Pharmacological heart rate lowering in patients with a preserved ejection fraction-review of a failing concept

Heart failure management with β-blockers: can we do better?

Heart failure (HF) is associated with disabling symptoms, poor quality of life, and a poor prognosis with substantial excess mortality in the years following diagnosis. Overactivation of the sympathetic nervous system is a key feature of the pathophysiology of HF and is an important driver of the process of adverse remodelling of the left ventricular wall that contributes to cardiac failure. Drugs which suppress the activity of the renin-angiotensin-aldosterone system, including β-blockers, are foundation therapies for the management of heart failure with reduced ejection fraction (HFrEF) and despite a lack of specific outcomes trials, are also widely used by cardiologist in patients with HF with preserved ejection fraction (HFpEF). Today, expert opinion has moved away from recommending that treatment for HF should be guided solely by the LVEF and interventions should rather address signs and symptoms of HF (e.g. oedema and tachycardia), the severity of HF, and concomitant conditions. β-blockers improve HF symptoms and functional status in HF and these agents have demonstrated improved survival, as well as a reduced risk of other important clinical outcomes such as hospitalisation for heart failure, in randomised, placebo-controlled outcomes trials. In HFpEF, β-blockers are anti-ischemic and lower blood pressure and heart rate. Moreover, β-blockers also reduce mortality in the setting of HF occurring alongside common comorbid conditions, such as diabetes, CKD (of any severity), and COPD. Higher doses of β-blockers are associated with better clinical outcomes in populations with HF, so that ensuring adequate titration of therapy to their maximal (or maximally tolerated) doses is important for ensuring optimal outcomes for people with HF. In principle, a patient with HF could have combined treatment with a β-blocker, renin-angiotensin-aldosterone system inhibitor/neprilysin inhibitor, mineralocorticoid receptor antagonist, and a SGLT2 inhibitor, according to tolerability.

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

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

Personalized accelerated physiologic pacing

Heart failure with preserved ejection fraction (HFpEF) is increasingly prevalent with a high socioeconomic burden. Pharmacological heart rate lowering was recommended to improve ventricular filling in HFpEF. This article discusses the misperceptions that have resulted in an overprescription of beta-blockers, which in all likelihood have untoward effects on patients with HFpEF, even if they have atrial fibrillation or coronary artery disease as a comorbidity. Directly contradicting the lower heart rate paradigm, faster heart rates provide haemodynamic and structural benefits, amongst which lower cardiac filling pressures and improved ventricular capacitance may be most important. Safe delivery of this therapeutic approach is feasible with atrial and ventricular conduction system pacing that aims to emulate or enhance cardiac excitation to maximize the haemodynamic benefits of accelerated pacing. This conceptual framework was first tested in the myPACE randomized controlled trial of patients with pre-existing pacemakers and preclinical or overt HFpEF. This article provides the background and path towards this treatment approach.

Investigating the effects of beta-blockers on circadian heart rhythm using heart rate variability in ischemic heart disease with preserved ejection fraction

Heart failure is characterized by sympathetic activation and parasympathetic withdrawal leading to an abnormal autonomic modulation. Beta-blockers (BB) inhibit overstimulation of the sympathetic system and are indicated in heart failure patients with reduced ejection fraction. However, the effect of beta-blocker therapy on heart failure with preserved ejection fraction (HFpEF) is unclear. ECGs of 73 patients with HFpEF > 55% were recruited. There were 56 patients in the BB group and 17 patients in the without BB (NBB) group. The HRV analysis was performed for the 24-h period using a window size of 1,4 and 8-h. HRV measures between day and night for both the groups were also compared. Percentage change in the BB group relative to the NBB group was used as a measure of difference. RMSSD (13.27%), pNN50 (2.44%), HF power (44.25%) and LF power (13.53%) showed an increase in the BB group relative to the NBB group during the day and were statistically significant between the two groups for periods associated with high cardiac risk during the morning hours. LF:HF ratio showed a decrease of 3.59% during the day. The relative increase in vagal modulated RMSSD, pNN50 and HF power with a decrease in LF:HF ratio show an improvement in the parasympathetic tone and an overall decreased risk of a cardiac event especially during the morning hours that is characterized by a sympathetic surge.

