Cardiac contractility modulation therapy in advanced systolic heart failure

Nonclinical evaluation of chronic cardiac contractility modulation on 3D human engineered cardiac tissues

INTRODUCTION

Cardiac contractility modulation (CCM) is a medical device-based therapy delivering non-excitatory electrical stimulations to the heart to enhance cardiac function in heart failure (HF) patients. The lack of human in vitro tools to assess CCM hinders our understanding of CCM mechanisms of action. Here, we introduce a novel chronic (i.e., 2-day) in vitro CCM assay to evaluate the effects of CCM in a human 3D microphysiological system consisting of engineered cardiac tissues (ECTs).

METHODS

Cryopreserved human induced pluripotent stem cell-derived cardiomyocytes were used to generate 3D ECTs. The ECTs were cultured, incorporating human primary ventricular cardiac fibroblasts and a fibrin-based gel. Electrical stimulation was applied using two separate pulse generators for the CCM group and control group. Contractile properties and intracellular calcium were measured, and a cardiac gene quantitative PCR screen was conducted.

RESULTS

Chronic CCM increased contraction amplitude and duration, enhanced intracellular calcium transient amplitude, and altered gene expression related to HF (i.e., natriuretic peptide B, NPPB) and excitation-contraction coupling (i.e., sodium-calcium exchanger, SLC8).

CONCLUSION

These data represent the first study of chronic CCM in a 3D ECT model, providing a nonclinical tool to assess the effects of cardiac electrophysiology medical device signals complementing in vivo animal studies. The methodology established a standardized 3D ECT-based in vitro testbed for chronic CCM, allowing evaluation of physiological and molecular effects on human cardiac tissues.

Novel Medical Treatments and Devices for the Management of Heart Failure with Reduced Ejection Fraction

Heart failure (HF) is a growing issue in developed countries; it is often the result of underlying processes such as ischemia, hypertension, infiltrative diseases or even genetic abnormalities. The great majority of the affected patients present a reduced ejection fraction (≤40%), thereby falling under the name of "heart failure with reduced ejection fraction" (HFrEF). This condition represents a major threat for patients: it significantly affects life quality and carries an enormous burden on the whole healthcare system due to its high management costs. In the last decade, new medical treatments and devices have been developed in order to reduce HF hospitalizations and improve prognosis while reducing the overall mortality rate. Pharmacological therapy has significantly changed our perspective of this disease thanks to its ability of restoring ventricular function and reducing symptom severity, even in some dramatic contexts with an extensively diseased myocardium. Notably, medical therapy can sometimes be ineffective, and a tailored integration with device technologies is of pivotal importance. Not by chance, in recent years, cardiac implantable devices witnessed a significant improvement, thereby providing an irreplaceable resource for the management of HF. Some devices have the ability of assessing (CardioMEMS) or treating (ultrafiltration) fluid retention, while others recognize and treat life-threatening arrhythmias, even for a limited time frame (wearable cardioverter defibrillator). The present review article gives a comprehensive overview of the most recent and important findings that need to be considered in patients affected by HFrEF. Both novel medical treatments and devices are presented and discussed.

Non-Pharmacological Treatment of Heart Failure-From Physical Activity to Electrical Therapies: A Literature Review

Heart failure (HF) represents a significant global health challenge that is still responsible for increasing morbidity and mortality despite advancements in pharmacological treatments. This review investigates the effectiveness of non-pharmacological interventions in the management of HF, examining lifestyle measures, physical activity, and the role of some electrical therapies such as catheter ablation, cardiac resynchronization therapy (CRT), and cardiac contractility modulation (CCM). Structured exercise training is a cornerstone in this field, demonstrating terrific improvements in functional status, quality of life, and mortality risk reduction, particularly in patients with HF with reduced ejection fraction (HFrEF). Catheter ablation for atrial fibrillation, premature ventricular beats, and ventricular tachycardia aids in improving left ventricular function by reducing arrhythmic burden. CRT remains a key intervention for selected HF patients, helping achieve left ventricular reverse remodeling and improving symptoms. Additionally, the emerging therapy of CCM provides a novel opportunity for patients who do not meet CRT criteria or are non-responders. Integrating non-pharmacological interventions such as digital health alongside specific medications is key for optimizing outcomes in HF management. It is imperative to tailor approaches to individual patients in this diverse patient population to maximize benefits. Further research is warranted to improve treatment strategies and enhance patient outcomes in HF management.

