (SMI) have elevated rates of morbidity and mortality and need intensive care and monitoring. An early predictor of SMI may lead to early diagnosis and medical treatment to prevent progression and adverse clinical events. Therefore, this paper was aimed to evaluate the radial pulse spectrum as risk markers to improve the risk stratification of SMI in type-2 diabetic patients; 195 diabetic patients at high-risk of SMI were enrolled. All patients underwent myocardial perfusion imaging and radial pressure wave measurement. The spectrum analysis of the radial pressure wave was calculated and transformed into Fourier series coefficients Cns and Pns. The risk of SMI (odds ratio: 4.46, 95%, C.I. 1.61–12.4, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$P<0.01$ \end{document}) was raised in diabetic patients classified high-risk group by C2. Multivariable regression analysis showed that C2 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$P<0.05$ \end{document}) and ankle–brachial index [(ABI) \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$P<0.05$ \end{document})] were related to SMI (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$R=0.46$ \end{document} and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$P<0.05$ \end{document}). The myocardial ischemic score (MIS), combining C2, C3, and P5, the albumin-to-creatinine ratio (ACR), and ABI, presented an excellent risk stratification performance in enrolled patients (odds ratio: 5.78, 95%, C.I. 2.29–14.6, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$P<0.01$ \end{document}). The area under receiver operating characteristic curves for C2, C3, P5, ABI, ACR, and MIS were 0.66, 0.60, 0.68, 0.51, 0.56, and 0.74, respectively, in identifying SMI. This paper demonstrated that C2 was independently associated with the extent of SMI in multivariable regression analysis. Odds ratio and chi-square tests reflected that C2 could be an important marker for the risk stratification of SMI. Furthermore, MIS, adding radial pulse spectrum analysis to ACR and ABI, could significantly improve the risk stratification of SMI in type-2 diabetic patients compared to any single risk factor.

How Heart Rate Should Be Controlled in Patients with Atherosclerosis and Heart Failure

PURPOSE OF REVIEW

Resting heart rate is an independent risk factor for all-cause and cardiovascular mortality in patients with heart failure. The main objectives are to discuss the prognosis of heart rate, its association with coronary atherosclerosis, and the modalities of control of the heart rate in sinus rhythm and in the rhythm of atrial fibrillation in patients with chronic heart failure.

RECENT FINDINGS

As a therapeutic option for control heart rate, medications such as beta-blockers, digoxin, and finally ivabradine have been studied. Non-dihydropyridine calcium channel blockers are contraindicated in patients with heart failure and reduced ejection fraction. The influence of the magnitude of heart rate reduction and beta-blocker dose on morbidity and mortality will be discussed. Regarding the patients with heart failure and atrial fibrillation, there are different findings in heart rate control with the use of a beta-blocker. Patients eligible for ivabradine have clinical benefits and increased ejection fraction. Vagal nerve stimulation has low efficacy for the control of heart rate. Complementary therapies such as tai chi and yoga showed no effect on heart rate. In this review, we discuss the main therapeutic options for the control of heart rate in patients with atherosclerosis and heart failure. More research is needed to examine the effects of therapeutic options for heart rate control in different population types, as well as their effects on clinical outcomes and impact on morbidity and mortality.

Ivabradine in Postural Orthostatic Tachycardia Syndrome: Preliminary Experience in Children

OBJECTIVE

Ivabradine is a selective and specific inhibitor of the I(f) current in the sinoatrial and atrioventricular nodes. It decreases heart rate and myocardial oxygen consumption at rest and during exercise. It is used in adults for management of heart failure and angina, but promising results have been obtained in postural orthostatic tachycardia syndrome (POTS). There is little experience of ivabradine in childhood, although it is used on a compassionate basis. Our aim was to review our experience of ivabradine in a retrospective evaluation of pediatric patients with POTS.

METHODS

We evaluated all patients younger than 18 years for whom ivabradine had been prescribed for this indication, from February 2008 to June 2014.

RESULTS

Twenty-two patients were identified (15 female). Median age was 14.5 years (11-17 years). The ivabradine dosage after up-titration was 0.1 mg/kg per dose twice daily. In 15 (68%) symptoms improved. Ivabradine was suspended in five, but only in one for worsening of symptoms. There was a reduction in heart rate on resting electrocardiogram (EKG) from a mean (standard deviation) of 82.5 (13.6) bpm to a mean of 71 (16.5) bpm (p = 0.007). No patient had increased duration of QTc (p = 0.44). One (4.5%) experienced phosphenes.

