Heart rate as an independent risk factor in patients with multiple organ dysfunction: a prospective, observational study

Effect of heart rate control with ivabradine on hemodynamic in patients with sepsis: study protocol for a prospective, multicenter, randomized controlled trial

INTRODUCTION

Sepsis, a life-threatening syndrome, is often accompanied by tachycardia in spite of hypovolemia and hypotension have been corrected. Recently, relevant studies have shown that sustained tachycardia in sepsis was related to high mortality, and appropriate control of heart rate (HR) could improve prognosis. Ivabradine reduces HR directly without a negative inotropic effect through inhibition of the If ionic current, which is different from the traditional rate control drug (beta-blockers).

METHODS AND ANALYSIS

This is a prospective, multicenter, randomized, open label study designed to investigate the effect of heart rate control with ivabradine on hemodynamic in patients with sepsis. Our study will enroll 172 patients with sepsis as defined by The Third International Consensus Definitions for Sepsis and Septic Shock criteria with sinus rate of 95 bpm or higher despite a hemodynamic optimization. Patients will be randomly assigned to standard treatment group (GS) or ivabradine group (GI, standard treatment for sepsis plus enteral ivabradine). Patients in GI will receive ivabradine to maintain HR between 70 and 94 bpm. The primary outcome is the difference of a reduction in HR below 95 bpm and the effect of ivabradine on hemodynamics between GI and GS group within the first 96 h after randomization. The secondary outcomes include organ function measures, the difference in SOFA score, incidence of adverse events, need for organ support, length of ICU stay, and 28-day overall mortality.

DISCUSSION

There are limited studies on ivabradine to control heart rate in patients with sepsis. Our study aims to evaluate whether direct sinus node inhibition can improve hemodynamics, as well as its impact on organ function and prognosis in patients with sepsis, so as to provide evidence for the safe usage in clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05882708. Registered on May 11, 2023, https://clinicaltrials.gov/ct2/show/NCT05882708 .

Cardiac index and heart rate as prognostic indicators for mortality in septic shock: A retrospective cohort study from the MIMIC-IV database

Background

Septic shock is a life-threatening condition that can lead to organ dysfunction and death. In the ICU, monitoring of cardiac index (CI) and heart rate (HR) is commonly used to guide management and predict outcomes in septic shock patients. However, there is a lack of research on the association between CI and HR and the risk of mortality in this patient population. Therefore, the aim of this study was to investigate the relationship between different levels of CI and HR and mortality in septic shock patients.

Methods

Data analysis was obtained from the MIMIC-IV version 2.0 database. Sepsis and septic shock were primarily defined by sepsis-3, the third international consensus on sepsis and septic shock. CI was computed using cardiac output (CO) and body surface area (BSA). To evaluate the incidence of CI with respect to each endpoint (7-, 14-, 21-, and 28-day mortality), a restricted cubic spline curve function (RCS) was used. The optimal cutoff value for predicted mortality was determined using the Youden index. Analyses of KM curves, cox regression, and logistic regression were conducted separately to determine the relationship between various CI and HR and 28-day mortality.

Results

This study included 1498 patients with septic shock. A U-shaped relationship between CI levels and risk of mortality in septic shock was found by RCS analysis (p < 0.001). CI levels within the intermediate range of 1.85-2.8 L/min/m2 were associated with a mortality hazard ratio (HR) < 1. In contrast, low CI (HR = 1.87 95% CI: 1.01-3.49) and high CI (HR = 1.93 95% CI: 1.26-2.97) had a significantly increased risk of mortality. The AUC for heart rate prediction of mortality by Youden index analysis was 0.70 95%CI:0.64-0.76 with a cut-off value of 93.63 bpm. According to the characteristics of HR and CI, patients were divided into six subgroups HR↓+CI intermediate group (n = 772), HR↓+CI↓ group (n = 126), HR↓+CI↑ group (n = 294), HR↑+CI intermediate group (n = 132), HR↑+CI↓ group (n = 24), and HR↑+CI↑ group (n = 150). The KM curves, COX regression, and logistic regression analysis showed that the survival rates the of HR↓+CI intermediate group, HR↓+CI↓ group, and HR↓+CI↑ were higher than the other groups. The risk factors of HR↑+CI intermediate group, HR↑+CI↓, and HR↑+CI↑ with ICU 28-day mortality were HR = 2.91 (95% CI: 1.39-5.97), HR = 3.67 (95% CI: 1.39-11.63), and HR = 5.77 (95% CI: 2.98-11.28), respectively.

Conclusion

Our retrospective study shows that monitoring cardiac index and heart rate in patients with septic shock may help predict the organismal response and hemodynamic consequences, as well as the prognosis. Thus, healthcare providers should carefully monitor changes in these parameters in septic shock patients transferred to the ICU for treatment.

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.

Wearable sensors for prediction of intraamniotic infection in women with preterm premature rupture of membranes: a prospective proof of principle study

PURPOSE

To evaluate the use of wearable sensors for prediction of intraamniotic infection in pregnant women with PPROM.

MATERIALS AND METHODS

In a prospective proof of principle study, we included 50 patients diagnosed with PPROM at the University Hospital Zurich between November 2017 and May 2020. Patients were instructed to wear a bracelet during the night, which measures physiological parameters including wrist skin temperature, heart rate, heart rate variability, and breathing rate. A two-way repeated measures ANOVA was performed to evaluate the difference over time of both the wearable device measured parameters and standard clinical monitoring values, such as body temperature, pulse, leucocytes, and C-reactive protein, between women with and without intraamniotic infection.

RESULTS

Altogether, 23 patients (46%) were diagnosed with intraamniotic infection. Regarding the physiological parameters measured with the bracelet, we observed a significant difference in breathing rate (19 vs 16 per min, P < .01) and heart rate (72 vs 67 beats per min, P = .03) in women with intraamniotic infection compared to those without during the 3 days prior to birth. In parallel to these changes standard clinical monitoring values were significantly different in the intraamniotic infection group compared to women without infection in the 3 days preceding birth.

CONCLUSION

Our results suggest that wearable sensors are a promising, noninvasive, patient friendly approach to support the early detection of intraamniotic infection in women with PPROM. However, confirmation of our findings in larger studies is required before implementing this technique in standard clinical management.

The Association Between Tachycardia and Mortality in Septic Shock Patients According to Serum Lactate Level: A Nationwide Multicenter Cohort Study

BACKGROUND

This study aimed to evaluate whether the effect of tachycardia varies according to the degree of tissue perfusion in septic shock.

METHODS

Patients with septic shock admitted to the intensive care units were categorized into the tachycardia (heart rate > 100 beats/min) and non-tachycardia (≤ 100 beats/min) groups. The association of tachycardia with hospital mortality was evaluated in each subgroup with low and high lactate levels, which were identified through a subpopulation treatment effect pattern plot analysis.

RESULTS

In overall patients, hospital mortality did not differ between the two groups (44.6% vs. 41.8%, P = 0.441), however, tachycardia was associated with reduced hospital mortality rates in patients with a lactate level ≥ 5.3 mmol/L (48.7% vs. 60.3%, P = 0.030; adjusted odds ratio [OR], 0.59, 95% confidence interval [CI], 0.35-0.99, P = 0.045), not in patients with a lactate level < 5.3 mmol/L (36.5% vs. 29.7%, P = 0.156; adjusted OR, 1.39, 95% CI, 0.82-2.35, P = 0.227).