Diastolic Filling Time, Chronotropic Response, and Exercise Capacity in Heart Failure and Preserved Ejection Fraction With Sinus Rhythm

Background

Exercise‐induced high heart rate may impair exercise tolerance by reducing diastolic filling time and ventricular filling in heart failure with preserved ejection fraction (HFpEF). Given the importance of chronotropic response, we hypothesized that reduction in diastolic filling time because of exercise‐induced increased heart rate would not impair cardiac output reserve and exercise capacity. We sought to determine the association between heart rate, diastolic filling time, hemodynamics, and exercise capacity in HFpEF.

Methods and Results

Patients with HFpEF (n=66) and controls without HF (n=107) underwent bicycle exercise echocardiography with simultaneous expired gas analysis to measure oxygen consumption. Diastolic filling time was assessed by the overlap time between mitral E‐ and A‐waves (longer overlap time indicates shorter diastolic filling duration). Overlap time increased (ie, diastolic filling time shortened) in HFpEF and controls as heart rate increased with exercise, and the relationship was similar between the groups. Greater heart rate response correlated with higher cardiac output (r=0.51, P<0.0001) and oxygen consumption (r=0.50, P<0.0001) during peak exercise. Shorter diastolic filling time, as assessed by longer overlap time, was correlated with higher cardiac output (r=0.47, P<0.0001) and peak oxygen consumption (r=0.38, P=0.007), not with E/e′ or right ventricular‐pulmonary artery uncoupling. Longer overlap time was associated with mitral A velocity (r=0.53, P<0.0001) and left atrial booster pump strain (r=0.42, P<0.0001).

Conclusions

Shortening of diastolic filling interval in tandem with increased heart rate during exercise does not limit cardiac output reserve or exercise capacity in HFpEF.

A G-protein-biased S1P1 agonist, SAR247799, improved LVH and diastolic function in a rat model of metabolic syndrome

Aim

Heart failure with preserved ejection fraction (HFpEF) is a major cause of death worldwide with no approved treatment. Left ventricular hypertrophy (LVH) and diastolic dysfunction represent the structural and functional components of HFpEF, respectively. Endothelial dysfunction is prevalent in HFpEF and predicts cardiovascular events. We investigated if SAR247799, a G-protein-biased sphingosine-1-phosphate receptor 1 (S1P1) agonist with endothelial-protective properties, could improve cardiac and renal functions in a rat model of metabolic syndrome LVH and diastolic function.

Methods

31- and 65-week-old obese ZSF1 (Ob-ZSF1) rats, representing adult and aged animals with LVH and diastolic dysfunction, were randomized to a chow diet containing 0.025% (w/w) of SAR247799, or control (CTRL) chow for 4 weeks. Age-matched lean ZSF1 (Le-ZSF1) rats were fed control chow. Echocardiography, telemetry, biochemical and histological analysis were performed to evaluate the effect of SAR247799.

Results

Echocardiography revealed that Ob-ZSF1 rats, in contrast to Le-ZSF1 rats, developed progressive diastolic dysfunction and cardiac hypertrophy with age. SAR247799 blunted the progression of diastolic dysfunction in adult and aged animals: in adult animals E/e’ was evaluated at 21.8 ± 1.4 for Ob-ZSF1-CTRL, 19.5 ± 1.2 for Ob-ZSF1-SAR247799 p<0.01, and 19.5 ± 2.3 for Le-ZSF1-CTRL (median ± IQR). In aged animals E/e’ was evaluated at 23.15 ± 4.45 for Ob-ZSF1-CTRL, 19.5 ± 5 for Ob-ZSF1-SAR247799 p<0.01, and 16.69 ± 1.7 for Le-ZSF1-CTRL, p<0.01 (median ± IQR). In aged animals, SAR247799 reduced cardiac hypertrophy (g/mm mean ± SEM of heart weight/tibia length 0.053 ± 0.001 for Ob-ZSF1-CTRL vs 0.046 ± 0.002 for Ob-ZSF1-SAR247799 p<0.01, Le-ZSF1-CTRL 0.035 ± 0.001) and myocardial perivascular collagen content (p<0.001), independently of any changes in microvascular density. In adult animals, SAR247799 improved endothelial function as assessed by the very low frequency bands of systolic blood pressure variability (mean ± SEM 67.8 ± 3.41 for Ob-ZSF1-CTRL 55.8 ± 4.27 or Ob-ZSF1-SAR247799, p<0.05 and 57.3 ± 1.82 Le-ZSF1-CTRL), independently of any modification of arterial blood pressure. In aged animals, SAR247799 reduced urinary protein/creatinine ratio, an index of glomerular injury, (10.3 ± 0.621 vs 8.17 ± 0.231 for Ob-ZSF1-CTRL vs Ob-ZSF1-SAR247799, respectively, p<0.05 and 0.294 ± 0.029 for Le-ZSF1-CTRL, mean ± SEM) and the fractional excretion of electrolytes. Circulating lymphocytes were not decreased by SAR247799, confirming lack of S1P1 desensitization.