CONCLUSIONS

From this initial experience, ivabradine is safe in patients younger than 18 years with POTS. We observed improvement of symptoms in 68% and phosphenes in less than 5%. Further studies are needed to assess the safety in a randomized control setting.

Discovery of novel heart rate-associated loci using the Exome Chip

Resting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This study aims to discover new genetic loci associated with heart rate from Exome Chip meta-analyses.Heart rate was measured from either elecrtrocardiograms or pulse recordings. We meta-analysed heart rate association results from 104 452 European-ancestry individuals from 30 cohorts, genotyped using the Exome Chip. Twenty-four variants were selected for follow-up in an independent dataset (UK Biobank, N = 134 251). Conditional and gene-based testing was undertaken, and variants were investigated with bioinformatics methods.We discovered five novel heart rate loci, and one new independent low-frequency non-synonymous variant in an established heart rate locus (KIAA1755). Lead variants in four of the novel loci are non-synonymous variants in the genes C10orf71, DALDR3, TESK2 and SEC31B. The variant at SEC31B is significantly associated with SEC31B expression in heart and tibial nerve tissue. Further candidate genes were detected from long-range regulatory chromatin interactions in heart tissue (SCD, SLF2 and MAPK8). We observed significant enrichment in DNase I hypersensitive sites in fetal heart and lung. Moreover, enrichment was seen for the first time in human neuronal progenitor cells (derived from embryonic stem cells) and fetal muscle samples by including our novel variants.Our findings advance the knowledge of the genetic architecture of heart rate, and indicate new candidate genes for follow-up functional studies.

Ivabradine Attenuates the Microcirculatory Derangements Evoked by Experimental Sepsis

Background

Experimental data suggest that ivabradine, an inhibitor of the pacemaker current in sinoatrial node, exerts beneficial effects on endothelial cell function, but it is unclear if this drug could prevent microcirculatory dysfunction in septic subjects, improving tissue perfusion and reducing organ failure. Therefore, this study was designed to characterize the microcirculatory effects of ivabradine on a murine model of abdominal sepsis using intravital videomicroscopy.

Methods

Twenty-eight golden Syrian hamsters were allocated in four groups: sham-operated animals, nontreated septic animals, septic animals treated with saline, and septic animals treated with ivabradine (2.0 mg/kg intravenous bolus + 0.5 mg · kg−1 · h−1). The primary endpoint was the effect of ivabradine on the microcirculation of skinfold chamber preparations, assessed by changes in microvascular reactivity and rheologic variables, and the secondary endpoint was its effects on organ function, evaluated by differences in arterial blood pressure, motor activity score, arterial blood gases, and hematologic and biochemical parameters among groups.

Results

Compared with septic animals treated with saline, those treated with ivabradine had greater functional capillary density (90 ± 4% of baseline values vs. 71 ± 16%; P &lt; 0.001), erythrocyte velocity in capillaries (87 ± 11% of baseline values vs. 62 ± 14%; P &lt; 0.001), and arteriolar diameter (99 ± 4% of baseline values vs. 91 ± 7%; P = 0.041) at the end of the experiment. Besides that, ivabradine-treated animals had less renal, hepatic, and neurologic dysfunction.

Conclusions

Ivabradine was effective in reducing microvascular derangements evoked by experimental sepsis, which was accompanied by less organ dysfunction. These results suggest that ivabradine yields beneficial effects on the microcirculation of septic animals.

Electrocardiogram Alterations Associated With Psychotropic Drug Use and CACNA1C Gene Variants in Three Independent Samples

