Association of Heart Rate and Outcomes in a Broad Spectrum of Patients With Chronic Heart Failure

Visit-to-visit changes in heart rate in heart failure: A pooled participant-level analysis of the PARADIGM-HF and PARAGON-HF trials

AIMS

Resting heart rate (HR) is a strong risk marker in patients with heart failure (HF), but the clinical implications of visit-to-visit changes in HR (ΔHR) are less well established. We aimed to explore the association between ΔHR and subsequent outcomes in a pooled dataset of two well-characterized cohorts of patients with HF across the full range of left ventricular ejection fraction (LVEF).

METHODS AND RESULTS

PARADIGM-HF and PARAGON-HF were randomized trials testing sacubitril/valsartan versus enalapril or valsartan, respectively, in patients with HF and LVEF ≤40% (PARADIGM-HF) or LVEF ≥45% (PARAGON-HF). We analysed the association between ΔHR from the preceding visit with the primary endpoint of HF hospitalization (HFH) or cardiovascular death using covariate-adjusted Cox proportional hazards models. A total of 13 194 patients (mean age 67 ± 11 years, 67% men, mean LVEF 40 ± 15%) were included. Over a median follow-up of 2.5 years, 3114 patients experienced a first HFH or cardiovascular death event (10.4 events per 100 patient-years). An increase in HR from the preceding visit, compared with no change, was associated with a higher risk (hazard ratio 1.12; 95% confidence interval [CI] 1.10-1.15; p < 0.001 per 5 bpm increase). Conversely, a drop in HR was associated with a lower risk (hazard ratio 0.97; 95% CI 0.94-1.00; p = 0.044 per 5 bpm drop). The prognostic implications of ΔHR were consistent across the range of LVEF and observed regardless of β-blocker use or presence of a permanent pacemaker. Visit-to-visit increases in HR were especially prognostic in patients without atrial fibrillation (pinteraction = 0.006).

CONCLUSION

Across a broad spectrum of patients with chronic HF, increases in HR from a preceding visit independently predicted clinical outcomes. The detection of notable increases in HR between outpatient visits may help identify patients at heightened risk of adverse events. Clinical Trial Registration; ClinicalTrials.gov NCT01035255 (PARADIGM-HF), NCT01920711 (PARAGON-HF).

High blood pressure with elevated resting heart rate: a high risk "Sympathetic" clinical phenotype

Epidemiological studies have unequivocally shown that elevated heart rate values measured at rest have an adverse prognostic impact in the hypertensive patient, being associated with an increased risk of cardiovascular events and complications. In recent years new data have been collected on this issue, strengthening the clinical relevance of elevated heart rate as a specific hypertensive phenotype. The present paper will review old and new data on the prognostic importance of resting tachycardia in the hypertensive patient. It will also examine the role of the sympathetic nervous system in the development of this alteration as well as its therapeutic implications. The different approaches to dynamically assess heart rate values in the clinical setting will be finally discussed.

Prognostic Clinical Phenotypes of Patients with Acute Decompensated Heart Failure

INTRODUCTION

Acute decompensated heart failure (AHF) is a clinical syndrome with a poor prognosis.

AIM

This study was conducted to identify clusters of inpatients with acute decompensated heart failure that shared similarities in their clinical features.

METHODS

We analyzed data from a cohort of patients with acute decompensated heart failure hospitalized between February 2013 and January 2017 in a Department of Cardiology. Patients were clustered using factorial analysis of mixed data. The clusters (phenotypes) were then compared using log-rank tests and profiled using a logistic model. In total, 458 patients (255; 55.7% male) with a mean (SD) age of 72.7 (11.1) years were included in the analytic dataset. The demographic, clinical, and laboratory features were included in the cluster analysis.

RESULTS

The two clusters were significantly different in terms of time to mortality and re-hospitalization (all P < 0.001). Cluster profiling yielded an accurate discriminating model (AUC = 0.934). Typically, high-risk patients were elderly females with a lower estimated glomerular filtration rate and hemoglobin on admission compared to the low-risk phenotype. Moreover, the high-risk phenotype had a higher likelihood of diabetes type 2, transient ischemic attack/cerebrovascular accident, previous heart failure or ischemic heart disease, and a higher serum potassium concentration on admission. Patients with the high-risk phenotype were of higher New York Heart Association functional classes and more positive in their medication history.

CONCLUSIONS

There are two phenotypes among patients with decompensated heart failure, high-risk and low-risk for mortality and re-hospitalization. They can be distinguished by easy-to-measure patients' characteristics.

Comparison of heart rate and cardiac output of VVI pacemaker settings in patients with atrial fibrillation with bradycardia

Background

While most VVI pacemakers in bradycardic patients are set to a low limit of 60/min, the optimal lower limit rate for VVI pacemakers in atrial fibrillation has not been established. Although an increase in heart rate within the normal range in the setting of a VVI pacemaker might be expected to lead to an increase in cardiac output with the shortening of the diastolic time, the changes in cardiac output at different pacemaker settings have not been fully clarified.

Methods

We included 11 patients with bradycardic atrial fibrillation who had VVI pacemakers implanted. Stroke volume was measured using the electrical cardiometry method (AESCULONⓇ mini; Osypka Medical) without pacing and at ventricular pacings of 60, 70, 80, and 90/min.

Results

Stroke volume decreased stepwise at ventricular pacing rates of 60, 70, 80, and 90/min (63.6 ± 11.2, 61.9 ± 10.6, 59.3 ± 12.2, and 57.5 ± 12.2 mL, p < .001), but cardiac output increased (3.81 ± 0.67, 4.33 ± 0.74, 4.74 ± 0.97, and 5.17 ± 1.09 L/min, p < .001). The rate of increase in cardiac output at a pacing rate of 70/min compared to 60/min correlated with left ventricular end-systolic volume (r = 0.711, p = .014).

Conclusions

Cardiac output increased at a pacing rate of 70 compared to 60 in bradycardic atrial fibrillation patients, and the rate of increase in cardiac output was greater in those with larger left ventricular end-systolic volume.

Patient phenotype profiling in heart failure with preserved ejection fraction to guide therapeutic decision making. A scientific statement of the Heart Failure Association, the European Heart Rhythm Association of the European Society of Cardiology, and the European Society of Hypertension

Heart failure with preserved ejection fraction (HFpEF) represents a highly heterogeneous clinical syndrome affected in its development and progression by many comorbidities. The left ventricular diastolic dysfunction may be a manifestation of various combinations of cardiovascular, metabolic, pulmonary, renal, and geriatric conditions. Thus, in addition to treatment with sodium-glucose cotransporter 2 inhibitors in all patients, the most effective method of improving clinical outcomes may be therapy tailored to each patient's clinical profile. To better outline a phenotype-based approach for the treatment of HFpEF, in this joint position paper, the Heart Failure Association of the European Society of Cardiology, the European Heart Rhythm Association and the European Hypertension Society, have developed an algorithm to identify the most common HFpEF phenotypes and identify the evidence-based treatment strategy for each, while taking into account the complexities of multiple comorbidities and polypharmacy.

Relationships between sympathetic markers and heart rate thresholds for cardiovascular risk in chronic heart failure

BACKGROUND

Results of recent clinical trials have shown that in heart failure (HF) heart rate (HR) values > 70 beats/minute are associated with an increased cardiovascular risk. No information is available on whether the sympathetic nervous system is differently activated in HF patients displaying resting HR values above or below this cutoff.

METHODS

In 103 HF patients aged 62.7 ± 0.9 (mean ± SEM) years and in 62 heathy controls of similar age we evaluated muscle sympathetic nerve traffic (MSNA, microneurography) and venous plasma norepinephrine (NE, HPLC assay), subdividing the subjects in different groups according to their resting clinic and 24-h HR values.

RESULTS

In HF progressively greater values of clinic or 24-h HR were associated with a progressive increase in both MSNA and NE. HR cutoff values adopted in large scale clinical trials for determining cardiovascular risk, i.e., 70 beats/minute, were associated with MSNA values significantly greater than the ones detected in patients with lower HR, this being the case also for NE. In HF both MSNA and NE were significantly related to clinic (r = 0.92, P < 0.0001 and r = 0.81, P < 0.0001, respectively) and 24-h (r = 0.91, P < 0.0001 and r = 0.79, P < 0.0001, respectively) HR. The behavior of sympathetic markers described in HF was specific for this clinical condition, being not observed in healthy controls.

CONCLUSIONS

Both clinic and 24-h HR values greater than 70 beats/minute are associated with an increased sympathetic activation, which parallels for magnitude the HR elevations. These findings support the relevance of using in the therapeutic approach to HF drugs exerting sympathomoderating properties.

New paradigm shift in the pharmacotherapy for heart failure-where are we now and where are we heading?

Over the past 30 years, accumulating evidence has shown that three main therapies including angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers, ß-blockers, and mineralocorticoid receptor antagonists are the standard treatment for patients with heart failure (HF) who exhibit reduced ejection fraction (EF). However, lessons learned from recent large-scale clinical trials have added a paradigm shift including angiotensin receptor-neprilysin inhibitor, sodium glucose co-transporter 2 inhibitor, and ivabradine. In addition, soluble guanyl cyclase stimulator and omecamtiv mecarbil are also suggested as next generation therapeutic measures for these patients. From these clinical trials, we learned some patients with preserved EF will benefit from certain agents, which has been one of the largest unmet needs over these decades. This article will review these paradigm shifts over the past 10 years and address a new therapeutic algorithm for patients with HF.