CONCLUSION

In septic shock patients, the effect of tachycardia on hospital mortality differed by serum lactate level. Tachycardia was associated with better survival in patients with significantly elevated lactate levels.

Norepinephrine dose, lactate or heart rate: what impacts prognosis in sepsis and septic shock? Results from a prospective, monocentric registry

OBJECTIVE

The study comprehensively investigates the prognostic value of norepinephrine (NE) dose, lactate and heart rate in patients with sepsis and septic shock.

BACKGROUND

Limited data regarding the prognostic value of NE dose, lactate and heart rate in patients meeting the sepsis-3 criteria is available.

METHODS

Consecutive patients with sepsis and septic shock from 2019 to 2021 were included. The prognostic value of NE dose, lactate and heart rate was tested for 30-day all-cause mortality. Statistical analyses included univariable t-tests, Spearman's correlations, C-statistics, Kaplan-Meier analyses, as well as one-factorial repeated measures analysis of variance (ANOVA) and Cox proportional regression analyses.

RESULTS

339 patients with sepsis or septic shock were included. With an area under the curve (AUC) of up to 0.638 and 0.685, NE dose and lactate revealed moderate prognostic accuracy for 30-day all-cause mortality, whereas heart rate was not associated with prognosis. Very high NE doses (i.e. > 1.0 mcg/kg/min) (HR = 2.938; 95% CI 1.933 - 4.464; p = .001) and lactate levels (i.e. ≥ 4 mmol/l) (HR = 2.963; 95% CI 2.095 - 4.191; p = .001) on admission were associated with highest risk of death. Finally, increasing NE doses and lactate levels from day 1 to 3 indicated increased risk of death, which was consistent after multivariable adjustment.

CONCLUSION

Both very high NE doses and lactate levels - but not heart rate - were associated with increased risk of 30-d all-cause mortality in patients with sepsis and septic shock.

Performance of heart rate adjusted heart rate variability for risk stratification of sudden cardiac death

PURPOSE

As a non-invasive tool for the assessment of cardiovascular autonomic function, the predictive value of heart rate variability (HRV) for sudden cardiac death (SCD) risk stratification remains unclear. In this study, we investigated the performance of the individualized heart rate (HR) adjusted HRV (HRV_I) for SCD risk stratification in subjects with diverse risks.

METHODS

A total of 11 commonly used HRV metrics were analyzed in 192 subjects, including 88 healthy controls (low risk group), 82 hypertrophic cardiomyopathy (HCM) patients (medium risk group), and 22 SCD victims (high risk group). The relationship between HRV metrics and HR was examined with long-term and short-term analysis. The performance HRV_I was evaluated by area under the receiver operating characteristic curve (AUC) and covariance of variation (CV).

RESULTS

Most of the HRV metrics were exponentially decayed with the increase of HR, while the exponential power coefficients were significantly different among groups. The HRV_I metrics discriminated low, medium and high risk subjects with a median AUC of 0.72[0.11], which was considerably higher than that of the traditional long-term (0.63[0.04]) and short-term (0.58[0.05]) HRV without adjustment. The average CV of the HRV_I metrics was also significantly lower than traditional short-term HRV metrics (0.09 ± 0.02 vs. 0.24 ± 0.13, p < 0.01).

CONCLUSIONS

Subjects with diverse risks of SCD had similar exponential decay relationship between HRV metrics and HR, but with different decaying rates. HRV_I provides reliable and robust estimation for risk stratification of SCD.

Evaluating the effects of Esmolol on cardiac function in patients with Septic cardiomyopathy by Speck-tracking echocardiography-a randomized controlled trial

BACKGROUND

Esmolol as one treatment of sepsis induced cardiomyopathy (SIC) is still controversial. The objective of this study is to evaluate cardiac function after reducing heart rate by Esmolol in patients with SIC using speck-tracking echocardiography.

METHODS

This study was a single-center, prospective, and randomized controlled study. A total of 100 SIC patients with a heart rate more than 100/min, admitted to the Intensive Care Department of Tianjin Third Central Hospital from March 1, 2020 to September 30, 2021, were selected as the research subjects. They were randomly divided into the Esmolol group (Group E) and the conventional treatment group (Group C), each with 50 cases. The target heart rate of patients in Group E was controlled between 80/min and 100/min. Speck-tracking echocardiography (STE) and pulse indicating continuous cardiac output monitoring (PICCO) were performed in both groups at 1 h, 24 h, 48 h, 72 h, 96 h and 7 d after admission, with data concerning left ventricular global longitudinal strain (GLS), left ventricular ejection fraction (LVEF) and global ejection fraction (GEF), left ventricular systolic force index (dP/dtmx) were obtained, respectively. Hemodynamics and other safety indicators were monitored throughout the whole process. These subjects were followed up to 90 d, with their mortality recorded at Day 28 and Day 90, respectively. Statistical analyses were performed using SPSS version 21.

RESULTS

With 24 h of Esmolol, all patients in Group E achieved the target heart rate, and there was no deterioration of GLS, or adverse events. However, compared with those in Group C, their GLS, GEF and dP/dtmx were increased, and the difference was statistically significant (P > 0.05). Compared with patients in Group C, those in Group E had lower short-term mortality, and logistic regression analysis also suggested that Esmolol improved patient outcomes.

CONCLUSION

In SIC patients, the application of Esmolol to lower heart rate decreased their short-term mortality while not making any impairment on the myocardial contractility.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2100047513. Registered June 20, 2021- Retrospectively registered, http://www.chictr.org.cn/index.aspx . The study protocol followed the CONSORT guidelines. The study protocol was performed in the relevant guidelines.

Sinus Tachycardia: a Multidisciplinary Expert Focused Review

Sinus tachycardia (ST) is ubiquitous, but its presence outside of normal physiological triggers in otherwise healthy individuals remains a commonly encountered phenomenon in medical practice. In many cases, ST can be readily explained by a current medical condition that precipitates an increase in the sinus rate, but ST at rest without physiological triggers may also represent a spectrum of normal. In other cases, ST may not have an easily explainable cause but may represent serious underlying pathology and can be associated with intolerable symptoms. The classification of ST, consideration of possible etiologies, as well as the decisions of when and how to intervene can be difficult. ST can be classified as secondary to a specific, usually treatable, medical condition (eg, pulmonary embolism, anemia, infection, or hyperthyroidism) or be related to several incompletely defined conditions (eg, inappropriate ST, postural tachycardia syndrome, mast cell disorder, or post-COVID syndrome). While cardiologists and cardiac electrophysiologists often evaluate patients with symptoms associated with persistent or paroxysmal ST, an optimal approach remains uncertain. Due to the many possible conditions associated with ST, and an overlap in medical specialists who see these patients, the inclusion of experts in different fields is essential for a more comprehensive understanding. This article is unique in that it was composed by international experts in Neurology, Psychology, Autonomic Medicine, Allergy and Immunology, Exercise Physiology, Pulmonology and Critical Care Medicine, Endocrinology, Cardiology, and Cardiac Electrophysiology in the hope that it will facilitate a more complete understanding and thereby result in the better care of patients with ST.