Several antipsychotics and antidepressants have been associated with QTc prolongation or other electrocardiogram (ECG) alterations, but their impact is still debated and other risk factors are known to affect QTc. We investigated the effect of antidepressants and antipsychotics on QTc and other ECG intervals/waves in three samples. Two discovery samples (cross-sectional sample n = 145 and prospective sample n = 68, naturalistic treatment) and a replication prospective sample (Clinical Antipsychotic Trials of Intervention Effectiveness, n = 515, randomized treatment) were analysed. In both prospective samples, baseline/follow-up changes in ECG parameters were analysed in relation to the number of psychotropic drugs stratified according to their known cardiovascular risk. In the cross-sectional sample, ECG parameters were compared among drugs with different risk profile. The possible effect of single nucleotide polymorphisms (SNPs) in the CACNA1C gene on QTc was also investigated. There was no evidence of mean QTc prolongation or increased risk of clinically relevant QTc prolongation (≥20 msec.) in association with psychotropic drugs stratified according to their known cardiovascular risk. The prescription of drugs with cardiovascular risk was less common in older individuals or individuals with cardiovascular comorbidities. Other factors (gender, baseline QTc, renal function) affected QTc. rs1006737 and SNPs in linkage disequilibrium with it modulated QTc duration/changes in all samples. An association between risk drugs and shorter RR interval or higher heart rate was found in all samples. A relevant effect of psychotropic drugs with cardiovascular risk on QTc duration was not observed. A number of factors other than psychotropic drugs may influence QTc. CACNA1C rs1006737 may modulate QTc in patients treated with psychotropic drugs.

Ivabradine, a novel medication for treatment of heart failure with reduced ejection fraction

PURPOSE

To critically evaluate current literature, review pharmacology, and discuss clinical role of ivabradine for patients with heart failure (HF) with reduced ejection fraction.

DATA SOURCES

A PubMed search was conducted using the search terms ivabradine and HF. All human studies analyzing the use of ivabradine in patients with HF with reduced ejection fraction and prescribing information were evaluated.

CONCLUSIONS

Greater benefit was seen in the prespecified subgroup with heart rate (HR) > 70 beats per minute (bpm) in the BEAUTIFUL study. Therefore, SHIFT examined the effect of ivabradine on patients with higher resting HR, lower ejection fraction, who had been hospitalized for HF within the previous year. A significant difference was found in the composite primary endpoint of cardiovascular death and hospitalizations for worsening HF in patients with HF and left ventricular systolic dysfunction, driven primarily by reduction in hospitalizations for worsening HF. The most common adverse effect was bradycardia.

IMPLICATIONS FOR PRACTICE

Ivabradine is a safe and effective medication for HR reduction to reduce hospitalizations in patients with stable, symptomatic HF (ejection fraction < 35%), in sinus rhythm, and HR > 70 bpm.

Effects of urinary cortisol levels and resting heart rate on the risk for fatal and nonfatal cardiovascular events

BACKGROUND AND AIMS

Higher cortisol levels are associated with cardiovascular mortality in the elderly. It is unclear whether this association also exists in a general population of younger adults and for non-fatal cardiovascular events. Likewise, resting heart rate is associated with cardiovascular mortality, but fewer studies have also considered non-fatal events. The goal of this study was to investigate whether twenty-four-hour urinary cortisol (24-h UFC) levels and resting heart rate (RHR) predict major adverse fatal and non-fatal cardiovascular events (MACE) in the general population.

METHODS

We used data from a subcohort of the PREVEND study, a prospective general population based cohort study with a follow-up of 6.4 years for 24-h UFC and 10.6 years for RHR. Participants were 3432 adults (mean age 49 years, range 28-75). 24-h UFC was collected and measured by liquid chromatography-tandem mass spectrometry. RHR was measured at baseline in a supine position for 10 min with the Dinamap XL Model 9300. Information about cardiovascular events and mortality was obtained from the Dutch national registry of hospital discharge diagnoses and the municipal register respectively.

RESULTS

24-h UFC did not significantly increase the hazard of MACE (hazard ratio = 0.999, 95% confidence interval = 0.993-1.006, p = 0.814). RHR increased the risk for MACE with 17% per 10 extra heart beats per minute (hazard ratio = 1.016, 95% confidence interval = 1.001-1.031, p = 0.036) after adjustment for conventional risk factors.

CONCLUSIONS

In contrast to 24-h UFC, RHR is a risk marker for MACE in the general population.