Identification of predictive factors interacting with heart rate reduction for potential beneficial clinical outcomes in chronic heart failure: A systematic literature review and meta-analysis

Background

There is an absence of clinical evidence on what factors modify the effect of heart rate (HR)-reducing treatment on mortality and morbidity in symptomatic heart failure patients with reduced ejection fraction (HFrEF). We performed a Bayesian meta-analysis and meta-regression to identify predictive factors that interact with HR-reducing therapy.

Methods

A systematic review was performed to identify randomized placebo-controlled trials that enrolled symptomatic HFrEF patients. The primary objective was to evaluate how different predictive factors modify the efficacy of HR-reducing therapy on clinical outcomes. Secondary objectives included the evaluation of subgroups stratified by a HR reduction threshold of 10 bpm.

Results

Data from 20 studies were synthesized and HR-reducing therapy was responsible for 16.7 %, 16.4 %, and 21.1 % risk reductions in all-cause mortality, cardiovascular (CV)-related mortality, and rehospitalization due to worsening HF (WHF), respectively. Empirical Bayes meta-regression showed that type 2 diabetes mellitus (T2DM) significantly modified the efficacy of HR-reducing therapy on all-cause mortality (slope = 0.012 in log risk ratio (RR) per 1 %-unit [95 % credible interval (CrI) 0.004, 0.021]) and CV-related mortality (0.01 in log RR per 1 %-unit [95 % CrI 0.0003, 0.0200]). There were insufficient studies to perform a meta-regression when stratifying by a HR reduction threshold of 10 bpm; however, when including all studies, we observed a significant effect modification for rehospitalization due to WHF (p = 0.004).

Conclusions

This meta-analysis focused on the central tenet of HR-reducing therapy and revealed that T2DM is a predictor of HR-reducing treatment effect on all-cause mortality and CV-related mortality in HFrEF patients.

Target heart rate in heart failure with reduced ejection fraction and atrial fibrillation: Goldilocks zone

The rates of atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF) continue to grow with many patients suffering from their combined impact on quality of life and prognosis. A lower heart rate (HR) in HFrEF is associated with reduced morbidity and mortality due to beta-blocker and ivabradine therapy. Postulated mechanisms include reduced neurohumoral activation, increased diastolic filling time and myocardial energy conservation. In contrast, the landmark randomised controlled non-inferiority RACE II trial demonstrated that a lenient rate control strategy (target HR <110 beats per minute [bpm]) was more attainable and safer than a strict rate control strategy (resting HR <80 bpm) in permanent AF. Physiologically, a higher HR is needed to compensate for the lost 'atrial kick' that contributes to the cardiac output by coordinated atrial contractions in normal sinus rhythm. This leaves the not insignificant number of patients with HFrEF and AF in a conundrum over optimal HR control. Retrospective analyses of AF and HR control in landmark HFrEF trials (e.g. CHARM, PARADIGM and ATMOSPHERE) point towards better outcomes with a less stringent target HR. However, this association disappears after adjustment for known prognostic markers in HFrEF, including left ventricular ejection fraction, New York Heart Association class and NT-proBNP levels. There is a clear need for dedicated randomised controlled trials, investigating rate control strategies in this increasingly large subgroup of patients. Regardless of rate control strategy, effective anti-coagulation and guideline-directed medical therapy must not be forgotten in the treatment of patients with HFrEF and AF.

Heart failure outcomes according to heart rate and effects of empagliflozin in patients of the EMPEROR-Preserved trial

AIMS

Empagliflozin reduces cardiovascular death (CVD) or heart failure hospitalization (HHF) in patients with heart failure and preserved ejection fraction (HFpEF). Treatment effects and safety in relation to resting heart rate (RHR) have not been studied.

METHODS AND RESULTS

The interplay of RHR and empagliflozin effects in EMPEROR-Preserved was evaluated. We grouped patients (n = 5988) according to their baseline RHR (<70 bpm [n = 2650], 70-75 bpm [n = 967], >75 bpm [n = 1736]) and explored the influence of RHR on CVD or HHF (primary outcome) and its components in sinus rhythm or atrial fibrillation/flutter (AF) and adverse events. We studied the efficacy of empagliflozin across the RHR spectrum. Compared to placebo, empagliflozin did not change heart rate over time. The primary outcome (p for trend = 0.0004) and its components CVD (p trend = 0.0002), first HHF (p for trend = 0.0099) and all-cause death (p <  0.0001) increased with RHR only in sinus rhythm but not AF. The risk increase with RHR was similar in patients with heart failure and mildly reduced ejection fraction (left ventricular ejection fraction [LVEF] 40-49%) and HFpEF (LVEF ≥50%). Baseline RHR had no influence on the effect of empagliflozin on the primary outcomes (p for trend = 0.20), first HHF (p for trend = 0.49). There were no clinically relevant differences in adverse events between empagliflozin and placebo across the RHR groups.

CONCLUSION

Resting heart rate associates with outcomes only in sinus rhythm but not in AF. Empagliflozin reduced outcomes over the entire RHR spectrum without increase of adverse events.

Elevated heart rate as sympathetic biomarker in human obesity

BACKGROUND AND AIM

The present study was aimed at determining whether and to what extent a specific heart rate (HR) cutoff value allows to identify in obeses a more pronounced level of adrenergic overdrive.

METHODS AND RESULTS

In 86 obese subjects aged 44.7 ± 0.9 (mean ± SEM) years and in 45 heathy lean controls of similar age we evaluated muscle sympathetic nerve traffic (MSNA, microneurography) and venous plasma norepinephrine (NE, HPLC assay), subdividing the subjects in 3 different groups according to their resting clinic and 24-h HR values (<70, 70-79 and 80-89 beats/minute). MSNA and plasma NE values detected in the three obese groups were almost superimposable each other, no significant difference between groups being observed. A similar behavior was observed when HR values were assessed during the 24-h Holter monitoring. In the group as a whole no significant relationship was detected between MSNA, plasma NE and clinic HR, this being the case also when 24-h HR replaced clinic HR in the correlation analysis. In contrast lean controls displayed a progressive significant increase in MSNA values form the group with clinic (and 24 Holter) values below 70 beats/minute to the ones with HR values between 70 and 79 and above 80 beats/minute.

CONCLUSIONS

In the obese state measurement of resting HR may allow to provide some general information on the functional status of the adrenergic cardiovascular drive. When the information required, however, are more subtle the sensitivity of the approach appears to be reduced and HR cannot be regarded as a faithful sympathetic biomarker.

Initiating ivabradine during hospitalization in patients with acute heart failure: A real‐world experience in China

Background

Initiating ivabradine in acute heart failure (HF) is still controversial.

Hypothesis

Ivabradine might be effective to be added in acute but hemodynamically stable HF.

Methods

A retrospective cohort of hemodynamically stable acute HF patients was enrolled from January 2018 to January 2020 and followed until July 2020. The primary endpoints were all‐cause mortality and rehospitalization for HF. Secondary endpoints included heart rate (HR), cardiac function measured by New York Heart Association (NYHA) class, and left ventricular ejection fraction (LVEF) and adverse events, which were compared between patients with or without ivabradine.

Results

A total of 126 patients were enrolled (50 males, median age 54 years, 81% with decompensated HF, median follow‐up of 9 months). In patients treated with ivabradine, although baseline HRs were higher than the reference group (96 vs. 80 bpm), they were comparable after 3 months; more patients tolerated high doses of β‐blockers (27% vs. 7.9%), improved to NYHA class I function (55.6% vs. 23.8%) and exhibited normal LVEFs (37.8% vs. 14.3%) than the reference group (all p < .05). Ivabradine was associated with a significant reduction of rehospitalization for HF than the reference group (25.4% vs.61.9%), with longer event‐free survival times (hazard ratio: 0.45, 95% confidence interval [CI]: 0.25–0.79), and was related with primary endpoints negatively (hazard ratio 0.51, 95% CI: 0.28–0.91) (all p < .05).

Conclusion

In patients with acute but hemodynamically stable HF, ivabradine may significantly reduce HR, improve cardiac function, and reduce HF rehospitalization.

The prognostic value of heart rate at discharge in acute decompensation of heart failure with reduced ejection fraction

AIMS

The effect of elevated heart rate (HR) on morbidity and mortality is evident in chronic stable heart failure; data in this regard in acute decompensated heart failure (ADHF) setting are scarce. In this single-centre study, we sought to address the prognostic value of HR and beta-blocker dosage at discharge on all-cause mortality among patients with heart failure and reduced ejection fraction and ADHF.

METHODS AND RESULTS

In this retrospective observational study, 2945 patients were admitted for the first time with the primary diagnosis of ADHF between January 2008 and February 2018. Patients were divided by resting HR at discharge into three groups (HR < 70 b.p.m., HR 70-90 b.p.m., and HR > 90 b.p.m.). Evidence-based beta-blockers were defined as metoprolol, bisoprolol, and carvedilol. The doses of prescribed beta-blockers were calculated into a percentage target dose of each beta-blocker and divided to four quartiles: 0 < Dose ≤ 25%, 25% < Dose ≤ 50%, 50% < Dose ≤ 75%, and >75% of the target dose. Cox regression was used to calculate the hazard ratio for various HR categories and adjusting for clinical and laboratory variables. At discharge, 1226 patients had an HR < 70 b.p.m., 1347 patients had an HR at range 70-90 b.p.m., and 372 patients with an HR > 90 b.p.m. The 30 day mortality rate was 2.2%, 3.7%, and 12.1% (P < 0.001), respectively. Concordantly, 1 year mortality rate was 14.6%, 16.7%, and 30.4% (P < 0.001) among patients with HR < 70 b.p.m., HR 70-90 b.p.m., and HR > 90 b.p.m., respectively. The adjusted hazard ratio was significantly increased only in HR above 90 b.p.m. category (hazard ratio, 2.318; 95% confidence interval, 1.794-2.996).