Conclusions

These experimental findings suggest that S1P1 activation with SAR247799 may be considered as a new therapeutic approach for LVH and diastolic dysfunction, major components of HFpEF.

Psychophysiological and Psychosocial Profile of Patients Attending Drug Addiction Centers

Drug treatment centres provide the highest level of rehab services for patients diagnosed with drug addictions. Most inpatient drug rehab programs focus on medical detox and mental health interventions. However, how to optimize the later remains a challenge. The aim of this study was to examine the psychophysiological and psychosocial profile of patients attending drug addiction centres in comparation with the general population. A total of 105 inpatient drug rehab patients and 50 participants from the general population were compared based on standardized psychophysiological and psychosocial measures. Results of this study suggest that patients attending drug addiction centers differ from general population in several different psychophysiological and psychosocial factors. Patients reported significantly lower levels of physical activity and increased sympathetic responsiveness, and significantly higher levels in loneliness, psychologically inflexibility and neuroticism. The results of this study highlight the importance of address healthy lifestyle behaviors such as sport practice and psychological variables such as loneliness, psychological (in)flexibility and neuroticism to improve current programs aim to prevent or reduce problematic drug consumptions.

Personalized pacing for diastolic dysfunction and heart failure with preserved ejection fraction: Design and rationale for the myPACE randomized controlled trial

Background

Patients with pacemakers and heart failure with preserved ejection fraction (HFpEF) or isolated diastolic dysfunction (DD) may benefit from a higher backup heart rate (HR) setting compared with the standard setting of 60 bpm.

Objective

The purpose of this study was to assess the effects of a personalized backup HR setting (myPACE group) compared with 60 bpm (control group).

Methods

In this prospective, blinded, randomized controlled study, pacemaker patients with DD or HFpEF and atrial pacing with intrinsic ventricular conduction or conduction system or biventricular pacing are randomized to the myPACE group or control group for 1 year. The primary outcome is the change in Minnesota Living with Heart Failure Questionnaire (MLHFQ) scores. Secondary endpoints include changes in N-terminal pro–brain natriuretic peptide levels, physical and emotional MLHFQ subscores, and pacemaker-detected atrial arrhythmia burden, patient activity levels, and thoracic impedance; hospitalization for heart failure, atrial fibrillation, cerebrovascular accident, or myocardial infarction; and loop diuretic or antiarrhythmic medication initiation or up-titration. A sample size of 118 subjects is expected to allow detection of a 5-point change in MLHFQ score in an intention-to-treat analysis and allow initial assessment of clinical outcomes and subgroup analyses.

Results

Enrollment began in July 2019. As of November 2020, 107 subjects have been enrolled. It is projected that the 1-year follow-up will be completed by December 2021.

Conclusion

Atrial pacing with intrinsic ventricular conduction or advanced ventricular pacing at a higher, personalized backup HR may be a therapeutic target for patients with isolated DD or HFpEF. The myPACE trial is designed to test this hypothesis.

Erythrocyte transfusion restored heart rate variability in children with thalassemia major

Thalassemia major (TM) is a severe transfusion-dependent anemia. Regular erytrocyte transfusion is required for the treatment of thalassemia patients. However, repeated transfusion may result in impairements in heart function. In this study, we aimed to investigate short-term effects of erythrocyte transfusion on autonomic control of heart in children with thalassemia major. For that purpose heart rate variability (HRV), which is a non-invasive method used to evaluate the effects of the autonomic nervous system on the heart rhythym, was measured before and after erythrocyte transfusion and compared to the healthy controls. Children diagnosed with TM (n = 17) and sex and age matched healthy children (HC, n = 30) were included in the study. HRV values of TM patients were measured 5 min before erythrocyte transfusion (BET, n = 17) and 5 min after erythrocyte transfusion (AET, n = 17). Parameters of time-domain and frequency-domain of HRV were evaluated in all participants. Heart rate (HR) was higher in the BET than AET (P = 0.002) but there was no difference between AET and HC groups (P > 0.05). HRV parameters were lower in BET than AET (P < 0.05) but there were no statistical difference between AET and HC (P> 0.05). The data suggest that, in thalassemia major patients, erythrocyte transfusion restores HR and HRV parameters to the levels observed in healthy controls and, thus, in short-terms, appears to be beneficial for the autonomic control of the heart.