Association between resting heart rate and cardiovascular risk factors in adolescents

This cross-sectional study was performed in 2011 and included 4619 Brazilian adolescents (14-19 years old) to analyze the association between elevated resting heart rate (RHR) and cardiovascular risk factors in boys and girls. RHR and blood pressure were measured using an oscillometric monitor. Overweight was assessed by body mass index and abdominal obesity by waist circumference. Physical activity levels and sedentary behaviors were obtained using a questionnaire. The effect of clustering of cardiovascular risk factors on RHR was analyzed. For boys, abdominal obesity (b = 0.106, p = 0.003), high sedentary behavior (b = 0.099, b < 0.001), physical inactivity (b = 0.049, p = 0.034), and high blood pressure (b = 0.160, p < 0.001) were associated with RHR, whereas for girls, only high blood pressure was associated with RHR (b = 0.259, p < 0.001), after adjustment for age, period of the day, and other cardiovascular risk factors. Boys with five risk factors presented significantly higher (p < 0.05) RHR values (82.5 ± 13.4 beats min(-1)) than those for boys without any cardiovascular risk factors (68.8 ± 10.4 beats min(-1)). The girls with five risk factors presented a mean RHR value of 89.8 ± 9.9 beats min(-1) that was higher (p < 0.05) than that for girls who had no risk factors (79.6 ± 10.9 beats min(-1)).

CONCLUSIONS

Our study demonstrated that while RHR was associated with cardiovascular risk factors in both sexes, the clustering of risk factors amplified the elevation of RHR in a gender-dependent fashion.

WHAT IS KNOWN

• Resting heart rate is a marker of cardiovascular disease and mortality in adults and associated with risk factor such as higher levels of blood pressure, triglycerides, glucose, and obesity in children and adolescents.

WHAT IS NEW

• The data from the current study suggest that the risk factor clustering is associated with elevated resting heart rate in adolescents and that the clustering of risk factors amplifies the elevation of resting heart rate in a gender-dependent fashion.

Impact of Ivabradine on Central Aortic Blood Pressure and Myocardial Perfusion in Patients With Stable Coronary Artery Disease

Treatment of hypertensive patients with β-blockers reduces heart rate and decreases central blood pressure less than other antihypertensive drugs, implying that reducing heart rate without altering brachial blood pressure could increase central blood pressure, explaining the increased cardiovascular risk reported with β-blocker. We describe a randomized, double-blind study to explore whether heart rate reduction with the If inhibitor ivabradine had an impact on central blood pressure. We included 12 normotensive patients with stable coronary artery disease, heart rate ≥70 bpm (sinus rhythm), and stable background β-blocker therapy. Patients received ivabradine 7.5 mg BID or matched placebo for two 3-week periods with a crossover design and evaluation by aplanation tonometry. Treatment with ivabradine was associated with a significant reduction in resting heart rate after 3 weeks versus no change with placebo (-15.8±7.7 versus +0.3±5.8 bpm; P=0.0010). There was no relevant between-group difference in change in central aortic systolic blood pressure (-4.0±9.6 versus +2.4±12.0 mm Hg; P=0.13) or augmentation index (-0.8±10.0% versus +0.3±7.6%; P=0.87). Treatment with ivabradine was associated with a modest increase in left ventricular ejection time (+18.5±17.8 versus +2.8±19.3 ms; P=0.074) and a prolongation of diastolic perfusion time (+215.6±105.3 versus -3.0±55.8 ms with placebo; P=0.0005). Consequently, ivabradine induced a pronounced increase in Buckberg index, an index of myocardial viability (+39.3±27.6% versus -2.5±13.5% with placebo; P=0.0015). In conclusion, heart rate reduction with ivabradine does not increase central aortic blood pressure and is associated with a marked prolongation of diastolic perfusion time and an improvement in myocardial perfusion index.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrialsregister.eu. Unique identifier: 2011-004779-35.

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

Introduction

The anti-anginal efficacy of ivabradine is well established. We describe a post hoc analysis in the ADDITIONS database to investigate effectiveness and tolerability of ivabradine in combination with beta-blocker in patients with angina who have had a percutaneous coronary intervention (PCI).

Methods

ADDITIONS was a non-interventional, multicenter prospective study including 2,330 patients with stable angina. In addition to beta-blocker, patients were treated with ivabradine in approved dosages for 4 months. We divided the population according to whether they had previously had a PCI or not, and explored the effect of ivabradine on heart rate, number of weekly angina attacks, frequency of nitrate consumption, as well as quality of life (QoL) and tolerability.