CONCLUSIONS

Patients with ADHF and an HR of <90 b.p.m. at discharge had significantly a lower 1 year mortality independent of the dosage of beta-blocker at discharge. It is conceivable to discharge these patients with lower HR.

Discharge heart rate and 1-year clinical outcomes in heart failure patients with atrial fibrillation

BACKGROUND

The association between heart rate and 1-year clinical outcomes in heart failure (HF) patients with atrial fibrillation (AF), and whether this association depends on left ventricular ejection fraction (LVEF), are unclear. We investigated the relationship between discharge heart rate and 1-year clinical outcomes after discharge among hospitalized HF patients with AF, and further explored this association that differ by LVEF level.

METHODS

In this analysis, we enrolled 1760 hospitalized HF patients with AF from the China Patient-centered Evaluative Assessment of Cardiac Events Prospective Heart Failure study from August 2016 to May 2018. Patients were categorized into three groups with low (<65 beats per minute [bpm]), moderate (65-85 bpm), and high (≥86 bpm) heart rate measured at discharge. Cox proportional hazard models were employed to explore the association between heart rate and 1-year primary outcome, which was defined as a composite outcome of all-cause death and HF rehospitalization.

RESULTS

Among 1760 patients, 723 (41.1%) were women, the median age was 69 (interquartile range [IQR]: 60-77) years, median discharge heart rate was 75 (IQR: 69-84) bpm, and 934 (53.1%) had an LVEF <50%. During 1-year follow-up, a total of 792 (45.0%) individuals died or had at least one HF hospitalization. After adjusting for demographic characteristics, smoking status, medical history, anthropometric characteristics, and medications used at discharge, the groups with low (hazard ratio [HR]: 1.32, 95% confidence interval [CI]: 1.05-1.68, P = 0.020) and high (HR: 1.34, 95% CI: 1.07-1.67, P = 0.009) heart rate were associated with a higher risk of 1-year primary outcome compared with the moderate group. A significant interaction between discharge heart rate and LVEF for the primary outcome was observed (P for interaction was 0.045). Among the patients with LVEF ≥50%, only those with high heart rate were associated with a higher risk of primary outcome compared with the group with moderate heart rate (HR: 1.38, 95% CI: 1.01-1.89, P = 0.046), whereas there was no difference between the groups with low and moderate heart rate. Among the patients with LVEF <50%, only those with low heart rate were associated with a higher risk of primary outcome compared with the group with moderate heart rate (HR: 1.46, 95% CI: 1.09-1.96, P = 0.012), whereas there was no difference between the groups with high and moderate heart rate.

CONCLUSIONS

Among the overall HF patients with AF, both low (<65 bpm) and high (≥86 bpm) heart rates were associated with poorer outcomes as compared with moderate (65-85 bpm) heart rate. Among patients with LVEF ≥50%, only a high heart rate was associated with higher risk; while among those with LVEF <50%, only a low heart rate was associated with higher risk as compared with the group with moderate heart rate.

TRAIL REGISTRATION

Clinicaltrials.gov; NCT02878811.

Mediators of the improvement in heart failure outcomes with empagliflozin in the EMPA-REG OUTCOME trial

Aims

In the EMPA‐REG OUTCOME trial, empagliflozin reduced risk of death from heart failure (HF) or hospitalization for heart failure (HHF) versus placebo in patients with type 2 diabetes mellitus (T2DM) and established cardiovascular (CV) disease. We evaluated post hoc the degree to which covariates mediated the effects of empagliflozin on HHF or HF death.

Methods and results

A mediator had to fulfil the following criteria: (i) affected by active treatment, (ii) associated with the outcome, and finally (iii) adjustment for it results in a reduced treatment effect compared with unadjusted analysis. Potential mediators were calculated as change from baseline or updated mean and evaluated in univariable analyses as time‐dependent covariates in Cox regression of time to HHF or HF death; those with the largest mediating effects were then included in a multivariable analysis. Increases in heart rate, log urine albumin‐to‐creatinine ratio (UACR), waist circumference, and uric acid were associated with increased risk of HHF or HF death; increases in high‐density lipoprotein cholesterol, estimated glomerular filtration rate, haematocrit, haemoglobin, and albumin were associated with reduced risk of HHF or HF death. In univariable analyses, change from baseline in haematocrit, haemoglobin, albumin, uric acid, and logUACR mediated 51%, 54%, 23%, 24%, and 27% of the risk reduction with empagliflozin versus placebo, respectively. Multivariable analysis including haemoglobin, logUACR, and uric acid mediated 85% of risk reduction with similar results when updated means were evaluated.

Conclusions

Changes in haematocrit and haemoglobin were the most important mediators of the reduction in HHF and death from HF in patients with T2DM and established CV disease treated with empagliflozin. Albumin, uric acid, and logUACR had smaller mediating effects in this population.

Effect of Heart Rate on the Outcome of Renal Denervation in Patients With Uncontrolled Hypertension

BACKGROUND

Sham-controlled trials demonstrated safety and efficacy of renal denervation (RDN) to lower blood pressure (BP). Association of baseline heart rate with BP reduction after RDN is incompletely understood.

OBJECTIVES

The purpose of this analysis was to evaluate the impact of baseline heart rate on BP reduction without antihypertensive medications in the SPYRAL HTN-OFF MED (Global Clinical Study of Renal Denervation With the Symplicity Spyral Multi-electrode Renal Denervation System in Patients With Uncontrolled Hypertension in the Absence of Antihypertensive Medications) Pivotal trial.

METHODS

Patients removed from any antihypertensive medications were enrolled with office systolic blood pressure (SBP) ≥150 and <180 mm Hg and randomized 1:1 to RDN or sham control. Patients were separated according to baseline office heart rate <70 or ≥70 beats/min. BP changes from baseline to 3 months between treatment arms were adjusted for baseline SBP using analysis of covariance.

RESULTS

Scatter plots of 3-month changes in 24-hour and office SBP illustrate a wide range of changes in SBP for different baseline heart rates. Treatment difference at 3 months between RDN and sham control with baseline office heart rate ≥70 beats/min for 24-hour SBP was -6.2 mm Hg (95% CI: -9.0 to -3.5 mm Hg) (P < 0.001) and for baseline office heart rate <70 beats/min it was -0.1 mm Hg (-3.8 to 3.6 mm Hg) (P = 0.97) with an interaction P value of 0.008. Results were similar for changes in office, daytime, and nighttime SBP at 3 months, with a greater reduction in SBP with baseline office heart rate ≥70 beats/min.

CONCLUSIONS

Reduction in mean office, 24-hour, daytime, and nighttime SBP for RDN at 3 months was greater with baseline office heart rate ≥70 than <70 beats/min, suggesting an association between baseline heart rate and BP reduction after RDN. (SPYRAL PIVOTAL-SPYRAL HTN-OFF MED Study; NCT02439749).

Lower rate limit for pacing by cardiac resynchronization defibrillators: Should lower rate programming be reconsidered?

BACKGROUND

No real-world large database associates lower rate limit (LRL) programming and survival of subjects with cardiac resynchronization therapy-defibrillators (CRT-Ds).

OBJECTIVE

The purpose of this study was to test the hypothesis that lower LRL programming is independently associated with survival, and that LRL and heart rate score (HrSc) are associated.

METHODS

All dual-chamber CRT-D devices in the Remote Patient Monitoring (RPM) ALTITUDE database (2006-2011) were queried. Baseline HrSc was defined as the percentage of all atrial sensed and paced beats in the tallest 10-beat histogram bin postimplant. LRL was assessed during repeated RPM uploads. Using a Cox model multivariable analysis, relationships between LRL, survival, HrSc, and other variables were evaluated. Survival was determined by query of death indices.

RESULTS

Data analyzed included 61,881 subjects (mean follow-up 2.9 years). LRL ranged from 40 to 85 bpm. Baseline lower LRL was associated with younger age, less atrial fibrillation, female sex, and lower HrSc (P <.001 for all covariates). Lower LRL was associated with improved survival, with LRL 40 associated with the largest survival benefit. This was significant for all 3 HrSc subgroups (P <.001). An interaction between HrSc and LRL was observed, with the largest survival difference between HrSc groups observed at LRL-40 (P <.001).

CONCLUSION

LRL programming and HrSc were associated, and lower values of both were associated with improved survival in a large database of CRT-D subjects. Relationships between survival, LRL programming, and HrSc merit further study.

In-hospital Heart Rate Reduction With Beta Blockers and Ivabradine Early After Recovery in Patients With Acute Decompensated Heart Failure Reduces Short-Term Mortality and Rehospitalization

Objective: In the past years, heart rate (HR) has emerged as a highly relevant modifiable risk factor for heart failure (HF) patients. However, most of the clinical trials so far evaluated the role of HR in stable chronic HF cohorts. The aim of this multi-center, prospective observational study was to assess the association between HR and therapy with HR modulators (beta blockers, ivabradine, or a combination of ivabradine and beta blockers) at hospital discharge with patients' cardiovascular mortality and re-hospitalization at 6 months in acutely decompensated HF patients.