Use of cardiac contractility modulation combined with left bundle branch pacing CRT-P in a female with a 22-year history of non-ischemic dilated cardiomyopathy: A case report

Cardiac contractility modulation (CCM) is a novel device-based therapy used to treat patients with heart failure with reduced ejection fraction (HFrEF). In both randomized clinical trials and real-life studies, CCM has been shown to improve exercise tolerance and quality of life, reverse left ventricular remodeling, and reduce hospitalization in patients with HFrEF. In this case report, we describe for the first time the use of CCM combined with left bundle branch pacing (LBBP) cardiac resynchronization therapy pacemaker (CRT-P) implantation therapy in a female with a 22-year history of non-ischemic dilated cardiomyopathy. With the optimal medical therapy and cardiac resynchronization therapy (CRT) strategies, the patient's quality of life initially recovered to some extent, but began to deteriorate in the past year. Additionally, heart transplantation was not considered due to economic reasons and late stage systolic heart failure. This is the first case of CCM implantation in Fujian Province and the first report of a combined CCM and left bundle branch pacing CRT-P implantation strategy in a patient with non-ischemic etiology dilated cardiomyopathy in China.

Electrical therapies in heart failure: Evolving technologies and indications

Device therapy for heart failure has rapidly evolved over 2 decades. The knowledge of indications, assessment lead and device technology has expanded to include CRT, leadless pacing and conduction system pacing such as His bundle and left bundle branch area pacing. But there is still a lack of evidence for these new technologies as well as for common indications such as atrial fibrillation and upgrading from a previous device. The role of personalized medicine will become increasingly important when selecting candidates for CRT, primary preventive ICD ablation procedures and emerging new devices such as cardiac contractility modulation (CCM). Rapidity of therapy is associated with outcome which will be a challenge. If properly implemented devices and drugs will have a large positive affect of HF outcomes.

Enhancing myocardial function with cardiac contractility modulation: potential and challenges

Cardiac contractility modulation (CCM) offers a novel therapeutic avenue for heart failure patients, particularly those unresponsive to cardiac resynchronization therapy within specific QRS duration ranges. This review elucidates CCM's mechanistic underpinnings, its impact on myocardial function, and utility across patient demographics. However, CCM is limited by insufficient data on mortality and hospitalization rate reductions, as well as the need for specialized device implantation skills. While prevailing research has concentrated on left ventricular effects, a knowledge gap persists for other patient subsets. Future inquiries should address combinatory treatment strategies, extended usage and the impact of atrial fibrillation on device implantation. Such expanded studies could refine therapeutic outcomes and widen the scope of beneficiaries.

Molecular effects of cardiac contractility modulation in patients with heart failure of ischemic aetiology uncovered by transcriptome analysis

Cardiac contractility modulation (CCM) is based on electrical stimulation of the heart without alteration of action potential and mechanical activation, the data on its fundamental molecular mechanisms are limited. Here we demonstrate clinical and physiological effect of 12 months CCM in 29 patients along with transcriptomic molecular data. Based on the CCM effect the patients were divided into two groups: responders (n = 13) and non-responders (n = 16). RNA-seq data were collected for 6 patients before and after CCM including 3 responders and 3 non-responders. The overall effect of CCM on gene expression was mainly provided by samples from the responder group and included the upregulation of the genes involved in the maintenance of proteostasis and mitochondrial structure and function. Using pathway enrichment analysis, we found that baseline myocardial tissue samples from responder group were characterized by upregulation of mitochondrial matrix-related genes, Z disc-protein encoding genes and muscle contraction-related genes. In summary, twelve months of ССM led to changes in signaling pathways associated with cellular respiration, apoptosis, and autophagy. The pattern of myocardial remodeling after CCM is associated with initial expression level of myocardial contractile proteins, adaptation reserves associated with mitochondria and low expression level of inflammatory molecules.

Current Approaches to Worsening Heart Failure: Pathophysiological and Molecular Insights

Worsening heart failure (WHF) is a severe and dynamic condition characterized by significant clinical and hemodynamic deterioration. It is characterized by worsening HF signs, symptoms and biomarkers, despite the achievement of an optimized medical therapy. It remains a significant challenge in cardiology, as it evolves into advanced and end-stage HF. The hyperactivation of the neurohormonal, adrenergic and renin-angiotensin-aldosterone system are well known pathophysiological pathways involved in HF. Several drugs have been developed to inhibit the latter, resulting in an improvement in life expectancy. Nevertheless, patients are exposed to a residual risk of adverse events, and the exploration of new molecular pathways and therapeutic targets is required. This review explores the current landscape of WHF, highlighting the complexities and factors contributing to this critical condition. Most recent medical advances have introduced cutting-edge pharmacological agents, such as guanylate cyclase stimulators and myosin activators. Regarding device-based therapies, invasive pulmonary pressure measurement and cardiac contractility modulation have emerged as promising tools to increase the quality of life and reduce hospitalizations due to HF exacerbations. Recent innovations in terms of WHF management emphasize the need for a multifaceted and patient-centric approach to address the complex HF syndrome.