Effects of Music Therapy on Vital Signs in Children with Chronic Disease

Background: Recent research found evidence supporting music therapy for hospitalized children with chronic diseases. The aim of this study was to investigate the effect of music therapy on hospitalized children’s vital signs. Methods: In this prospective study, children with chronic gastroenterological and nephrological diseases received active or receptive music therapy two to four times a week until discharge from hospital at the pediatric special care unit (SCU) and pediatric intensive care unit (ICU). Baseline and post-therapy heart rate, oxygen saturation and blood pressure were recorded and analyzed as control values at three points on the same day when the children were alone in their patient room at rest. Results: A total of 83 children, median 3 age of years (range one month to eighteen years) received music therapy. In total, 377 music therapy sessions were treated: 200 receptive therapy (78 ICU, 122 SCU) and 177 with active therapy (0 ICU, 177 SCU). Music therapy interventions showed changes in vital signs during music therapy sessions. After music therapy, heart rates decreased by 18 beats per minute (95% confidence interval (CI), −19.4 to (−16.8)), oxygen saturation increased by 2.3% (95% CI, 2.2 to 2.5), systolic blood pressure decreased by 9.2 (95% CI, −10.6 to −7.7) and diastolic blood pressure decreased by 7.9 (95% CI, −9.6 to −6.3). When music therapy was applied at the SCU (ICU), heart rates significantly reduced by 17.9 (18.9) beats per min, oxygen saturation increased by 2.4% (2.1%) and blood pressure reduced by 9.2 (2.8) mmHg (systolic) and 7.9 (0.3) mmHg (diastolic). Almost all control values were better than directly before the intervention. However, after music therapy intervention, the children showed better values in vital signs compared to being alone in their patient room. Conclusion: Music therapy is an added value for children with kidney and liver/gastrointestinal diseases during their hospital stay.

Association between circadian variation of heart rate and mortality among critically ill patients: a retrospective cohort study

Background

Heart rate (HR) related parameters, such as HR variability, HR turbulence, resting HR, and nighttime mean HR have been recognized as independent predictors of mortality. However, the influence of circadian changes in HR on mortality remains unclear in intensive care units (ICU). The study is designed to evaluate the relationship between the circadian variation in HR and mortality risk among critically ill patients.

Methods

The present study included 4,760 patients extracted from the Multiparameter Intelligent Monitoring in Intensive Care II database. The nighttime mean HR/daytime mean HR ratio was adopted as the circadian variation in HR. According to the median value of the circadian variation in HR, participants were divided into two groups: group A (≤ 1) and group B (> 1). The outcomes included ICU, hospital, 30-day, and 1-year mortalities. The prognostic value of HR circadian variation was investigated by multivariable logistic regression models and Cox proportional hazards models.

Results

Patients in group B (n = 2,471) had higher mortality than those in group A (n = 2,289). Multivariable models revealed that the higher circadian variation in HR was associated with ICU mortality (odds ratio [OR], 1.393; 95% confidence interval [CI], 1.112–1.745; P = 0.004), hospital mortality (OR, 1.393; 95% CI, 1.112–1.745; P = 0.004), 30-day mortality (hazard ratio, 1.260; 95% CI, 1.064–1.491; P = 0.007), and 1-year mortality (hazard ratio, 1.207; 95% CI, 1.057–1.378; P = 0.005), especially in patients with higher SOFA scores.

Conclusions

The circadian variation in HR might aid in the early identification of critically ill patients at high risk of associated with ICU, hospital, 30-day, and 1-year mortalities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01586-9.

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.

Resting heart rate and cardiovascular outcomes in diabetic and non-diabetic individuals at high cardiovascular risk analysis from the ONTARGET/TRANSCEND trials

AIMS

Resting heart rate (RHR) has been shown to be associated with cardiovascular outcomes in various conditions. It is unknown whether different levels of RHR and different associations with cardiovascular outcomes occur in patients with or without diabetes, because the impact of autonomic neuropathy on vascular vulnerability might be stronger in diabetes.

METHODS AND RESULTS

We examined 30 937 patients aged 55 years or older with a history of or at high risk for cardiovascular disease and after myocardial infarction, stroke, or with proven peripheral vascular disease from the ONTARGET and TRANSCEND trials investigating ramipril, telmisartan, and their combination followed for a median of 56 months. We analysed the association of mean achieved RHR on-treatment with the primary composite outcome of cardiovascular death, myocardial infarction, stroke, hospitalization for heart failure, the components of the composite primary outcome, and all-cause death as continuous and categorical variables. Data were analysed by Cox regression analysis, ANOVA, and χ2 test. These trials were registered with ClinicalTrials.gov.number NCT00153101. Patients were recruited from 733 centres in 40 countries between 1 December 2001 and 31 July 2008 (ONTARGET) and 1 November 2001 until 30 May 2004 (TRANSCEND). In total, 19 450 patients without diabetes and 11 487 patients with diabetes were stratified by mean RHR. Patients with diabetes compared to no diabetes had higher RHRs (71.8 ± 9.0 vs. 67.9 ± 8.8, P < 0.0001). In the categories of <60 bpm, 60 ≤ 65 bpm, 65 ≤ 70 bpm, 70 ≤ 75 bpm, 75 ≤ 80 bpm and ≥80 bpm, non-diabetic patients had an increased hazard of the primary outcome with mean RHR of 75 ≤ 80 bpm (adjusted hazard ratio [HR] 1.17 (1.01-1.36)) compared to RHR 60 ≤ 65 bpm. For patients with in-trial RHR ≥80 bpm the hazard ratios were highest (diabetes: 1.96 (1.64-2.34), no diabetes: 1.73 (1.49-2.00), For cardiovascular death hazards were also clearly increased at RHR ≥80 bpm (diabetes [1.99, (1.53-2.58)], no diabetes [1.73 (1.38-2.16)]. Similar results were obtained for hospitalization for heart failure and all-cause death while the effect of RHR on myocardial infarction and stroke was less pronounced. Results were robust after adjusting for various risk indicators including beta-blocker use and atrial fibrillation. No significant association to harm was observed at lower RHR.

CONCLUSION

Mean RHR above 75-80 b.p.m. was associated with increased risk for cardiovascular outcomes except for stroke. Since in diabetes, high RHR is associated with higher absolute event numbers and patients have higher RHRs, this association might be of particular clinical importance in diabetes. These data suggest that RHR lowering in patients with RHRs above 75-80 b.p.m. needs to be studied in prospective trials to determine if it will reduce outcomes in diabetic and non-diabetic patients at high cardiovascular risk.

CLINICAL TRIAL REGISTRATION

http://clinicaltrials.gov.Unique identifier: NCT00153101.

Impact of patient characteristics on the efficacy and safety of landiolol in patients with sepsis-related tachyarrhythmia: Subanalysis of the J-Land 3S randomised controlled study

BACKGROUND

The J-Land 3S trial demonstrated that landiolol is effective and tolerated for treating sepsis-related tachyarrhythmias. Patient characteristics (e.g. baseline heart rate [HR], type of tachyarrhythmia, and concomitant disorders) may impact the outcomes of landiolol therapy. We performed subanalyses of J-Land 3S to evaluate the impact of patient characteristics on the efficacy and safety of landiolol for treating sepsis-related tachyarrhythmia.