Results

Data were available for 2,319 patients, of whom 51.4% had previously had a PCI. There was no difference in the effect of ivabradine on mean heart rate between patients with a previous PCI [64.4 ± 7.6 beats per minute (bpm)] than those without (66.8 ± 8.5 bpm) at 4 months (both P < 0.0001). Similarly, the number of angina attacks decreased from 1.9 ± 2.4 to 0.5 ± 1.5 per week in patients with a previous PCI and 1.5 ± 2.0 to 0.3 ± 1.0 per week in patients without a previous PCI (both P < 0.0001). The frequency of nitrate consumption fell from 2.7 ± 3.7 to 1.0 ± 1.9 per week and 1.8 ± 2.8 to 0.6 ± 1.5 per week (both P < 0.0001) in patients with and without a previous PCI, respectively. There was no difference in the improvements in Canadian Cardiovascular Society class of angina, QoL, and physicians’ assessment of effectiveness and tolerability between patients with a previous PCI and those without.

Conclusion

Ivabradine is an effective and well-tolerated anti-anginal treatment in patients with stable angina after PCI. Ivabradine reduced the frequency of weekly angina attacks and nitrate consumption, led to an improvement in Canadian Cardiovascular Society class and a substantial improvement in the QoL of stable angina patients.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-015-0182-8) contains supplementary material, which is available to authorized users.

Ivabradine in stable coronary artery disease without clinical heart failure

BACKGROUND

An elevated heart rate is an established marker of cardiovascular risk. Previous analyses have suggested that ivabradine, a heart-rate-reducing agent, may improve outcomes in patients with stable coronary artery disease, left ventricular dysfunction, and a heart rate of 70 beats per minute or more.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial of ivabradine, added to standard background therapy, in 19,102 patients who had both stable coronary artery disease without clinical heart failure and a heart rate of 70 beats per minute or more (including 12,049 patients with activity-limiting angina [class ≥II on the Canadian Cardiovascular Society scale, which ranges from I to IV, with higher classes indicating greater limitations on physical activity owing to angina]). We randomly assigned patients to placebo or ivabradine, at a dose of up to 10 mg twice daily, with the dose adjusted to achieve a target heart rate of 55 to 60 beats per minute. The primary end point was a composite of death from cardiovascular causes or nonfatal myocardial infarction.

RESULTS

At 3 months, the mean (±SD) heart rate of the patients was 60.7±9.0 beats per minute in the ivabradine group versus 70.6±10.1 beats per minute in the placebo group. After a median follow-up of 27.8 months, there was no significant difference between the ivabradine group and the placebo group in the incidence of the primary end point (6.8% and 6.4%, respectively; hazard ratio, 1.08; 95% confidence interval, 0.96 to 1.20; P=0.20), nor were there significant differences in the incidences of death from cardiovascular causes and nonfatal myocardial infarction. Ivabradine was associated with an increase in the incidence of the primary end point among patients with activity-limiting angina but not among those without activity-limiting angina (P=0.02 for interaction). The incidence of bradycardia was higher with ivabradine than with placebo (18.0% vs. 2.3%, P<0.001).

CONCLUSIONS

Among patients who had stable coronary artery disease without clinical heart failure, the addition of ivabradine to standard background therapy to reduce the heart rate did not improve outcomes. (Funded by Servier; SIGNIFY Current Controlled Trials number, ISRCTN61576291.).

Inadequate heart rate control despite widespread use of beta-blockers in outpatients with stable CAD: findings from the international prospective CLARIFY registry

BACKGROUND

To use CLARIFY, a prospective registry of patients with stable CAD (45 countries), to explore heart rate (HR) control and beta-blocker use.

METHODS

We analyzed the CLARIFY population according to beta-blocker use via descriptive statistics with Pearson's χ(2) test for comparisons, as well as a multivariable stepwise model.

RESULTS

Data on beta-blocker use was available for 32,914 patients, in whom HR was 68 ± 11 bpm; patients with angina, previous myocardial infarction, and heart failure had HRs of 69 ± 12, 68 ± 11, and 70 ± 12 bpm, respectively. 75% of these patients were receiving beta-blockers. Bisoprolol (34%), metoprolol tartrate (16%) or succinate (13%), atenolol (15%), and carvedilol (12%) were mostly used; mean dosages were 49%, 76%, 35%, 53%, and 45% of maximum doses, respectively. Patients aged <65 years were more likely to receive beta-blockers than patients ≥ 75 years (P<0.0001). Gender had no effect. Subjects with HR ≤ 60 bpm were more likely to be on beta-blockers than patients with HR ≥ 70 bpm (P<0.0001). Patients with angina, previous myocardial infarction, heart failure, and hypertension were more frequently receiving beta-blockers (all P<0.0001), and those with PAD and asthma/COPD less frequently (both P<0.0001). Beta-blocker use varied according to geographical region (from 87% to 67%).