Emerging devices for heart failure management

There have been significant advances in the treatment of heart failure (HF) in recent years, driven by significant strides in guideline-directed medical therapy (GDMT). Despite this, HF is still associated with high levels of morbidity and mortality, and most patients do not receive optimal medical therapy. In conjunction with the improvement of GDMT, novel device therapies have been developed to better treat HF. These devices include technology capable of remotely monitoring HF physiology, devices that modulate the autonomic nervous system, and those that structurally change the heart with the ultimate aim of addressing the root causes of HF physiology As these device therapies gradually integrate into the fabric of HF patient care, it becomes increasingly important for modern cardiologists to become familiar with them. Hence, the objective of this review is to shed light on currently emerging devices for the treatment of HF.

Basic science of cardiac contractility modulation therapy: Molecular and electrophysiological mechanisms

In heart failure with reduced ejection fraction and heart failure with preserved ejection fraction, profound cellular and molecular changes have recently been documented in the failing myocardium. These changes include altered calcium handling and metabolic efficiency of the cardiac myocyte, reactivation of the fetal gene program, changes in the electrophysiological properties of the heart, and accumulation of collagen (fibrosis) at the interstitial level. Cardiac contractility modulation therapy is an innovative device-based therapy currently approved for heart failure with reduced ejection fraction in patients with narrow QRS complex and under investigation for the treatment of heart failure with preserved ejection fraction. This therapy is based on the delivery of high-voltage biphasic electrical signals to the septal wall of the right ventricle during the absolute refractory period of the myocardium. At the cellular level, in patients with heart failure with reduced ejection fraction, cardiac contractility modulation therapy has been shown to restore calcium handling and improve the metabolic status of cardiac myocytes, reverse the heart failure-associated fetal gene program, and reduce the extent of interstitial fibrosis. This review summarizes the preclinical literature on the use of cardiac contractility modulation therapy in heart failure with reduced and preserved ejection fraction, correlating the molecular and electrophysiological effects with the clinical benefits demonstrated by this therapy.

Cardiac Contractility Modulation for Heart Failure: Current and Future Directions

Cardiac contractility modulation (CCM) is a Food and Drug Administration-approved device-based therapy for patients with heart failure. The system delivers biphasic electric stimulation to the ventricular myocardium during the absolute refractory period to augment left ventricular contraction. CCM therapy promotes acute and chronic changes at the cellular level, leading to favorable remodeling throughout the myocardium. CCM improves quality of life, New York Heart Association class, left ventricular ejection fraction, peak oxygen uptake, and the composite end point of cardiovascular death and heart failure hospitalizations. This review will focus on the biological basis, indications, and evidence for CCM, as well as the future applications of this technology.

Reverse Left Ventricular Remodeling With Transcatheter Interventions in Chronic Heart Failure Syndromes: An Updated Appraisal of the Device Landscape

Chronic heart failure (HF) is a clinical syndrome of myocardial dysfunction characterized by inadequate cardiac output or preserved output that can only be achieved by sustaining abnormal loading conditions. Morphologically, HF with reduced left ventricular function results in progressive chamber remodeling, meaning the ventricle dilates, operating at larger end-diastolic and end-systolic volumes, and takes on an abnormal, spherical shape that increases wall stress. Reverse remodeling is the goal of HF-directed therapies and can be achieved by biological means, ie, altering the loading conditions that, at a cellular level, promote myocardial dysfunction, or physical means, ie, directly altering myocardial mass or shape. In this review, we highlight the existing and emerging device-based mechanisms for biologically and physically reverse remodeling the left ventricle in chronic HF.

Device Interventions for Heart Failure

Despite remarkable advances in drug therapy for heart failure (HF), the residual HF-related morbidity, mortality, and hospitalizations remain substantial across all HF phenotypes, and significant proportions of patients with HF remain symptomatic despite optimal drug therapy. Driven by these unmet clinical needs, the exponential growth of transcatheter interventions, and a recent shift in the regulatory landscape of device-based therapies, novel device-based interventions have emerged as a potential therapy for various phenotypes of HF. Device-based interventions can overcome some of the limitations of drug therapy (eg, intolerance, nonadherence, inconsistent delivery, and recurrent and long-term cost) and can target some HF-related pathophysiologic pathways more effectively than drug therapy. This paper reviews the current evolving landscape of device-based interventions in HF and highlights critical points related to implementation of these therapies in the current workflow of HF management.

Bridging the gap in the symptomatic heart failure patient journey: insights from the Italian scenario

BACKGROUND

The prognosis for heart failure (HF) patients remains poor, with a high mortality rate, and a marked reduction in quality of life (QOL) and functional status. This study aims to explore the ongoing needs of HF management and the epidemiology of patients followed by Italian HF clinics, with a specific focus on cardiac contractility modulation (CCM).

RESEARCH DESIGN AND METHODS

Data from patients admitted to 14 HF outpatients clinics over 4 weeks were collected and compared to the results of a survey open to physicians involved in HF management operating in Italian centers.