Materials and Methods: We recruited 289 HF patients discharged alive after admission for HF decompensation from 10 centers in northern Italy over 9 months (from April 2017 to January 2018). The primary endpoint was the combination of cardiovascular mortality or re-hospitalizations for HF at 6 months.

Results: At 6 months after discharge, 64 patients were readmitted (32%), and 39 patients died (16%). Multivariate analysis showed that HR at discharge ≥ 90 bpm (OR = 8.47; p = 0.016) independently predicted cardiovascular mortality, while therapy with beta blockers at discharge was found to reduce the risk of the composite endpoint. In patients receiving HR modulators the event rates for the composite endpoint, all-cause mortality, and cardiovascular mortality were lower than in patients not receiving HR modulators.

Conclusions: Heart rate at discharge ≥90 bpm predicts cardiovascular mortality, while therapy with beta blockers is negatively associated with the composite endpoint of cardiovascular mortality and hospitalization at 6 months in acutely decompensated HF patients. Patients receiving a HR modulation therapy at hospital discharge showed the lowest rate of cardiovascular mortality and re-hospitalization.

Beta-blockers and inhibitors of the renin-angiotensin aldosterone system for chronic heart failure with preserved ejection fraction

BACKGROUND

Beta-blockers and inhibitors of the renin-angiotensin-aldosterone system improve survival and reduce morbidity in people with heart failure with reduced left ventricular ejection fraction (LVEF); a review of the evidence is required to determine whether these treatments are beneficial for people with heart failure with preserved ejection fraction (HFpEF).

OBJECTIVES

To assess the effects of beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, angiotensin receptor neprilysin inhibitors, and mineralocorticoid receptor antagonists in people with HFpEF.

SEARCH METHODS

We updated searches of CENTRAL, MEDLINE, Embase, and one clinical trial register on 14 May 2020 to identify eligible studies, with no language or date restrictions. We checked references from trial reports and review articles for additional studies.  SELECTION CRITERIA: We included randomised controlled trials with a parallel group design, enrolling adults with HFpEF, defined by LVEF greater than 40%.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 41 randomised controlled trials (231 reports), totalling 23,492 participants across all comparisons. The risk of bias was frequently unclear and only five studies had a low risk of bias in all domains. Beta-blockers (BBs) We included 10 studies (3087 participants) investigating BBs. Five studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 30 years to 81 years. A possible reduction in cardiovascular mortality was observed (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.62 to 0.99; number needed to treat for an additional benefit (NNTB) 25; 1046 participants; three studies), however, the certainty of evidence was low. There may be little to no effect on all-cause mortality (RR 0.82, 95% CI 0.67 to 1.00; 1105 participants; four studies; low-certainty evidence). The effects on heart failure hospitalisation, hyperkalaemia, and quality of life remain uncertain. Mineralocorticoid receptor antagonists (MRAs) We included 13 studies (4459 participants) investigating MRA. Eight studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 54.5 to 80 years. Pooled analysis indicated that MRA treatment probably reduces heart failure hospitalisation (RR 0.82, 95% CI 0.69 to 0.98; NNTB = 41; 3714 participants; three studies; moderate-certainty evidence). However, MRA treatment probably has little or no effect on all-cause mortality (RR 0.91, 95% CI 0.78 to 1.06; 4207 participants; five studies; moderate-certainty evidence) and cardiovascular mortality (RR 0.90, 95% CI 0.74 to 1.11; 4070 participants; three studies; moderate-certainty evidence). MRA treatment may have little or no effect on quality of life measures (mean difference (MD) 0.84, 95% CI -2.30 to 3.98; 511 participants; three studies; low-certainty evidence). MRA treatment was associated with a higher risk of hyperkalaemia (RR 2.11, 95% CI 1.77 to 2.51; number needed to treat for an additional harmful outcome (NNTH) = 11; 4291 participants; six studies; high-certainty evidence). Angiotensin-converting enzyme inhibitors (ACEIs) We included eight studies (2061 participants) investigating ACEIs. Three studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 70 to 82 years. Pooled analyses with moderate-certainty evidence suggest that ACEI treatment likely has little or no effect on cardiovascular mortality (RR 0.93, 95% CI 0.61 to 1.42; 945 participants; two studies), all-cause mortality (RR 1.04, 95% CI 0.75 to 1.45; 1187 participants; five studies) and heart failure hospitalisation (RR 0.86, 95% CI 0.64 to 1.15; 1019 participants; three studies), and may result in little or no effect on the quality of life (MD -0.09, 95% CI -3.66 to 3.48; 154 participants; two studies; low-certainty evidence). The effects on hyperkalaemia remain uncertain. Angiotensin receptor blockers (ARBs) Eight studies (8755 participants) investigating ARBs were included. Five studies used a placebo comparator and in three the comparator was usual care. The mean age of participants ranged from 61 to 75 years. Pooled analyses with high certainty of evidence suggest that ARB treatment has little or no effect on cardiovascular mortality (RR 1.02, 95% 0.90 to 1.14; 7254 participants; three studies), all-cause mortality (RR 1.01, 95% CI 0.92 to 1.11; 7964 participants; four studies), heart failure hospitalisation (RR 0.92, 95% CI 0.83 to 1.02; 7254 participants; three studies), and quality of life (MD 0.41, 95% CI -0.86 to 1.67; 3117 participants; three studies). ARB was associated with a higher risk of hyperkalaemia (RR 1.88, 95% CI 1.07 to 3.33; 7148 participants; two studies; high-certainty evidence). Angiotensin receptor neprilysin inhibitors (ARNIs) Three studies (7702 participants) investigating ARNIs were included. Two studies used ARBs as the comparator and one used standardised medical therapy, based on participants' established treatments at enrolment. The mean age of participants ranged from 71 to 73 years. Results suggest that ARNIs may have little or no effect on cardiovascular mortality (RR 0.96, 95% CI 0.79 to 1.15; 4796 participants; one study; moderate-certainty evidence), all-cause mortality (RR 0.97, 95% CI 0.84 to 1.11; 7663 participants; three studies; high-certainty evidence), or quality of life (high-certainty evidence). However, ARNI treatment may result in a slight reduction in heart failure hospitalisation, compared to usual care (RR 0.89, 95% CI 0.80 to 1.00; 7362 participants; two studies; moderate-certainty evidence). ARNI treatment was associated with a reduced risk of hyperkalaemia compared with valsartan (RR 0.88, 95% CI 0.77 to 1.01; 5054 participants; two studies; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

There is evidence that MRA and ARNI treatment in HFpEF probably reduces heart failure hospitalisation but probably has little or no effect on cardiovascular mortality and quality of life. BB treatment may reduce the risk of cardiovascular mortality, however, further trials are needed. The current evidence for BBs, ACEIs, and ARBs is limited and does not support their use in HFpEF in the absence of an alternative indication. Although MRAs and ARNIs are probably effective at reducing the risk of heart failure hospitalisation, the treatment effect sizes are modest. There is a need for improved approaches to patient stratification to identify the subgroup of patients who are most likely to benefit from MRAs and ARNIs, as well as for an improved understanding of disease biology, and for new therapeutic approaches.

Dynamic change of heart rate in the acute phase and clinical outcomes after intracerebral hemorrhage: a cohort study

BACKGROUND

Dynamic change of heart rate in the acute phase and clinical outcomes after intracerebral hemorrhage (ICH) remains unknown. We aimed to investigate the associations of heart rate trajectories and variability with functional outcome and mortality in patients with acute ICH.

METHODS

This prospective study was conducted among 332 patients with acute ICH. Latent mixture modeling was used to identify heart rate trajectories during the first 72 h of hospitalization after ICH onset. Mean and coefficient of variation of heart rate measurements were calculated. The study outcomes included unfavorable functional outcome, ordinal shift of modified Rankin Scale score, and all-cause mortality.

RESULTS

We identified 3 distinct heart rate trajectory patterns (persistent-high, moderate-stable, and low-stable). During 3-month follow-up, 103 (31.0%) patients had unfavorable functional outcome and 46 (13.9%) patients died. In multivariable-adjusted model, compared with patients in low-stable trajectory, patients in persistent-high trajectory had the highest odds of poor functional outcome (odds ratio 15.06, 95% CI 3.67-61.78). Higher mean and coefficient of variation of heart rate were also associated with increased risk of unfavorable functional outcome (P trend < 0.05), and the corresponding odds ratios (95% CI) comparing two extreme tertiles were 4.69 (2.04-10.75) and 2.43 (1.09-5.39), respectively. Likewise, similar prognostic effects of heart rate dynamic changes on high modified Rankin Scale score and all-cause mortality were observed.

CONCLUSIONS

Persistently high heart rate and higher variability in the acute phase were associated with increased risk of unfavorable functional outcome in patients with acute ICH.

Resting heart rate predicts all-cause mortality in sub-Saharan African patients with heart failure: a prospective analysis from the Douala Heart failure registry (Do-HF)

Background

Higher resting heart rate (HR) is associated with mortality amongst Caucasians with heart failure (HF), but its significance has yet to be established in sub-Saharan Africans in whom HF differs in terms of characteristics and etiologies. We assessed the association of HR with all-cause mortality in patients with HF in sub-Saharan Africa.

Methods

The Douala HF registry (Do-HF) is an ongoing prospective data collection on patients with HF receiving care at four cardiac referral services in Douala, Cameroon. Patients included in this report were followed-up for 12 months from their index admission, for all-cause mortality. We used Cox-regression analysis to study the association of HR with all-cause mortality during follow-up.