METHODS

Patients (≥20 years old; N = 151) hospitalised with sepsis at 54 participating hospitals in Japan with HR ≥100 beats/min for ≥10 min accompanied by diagnosis of tachyarrhythmia were randomised 1:1 to conventional sepsis therapy alone (control group) or conventional sepsis therapy plus landiolol (landiolol group). The efficacy and safety of landiolol were assessed in prespecified analyses of patients divided into subgroups by baseline characteristics and in post hoc, multivariate analyses with adjustment for age and HR at baseline.

FINDINGS

The percentage of patients with HR of 60-94 beats/min at 24 h after randomisation (primary endpoint) was greater in the landiolol group in most subgroups in univariate unadjusted analyses and in multivariate logistic regression. The incidence of new-onset arrhythmia by 168 h and mortality by 28 days were also lower in the landiolol group in most subgroups in univariate and multivariate Cox proportional hazards models. No subgroups showed a markedly higher incidence of adverse events in univariate or multivariate logistic regression analyses.

INTERPRETATION

These results of the J-Land 3S study suggest that the efficacy and safety of landiolol are generally unaffected by key patient characteristics.

FUNDING

Ono Pharmaceutical Co., Ltd.

Heart Rate Control during Experimental Sepsis in Mice: Comparison of Ivabradine and β-Blockers

BACKGROUND

Tachycardia is a hallmark of sepsis. An elevated heart rate could impair ventricular filling and increase myocardial oxygen demand. β-Blockers and ivabradine (a selective inhibitor of If channels in the sinoatrial node) are both able to control sinus tachycardia, with the latter drug being devoid of negative inotropic effect. This work aimed at assessing the hemodynamic effects of ivabradine as compared with a β-blocker (atenolol) during murine peritonitis.

METHODS

Ivabradine (3 μg/g), atenolol (3 μg/g), or placebo was administered intraperitoneally 2 h after induction of peritonitis (cecal ligation and puncture) in male C57BL6 mice. The authors used invasive (left ventricular catheterization) and noninvasive (transthoracic echocardiography) monitoring to assess hemodynamics 20 h after surgery, including heart rate, blood pressure, left ventricular systolic, and diastolic function (n = 10 mice/group). The authors also assessed overall mortality 30 and 60 h after surgery in a distinct subset of animals (n = 20 mice/group). Descriptive data are presented as median (25th to 75th percentile).

RESULTS

As compared with placebo (601 beats/min [547 to 612]), ivabradine (447 beats/min [430 to 496]) and atenolol (482 beats/min [412 to 505]) blunted sepsis-induced tachycardia assessed by transthoracic echocardiography in awake animals (P < 0.001 and P = 0.004, respectively). Unlike ivabradine, atenolol reduced cardiac output, systolic blood pressure, and left ventricular systolic function (as assessed by ejection fraction, maximal left ventricular pressure rise, and anterior wall strain rate) as compared with septic mice receiving placebo. There was no difference in survival 60 h after sepsis induction with ivabradine (6 of 20, 30%) or atenolol (7 of 20, 35%), as compared with placebo (5 of 20, 25%; P = 0.224).

CONCLUSIONS

Heart rate control could be similarly achieved by ivabradine or atenolol, with preservation of blood pressure, cardiac output, and left ventricular systolic function with the former drug.

Landiolol in patients with septic shock resident in an intensive care unit (LANDI-SEP): study protocol for a randomized controlled trial

Background

In patients with septic shock, the presence of an elevated heart rate (HR) after fluid resuscitation marks a subgroup of patients with a particularly poor prognosis. Several studies have shown that HR control in this population is safe and can potentially improve outcomes. However, all were conducted in a single-center setting. The aim of this multicenter study is to demonstrate that administration of the highly beta1-selective and ultrashort-acting beta blocker landiolol in patients with septic shock and persistent tachycardia (HR ≥ 95 beats per minute [bpm]) is effective in reducing and maintaining HR without increasing vasopressor requirements.

Methods

A phase IV, multicenter, prospective, randomized, open-label, controlled study is being conducted. The study will enroll a total of 200 patients with septic shock as defined by The Third International Consensus Definitions for Sepsis and Septic Shock criteria and tachycardia (HR ≥ 95 bpm) despite a hemodynamic optimization period of 24–36 h. Patients are randomized (1:1) to receive either standard treatment (according to the Surviving Sepsis Campaign Guidelines 2016) and continuous landiolol infusion to reach a target HR of 80–94 bpm or standard treatment alone. The primary endpoint is HR response (HR 80–94 bpm), the maintenance thereof, and the absence of increased vasopressor requirements during the first 24 h after initiating treatment.

Discussion

Despite recent studies, the role of beta blockers in the treatment of patients with septic shock remains unclear. This study will investigate whether HR control using landiolol is safe, feasible, and effective, and further enhance the understanding of beta blockade in patients with septic shock.

Trial registration

EU Clinical Trials Register; EudraCT, 2017-002138-22. Registered on 8 August 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3024-6) contains supplementary material, which is available to authorized users.

Intravenous ivabradine versus placebo in patients with low cardiac output syndrome treated by dobutamine after elective coronary artery bypass surgery: a phase 2 exploratory randomized controlled trial

BACKGROUND

Low cardiac output syndrome (LCOS) is a severe condition which can occur after cardiac surgery, especially among patients with pre-existing left ventricular dysfunction. Dobutamine, its first-line treatment, is associated with sinus tachycardia. This study aims to assess the ability of intravenous ivabradine to decrease sinus tachycardia associated with dobutamine infused for LCOS after coronary artery bypass graft (CABG) surgery.

METHODS

In a phase 2, multi-center, single-blind, randomized controlled trial, patients with left ventricular ejection fraction below 40% presenting sinus tachycardia of at least 100 beats per minute (bpm) following dobutamine infusion for LCOS after CABG surgery received either intravenous ivabradine or placebo (three ivabradine for one placebo). Treatment lasted until dobutamine weaning or up to 48 h. The primary endpoint was the proportion of patients achieving a heart rate (HR) in the 80- to 90-bpm range. Secondary endpoints were invasive and non-invasive hemodynamic parameters and arrhythmia events.

RESULTS

Nineteen patients were included. More patients reached the primary endpoint in the ivabradine than in the placebo group (13 (93%) versus 2 (40%); P = 0.04). Median times to reach target HR were 1.0 h in the ivabradine group and 5.7 h in the placebo group. Ivabradine decreased HR (112 to 86 bpm, P <0.001) while increasing cardiac index (P = 0.02), stroke volume (P <0.001), and systolic blood pressure (P = 0.03). In the placebo group, these parameters remained unchanged from baseline. In the ivabradine group, five patients (36%) developed atrial fibrillation (AF) and one (7%) was discontinued for sustained AF; two (14%) were discontinued for bradycardia.

CONCLUSION

Intravenous ivabradine achieved effective and rapid correction of sinus tachycardia in patients who received dobutamine for LCOS after CABG surgery. Simultaneously, stroke volume and systolic blood pressure increased, suggesting a beneficial effect of this treatment on tissue perfusion.

TRIAL REGISTRATION

European Clinical Trials Database: EudraCT 2009-018175-14 . Registered February 2, 2010.

MicroDAIMON study: Microcirculatory DAIly MONitoring in critically ill patients: a prospective observational study

Background

Until now, the prognostic value of microcirculatory alterations in critically ill patients has been mainly evaluated in highly selected subgroups. Aim of this study is to monitor the microcirculation daily in mixed group of Intensive Care Unit (ICU)-patients and to establish the association between (the evolution of) microcirculatory alterations and outcome.