RESULTS

One hundred and five physicians took part in the survey. Despite 94% of patients receive a regular follow-up every 3-6 months, available therapies are considered insufficient in 30% of cases. Physicians reported a lack of treatment options for 23% of symptomatic patients with reduced ejection fraction (EF) and for 66% of those without reduced EF. Approximately 3% of HF population (two patients per month per HF clinic) meets the criteria for immediate CCM treatment, which is considered a useful option by 15% of survey respondents.

CONCLUSIONS

Despite this relatively small percentage, considering total HF population, CCM could potentially benefit numerous HF patients, particularly the elderly, by reducing hospitalizations, improving functional capacity and QOL.

Cardiac Contractility Modulation Therapy in Patients with Amyloid Cardiomyopathy and Heart Failure, Case Report, Review of the Biophysics of CCM Function, and AMY-CCM Registry Presentation

Cardiac amyloidosis may result in an aggressive form of heart failure (HF). Cardiac contractility modulation (CCM) has been shown to be a concrete therapeutic option in patients with symptomatic HF, but there is no evidence of its application in patients with cardiac amyloidosis. We present the case of TTR amyloidosis, where CCM therapy proved to be effective. The patient had a history of multiple HF hospitalizations due to an established diagnosis of wild type TTR-Amyloidosis with significant cardiac involvement. Since he was highly symptomatic, except during continuous dobutamine and diuretic infusion, it was opted to pursue CCM therapy device implantation. At follow up, a significant improvement in clinical status was reported with an increase of EF, functional status (6 min walk test improved from zero meters at baseline, to 270 m at 1 month and to 460 m at 12 months), and a reduction in pulmonary pressures. One year after device implantation, no other HF hospital admission was needed. CCM therapy may be effective in this difficult clinical setting. The AMY-CCM Registry, which has just begun, will evaluate the efficacy of CCM in patients with HF and diagnosed TTR amyloidosis to bring new evidence on its potential impact as a therapeutic option.

One-Year Outcome of Cardiac Contractility Modulation in Patients With Reduced Ejection Fraction, Atrial Fibrillation, and Previous Resynchronization: A Pilot Study

BACKGROUND

After 6 months of therapy, cardiac contractility modulation (CCM) has been shown to improve symptoms, exercise tolerance, and quality of life as well as reduce the rate of hospitalizations in patients with heart failure with reduced left ventricular ejection fraction (HFrEF), but long-term effects data are lacking, with no randomized trial to date.

STUDY QUESTION

What is the long-term benefit of the CCM device implantation in symptomatic patients with severe, optimally treated HFrEF?

STUDY DESIGN

We conducted a prospective trial involving patients with symptomatic HFrEF [New York Heart Association (NYHA) Class III or IV, left ventricular ejection fraction (LVEF) ≤35%] who were supported by a CCM device.

RESULTS

Twenty patients (19 men), aged 66.5 ± 6.9 years, were provided with CCM therapy and followed up for an average duration of 321.7 ± 113.5 days. The etiology of heart failure was ischemic in 16 patients (80%), 9 patients (45%) had atrial fibrillation, 6 patients (30%) had diabetes mellitus, and mean creatinine clearance value was 54.8 ± 13.0 mL/min. Eleven patients (60%) had LVEF ≤25%. Although all the patients had an implanted cardioverter-defibrillator, 6 of them (30%) also had resynchronization therapy. The pharmacological treatment has been optimized in all patients. One year after implantation, the LVEF increased from 24.68% ± 4.5 to 34.6 ± 5 ( P < 0.0001), NYHA class improved from 3.2 ± 0.5 to 1.4 ± 0.5 ( P < 0.0001), and exercise tolerance evaluated with a 6-Minute Walk Test increased (from 307.9 ± 74.1 m to 567 ± 99.5 m; P < 0.00001). These improvements were largely seen in the first 6 months.

CONCLUSIONS

Over the course of a year, CCM therapy was associated with improved LVEF and NYHA class, as well as significantly better exercise tolerance, even in patients with atrial fibrillation and cardiac resynchronization therapy and did not seem to be associated with additional significant device-related problems.

Efficacy of the New Inotropic Agent Istaroxime in Acute Heart Failure

Current therapeutic strategies for acute heart failure (AHF) are based on traditional inotropic agents that are often associated with untoward effects; therefore, finding new effective approaches with a safer profile is dramatically needed. Istaroxime is a novel compound, chemically unrelated to cardiac glycosides, that is currently being studied for the treatment of AHF. Its effects are essentially related to its inotropic and lusitropic positive properties exerted through a dual mechanism of action: activation of the sarcoplasmic reticulum Ca2+ ATPase isoform 2a (SERCA2a) and inhibition of the Na+/K+-ATPase (NKA) activity. The advantages of istaroxime over the available inotropic agents include its lower arrhythmogenic action combined with its capability of increasing systolic blood pressure without augmenting heart rate. However, it has a limited half-life (1 hour) and is associated with adverse effects including pain at the injection site and gastrointestinal issues. Herein, we describe the main mechanism of action of istaroxime and we present a systematic overview of both clinical and preclinical trials testing this drug, underlining the latest insights regarding its adoption in clinical practice for AHF.