[Frequency of use and Indications for Beta-Blockers in Heart Failure with Preserved Ejection Fraction]

Aim      To evaluate trends in beta-blocker prescribing and incidence of possible reasons for beta-blocker administration, including arterial hypertension (AH), atrial fibrillation (AF), ischemic heart disease (IHD), and myocardial infarction, in participants of clinical studies enrolling patients with chronic heart failure with preserved ejection fraction (CHF-PEF).Material and methods  A systematic literature search was performed in the PubMed and EMBASE databases. The study included RCSs of pharmacological therapies for patients with CHF-PEF conducted from 1993 through 2019. Studies of beta-blocker efficacy or those including a specific population (CHF-PEF+IHD or CHF-PEF+AH, etc.) were excluded from the analysis. Baseline characteristics of patients, incidence rate of beta-blocker prescribing, and prevalence of AH, AF, IHD, and MI were recorded. Trends in prevalence of concomitant diseases and the proportion of patients using beta-blockers by the year of enrollment to the study were analyzed with the Mann-Kendall test.Results 14 RCSs of 718 selected publications completely met the inclusion and exclusion criteria. Beta-blocker prescribing significantly increased between 1993 and 2019 (tau=0.51; p=0.014) and reached 80 % in recent studies. Furthermore, prevalence of IHD, MI, AH, and AF did not significantly change among the RCS participants (p&gt;0.05 for all). However, while for AH and AF, a tendency toward an increasing prevalence (tau=0.4; p=0.055 and tau=0.043; p=0.063, respectively) could be considered and became statistically significant for AF when the ALDO-DHF study was excluded from the analysis (tau=0.5; p=0.042), the MI prevalence tended to decrease (tau= -0.73; p=0.06).Conclusion      Beta-blocker prescribing to patients upon inclusion into RCSs for CHF-PEF has significantly increased for the recent 20 years while the incidence of formal reasons for beta-blocker administration (AF, AH, MI, IHD) did not significantly change.

Beta-blockers withdrawal in patients with heart failure with preserved ejection fraction and chronotropic incompetence: Effect on functional capacity rationale and study design of a prospective, randomized, controlled trial (The Preserve-HR trial)

Background

The pathophysiology of heart failure with preserved ejection fraction (HFpEF) is complex and multifactorial. Chronotropic incompetence (ChI) has emerged as a crucial pathophysiological mechanism. Beta‐blockers, drugs with negative chronotropic effects, are commonly used in HFpEF, although current evidence does not support its routine use in these patients.

Hypothesis

We postulate beta‐blockers may have deleterious effects in HFpEF and ChI. This work aims to evaluate the short‐term effect of beta‐blockers withdrawal on functional capacity assessed by the maximal oxygen uptake (peakVO2) in patients with HFpEF and ChI.

Methods

This is a prospective, crossover, randomized (1:1) and multicenter study. After randomization, the clinical and cardiac rhythm will be continuously registered for 30 days. PeakVO2 is assessed by cardiopulmonary exercise testing (CPET) at 15 and 30 days in both groups. Secondary endpoints include quality of life, cognitive, and safety assessment. Patients with stable HFpEF, functional class New York Heart Association (NYHA) II‐III, chronic treatment with beta‐blockers, and ChI will be enrolled. A sample size estimation [alfa: 0.05, power: 90%, a 20% loss rate, and delta change of mean peakVO2: +1.2 mL/kg/min (SD ± 2.0)] of 52 patients is necessary to test our hypothesis.

Results

Patients started enrolling in October 2018. As January 14th, 2020, 28 patients have been enrolled. It is projected to enroll the last patient at the end of July 2020.

Conclusions

Optimizing therapy that improves functional capacity remains an unmeet priority in HFpEF. Deprescribing beta‐blockers in patients with HFpEF and ChI seems a plausible intervention to improve functional capacity. This trial is an attempt towards precision medicine in this complex syndrome.

Trial registration

http://clinicaltrials.gov: NCT03871803.