Methods

This is a prospective longitudinal observational single-centre study in adult patients admitted to a 12-bed ICU in an Italian teaching hospital. Sublingual microcirculation was evaluated daily, from admission to discharge/death, using Sidestream Dark Field imaging. Videos were analysed offline to assess flow and density variables. Laboratory and clinical data were recorded simultaneously. A priori, a Microvascular Flow Index (MFI) < 2.6 was defined as abnormal. A binary logistic regression analysis was performed to evaluate the association between microcirculatory variables and outcomes; a Kaplan–Meier survival curve was built. Outcomes were ICU and 90-day mortality.

Results

A total of 97 patients were included. An abnormal MFI was present on day 1 in 20.6%, and in 55.7% of cases during ICU admission. Patients with a baseline MFI < 2.6 had higher ICU, in-hospital and 90-day mortality (45 vs. 15.6%, p = 0.012; 55 vs. 28.6%, p = 0.035; 55 vs. 26%, p = 0.017, respectively). An independent association between baseline MFI < 2.6 and outcome was confirmed in a binary logistic analysis (odds ratio 4.594 [1.340–15.754], p = 0.015). A heart rate (HR) ≥ 90 bpm was an adjunctive predictor of mortality. However, a model with stepwise inclusion of mean arterial pressure < 65 mmHg, HR ≥ 90 bpm, lactate > 2 mmol/L and MFI < 2.6 did not detect significant differences in ICU mortality. In case an abnormal MFI was present on day 1, ICU mortality was significantly higher in comparison with patients with an abnormal MFI after day 1 (38 vs. 6%, p = 0.001), indicating a time-dependent significant difference in prognostic value.

Conclusions

In a general ICU population, an abnormal microcirculation at baseline is an independent predictor for mortality. In this setting, additional routine daily microcirculatory monitoring did not reveal extra prognostic information. Further research is needed to integrate microcirculatory monitoring in a set of commonly available hemodynamic variables.

Trial registration NCT 02649088, www.clinicaltrials.gov. Date of registration: 23 December 2015, retrospectively registered

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0411-9) contains supplementary material, which is available to authorized users.

Interaction of systolic blood pressure and resting heart rate with clinical outcomes in takotsubo syndrome: insights from the International Takotsubo Registry

AIMS

The present study aimed to determine the prognostic impact of resting heart rate (HR) and systolic blood pressure (SBP) in takotsubo syndrome (TTS).

METHODS AND RESULTS

Patients from the International Takotsubo Registry with complete data on HR and SBP were enrolled. We analysed all-cause mortality and major adverse cardiac and cerebrovascular events (MACCE) in tertiles of HR (<77 b.p.m., 77-94 b.p.m., >94 b.p.m.) and SBP (<119 mmHg, 119-140 mmHg, >140 mmHg). In addition, linear splines with interactions between HR and SBP were analysed. The risk of all-cause mortality was higher in the second HR tertile (1.89, 1.15-3.10; P = 0.012) and the third HR tertile (3.01, 1.90-4.79; P < 0.001) than in the first tertile. Similar effects were observed for MACCE. Low SBP was related to an increased risk of all-cause mortality (P < 0.001) and MACCE (P = 0.002). In a multivariable analysis of all-cause mortality, at HR >70 b.p.m., every 1 b.p.m. increase in HR was associated with a 1.7% increase (P < 0.001), and every 1 mmHg increase in SBP up to 130 mmHg was associated with a 2% risk reduction (P < 0.001). The risk of all-cause mortality thus was particularly elevated when low SBP occurred together with high HR.

CONCLUSIONS

High HR and low SBP are associated with an increased risk of all-cause mortality in TTS. HR reduction might be worthy of being investigated as a therapeutic strategy for this condition and high HR and low SBP can be used to evaluate risk in this acute presentation of TTS.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT01947621.

If Channel Inhibition With Ivabradine Does Not Improve Cardiac and Vascular Function in Experimental Septic Shock

OBJECTIVE

Previous studies have suggested that lowering heart rate (HR) by selective β1-blockers improves sepsis-induced cardiac and vascular dysfunction primarily by decreasing proinflammatory pathways. However, the impact of isolated heart rate reduction (HRR) on hemodynamics and inflammatory pathways remains unknown. The present study was designed to assess the effects of HRR by ivabradine, an If channel inhibitor, on cardiovascular function and inflammatory pathways in peritonitis-induced septic shock in rats.

DESIGN

Randomized animal study.

SETTING

University research laboratory.

INTERVENTIONS

Four hours after cecal ligation and puncture (CLP), Wistar rats were randomly allocated to the following groups: CLP (n = 8) and CLP + ivabradine (n = 8, administered per os 4 h after the surgery). Another eight Wistar male rats underwent sham operation. All rats received a continuous infusion of saline (10 mL kg h), analgesic (nalbuphine: 0.2 mg kg h), and antibiotics (imipenem and cilastatin sodium: 10 mg kg) 4 h after the surgery. Assessment at 18 h included hemodynamics, in vivo cardiac function by echocardiography, and ex vivo vasoreactivity by myography. Circulating cytokine levels (TNF-α, IL-6, and IL-10) were measured by ELISA, whereas cardiac and vascular protein expressions of NF-κB/IκBα/iNOS and Akt/eNOS were assessed by Western blotting.

RESULTS

Compared with sham animals, CLP induced tachycardia, hypotension, decreased cardiac output, hyperlactatemia, and vascular hyporesponsiveness to vasopressors. Compared with the CLP group, adjunction of ivabradine decreased the HR without any impact on blood pressure, lactatemia, or vascular responsiveness to vasopressors. Adjunction of ivabradine to CLP rats had no impact on TNF-α, IL-6, and IL-10 cytokines, or on the protein expression levels of phosphorylated forms of NF-κB, Akt, eNOS, and degradation of IκBα in cardiac and vascular tissues.

CONCLUSION

Isolated HRR by ivabradine in an experimental model of septic shock does not appear to be associated with any effect on the tested parameters of cardiac function or on vascular responsiveness to vasopressors. Moreover, in this setting, ivabradine does not alter the circulating levels of selected pro/anti-inflammatory cytokines or cardiac and vascular NF-κB/IκBα protein expression levels.

Advances in the management of heart failure: the role of ivabradine

A high resting heart rate (≥70–75 b.p.m.) is a risk factor for patients with heart failure (HF) with reduced ejection fraction (EF), probably in the sense of accelerated atherosclerosis, with an increased morbidity and mortality. Beta-blockers not only reduce heart rate but also have negative inotropic and blood pressure-lowering effects, and therefore, in many patients, they cannot be given in the recommended dose. Ivabradine specifically inhibits the pacemaker current (funny current, I_f) of the sinoatrial node cells, resulting in therapeutic heart rate lowering without any negative inotropic and blood pressure-lowering effect. According to the European Society of Cardiology guidelines, ivabradine should be considered to reduce the risk of HF hospitalization and cardiovascular death in symptomatic patients with a reduced left ventricular EF ≤35% and sinus rhythm ≥70 b.p.m. despite treatment with an evidence-based dose of beta-blocker or a dose below the recommended dose (recommendation class “IIa” = weight of evidence/opinion is in favor of usefulness/efficacy: “should be considered”; level of evidence “B” = data derived from a single randomized clinical trial or large nonrandomized studies). Using a heart rate cutoff of ≥ 75 b.p.m., as licensed by the European Medicines Agency, treatment with ivabradine 5–7.5 mg b.i.d. reduces cardiovascular mortality by 17%, HF mortality by 39% and HF hospitalization rate by 30%. A high resting heart rate is not only a risk factor in HF with reduced EF but also at least a risk marker in HF with preserved EF, in acute HF and also in special forms of HF. In this review, we discuss the proven role of ivabradine in the validated indication “HF with reduced EF” together with interesting preliminary findings, and the potential role of ivabradine in further, specific forms of HF.