Improved Physical Function After Cardiac Contractility Modulation Therapy in 10 Patients With Chronic Heart Failure

BACKGROUND

A new generation of therapeutic devices has expanded the options for managing advanced heart failure. We examined the outcomes of cardiac contractility therapy in a series of 10 patients with chronic heart failure.

METHODS

Ten patients with chronic heart failure were nonrandomly selected to receive cardiac contractility modulation therapy. Hemodynamics, left ventricular ejection fraction, functional capacity, and clinical outcomes were evaluated at baseline and after 6 months of therapy.

RESULTS

Eight male and 2 female patients (mean [SD] age, 63.4 [9.4] years) received cardiac contractility modulation therapy. Between baseline and 6-month follow-up, mean (SD) left ventricular ejection fraction improved from 27.1% (4.18%) to 35.1% (9.89%), New York Heart Association class declined from 3.9 (0.32) to 2.44 (0.52), and 6-minute walk test distance increased from 159.2 (93.79) m to 212.4 (87.24) m. Furthermore, the mean (SD) number of hospital admissions within the 6 months before cardiac contractility modulation therapy was 2.4 (2.27) compared with 1 (1.52) during the 6 months after therapy.

CONCLUSION

Cardiac contractility modulation therapy improved physical functioning and reduced hospital admissions in these patients.

Human in vitro neurocardiac coculture (ivNCC) assay development for evaluating cardiac contractility modulation

Two of the most prominent organ systems, the nervous and the cardiovascular systems, are intricately connected to maintain homeostasis in mammals. Recent years have shown tremendous efforts toward therapeutic modulation of cardiac contractility and electrophysiology by electrical stimulation. Neuronal innervation and cardiac ganglia regulation are often overlooked when developing in vitro models for cardiac devices, but it is likely that peripheral nervous system plays a role in the clinical effects. We developed an in vitro neurocardiac coculture (ivNCC) model system to study cardiac and neuronal interplay using human induced pluripotent stem cell (hiPSC) technology. We demonstrated significant expression and colocalization of cardiac markers including troponin, α-actinin, and neuronal marker peripherin in neurocardiac coculture. To assess functional coupling between the cardiomyocytes and neurons, we evaluated nicotine-induced β-adrenergic norepinephrine effect and found beat rate was significantly increased in ivNCC as compared to monoculture alone. The developed platform was used as a nonclinical model for the assessment of cardiac medical devices that deliver nonexcitatory electrical pulses to the heart during the absolute refractory period of the cardiac cycle, that is, cardiac contractility modulation (CCM) therapy. Robust coculture response was observed at 14 V/cm (5 V, 64 mA), monophasic, 2 ms pulse duration for pacing and 20 V/cm (7 V, 90 mA) phase amplitude, biphasic, 5.14 ms pulse duration for CCM. We observed that the CCM effect and kinetics were more pronounced in coculture as compared to cardiac monoculture, supporting a hypothesis that some part of CCM mechanism of action can be attributed to peripheral nervous system stimulation. This study provides novel characterization of CCM effects on hiPSC-derived neurocardiac cocultures. This innervated human heart model can be further extended to investigate arrhythmic mechanisms, neurocardiac safety, and toxicity post-chronic exposure to materials, drugs, and medical devices. We present data on acute CCM electrical stimulation effects on a functional and optimized coculture using commercially available hiPSC-derived cardiomyocytes and neurons. Moreover, this study provides an in vitro human heart model to evaluate neuronal innervation and cardiac ganglia regulation of contractility by applying CCM pulse parameters that closely resemble clinical setting. This ivNCC platform provides a potential tool for investigating aspects of cardiac and neurological device safety and performance.

Reverse re-modelling chronic heart failure by reinstating heart rate variability

Heart rate variability (HRV) is a crucial indicator of cardiovascular health. Low HRV is correlated with disease severity and mortality in heart failure. Heart rate increases and decreases with each breath in normal physiology termed respiratory sinus arrhythmia (RSA). RSA is highly evolutionarily conserved, most prominent in the young and athletic and is lost in cardiovascular disease. Despite this, current pacemakers either pace the heart in a metronomic fashion or sense activity in the sinus node. If RSA has been lost in cardiovascular disease current pacemakers cannot restore it. We hypothesized that restoration of RSA in heart failure would improve cardiac function. Restoration of RSA in heart failure was assessed in an ovine model of heart failure with reduced ejection fraction. Conscious 24 h recordings were made from three groups, RSA paced (n = 6), monotonically paced (n = 6) and heart failure time control (n = 5). Real-time blood pressure, cardiac output, heart rate and diaphragmatic EMG were recorded in all animals. Respiratory modulated pacing was generated by a proprietary device (Ceryx Medical) to pace the heart with real-time respiratory modulation. RSA pacing substantially increased cardiac output by 1.4 L/min (20%) compared to contemporary (monotonic) pacing. This increase in cardiac output led to a significant decrease in apnoeas associated with heart failure, reversed cardiomyocyte hypertrophy, and restored the T-tubule structure that is essential for force generation. Re-instating RSA in heart failure improves cardiac function through mechanisms of reverse re-modelling; the improvement observed is far greater than that seen with current contemporary therapies. These findings support the concept of re-instating RSA as a regime for patients who require a pacemaker.