Results

Of 347 patients included, 343 (98.8%) completed follow-up. The mean age was 64±14 years, 176 (50.7%) were female, and median admission HR was 85 bpm. During a median follow-up of 12 months, 78 (22.7%) patients died. Mortality increased steadily with HR increase and ranged from 12.2% in the lower quartile of HR (≤69 bpm) to 34.1% in the upper quartile of HR (>100 bpm). Hazard ratio of 12-month death per 10 bpm higher HR was 1.16 (1.04-1.29), with consistent effects across most subgroups, but a higher effect in participants with hypertension vs. those without (interaction P=0.044).

Conclusions

HR was independently associated with increased risk of all-cause mortality in this study, particularly among participants with hypertension. The implication of this finding for risk prediction or reduction should be actively investigated.

Exercise Ventricular Rates, Cardiopulmonary Exercise Performance, and Mortality in Patients With Heart Failure With Atrial Fibrillation

BACKGROUND

In heart failure (HF) with sinus rhythm, resting and exercise heart rates correlate with exercise capacity and mortality. However, in HF with atrial fibrillation (AF), this correlation is unknown. Our aim is to investigate the association of resting and exercise ventricular rates (VRs) with exercise capacity and mortality in HF with AF.

METHODS

We identified 903 patients with HF and AF referred for cardiopulmonary stress testing. AF was defined as history of AF and AF during cardiopulmonary stress testing. We constructed multivariable models to evaluate the association of resting VR, peak exercise VR, VR reserve (peak VR-resting VR), and chronotropic index with (1) peak oxygen consumption (PVO₂) ≤18 mL/kg per minute, (2) continuous PVO₂, and (3) 10-year all-cause mortality.

RESULTS

Median (25th-75th percentile) age was 60 (52-67) years, left ventricular ejection fraction was 25 (15-50)%, and 76.1% were males. Patients with lower (quartile 1) compared with higher (quartile 4) peak VR, VR reserve, and chronotropic index were more likely to have PVO₂ ≤18 mL/kg per min (adjusted odds ratio [95% CI]: 14.92 [8.07-27.58], 24.60 [12.36-48.98], and 22.31 [11.24-44.27], respectively), and higher all-cause mortality (adjusted hazard ratio [95% CI]: 2.56 [1.62-4.04], 2.29 [1.47-3.59], and 2.30 [1.51-3.49], respectively). For every 10 beats per minute increase in VR reserve, PVO₂ increased by 1.05 mL/kg per minute (B-coefficient [95% CI]: 1.05 [0.94-1.15]) and mortality decreased by 12% (adjusted hazard ratio [95% CI]: 0.88 [0.83-0.94]). Resting VR was associated with PVO₂ (B-coefficient [95% CI]: -0.46 [-0.70 to -0.23]) but not mortality (adjusted hazard ratio [95% CI]: 0.97 [0.88-1.06]).

CONCLUSIONS

In patients with HF and AF, higher resting VR and lower peak exercise VR, VR reserve, and chronotropic index were all associated with worse peak exercise capacity, but only lower exercise VR parameters were associated with higher mortality. Dedicated studies are needed to gauge whether modulating exercise VR enhances exercise performance and outcomes.

Electrocardiographic features and their echocardiographic correlates in peripartum cardiomyopathy: results from the ESC EORP PPCM registry

AIMS

In peripartum cardiomyopathy (PPCM), electrocardiography (ECG) and its relationship to echocardiography have not yet been investigated in large multi-centre and multi-ethnic studies. We aimed to identify ECG abnormalities associated with PPCM, including regional and ethnic differences, and their correlation with echocardiographic features.

METHODS AND RESULTS

We studied 411 patients from the EURObservational PPCM registry. Baseline demographic, clinical, and echocardiographic data were collected. ECGs were analysed for rate, rhythm, QRS width and morphology, and QTc interval. The median age was 31 [interquartile range (IQR) 26-35] years. The ECG was abnormal in > 95% of PPCM patients. Sinus tachycardia (heart rate > 100 b.p.m.) was common (51%), but atrial fibrillation was rare (2.27%). Median QRS width was 82 ms [IQR 80-97]. Left bundle branch block (LBBB) was reported in 9.30%. Left ventricular (LV) hypertrophy (LVH), as per ECG criteria, was more prevalent amongst Africans (59.62%) and Asians (23.17%) than Caucasians (7.63%, P < 0.001) but did not correlate with LVH on echocardiography. Median LV end-diastolic diameter (LVEDD) was 60 mm [IQR 55-65] and LV ejection fraction (LVEF) 32.5% [IQR 25-39], with no significant regional or ethnic differences. Sinus tachycardia was associated with an LVEF < 35% (OR 1.85 [95% CI 1.20-2.85], P = 0.006). ECG features that predicted an LVEDD > 55 mm included a QRS complex > 120 ms (OR 11.32 [95% CI 1.52-84.84], P = 0.018), LBBB (OR 4.35 [95% CI 1.30-14.53], P = 0.017), and LVH (OR 2.03 [95% CI 1.13-3.64], P = 0.017).

CONCLUSIONS

PPCM patients often have ECG abnormalities. Sinus tachycardia predicted poor systolic function, whereas wide QRS, LBBB, and LVH were associated with LV dilatation.

Increased heart rate with sleep disordered breathing in hypertrophic cardiomyopathy

BACKGROUND

Current guidelines recommend medications with rate control properties for symptomatic patients with hypertrophic cardiomyopathy (HCM) based on the rationale that lowering heart rate (HR) improves their symptoms. Whether sleep disordered breathing (SDB) is associated with increased HR in HCM patients is not known.

METHOD

We diagnosed uncontrolled SDB (oxygen desaturation index ≥5) in consecutive echocardiographically confirmed HCM patients seen at Mayo Clinic, Rochester, and analyzed their HR as recorded by a 24-h Holter monitor. We compared mean, minimum, maximum HR between those with vs without SDB. In a pilot subanalysis of HCM patients with SDB who also underwent subsequent diagnostic polysomnography (PSG), we analyzed RR interval changes coinciding with obstructive sleep apnea and hypopnea episodes.

RESULTS

Of the 230 HCM patients included in this study (age 54 ± 16 years; 138 male; LVOT pressure gradient at rest 45 ± 39 mmHg), 115 (50%) patients had SDB. HCM patients with SDB were recorded to have higher mean HR (71 vs. 67 bpm; p = .002, adjusted p = .001), and this difference was most pronounced during night hours of 10 PM to 5 AM (61 vs. 67 bpm; p < .001). In the pilot analysis of the available PSG data, the release of obstructive sleep apneas and hypopneas coincided with fluctuation of HR.

CONCLUSIONS

SDB is independently associated with higher mean HR in patients with HCM, and this difference is most significant during sleep. Treatment of SDB, which is readily available, should be tested as a complementary modality to the currently recommended pharmacotherapy aimed at lowering HR in patients with symptomatic HCM.

Elevated heart rate and cardiovascular risk in hypertension

Epidemiological studies have shown that chronically elevated resting heart rate (HR) is significantly associated with organ damage, morbidity and mortality in a wide range of patients including hypertensive patients. Evidence is also available that an increased HR reflects sympathetic nervous system overdrive which is also known to adversely affect organ structure and function and to increase the risk of unfavourable outcomes in several diseases. The causal relationship between elevated HR, organ damage, and cardiovascular outcomes can thus be explained by its relationship with sympathetic cardiovascular influences although evidence of sympathetically-independent adverse effect of HR increases per se makes it more complex. Interventions that target HR by modulating the sympathetic nervous system have therefore a strong pathophysiological and clinical rationale. As most clinical guidelines now recommend the use of combination therapies in patients with hypertension, it might be desirable to consider as combination components drugs which lower HR, if HR is elevated such as, according to guideliines, when it is above 80 b/min.

Is Current Drug Therapy for Heart Failure Sufficient to Control Heart Rate of Patients?

BACKGROUND

Studies have shown that heart failure (HF) patients with heart rate (HR) < 70 bpm have had a better clinical outcome and lower morbidity and mortality compared with those with HR > 70 bpm. However, many HF patients maintain an elevated HR.

OBJECTIVE

To evaluate HR and the prescription of medications known to reduce mortality in HF patients attending an outpatient cardiology clinic.

METHODS

We consecutively evaluated patients seen in an outpatient cardiology clinic, aged older than 18 years, with diagnosis of HF and left ventricular ejection fraction (LVEF) < 45%. Patients with sinus rhythm were divided into two groups - HR ≤ 70 bpm (G1) and HR > 70 bpm (G2). The Student's t-test and the chi-square test were used in the statistical analysis, and a p-value < 0.05 was considered statistically significant. The SPSS software was used for the analyses.