Increased heart rate on first day in Intensive Care Unit is associated with increased mortality

OBJECTIVE

To investigate the association of maximum HR during the first day of intensive care unit (ICU) and mortality.

METHODS

Data of 850 patients over 45 years of age, who were hospitalized in ICU, was retrospectively analyzed. They were divided into two groups; Group-I, patients with maximum HR<100/min Group-II, patients with maximum HR≥100/min on first day. The groups were compared regarding age, sex, use of beta-blockers, use of inotropic and vasopressor drugs, hemodynamic parameters, anemia, mechanical ventilation, length of hospitalization (ICU and total), mortality (ICU and total), and CHARLSON & APACHE-II scores.

RESULTS

The mean age of patients was 63±12 years and 86% were after non-cardiac surgery. Maximum HR was 83±11 in Group-I and 115±14/min in Group-II (p=0.002). Group-II patients had more frequent vasopressor and inotropic drugs usage, (p<0.001), anemia, mechanical ventilation (p<0.005), higher CHARLSON & APACHE-II scores, stayed longer in ICU and hospital, and had higher ICU and hospital mortality compared to group-I (p<0.05). APACHE-II scores and maximum HR<100/min were independent variables predicting ICU mortality in multivariate logistic regression analysis whereas usage of beta-blockers was not.

CONCLUSIONS

Our study showed that maximum HR less than100/minute during the first day of ICU is associated with decreased mortality in Intensive Care Unit.

Direct inhibition, but indirect sensitization of pacemaker activity to sympathetic tone by the interaction of endotoxin with HCN-channels

In critically ill patients regulation of heart-rate is often severely disturbed. Interaction of bacterial endotoxin (lipopolysaccharide, LPS) with hyperpolarization-activated cyclic nucleotide-gated cation-(HCN)-channels may interfere with heart-rate regulation. This study analyzes the effect of LPS, the HCN-channel blocker ivabradine or Ca(2+) -channel blockers (nifedipine, verapamil) on pacemaking in spontaneously beating neonatal rat cardiomyocytes (CM) in vitro. In vivo, the effect of LPS on the heart-rate of adult CD1-mice with and without autonomic blockade is analyzed telemetrically. LPS (100 ng/mL) and ivabradine (5 μg/mL) reduced the beating-rate of CM by 20.1% and 24.6%, respectively. Coincubation of CM with both, LPS and ivabradine, did not further reduce the beating-rate, indicating interaction of both compounds with HCN-channels, while coincubation with Ca(2+) -channel blockers and LPS caused additive beating-rate reduction. In CD1-mice (containing an active autonomic-nervous-system), injection of LPS (0.4 mg/kg) expectedly resulted in increased heart-rate. However, if the autonomic nervous system was blocked by propranolol and atropine, in line with the in vitro data, LPS induced a significant reduction of heart-rate, which was not additive to ivabradine. The in vivo and in vitro results indicate that LPS interacts with HCN-channels of cardiomyocytes. Thus, LPS indirectly sensitizes HCN-channels for sympathetic activation (tachycardic-effect), and in parallel directly inhibits channel activity (bradycardic-effect). Both effects may contribute to the detrimental effects of septic cardiomyopathy and septic autonomic dysfunction.

International study on microcirculatory shock occurrence in acutely ill patients

OBJECTIVES

Microcirculatory alterations are associated with adverse outcome in subsets of critically ill patients. The prevalence and significance of microcirculatory alterations in the general ICU population are unknown. We studied the prevalence of microcirculatory alterations in a heterogeneous ICU population and its predictive value in an integrative model of macro- and microcirculatory variables.

DESIGN

Multicenter observational point prevalence study.

SETTING

The Microcirculatory Shock Occurrence in Acutely ill Patients study was conducted in 36 ICUs worldwide.

PATIENTS

A heterogeneous ICU population consisting of 501 patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographic, hemodynamic, and laboratory data were collected in all ICU patients who were 18 years old or older. Sublingual Sidestream Dark Field imaging was performed to determine the prevalence of an abnormal capillary microvascular flow index (< 2.6) and its additional value in predicting hospital mortality. In 501 patients with a median Acute Physiology and Chronic Health Evaluation II score of 15 (10-21), a Sequential Organ Failure Assessment score of 5 (2-8), and a hospital mortality of 28.4%, 17% exhibited an abnormal capillary microvascular flow index. Tachycardia (heart rate > 90 beats/min) (odds ratio, 2.71; 95% CI, 1.67-4.39; p < 0.001), mean arterial pressure (odds ratio, 0.979; 95% CI, 0.963-0.996; p = 0.013), vasopressor use (odds ratio, 1.84; 95% CI, 1.11-3.07; p = 0.019), and lactate level more than 1.5 mEq/L (odds ratio, 2.15; 95% CI, 1.28-3.62; p = 0.004) were independent risk factors for hospital mortality, but not abnormal microvascular flow index. In reference to microvascular flow index, a significant interaction was observed with tachycardia. In patients with tachycardia, the presence of an abnormal microvascular flow index was an independent, additive predictor for in-hospital mortality (odds ratio, 3.24; 95% CI, 1.30-8.06; p = 0.011). This was not true for nontachycardic patients nor for the total group of patients.

CONCLUSIONS

In a heterogeneous ICU population, an abnormal microvascular flow index was present in 17% of patients. This was not associated with mortality. However, in patients with tachycardia, an abnormal microvascular flow index was independently associated with an increased risk of hospital death.

Resting heart rate: risk indicator and emerging risk factor in cardiovascular disease

Resting heart rate is central to cardiac output and is influenced by changes occurring in numerous diseases. It predicts longevity and cardiovascular diseases, and current evidence suggests that it is also an important marker of outcome in cardiovascular disease, including heart failure. Beta-blockers improve outcomes in heart failure; however, they have effects outside reducing heart rate. Ivabradine has demonstrated efficacy in reducing rehospitalizations and mortality in heart failure and in improving exercise tolerance and reducing angina attacks in patients with coronary artery disease, whereas selective heart rate reduction may also prove to be beneficial in therapeutic areas outside those in which ivabradine has already demonstrated clinical efficacy. This review provides an update on the associations between heart rate and cardiovascular outcomes in various conditions, the experimental effects of heart rate reduction with ivabradine, and the potential new indications in cardiovascular disease.

Novel and nonpharmacologic approaches to cardio-protection in hypertension

Hypertension has wide (30-45 %) prevalence in the general population and is related to important increases in overall cardiovascular morbidity and mortality. Despite lifestyle modifications and optimal medical therapy (three drugs, one being diuretic), about 5-20 % of hypertensives are affected by resistant hypertension. Chronic high blood pressure has adverse effects on the heart and other organs such as the kidneys and vasculature. Renal sympathetic denervation and baroreceptor stimulation are invasive approaches initially investigated to treat resistant hypertension. Their pleiotropic effects appear promising in cardiovascular remodeling, heart failure and arrhythmias and could potentially affect cardiovascular morbidity and mortality.