OUP accepted manuscript

Electrical disturbances, such as atrial fibrillation (AF), dyssynchrony, tachycardia, and premature ventricular contractions (PVCs), are present in most patients with heart failure (HF). While these disturbances may be the consequence of HF, increasing evidence suggests that they may also cause or aggravate HF. Animal studies show that longer-lasting left bundle branch block, tachycardia, AF, and PVCs lead to functional derangements at the organ, cellular, and molecular level. Conversely, electrical treatment may reverse or mitigate HF. Clinical studies have shown the superiority of atrial and pulmonary vein ablation for rhythm control and AV nodal ablation for rate control in AF patients when compared with medical treatment. Ablation of PVCs can also improve left ventricular function. Cardiac resynchronization therapy (CRT) is an established adjunct therapy currently undergoing several interesting innovations. The current guideline recommendations reflect the safety and efficacy of these ablation therapies and CRT, but currently, these therapies are heavily underutilized. This review focuses on the electrical treatment of HF with reduced ejection fraction (HFrEF). We believe that the team of specialists treating an HF patient should incorporate an electrophysiologist in order to achieve a more widespread use of electrical therapies in the management of HFrEF and should also include individual conditions of the patient, such as body size and gender in therapy fine-tuning.

Emerging Implantable Device Technology for Patients at the Intersection of Electrophysiology and Heart Failure Interdisciplinary Care

Cardiac implantable electronic devices (CIEDs), including implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT), are part of guideline- indicated treatment for a subset of patients with heart failure with reduced ejection fraction (HFrEF). Current technological advancements in CIEDs have allowed the detection of specific patient physiologic parameters used for forecasting clinical decompensation through algorithmic, multiparameter remote monitoring. Other recent emerging technologies, including cardiac contractility modulation (CCM) and baroreflex activation therapy (BAT), may provide symptomatic or physiologic benefit in patients without an indication for CRT. Our goal in this state-of-the-art review is to describe the commercially available new technologies, purported mechanisms of action, evidence surrounding their clinical role, limitations, and future directions. Finally, we underline the need for standardized workflow and close interdisciplinary management of this population to ensure the delivery of high-quality care.

Acute effects of cardiac contractility modulation on human induced pluripotent stem cell-derived cardiomyocytes

Cardiac contractility modulation (CCM) is an intracardiac therapy whereby nonexcitatory electrical simulations are delivered during the absolute refractory period of the cardiac cycle. We previously evaluated the effects of CCM in isolated adult rabbit ventricular cardiomyocytes and found a transient increase in calcium and contractility. In the present study, we sought to extend these results to human cardiomyocytes using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to develop a robust model to evaluate CCM in vitro. HiPSC-CMs (iCell Cardiomyocytes2 , Fujifilm Cellular Dynamic, Inc.) were studied in monolayer format plated on flexible substrate. Contractility, calcium handling, and electrophysiology were evaluated by fluorescence- and video-based analysis (CellOPTIQ, Clyde Biosciences). CCM pulses were applied using an A-M Systems 4100 pulse generator. Robust hiPSC-CMs response was observed at 14 V/cm (64 mA) for pacing and 28 V/cm (128 mA, phase amplitude) for CCM. Under these conditions, hiPSC-CMs displayed enhanced contractile properties including increased contraction amplitude and faster contraction kinetics. Likewise, calcium transient amplitude increased, and calcium kinetics were faster. Furthermore, electrophysiological properties were altered resulting in shortened action potential duration (APD). The observed effects subsided when the CCM stimulation was stopped. CCM-induced increase in hiPSC-CMs contractility was significantly more pronounced when extracellular calcium concentration was lowered from 2 mM to 0.5 mM. This study provides a comprehensive characterization of CCM effects on hiPSC-CMs. These data represent the first study of CCM in hiPSC-CMs and provide an in vitro model to assess physiologically relevant mechanisms and evaluate safety and effectiveness of future cardiac electrophysiology medical devices.