CONCLUSIONS

Three-quarters of patients with stable CAD receive beta-blockers. Even so, HR is insufficiently controlled in many patients, despite recent guidelines for the management of CAD. There is still much room for improvement in HR control in the management of stable CAD.

Selective and specific inhibition of If with ivabradine for the treatment of coronary artery disease or heart failure

Heart rate is an important contributor in the pathophysiology of both coronary artery disease (CAD) and heart failure (HF). Ivabradine is an anti-anginal and anti-ischaemic agent, which selectively and specifically inhibits the I_f current in the sino-atrial node and provides pure heart rate reduction without altering other cardiac parameters, including conduction, and without directly affecting other haemodynamic parameters. It is approved for the treatment of CAD and HF. This article summarises the pharmacological properties, pharmacokinetics, clinical efficacy and tolerability of ivabradine in the treatment of CAD and HF, and presents evidence demonstrating that the pharmacological and clinical properties and clinical efficacy of ivabradine make it an important therapeutic choice for patients with stable CAD or HF. The positive effect of ivabradine on angina pectoris symptoms and its ability to reduce myocardial ischemia make it an important agent in the management of patients with stable CAD or chronic HF. Further studies are underway to add to the already robust evidence of ivabradine for the prevention of cardiovascular events in patients with CAD but without clinical HF. The SIGNIFY (Study assessInG the morbidity–mortality beNefits of the I_f inhibitor ivabradine in patients with coronarY artery disease) trial includes patients with stable CAD and an LVEF above 40 %, with no clinical sign of HF, and is investigating the long-term effects (over a period of 48 months) of ivabradine in a large study population. So far, this study has included more than 19,000 patients from 51 countries.

Effect of ivabradine-induced heart rate reduction on flow-mediated dilation measured with high-sensitivity ultrasound in patients with stable coronary heart disease

Background

Experimental data suggests that exclusive heart rate reduction with ivabradine is associated with the amelioration of the endothelial function. Since it is presently unknown whether this also applies to humans, the aim of this pilot study was to investigate whether heart rate reduction with ivabradine modulates the endothelial function in humans with an established coronary heart disease.

Methods

Using high-sensitivity ultrasound, we analysed the flow-mediated (FMD) and nitro-mediated dilation (NMD) of the brachial artery in 25 patients (62.9 ± 8.4 years) with a stable coronary heart disease and a resting heart rate of ≥70 beats per minute (bpm). To assess acute effects, measurements were performed before and 4 hours after the first intake of ivabradine 7.5 mg. Sustained effects of an ivabradine therapy (5 mg to 7.5 mg twice daily) were investigated after 4 weeks.

Results

We found a significant decrease in heart rate, both 4 hours after the intake of 7.5 mg of ivabradine (median -8 [interquartile range (IQR) -14 to -4] bpm) and after 4 weeks of twice daily intake (median -10 [IQR-17 to -5] bpm) (p < 0.05). However, the FMD did not change significantly: neither after first dose of ivabradine nor after sustained therapy (baseline FMD: median 5.0 [IQR 2.4 to 7.9]%; FMD 4 hours after 7.5 mg of ivabradine: median 4.9 [IQR 2.7 to 9.8]%; FMD after 4 weeks of ivabradine therapy: median 6.1 [IQR 4.3 to 8.2]%). No significant changes of the NMD were observed. In regression analysis, the heart rate and FMD did not correlated, irrespective of the ivabradine intake (r² = 0.086).

Conclusion

In conclusion, in our study heart rate reduction through ivabradine does not improve the endothelial function in patients with a stable coronary heart disease. Moreover, we found no correlation between the heart rate and the endothelial function.

Screening entire health system ECG databases to identify patients at increased risk of death

BACKGROUND

Current methods to identify patients at higher risk for sudden cardiac death, primarily left ventricular ejection fraction ≤35%, miss ≈80% of patients who die suddenly. We tested the hypothesis that patients with elevated QRS-scores (index of myocardial scar) and wide QRS-T angles (index abnormal depolarization-repolarization relationship) have high 1-year all-cause mortality and could be further risk stratified with clinical characteristics.