Hemodynamic effects of Ivabradine in addition to dobutamine in patients with severe systolic dysfunction

BACKGROUND

Dobutamine induced tachycardia increases myocardial oxygen consumption and impairs ventricular filling. We hypothesized that Ivabradine may be efficient to control dobutamine induced tachycardia.

METHODS

We assessed the effects of Ivabradine in addition to dobutamine in stable heart failure (HF) patients (LVEF < 35%, n = 22, test population) and validated its effects in refractory cardiogenic shock patients (n = 9, validation population) with contraindication to cardiac assistance or transplant. In the test population (62 ± 17 years, LVEF = 24 ± 8%), systolic and diastolic function were assessed at rest and under dobutamine [10 γ/min], before and after Ivabradine [5mg per os]. In the validation population (54 ± 11 years, LVEF = 22 ± 7%), Ivabradine [5mg twice a day] was added to the dobutamine infusion.

RESULTS

In the test population, Ivabradine decreased heart rate [HR] at rest and during dobutamine echocardiography (-9 ± 8 bpm, P = 0.0004). The decrease in HR was associated with a decrease in cardiac power output and an increase in diastolic duration at rest (+ 74 ± 67 ms, P = 0.0002), and during dobutamine infusion (+ 75 ± 67 ms, P < 0.0001). Change in LVEF during dobutamine was greater after Ivabradine treatment than before (+ 7.2 ± 4.7% vs. + 3.6 ± 4.2%, P = 0.002). In the validation population, Ivabradine decreased HR (-18 ± 11 bpm, P = 0.008) and improved diastolic filling time (+ 67 ± 42 ms, P = 0.012) without decreasing cardiac output. At 24h, Ivabradine improved systolic blood pressure (+ 9 ± 5 mmHg, P = 0.007), daily urine output (+ 0.7 ± 0.5L, P = 0.008), oxygen balance (ΔScv02 = + 13 ± 15%, P = 0.010), and NT-pro BNP (-2270 ± 1912 pg/mL, P = 0.017). Finally, only 2/9 (22%) patients died whereas expected mortality determined from a historical cohort was 78% (P = 0.017).

CONCLUSION

This pilot study demonstrates the safety and potential benefit of a HR lowering agent in cardiogenic shock.

Heart rate reduction with ivabradine in patients with acute decompensated systolic heart failure

INTRODUCTION

In patients with acute decompensated systolic heart failure (ADSHF) high resting heart rate (HR) could be either a compensatory mechanism or contribute to worsening heart failure. The aim of this study was to evaluate, in patients with ADSHF and resting HR >70 bpm, the early (within 24 h) and late (at discharge) effects of oral administration of ivabradine on HR reduction.

METHODS

Ten consecutive patients with ADSHF, left ventricular ejection fraction <40 % and HR >70 bpm, without other acute conditions or inotropic therapy, began open-label treatment with oral ivabradine according to a pre-established Heart Failure Unit protocol. We obtained clinical and laboratory data at four periods: admission (T0), immediately before initiation of ivabradine (T2), 24 h after initiation of ivabradine (T3), and at discharge (T4).

RESULTS

Ivabradine was administered in 60 % of the patients before the second day. HR decreased 10.7 ± 7.2 bpm at T3 (p < 0.001) and 16.3 ± 8.2 bpm at T4 (p = 0.002). The systolic blood pressure decreased at T3 (p = 0.012), returning to baseline values at T4. There was no change in diastolic and mean blood pressure. New York Heart Association (NYHA) class improvement by two levels was associated with lower HR at T4 (p = 0.033). HR and N-terminal pro-brain natriuretic peptide (Nt-ProBNP) at baseline correlated significantly [Spearman correlation coefficient (rs) = 0.789, p = 0.013]. Total Nt-ProBNP reduction correlated with the HR before (r = 0.762, p = 0.028) and after (T3: r = 0.647, p = 0.083; T4: r = 0.738, p = 0.037) ivabradine addition.

CONCLUSION

In the present cohort of patients with ADSHF and HR >70 bpm, the selective reduction of HR with oral ivabradine was safe and efficient.

I(f) blocking potency of ivabradine is preserved under elevated endotoxin levels in human atrial myocytes

Lower heart rate is associated with better survival in patients with multiple organ dysfunction syndrome (MODS), a disease mostly caused by sepsis. The benefits of heart rate reduction by ivabradine during MODS are currently being investigated in the MODI_fY clinical trial. Ivabradine is a selective inhibitor of the pacemaker current I_f and since I_f is impaired by lipopolysaccharide (LPS, endotoxin), a trigger of sepsis, we aimed to explore I_f blocking potency of ivabradine under elevated endotoxin levels in human atrial cardiomyocytes. Treatment of myocytes with S-LPS (containing the lipid A moiety, a core oligosaccharide and an O-polysaccharide chain) but not R595 (an O-chain lacking LPS-form) caused I_f inhibition under acute and chronic septic conditions. The specific interaction of S-LPS but not R595 to pacemaker channels HCN2 and HCN4 proves the necessity of O-chain for S-LPS–HCN interaction. The efficacy of ivabradine to block I_f was reduced under septic conditions, an observation that correlated with lower intracellular ivabradine concentrations in S-LPS- but not R595-treated cardiomyocytes. Computational analysis using a sinoatrial pacemaker cell model revealed that despite a reduction of I_f under septic conditions, ivabradine further decelerated pacemaking activity. This novel finding, i.e. I_f inhibition by ivabradine under elevated endotoxin levels in vitro, may provide a molecular understanding for the efficacy of this drug on heart rate reduction under septic conditions in vivo, e.g. the MODI_fY clinical trial.

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S-LPS impairs I_f via interaction of its O-chain to HCN channels.

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Efficacy of ivabradine for I_f blockage is reduced under elevated endotoxin levels.

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S-LPS reduces intracellular ivabradine concentrations.

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Ivabradine is efficient to decelerate sinoatrial pacemaking activity under septic conditions in silico.

Anemia is associated with an increased central venous pressure and mortality in a broad spectrum of cardiovascular patients

BACKGROUND

Anemia is frequently observed in patients with cardiovascular disease. Multiple factors have been associated with anemia, but the role of hemodynamics is largely unknown. Therefore, we investigated the association between hemoglobin (Hb) levels, hemodynamics and outcome in a broad spectrum of cardiovascular patients.