RESULTS

A total of 212 consecutive patients were studied; 41 (19.3%) had atrial fibrillation or had a pacemaker implanted and were excluded from the analysis, yielding 171 patients. Mean age of patients was 63.80 ± 11.77 years, 59.6% were men, and mean LVEF 36.64±7.79%. The most prevalent HF etiology was ischemic (n=102; 59.6%), followed by Chagasic (n=17; 9.9%). One-hundred thirty-one patients (76.6%) were hypertensive and 63 (36.8%) diabetic. Regarding HR, 101 patients had a HR ≤70 bpm (59.1%) and 70 patients (40.93%) had a HR >70 bpm (G2). Mean HR of G1 and G2 was 61.5±5.3 bpm and 81.8±9.5 bpm, respectively (p<0.001). Almost all patients (98.8%) were receiving carvedilol, prescribed at a mean dose of 42.1±18.5 mg/day in G1 and 42.5±21.1mg/day in G2 (p=0.911). Digoxin was used in 5.9% of patients of G1 and 8.5% of G2 (p=0.510). Mean dose of digoxin in G1 and G2 was 0.19±0.1 mg/day and 0.19±0.06 mg/day, respectively (p=0,999). Most patients (87.7%) used angiotensin converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB), and 56.7% used spironolactone. Mean dose of enalapril was 28.9±12.7 mg/day and mean dose of ARB was 87.8±29.8 mg/day. The doses of ACEI and ARB were adequate in most of patients.

CONCLUSION

The study revealed that HR of 40.9% of patients with HF was above 70 bpm, despite treatment with high doses of beta blockers. Further measures should be applied for HR control in HF patients who maintain an elevated rate despite adequate treatment with beta blocker. (Arq Bras Cardiol. 2020; 115(6):1063-1069).

Heart rate at discharge in patients with acute decompensated heart failure is a predictor of mortality

AIMS

Heart failure is a syndrome with increasing prevalence in concordance with the aging population and better survival rates from myocardial infarction. Morbidity and mortality are high in chronic heart failure patients, particularly in those with hospital admission for acute decompensation. Several risk stratification tools and score systems have been established to predict mortality in chronic heart failure patients. However, identification of patients at risk with easy obtainable clinical factors that can predict mortality in acute decompensated heart failure (ADHF) are needed to optimize the care-path.

METHODS AND RESULTS

We retrospectively analyzed electronic medical records of 78 patients with HFrEF and HFmrEF who were hospitalized with ADHF in the Heart Center of the University Hospital Cologne in the year 2011 and discharged from the ward after successful treatment. 37.6 ± 16.4 months after index hospitalization 30 (38.5%) patients had died. This mortality rate correlated well with the calculated predicted survival with the Seattle Heart Failure Model (SHFM) for each individual patient. In our cohort, we identified elevated heart rate at discharge as an independent predictor for mortality (p = 0.016). The mean heart rate at discharge was lower in survived patients compared to patients who died (72.5 ± 11.9 vs. 79.1 ± 11.2 bpm. Heart rate of 77 bpm or higher was associated with an almost doubled mortality risk (p = 0.015). Heart rate elevation of 5 bpm was associated with an increase of mortality of 25% (p = 0.022).

CONCLUSIONS

Patients hospitalized for ADHF seem to have a better prognosis, when heart rate at discharge is < 77 bpm. Heart rate at discharge is an easily obtainable biomarker for risk prediction of mortality in HFrEF and HFmrEF patients treated for acute cardiac decompensation. Taking into account this parameter could be useful for guiding treatment strategies in these high-risk patients. Prospective data for validation of this biomarker and specific intervention are needed.

The impact of pre-procedure heart rate on adverse clinical outcomes in patients undergoing percutaneous coronary intervention: Results from a 2-year follow-up of the GLOBAL LEADERS trial

BACKGROUND AND AIMS

The prognostic impact of pre-procedure heart rate (PHR) following percutaneous coronary intervention (PCI) has not yet been fully investigated. This post-hoc analysis sought to assess the impact of PHR on medium-term outcomes among patients having PCI, who were enrolled in the "all-comers" GLOBAL LEADERS trial.

METHODS AND RESULTS

The primary endpoint (composite of all-cause death or new Q-wave myocardial infarction [MI]) and key secondary safety endpoint (bleeding according to Bleeding Academic Research Consortium [BARC] type 3 or 5) were assessed at 2 years. PHR was available in 15,855 patients, and when evaluated as a continuous variable (5 bpm increase) and following adjustment using multivariate Cox regression, it significantly correlated with the primary endpoint (hazard ratio [HR] 1.06, 95% confidence interval [CI] 1.03-1.09, p < 0.001). Using dichotomous cut-off criteria, a PHR>67 bpm was associated with increased all-cause mortality (HR 1.38, 95%CI 1.13-1.69, p = 0.002) and more frequent new Q-wave MI (HR 1.41, 95%CI 1.02-1.93, p = 0.037). No significant association was found between PHR and BARC 3 or 5 bleeding (HR 1.04, 95% CI 0.99-1.09, p = 0.099). There was no interaction with the primary (p-inter = 0.236) or secondary endpoint (p-inter = 0.154) when high and low PHR was analyzed according to different antiplatelet strategies.

CONCLUSIONS

Elevated PHR was an independent predictor of all-cause mortality at 2 years following PCI in the "all-comer" GLOBAL LEADERS trial. The prognostic value of increased PHR on outcomes was not affected by the different antiplatelet strategies in this trial.

Association of pulse rate with outcomes in heart failure with reduced ejection fraction: a retrospective cohort study

BACKGROUND

In a real-world setting, the effect of pulse rate measured at the time of diagnosis and serially during follow-up and management, on outcomes in heart failure with reduced ejection fraction (HFrEF), has not been well-studied. Furthermore, how beta-blockade use in a real-world situation modifies this relation between pulse rate and outcomes in HFrEF is not well-known. Hence, we identified a large, national, real-world cohort of HFrEF to examine the association of pulse rate and outcomes.

METHODS

Using Veterans Affairs (VA) national electronic health records we identified incident HFrEF cases between 2006 and 2012. We examined the associations of both baseline and serially measured pulse rates, with mortality and days hospitalized per year for heart failure and for any cause, using crude and multivariable Cox proportional hazards and Poisson or negative binomial models, respectively. The exposure was examined as continuous, dichotomous, and categorical. Post-hoc analyses addressed the interaction of pulse rate and beta-blocker target dose.

RESULTS

We identified 51,194 incident HFrEF cases (67 ± 12 years, 98% male, 77% white. A significant positive, near linear relationship was observed for both baseline and serially measured pulse rates with all-cause mortality, all-cause hospitalization and heart failure hospitalization after adjusting for covariates including beta-blocker use. Patients who had a pulse rate ≥ 70 bpm in the past 6 months had 36% (95% CI: 31-42%), 25% (95% CI: 19-32%), and 51% (95% CI: 33-72%) increased rates of mortality, all-cause hospitalization, and heart failure hospitalization, respectively, compared to patients with pulse rates < 70 bpm. A minority of subjects (15%) were treated with guideline directed beta blockade ≥50% of recommended target dose, among whom better outcomes were seen compared to those who did not achieve target dose in patients with pulse rates both above and below 70 beats per minute.

CONCLUSIONS

High pulse rate, both at the time of diagnosis and during follow-up, is strongly associated with increased risk of adverse outcomes in HFrEF patients, independent of the use of beta-blockers. In a real-world setting, the majority of HFrEF patients do not achieve target dose of beta-blockade; greater use of strategies to reduce heart rate may improve outcomes in HFrEF.

Prognostic value of discharge heart rate in acute heart failure patients: More relevant in atrial fibrillation?

AIMS

The prognostic impact of heart rate (HR) in acute heart failure (AHF) patients is not well known especially in atrial fibrillation (AF) patients. The aim of the study was to evaluate the impact of admission HR, discharge HR, HR difference (admission-discharge) in AHF patients with sinus rhythm (SR) or AF on long- term outcomes.

METHODS

We included 1398 patients consecutively admitted with AHF between October 2013 and December 2014 from a national multicentre, prospective registry. Logistic regression models were used to estimate the association between admission HR, discharge HR and HR difference and one- year all-cause mortality and HF readmission.

RESULTS

The mean age of the study population was 72 ± 12 years. Of these, 594 (42.4%) were female, 655 (77.8%) were hypertensive and 655 (46.8%) had diabetes. Among all included patients, 745 (53.2%) had sinus rhythm and 653 (46.7%) had atrial fibrillation. Only discharge HR was associated with one year all-cause mortality (Relative risk (RR) = 1.182, confidence interval (CI) 95% 1.024-1.366, p = 0.022) in SR. In AF patients discharge HR was associated with one year all cause mortality (RR = 1.276, CI 95% 1.115-1.459, p ≤ 0.001). We did not observe a prognostic effect of admission HR or HRD on long-term outcomes in both groups. This relationship is not dependent on left ventricular ejection fraction.

CONCLUSIONS

In AHF patients lower discharge HR, neither the admission nor the difference, is associated with better long-term outcomes especially in AF patients.

Relation between resting heart rate and the risk of ventricular tachyarrhythmias in MADIT-RIT

AIMS

To explore the association between resting heart rate (RHR) and ventricular tachyarrhythmias (VTA) events among patients who were enrolled in MADIT-RIT.

METHODS AND RESULTS

Multivariate Cox proportional hazards regression modelling was employed to evaluate the association between baseline RHR [dichotomized at the lower quartile (≤63 b.p.m.) and further assessed as a continuous measure] and the risk for any VTA, fast VTA (>200 b.p.m.), and appropriate implantable cardioverter-defibrillator (ICD) therapy, among 1500 patients who were enrolled in MADIT-RIT. Kaplan-Meier survival analysis showed that at 2 years of follow-up the rate of any VTA was significantly lower among patients with low baseline RHR (≤63 b.p.m.) as compared with faster RHR (11% vs. 19%, respectively; P = 0.001 for the overall difference during follow-up). Similar results were shown for the association with the rate of fast VTA (8% vs. 14%, respectively; P = 0.016), and appropriate ICD therapy (10% vs. 18%, respectively; P = 0.004). Multivariate analysis, after adjustment for medical therapy, showed that low baseline RHR was associated with a significant 45% (P = 0.002) reduction in the VTA risk as compared with faster baseline RHRs. When assessed as a continuous measure, each 10 b.p.m. decrement in RHR was associated with a corresponding 13% (P = 0.014) reduction in the VTA risk.