Cardiac Contractility Modulation in Patients with Ischemic versus Non-ischemic Cardiomyopathy: Results from the MAINTAINED Observational Study

BACKGROUND

Cardiac contractility modulation (CCM) is an FDA-approved device-based therapy for patients with systolic heart failure and normal QRS width who are symptomatic despite optimal drug therapy. The purpose of this study was to compare the long-term therapeutic effects of CCM therapy in patients with ischemic (ICM) versus non-ischemic cardiomyopathy (NICM).

METHODS

Changes in NYHA class, KDIGO CKD stage, left ventricular ejection fraction (LVEF), tricuspid annular plane systolic excursion (TAPSE), and NT-proBNP levels were compared as functional parameters. Moreover, observed mortality rates at 1 and 3 years were compared to those predicted by the MAGGIC heart failure risk score, and observed mortality rates were compared between groups for the entire follow-up period.

RESULTS

One hundred and seventy-four consecutive patients with chronic heart failure and CCM device implantation between 2002 and 2019 were included in this retrospective analysis. LVEF was significantly higher in NICM patients after 3 years of CCM therapy (35 ± 9 vs. 30 ± 9%; p = 0.0211), and after 5 years, also TAPSE of NICM patients was significantly higher (21 ± 5 vs. 18 ± 5%; p = 0.0437). There were no differences in other effectiveness parameters. Over the entire follow-up period, 35% of all patients died (p = 0.81); only in ICM patients, mortality was lower than predicted at 3 years (35 vs. 43%, p = 0.0395).

CONCLUSIONS

Regarding improvement of biventricular systolic function, patients with NICM appear to benefit particularly from CCM therapy.

Four-year follow-up of a patient with mixed cardiomyopathy and an implanted cardiac contractility modulation device: a case report

The article presents a case report of a 28-year-old male patient with mixed dilated cardiomyopathy: myocardial noncompaction and chemotherapy-related cardiotoxicity, which led to severe heart failure (HF). With optimal drug therapy, the patient was implanted with a cardiac contractility modulation device in order to improve exercise tolerance, quality of life and relieve HF symptoms. Complex therapy has led to significant clinical and echocardiographic improvement. This case demonstrates a 4-year follow-up of a patient with a reduced left ventricular ejection fraction and an implanted cardiac contractility modulation device, whose condition, after several severe HF decompensations, was stabilized.

Evolving Cardiac Electrical Therapies for Advanced Heart Failure Patients

Symptomatic heart failure (HF) patients despite optimal medical therapy and advances such as invasive hemodynamic monitoring remain challenging to manage. While cardiac resynchronization therapy remains a highly effective therapy for a subset of HF patients with wide QRS, a majority of symptomatic HF patients are poor candidates for such. Recently, cardiac contractility modulation, neuromodulation based on carotid baroreceptor stimulation, and phrenic nerve stimulation have been approved by the US Food and Drug Administration and are emerging as therapeutic options for symptomatic HF patients. This state-of-the-art review examines the role of these evolving electrical therapies in advanced HF.

Cardiac Contractility Modulation in Patients with Heart Failure with Reduced Left Ventricular Ejection Fraction

Cardiac contractility modulation is an innovative therapy conceived for the treatment of heart failure. It is a device-based therapy, employing multiple electrodes to deliver relatively high-voltage (~7.5 V) biphasic signals to the endocardium of the right ventricular septum, in order to improve heart failure symptoms, exercise capacity and quality of life. Multiple clinical and mechanistic studies have been conducted to investigate the potential usefulness of this technology and, as of now, they suggest that it could have a place in therapy and meet a relevant medical need for a specific sub-category of underserved heart failure patients with reduced left ventricular ejection fraction. More studies are needed to further investigate its effect on outcomes such as mortality and rate of hospitalizations.

Cardiac contractility modulation for the treatment of moderate to severe HF

Introduction: Heart failure (HF) affects over 6 million Americans and approximately 650,000 new cases are diagnosed annually, with patients evenly split between HFrEF and HFpEF. Recent advances in therapy for these patients have been limited to pharmaceutical agents, with CRT remaining the most reliable device therapy option since its advent almost twenty years ago. In 2019, after almost two decades without the introduction of a new device therapy for the treatment of moderate HF, the FDA approved CCM® therapy, delivered by the Optimizer Smart device, for patients with NYHA Class III HF who are on guideline-directed medical therapy (GDMT), in normal sinus rhythm (NSR), and with EF ranging from 25% to 45%, and who are ineligible for CRT.Areas covered: Multiple clinical trials support the use of CCM to improve quality of life, functional class, and 6-min hall walk distance. This article will discuss the science behind CCM therapy, the presumed mechanisms of action, the pre-clinical studies that shaped subsequent endeavors, and the clinical trials that support its use.Expert opinion: The introduction of CCM therapy bridges a therapeutic gap for patients with few or no other therapeutic options for NYHA III heart failure.