METHODS AND RESULTS

We screened all 12-lead ECGs over 6 months at 2 large hospital systems and analyzed clinical characteristics and 1-year mortality. Patients with ECGs obtained in hospital areas with known high mortality rates were excluded. At the first hospital, QRS-score ≥5 and QRS-T angle ≥105° identified 8.0% of patients and was associated with an odds ratio of 2.79 (95% confidence interval, 2.10-3.69) for 1-year mortality compared with patients below both ECG thresholds (13.9% versus 5.5% death rate). Left ventricular ejection fraction was >35% in 82% of the former group of patients, and addition of ECG measures to left ventricular ejection fraction increased the discrimination of death risk (P<0.0001). At the second hospital, the odds ratio was 2.42 (1.95-3.01) for 1-year mortality (8.8% versus 3.8%). Adjustment for patient characteristics eliminated interhospital differences. Multivariable adjusted odds ratio combining data from both hospitals was 1.53 (1.28-1.83). Increasing heart rate and chronic renal impairment further predicted mortality.

CONCLUSIONS

Screening hospital ECG databases with QRS-scoring and QRS-T angle analysis identifies patients with high 1-year all-cause mortality and predominantly preserved left ventricular ejection fraction. This approach may represent a widely available method to identify patients at increased risk of death.

Rationale, design, and baseline characteristics of the Study assessInG the morbidity-mortality beNefits of the If inhibitor ivabradine in patients with coronarY artery disease (SIGNIFY trial): a randomized, double-blind, placebo-controlled trial of ivabradine in patients with stable coronary artery disease without clinical heart failure

BACKGROUND

Elevated heart rate in stable coronary artery disease (CAD) is associated with worse outcomes, particularly increased risk of myocardial infarction. Heart rate reduction with the If inhibitor ivabradine confers symptomatic benefits in angina pectoris and reduces coronary events in patients with stable CAD and left ventricular (LV) systolic dysfunction, with a resting heart rate of ≥70 beats/min. The SIGNIFY trial is testing the hypothesis that heart rate reduction using ivabradine reduces mortality and cardiovascular events in patients with stable CAD, but without clinical heart failure.

METHODS

The SIGNIFY trial is a randomized, double-blind, parallel-group, placebo-controlled, event-driven study in patients with stable CAD (1,139 centers, 51 countries). Participants are 55 years or older, with stable CAD and an LV ejection fraction >40%, in sinus rhythm, with a baseline resting heart rate of ≥70 beats/min, and with at least 1 additional cardiovascular risk factor. At inclusion, patients receive ivabradine 7.5 mg twice a day or matching placebo, which is adjusted at every visit to a heart rate target of 60 beats/min. Participants should receive the best possible background treatment for stable CAD. The primary end point is a composite of cardiovascular death or nonfatal myocardial infarction.

RESULTS

Recruitment lasted from October 2009 to April 2012. The SIGNIFY trial has recruited 19,102 patients (age 65.0 ± 7.2 years, resting heart rate 77.2 ± 7.0 beats/min, 72% male) with no evidence for LV dysfunction (ejection fraction 56.5% ± 8.6%).

CONCLUSION

The SIGNIFY trial will shed further light on the role of heart rate lowering with ivabradine in patients with stable CAD without clinical heart failure. The study is expected to end in 2014.

Management of pericarditis and myocarditis: could heart-rate-reducing drugs hold a promise?

Rest is usually recommended in acute pericarditis and acute myocarditis. Given that myocarditis often leads to hospitalization, this task seems easy to carry out in hospital practice; however, it could be a real challenge at home in daily life. Heart rate-lowering treatments (mainly beta-blockers) are usually recommended in case of acute myocarditis, especially in case of heart failure or arrhythmias, but level of proof remains weak. Calcium channel inhibitors and digoxin are sometimes proposed, albeit in limited situations. It is possible that rest or even heart rate-lowering treatments could help to manage these patients by preventing heart failure as well as by limiting "mechanical inflammation" and controlling arrhythmias, especially life-threatening ones. Whether heart rate has an effect on inflammation remains unclear. Several questions remain unsolved, such as the duration of such treatments, especially in light of new heart rate-lowering treatments, such as ivabradine. In this review, we discuss rest and heart-rate lowering medications for the treatment of pericarditis and myocarditis. We also highlight some work in experimental models that indicates the beneficial effects of such treatments for these conditions. Finally, we suggest certain experimental avenues, through the use of animal models and clinical studies, which could lead to improved management of these patients.