CONCLUSION

In MADIT-RIT, low RHR was independently associated with a lower risk for life-threatening arrhythmic events. These findings suggest a possible role for RHR for improved selection of candidates for ICD therapy.

β-Blocker Doses and Heart Rate in Patients with Heart Failure: Results from the National Norwegian Heart Failure Registry

BACKGROUND

Use of β-blockers and titration to the highest tolerated dose are highly recommended by the European Society of Cardiology (ESC) guidelines for treatment of chronic heart failure (HF) with a reduced ejection fraction (HFrEF), but little attention has been paid to the achieved heart rate (HR) during this treatment.

OBJECTIVES

The aim of the present study was to examine the achieved HR in relation to the use of β-blockers in these patients.

METHODS

All of the patients (n = 2,689) in the National Norwegian Heart Failure Registry as part of the Norwegian Cardiovascular Disease Registry with a sinus rhythm and left ventricular ejection fraction (LVEF) <40% at stable follow-up visiting specialised hospital outpatient HF clinics in Norway were included. The β-blocker doses were calculated as a percent of the target dose according to ESC HF guidelines. Differences between baseline variables according to the achieved HR were analysed by the Student's t test for continuous variables and Pearson's χ2 test for categorical variables. Linear regression was used to determine the predictors of HR ≥70 beats/min (bpm) in the multivariate analysis.

RESULTS

One third of the patients had a resting HR ≥70 bpm. Of the patients with an HR ≥70 bpm, 72.3% used less than the target dose of β-blocker; they were younger and had a higher NYHA class, more diabetes mellitus and chronic obstructive pulmonary disease (COPD), and higher N-terminal pro-B type natriuretic peptide (NT-proBNP) levels and estimated glomerular filtration rates compared to the patients with an HR <70 bpm. The 1-year mortality was 3.1, 3.7, 5.8, and 9.1% among the patients with an HR <70, 70-79, 80-89, and >89 bpm, respectively. Only 2 patients used ivabradine.

CONCLUSIONS

In patients with HFrEF and sinus rhythm, an HR ≥70 bpm was associated with worse clinical variables and outcomes. A high proportion of the patients who had an HR ≥70 bpm was not treated with or/did not tolerate the target dose of a β-blocker, although the β-blocker dose was higher than in patients with an HR <70 bpm. This may suggest that increased efforts should be made to further increase the β-blocker dose, and treatment with ivabradine could be considered among patients with an HR ≥70 bpm.

Circadian-timed quick-release bromocriptine lowers elevated resting heart rate in patients with type 2 diabetes mellitus

OBJECTIVE

Sympathetic nervous system (SNS) overactivity is a risk factor for insulin resistance and cardiovascular disease (CVD). We evaluated the impact of bromocriptine-QR, a dopamine-agonist antidiabetes medication, on elevated resting heart rate (RHR) (a marker of SNS overactivity in metabolic syndrome), blood pressure (BP) and the relationship between bromocriptine-QR's effects on RHR and HbA1c in type 2 diabetes subjects.

DESIGN AND SUBJECTS

RHR and BP changes were evaluated in this post hoc analysis of data from a randomized controlled trial in 1014 type 2 diabetes subjects randomized to bromocriptine-QR vs placebo added to standard therapy (diet ± ≤2 oral antidiabetes medications) for 24 weeks without concomitant antihypertensive or antidiabetes medication changes, stratified by baseline RHR (bRHR).

RESULTS

In subjects with bRHR ≥70 beats/min, bromocriptine-QR vs placebo reduced RHR by -3.4 beats/min and reduced BP (baseline 130/79; systolic, diastolic, mean arterial BP reductions [mm Hg]: -3.6 [P = .02], -1.9 [P = .05], -2.5 [P = .02]). RHR reductions increased with higher baseline HbA1c (bHbA1c) (-2.7 [P = .03], -5 [P = .002], -6.1 [P = .002] with bHbA1c ≤7, >7, ≥7.5%, respectively] in the bRHR ≥70 group and more so with bRHR ≥80 (-4.5 [P = .07], -7.8 [P = .015], -9.9 [P = .005]). Subjects with bRHR <70 had no significant change in RHR or BP. With bHbA1c ≥7.5%, %HbA1c reductions with bromocriptine-QR vs placebo were -0.50 (P = .04), -0.73 (P = .005) and -1.22 (P = .008) with bRHR <70, ≥70 and ≥80, respectively. With bRHR ≥70, the magnitude of bromocriptine-QR-induced RHR reduction was an independent predictor of bromocriptine-QR's HbA1c lowering effect.

CONCLUSION

Bromocriptine-QR lowers elevated RHR with concurrent decrease in BP and hyperglycaemia. These findings suggest a potential sympatholytic mechanism contributing to bromocriptine-QR's antidiabetes effect and potentially its previously demonstrated effect to reduce CVD events.

Hyperventilation-induced heart rate response as a potential marker for cardiovascular disease

An increase of heart rate to physical or mental stress reflects the ability of the autonomous nervous system and the heart to respond adequately. Hyperventilation is a user-controlled breathing maneuver that has a significant impact on coronary function and hemodynamics. Thus, we aimed to investigate if the heart rate response to hyperventilation (HRRHV) can provide clinically useful information. A pooled analysis of the HRRHV after 60 s of hyperventilation was conducted in 282 participants including healthy controls; patients with heart failure (HF); coronary artery disease (CAD); a combination of both; or patients suspected of CAD but with a normal angiogram. Hyperventilation significantly increased heart rate in all groups, although healthy controls aged 55 years and older (15 ± 9 bpm) had a larger HRRHV than each of the disease groups (HF: 6 ± 6, CAD: 8 ± 8, CAD+/HF+: 6 ± 4, and CAD-/HF-: 8 ± 6 bpm, p < 0.001). No significant differences were found between disease groups. The HRRHV may serve as an easily measurable additional marker of cardiovascular health. Future studies should test its diagnostic potential as a simple, inexpensive pre-screening test to improve patient selection for other diagnostic exams.

The Importance of Heart Rate in Heart Failure and Reduced Ejection Fraction

BACKGROUND

Heart failure with reduced ejection fraction (HFrEF) is a progressive, chronic, and burdensome cardiovascular condition. It is associated with limiting symptoms, such as dyspnea and fatigue; a decline in functional capacity; and premature mortality and hospitalization. In heart failure (HF) management, heart rate is commonly assessed yet frequently overlooked as a modifiable risk factor and a predictor of mortality. An elevated heart rate increases myocardial demand and decreases diastolic filling time. Hospitalized patients with HFrEF who have a heart rate greater than 70 beats per minute at discharge were found to have lower survival rates.

PURPOSE

The aims of this study were to review the association between heart rate and clinical outcome in patients with HF and discuss the contribution of heart rate to HFrEF pathophysiology. Medications currently used to modulate heart rate in patients with HF are also reviewed.

CONCLUSIONS

In patients with HFrEF, an elevated heart rate contributes to HF progression, and it is both a prognostic and modifiable risk factor. Medications such as an evidence-based β-blockers, digoxin, and ivabradine are recommended for modulation of heart rate in patients with HFrEF.

CLINICAL IMPLICATIONS

Nurses play a pivotal role in managing HFrEF and must understand current evidence of the pathophysiology of elevated heart rate, risks, and management strategies. Early recognition of elevated heart rate and application of guideline-directed pharmacologic treatment for patients with HFrEF and an elevated heart rate remains key to improving patient outcomes.

Heightened risk of intensive rate control in patients with atrial fibrillation who are obese or have type 2 diabetes: A critical review and re-evaluation

Atrial fibrillation (AF) is common in patients with obesity and diabetes; the arrhythmia (if long-standing) is typically managed by rate control and anticoagulation. However, the coexistence of these two metabolic disorders complicates therapeutic options for rate control. The likely pathogenesis of AF in these patients is an expansion of epicardial adipose tissue whose inflammation is transmitted to the left atrium causing electromechanical remodeling. However, this same process is also transmitted to the left ventricle (LV), impairing its distensibility and its ability to tolerate volume, leading to heart failure with preserved ejection fraction. Unfortunately, the latter diagnosis (although commonly present in patients with AF and a coexistent metabolic disorder) is often ignored. To achieve rate control, physicians prescribe intensive treatment with atrioventricular (AV) nodal-blocking drugs, often at doses that are titrated to blunt exercise as well as resting heart rate responses. However, strict rate control (target rate, <80/min) is associated with somewhat worse outcomes than lenient rate control (target rate, <110/min). Furthermore, any rate slowing that facilitates diastolic filling may aggravate filling pressures that are already disproportionately increased because the LV is stiff and overfilled as a result of cardiac inflammation. Rate slowing in AF with beta blockers may not achieve the benefit expected from the blockade of adrenergically mediated cardiotoxicity, and some AV nodal-blocking drugs (digoxin and dronedarone) can increase the risk of death in patients with AF. Finally, cardiac fibrosis in obesity and diabetes may affect the conduction system, which can predispose to serious bradyarrhythmias if patients are prescribed AV nodal-blocking drugs.