METHODS AND RESULTS

A total of 2,009 patients who underwent right heart catheterization at the University Medical Center Groningen, the Netherlands, between 1989 and 2006 were identified and data were extracted from electronic databases. Anemia was defined by the WHO criteria (male, hemoglobin <13.0 g/dL; female, hemoglobin <12.0 g/dL). The associations between central venous pressure (CVP), cardiac index (CI), systemic vascular resistance (SVR), hemoglobin (Hb), anemia and all-cause mortality were assessed with linear, logistic and Cox-proportional hazards analysis. The mean age was 57 ± 15 years, 57 % were male, mean Hb was 13.2 ± 0.4 g/dL, and 27.4 % of the patients were anemic. Patients with anemia had higher CVP levels (7.0 ± 5.4 mmHg) compared to non-anemic patients (5.6 ± 4.1 mmHg; p < 0.001). CI was higher in anemic patients; 3.0 ± 2.9 vs. 2.9 ± 0.8 L/min/m(2) (p < 0.001), whereas SVR was lower (1,212 ± 479 vs. 1,356 ± 555 dyn s cm(-5), p < 0.001). CVP and CI were both independent predictors of anemia (OR 1.49; CI 1.24-1.81, p < 0.001 and OR 1.93; CI 1.54-2.42, p < 0.001, respectively). Hemoglobin and CVP were both independent predictors of survival. Independent of CI and renal function, patients with anemia and an elevated CVP had the worst prognosis (HR 2.17; 95 % CI 1.62-2.90; p < 0.001).

CONCLUSION

Anemia is common in cardiovascular patients and independently related to an elevated CVP and CI. Patients with anemia and an elevated CVP have the worst prognosis.

Early NT-proBNP decrease with ivabradine in ambulatory patients with systolic heart failure

BACKGROUND

Heart rate (HR) reduction in patients with systolic heart failure (HF) is a cornerstone of current therapy. The aim of this study was to evaluate the short-term effect of the HR reduction with ivabradine on N-terminal pro-brain natriuretic peptide (NT-proBNP) in outpatients with systolic HF.

HYPOTHESIS

Ivabradine improves survival and promotes left ventricle remodelling by reducing resting heart rate. Nt-ProBNP absolute and trends predict prognosis. We hypothesized a possible association between heart rate decrease and Nt-ProBNP values.

METHODS

We included 25 outpatients with systolic HF on optimized medical therapy (80% on angiotensin-converting enzyme inhibitors, 56% on spironolactone, and 88% on β-blocker therapy), left ventricle ejection fraction <40%, and sinus rhythm and HR >70/bpm. After a 1 month running-out period, to establish the clinical and NT-proBNP stability, patients were started on ivabradine for 3 months.

RESULTS

Ivabradine decreased NT-proBNP (P = 0.002) from a median of 2850 pg/mL to 1802 pg/mL, corresponding to a median absolute and percent decrease of 964 pg/mL and 44.5%, respectively. The baseline HR correlated significantly with the baseline NT-proBNP (rs = 0.411, P = 0.041). The absolute and percent HR decrease correlated with the absolute NT-proBNP decrease (rs = 0.442, P = 0.027; rs = 0.395, P = 0.05). The greater the NT-proBNP absolute decrease tertile, the greater the baseline HR (P = 0.023) and the absolute (P = 0.028) and percent (P = 0.064) HR variation.

CONCLUSIONS

In outpatients with systolic HF, the NT-proBNP reduction obtained by short-term ivabradine treatment correlates closely with the degree of HR reduction.

Heart rate before ICU discharge: a simple and readily available predictor of short- and long-term mortality from critical illness

PURPOSE

A heart rate >90 bpm serves as one of four characteristics defining the systemic inflammatory response syndrome and is used in scoring systems to predict in-hospital mortality of intensive care unit (ICU) patients. Despite its central role in critical illness, specific data regarding the relationship between heart rate and outcome are rare.

METHODS

In this post hoc analysis of a prospectively collected database, we analyzed the value of heart rate averaged from four predefined time points during the last 24 h before ICU discharge as a predictor of post-ICU in-hospital and post-hospital mortality in medical ICU patients. Furthermore, the relationship between heart rate and inflammation, as well as the influence of rate control medications on the association between heart rate and outcome were identified.

RESULTS

Among the 702 ICU patients discharged from the ICU, 7.1 % died before hospital discharge. At 4 years of follow-up, post-hospital mortality was 14.4 %. Multivariate Cox proportional hazards models revealed heart rate before ICU discharge (HR 5.95; 95 % CI 1.24-28.63; p = 0.03) as an independent predictor of post-ICU in-hospital mortality. Both heart rate (HR 2.56; 95 % CI, 1.05-6.34; p = 0.04) and the C-reactive protein serum concentration before ICU discharge (HR, 1.26; 95 % CI, 1.09-1.46; p = 0.002) were independently associated with post-hospital mortality. Heart rate control therapy reduced the risk of post-ICU in-hospital (HR 0.38; 95 % CI, 0.18-0.81; p = 0.01) and post-hospital (HR, 0.47; 95 % CI, 0.22-1.00; p = 0.05) mortality.

CONCLUSION

Heart rate evaluated 24 h before ICU discharge was independently associated with post-ICU in-hospital and post-hospital mortality. Pharmacological interventions to control heart rate may beneficially influence post-ICU mortality.

Ivabradine: potential clinical applications in critically ill patients

It has been extensively demonstrated that an elevated heart rate is a modifiable, independent risk factor for cardiovascular events. A high heart rate increases myocardial oxygen consumption and reduces diastolic perfusion time. It can also increase ventricular diastolic pressures and induce ventricular arrhythmias. Critical care patients are prone to develop a stress induced cardiac impairment and consequently an increase in sympathetic tone. This in turn increases heart rate. In this setting, however, heart rate lowering might be difficult because the effects of inotropic drugs could be hindered by heart rate reducing drugs like beta-blockers. Ivabradine is a new selective antagonist of funny channels. It lowers heart rate, reducing the diastolic depolarization slope. Moreover, ivabradine is not active on sympathetic pathways, thus avoiding any interference with inotropic amines. We reviewed the literature available regarding heart rate control in critical care patients, focusing our interest on the use of ivabradine to assess the potential benefits of the drug in this particular setting.

Comparison between ATS/ERS age- and gender-adjusted criteria and GOLD criteria for the detection of irreversible airway obstruction in chronic heart failure

BACKGROUND

Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria (FEV1/FVC <70%) are extensively used for diagnosis of chronic obstructive lung disease in heart failure (HF). The American Thoracic Society (ATS)/European Respiratory Society (ERS) recommends the use of age- and gender-specific lower limit of normal (LLN) for FEV1/FVC. We compared the impact of these definitions on apparent prevalence of airway obstruction in chronic HF.

METHODS

Standardized pre- and post-bronchodilator spirometry was performed in HF patients. Airway obstruction was defined by ATS/ERS criteria as diagnostic standard. Additionally, airway obstruction was calculated using the GOLD criteria.

RESULTS

Of the 89 participants who fulfilled the ATS criteria for acceptability and reproducibility, 24.7% met ATS/ERS and 43.8% GOLD criteria for airway obstruction (Chi-square p = 0.007, McNemar <0.001). Sensitivity of GOLD criteria was 100%, specificity 74.6%, positive predictive value 56.4% and negative predictive value 100%. Among all individuals with an FEV1/FVC > LLN, 25.4% were falsely identified when using the GOLD criteria. A majority of false positives qualified for airway obstruction GOLD stage I (FEV1% ≥80%), which was significantly less often observed among true positives (76.5 vs. 31.8%; p < 0.001). Only 31.8% of patients with irreversible airway obstruction detected by the ATS/ERS criteria reported a history of COPD.

CONCLUSIONS

In all HF patients with persistent dyspnoea despite optimal HF treatment, spirometric testing should be performed. Application of the GOLD criteria leads to overdiagnosis of irreversible airway obstruction in patients with HF, which may result in inappropriate medical therapy and health-care decisions.