Effects of a Higher Heart Rate on Quality of Life and Functional Capacity in Patients With Left Ventricular Diastolic Dysfunction

There is no evidence-based treatment for heart failure with preserved ejection fraction. Although lower heart rates (HRs) provide an unequivocal benefit for patients with HF with reduced ejection fraction, higher HR might convey important hemodynamic and substrate-modifying benefits in patients with diastolic dysfunction. In a prospective study of 20 stable outpatients with diastolic dysfunction and pacemakers, we evaluated the effects of a 4-week increase in the lower pacemaker rate to 80 beats/min followed by reversal to the previous lower HR setting from weeks 4 to 6. We assessed quality of life (Minnesota Living with Heart Failure Questionnaire), 6-minute walk test and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. Pacing at 80 beats/min significantly improved quality of life and the 6-minute walk test (p ≤0.05). There was a strong positive correlation between the pacing-induced changes in NT-proBNP and baseline QRS intervals (r² = 0.31, p <0.01). Stratification by QRS duration revealed that pacing at 80 beats/min led to -21 ± 26% reduction in NT-proBNP in patients with QRS ≤150 ms, whereas QRS >150 ms was associated with a 26 ± 35% increase in NT-proBNP (p <0.01). Patients physiologically paced from the conduction system had a -46 ± 26% reduction in NT-proBNP at 80 beats/min as compared with 4 ± 26% and 13 ± 26% change with pacing from the right atrial appendage and right ventricular apical septum (p_interaction = 0.04). In conclusion, increasing the lower rate setting of pacemakers to 80 beats/min in patients with diastolic dysfunction improves quality of life, functional capacity, and NT-proBNP for those patients with a baseline QRS ≤150 ms. These findings suggest that higher HRs may provide meaningful benefits to patients with left ventricular diastolic dysfunction and heart failure with preserved ejection fraction.

Taking the Pulse of Atrial Fibrillation: A Practical Approach to Rate Control

Despite major advances in atrial fibrillation (AF) catheter ablation, rate control remains the most widely used management strategy for AF in the general population. In addition to its use as a primary approach to control symptoms and prevent complications of AF, rate control is often a necessary complement to rhythm-control strategies, especially with antiarrhythmic drugs. The value of rate-control therapy is supported by several large randomized clinical trials showing no difference in major cardiovascular outcomes between rate-control and rhythm-control strategies with currently available therapeutic approaches (antiarrhythmic drugs and/or catheter ablation). Despite its extensive use, the rational basis for rate-control therapy is underemphasized in clinical teaching and practice. In this article, we aim to provide evidence-based thoughts on important practical aspects of rate-control therapy in AF by reviewing 5 clinically relevant issues. We (1) highlight the pharmacological differences between the mechanisms of action of β-blockers and Ca²⁺-channel blockers for AF rate control and the practical implications for therapeutic decision making; (2) review the controversies surrounding the use of digoxin for AF rate control in the light of recently published work; (3) discuss the evidence for rate-control heart rate targets in patients with AF and preserved left-ventricular function; (4) examine how heart rate targets may differ in patients with heart failure and reduced vs preserved left-ventricular ejection fraction and the importance of heart-rate lowering for the effectiveness of cardiac resynchronization therapy in patients with heart failure and AF; (5) discuss the relationship between AF, exercise capacity, and rate-controlling drug class.

Safety and Feasibility of a Nocturnal Heart Rate Elevation-Exploration of a Novel Treatment Concept

BACKGROUND

Diastolic dysfunction and heart failure with preserved ejection fraction (HFpEF) are associated with myocardial fibrosis and concentric left ventricular hypertrophy (LVH). In a preclinical model of LVH, we demonstrated that a moderate increase in heart rate can reduce interstitial fibrosis and improve LV compliance. We therefore hypothesized that moderately elevated heart rates can be used to beneficially modify the myocardial substrate in patients with diastolic dysfunction and HFpEF. As a preliminary step to test this hypothesis, we evaluated if patients can tolerate this novel pacemaker-based treatment approach without adverse effects.

METHODS AND RESULTS

A pacemaker-mediated increase in heart rate to 100 beats/min for 5 hours at night was tested over 4 weeks in 10 patients with diastolic dysfunction. The patients underwent a physical examination, biomarker collection, 6-minute walk test, heart failure questionnaire, and echocardiography before and after the pacing intervention. None of the patients reported any symptoms at night. No arrhythmias were induced. Eight patients completed the protocol. Three patients experienced unanticipated daytime pacing from an interfering pacemaker function. There were no detrimental changes in biomarkers or LV systolic function.

CONCLUSIONS

Nocturnal pacing at a rate of 100 beats/min appears to be safe and well tolerated in this small exploratory patient cohort.