Prognostic Significance of Heart Rate and Beta-Blocker Use in Sinus Rhythm in Patients with Heart Failure and Preserved Ejection Fraction

INTRODUCTION

Prognostic significance of heart rate (HR) in heart failure with preserved ejection fraction (HFpEF) remains poorly understood.

AIM

To evaluate the association of HR and beta-blocker use with all-cause mortality and the optimal HR range in patients with HFpEF and sinus rhythm (SR).

METHODS

During a follow-up of 2.7 years (IQR 1.2-4.1 years), the 330 patients with median age 73 (IQR 64-79) years, 52.1% men, were included. HFpEF was defined as patients with EF ≥ 50%. The outcome measure was all-cause mortality.

RESULTS

In total, 96 (29.1%) of patients with HFpEF and SR died. A linear tendency between HR and mortality was observed in SR. Compared to the reference strata HR ≤ 60 bpm, HR increment was associated with progressively increased risk in mortality (Chi-square = 13.90, Log rank P = 0.001) by Kaplan-Meier analyses. Univariate Cox regression showed that in SR, compared with that in HR 61-80 bpm, the unadjusted hazard ratios for mortality were 0.41 (95% CI 0.23-0.74, P  = 0.003) in HR ≤ 60 bpm, 1.38 (95% CI 0.85-2.24, P  = 0.189) in HR > 80 bpm. Multivariate Cox regression showed that compared with that in HR 61-80 bpm, the adjusted hazard ratios for mortality were 0.37 (95% CI 0.19-0.75, P  =  0.005) in HR ≤ 60 bpm, 0.96 (95% CI 0.52-1.74, P  = 0.899) in HR > 80 bpm. Univariate Cox regression showed that the unadjusted hazard ratios for mortality were 0.52 (95% CI 0.33-0.84, P = 0.003) in patients with beta-blocker as compared patients without beta-blocker. Multivariate Cox regression showed that the adjusted hazard ratios for mortality were 0.48 (95% CI 0.26-0.87, P = 0.016) in patients with beta-blocker as compared patients without beta-blocker.

CONCLUSIONS

HR is independently associated with increased all-cause mortality in SR and a lower HR (≤ 60 bpm) is favorable for better outcome in HFpEF patients with SR. Beta-blocker use is associated with reduced mortality and a lower HR is associated with reduced mortality in HFpEF patients with SR.

Association of Resting Heart Rate and Temporal Changes in Heart Rate With Outcomes in Participants of the Atherosclerosis Risk in Communities Study

Importance

Time-updated heart rate (HR) and temporal change in HR (ΔHR) are associated with outcome in individuals with established heart failure (HF). Whether these factors are associated with outcomes in a community-based cohort is unclear.

Objective

To determine whether the time-updated analysis of resting HR, defined as the most recent HR value measured before occurrence of an event or the end of study, and ΔHR over time are associated with outcomes in a community-based cohort.

Design, Setting, and Participants

A total of 15 680 participants were enrolled in the Atherosclerosis Risk in Communities cohort study, with HR recorded at baseline and during 3 follow-up visits from 1987 to 1998, with a median interval between visits of 3.0 (interquartile range, 2.9-4.0) years. The ΔHR was calculated by assessing a change in HR from the preceding visit. Participants were followed up until December 31, 2014, equating to 28 years of follow-up. The present study was conducted from March 2014 to June 2016 with updated analysis.

Main Outcomes and Measures

Baseline HR, time-updated HR, and ΔHR associated with outcomes, adjusted for established baseline and time-updated risk factors and medications. The main outcomes measures included all-cause mortality, incident HF, incident myocardial infarction, stroke, and cardiovascular and noncardiovascular death.

Results

Of the 15 680 participants, 8656 (55.2%) were women, mean (SD) age was 54 (6) years, and 4218 (26.9%) were African American. Time-updated HR and ΔHR were associated with death, incident HF, incident myocardial infarction, stroke, and cardiovascular and noncardiovascular death compared with baseline HR. For example, a ΔHR from the preceding visit was significantly associated with increased risk of all-cause mortality (adjusted hazard ratio, 1.12; 95% CI, 1.10-1.15; P < .001 for every 5-bpm increase in HR from the preceding visit) and time-updated HR was also significantly associated with increased risk of all-cause mortality (adjusted hazard ratio, 1.14; 95% CI, 1.12-1.17; P < .001 for every 5-bpm higher time-updated HR).

Conclusions and Relevance

In a community-based cohort, time-updated HR and ΔHR are associated with mortality and nonfatal outcomes of incident HF, myocardial infarction, and stroke.

A Compelling Case for Less Aggressive Arrhythmia Management in Patients With Chronic Heart Failure and Long-Standing Atrial Fibrillation

BACKGROUND AND METHODS

Atrial fibrillation (AF) is common in chronic heart failure, and some have advocated intensive rate and/or rhythm control strategies for these patients. However, the loss of atrial systole and irregularity of the ventricular response has not been shown to contribute to the progression of heart failure, and the presence or rate of long-standing AF in patients with chronic heart failure does not have prognostic significance.

RESULTS

In randomized clinical trials, pharmacological rhythm control has not been shown to be superior to rate-control in influencing long-term outcomes, but the use of membrane-active antiarrhythmic drugs can increase the risk of both pump failure and arrhythmic deaths in patients with heart failure. Additionally, intensive efforts to slow the ventricular rate in AF can potentially cause clinically inapparent bradyarrhythmias, which can trigger rate-dependent lethal rhythm disturbances or hemodynamic abnormalities. In patients with AF, a more stringent approach to rate control (target rate <80/min) is not superior to a more lenient strategy (target rate <110/min) on the risk of major events. Little is known about the effects of catheter ablation of long-standing AF in established heart failure, particularly in patients with a preserved or a meaningfully reduced ejection fraction, but ablation can add to the fibrotic burden of the left atrium and impair its capacitance functions.

CONCLUSIONS

For all of these reasons, the management of heart failure and long-standing AF should be primarily directed to slowing of the progression of their underlying cardiomyopathic process rather than the treatment of the arrhythmia. In addition, patients should receive long-term oral anticoagulation with non-vitamin K-antagonist oral anticoagulants to reduce the risk of thromboembolic events. The utility of intensive rate and rhythm control interventions for long-standing AF in patients with established heart failure requires further study.

Chronotropic Incompetence in Chronic Heart Failure

Chronotropic incompetence (CI) is generally defined as the inability to increase the heart rate (HR) adequately during exercise to match cardiac output to metabolic demands. In patients with heart failure (HF), however, this definition is unsuitable because metabolic demands are unmatched to cardiac output in both conditions. Moreover, HR dynamics in patients with HF differ from those in healthy subjects and may be affected by β-blocking medication. Nevertheless, it has been demonstrated that CI in HF is associated with reduced functional capacity and poor survival. During exercise, the normal heart increases both stroke volume and HR, whereas in the failing heart, contractility reserve is lost, thus rendering increases in cardiac output primarily dependent on cardioacceleration. Consequently, insufficient cardioacceleration because of CI may be considered a major limiting factor in the exercise capacity of patients with HF. Despite the profound effects of CI in this specific population, the issue has drawn limited attention during the past years and is often overlooked in clinical practice. This might partly be caused by a lack of standardized approach to diagnose the disease, further complicated by changes in HR dynamics in the HF population, which render reference values derived from a normal population invalid. Cardiac implantable electronic devices (implantable cardioverter defibrillator; cardiac resynchronization therapy) now offer a unique opportunity to study HR dynamics and provide treatment options for CI by rate-adaptive pacing using an incorporated sensor that measures physical activity. This review provides an overview of disease mechanisms, diagnostic strategies, clinical consequences, and state-of-the-art device therapy for CI in HF.

The effects of heart rate control in chronic heart failure with reduced ejection fraction

Elevated heart rate has been associated with worse prognosis both in the general population and in patients with heart failure. Heart rate is finely modulated by neurohormonal signals and it reflects the balance between the sympathetic and the parasympathetic limbs of the autonomic nervous system. For this reason, elevated heart rate in heart failure has been considered an epiphenomenon of the sympathetic hyperactivation during heart failure. However, experimental and clinical evidence suggests that high heart rate could have a direct pathogenetic role. Consequently, heart rate might act as a pathophysiological mediator of heart failure as well as a marker of adverse outcome. This hypothesis has been supported by the observation that the positive effect of beta-blockade could be linked to the degree of heart rate reduction. In addition, the selective heart rate control with ivabradine has recently been demonstrated to be beneficial in patients with heart failure and left ventricular systolic dysfunction. The objective of this review is to examine the pathophysiological implications of elevated heart rate in chronic heart failure and explore the mechanisms underlying the effects of pharmacological heart rate control.

Devices and interventions for the prevention of adverse outcomes of tachycardia on heart failure

Heart failure (HF) is the leading cause of hospitalization in the USA. Despite advances in pharmacologic management, the incidence of HF is on the rise and survivability is persistently reduced. Sympathetic overdrive is implicated in the pathophysiology of HF, particularly HF with reduced ejection fraction (HFrEF). Tachycardia can be particularly deleterious and thus has spurred significant investigation to mitigate its effects. Various modalities including vagus nerve stimulation, baroreceptor activation therapy, spinal cord stimulation, renal sympathetic nerve denervation, left cardiac sympathetic denervation, and carotid body removal will be discussed. However, the effects of these modalities on tachycardia and its outcomes in HFrEF have not been well-studied. Further studies to characterize this are necessary in the future.