Cardiac contractility modulation for patient with refractory heart failure: an updated evidence-based review

Heart failure is the cardiovascular epidemic of the twenty-first century, with poor prognosis and quality of life despite optimized medical treatment. Despite over the last decade significant improvements, with a major impact on morbidity and mortality, have been made in therapy for heart failure with reduced ejection fraction, little progress was made in the development of devices, with the implantable defibrillator indicated for patients with left ventricle ejection fraction ≤ 35% and cardiac resynchronization therapy for those with QRS ≥ 130 ms and evidence of left bundle branch block. Nevertheless, only a third of patients meet these criteria and a high percentage of patients are non-responders in terms of improving symptoms. Nowadays, in patients with symptomatic heart failure with ejection fraction between 25% and 45% and QRS < 130 ms, not eligible for cardiac resynchronization, the cardiac contractility modulation (CCM) represents a concrete therapeutic option, having proved to be safe and effective in reducing hospitalizations for heart failure and improving symptoms, functional capacity, and quality of life. The aim of this review is therefore to summarize the pathophysiological mechanisms, the current indications, and the recent developments regarding the new applications of the CCM for patients with chronic heart failure.

Cardiac contractility modulation for the treatment of heart failure with reduced ejection fraction

There has been a progressive evolution in the management of patients with chronic heart failure and reduced ejection fraction (HFrEF), including cardiac resynchronisation therapy (CRT) in those that fulfil pre-defined criteria. However, there exists a significant proportion with refractory symptoms in whom CRT devices are not clinically indicated or ineffective. Cardiac contractility modulation (CCM) is a novel therapy that incorporates administration of non-excitatory electrical impulses to the interventricular septum during the absolute refractory period. Implantation is analogous to a traditional transvenous pacemaker system, but with the use of two right ventricular leads. Mechanistic studies have shown augmentation of left ventricular contractility and beneficial global effects on reverse remodeling, primarily through alterations in calcium handling. This appears to occur without increasing myocardial oxygen consumption. Data from clinical trials have shown translational improvements in functional capacity and quality of life, though long-term outcome data are lacking. This review explores the rationale, evidence base and limitations of this nascent technology.

A comprehensive individual patient data meta-analysis of the effects of cardiac contractility modulation on functional capacity and heart failure-related quality of life

Aims

Cardiac contractility modulation, also referred to as CCM™, has emerged as a promising device treatment for heart failure (HF) in patients not indicated for cardiac resynchronization therapy. We performed a comprehensive individual patient data meta‐analysis of all non‐confounded prospective randomized controlled trials of CCM vs. control that have measured functional capacity and/or quality of life questionnaires in patients with HF.

Methods and results

The Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE were searched in January 2020 to identify eligible randomized controlled trials. We also asked the sole manufacturer of the device for their list of known trials. Primary outcomes of interest were peak oxygen consumption (peak VO₂), 6 min walk test distance, and quality of life measured by Minnesota Living with Heart Failure Questionnaire (MLWHFQ), and all data were received as individual patient and individual time point data‐points. Mean differences and 95% confidence intervals (CIs) were calculated for continuous data using a fixed‐effects model. Five trials were identified, four randomized studies enrolling 801 participants for all endpoints of interest, and for peak VO₂ alone (n = 60), there was an additional single arm non‐randomized trial (FIX‐HF‐5C2) with a prospective comparison of its 24 week peak VO₂ data compared with the control group of the FIX‐HF‐5C control patients. Pooled analysis showed that, compared with control, CCM significantly improved peak VO₂ (mean difference +0.93, 95% CI 0.56 to 1.30 mL/kg/min, P < 0.00001), 6 min walk test distance (mean difference +17.97, 95% CI 5.48 to 30.46 m, P = 0.005), and quality of life measured by MLWHFQ (mean difference −7.85, 95% CI −10.76 to −4.94, P < 0.00001). As a sensitivity analysis, we excluded the FIX‐HF‐5C2 trial (only relevant for peak VO₂), and the result was similar, mean difference +0.65, 95% CI 0.21 to 1.08 mL/kg/min, P = 0.004.

Conclusions

This comprehensive meta‐analysis of individual patient data from all known randomized trials has shown that CCM provides statistically significant and clinically meaningful benefits in measures of functional capacity and HF‐related quality of life.

Safety, Performance, and Efficacy of Cardiac Contractility Modulation Delivered by the 2-Lead Optimizer Smart System

Background:

Prior studies of cardiac contractility modulation (CCM) employed a 3-lead Optimizer system. A new 2-lead system eliminated the need for an atrial lead. This study tested the safety and effectiveness of this 2-lead system compared with the 3-lead system.

Methods:

Patients with New York Heart Association III/IVa symptoms despite medical therapy, left ventricular ejection fraction 25% to 45%, and not eligible for cardiac resynchronization therapy could participate. All subjects received an Optimizer 2-lead implant. The primary end point was the estimated difference in the change of peak VO 2 from baseline to 24 weeks between FIX-HF-5C2 (2-lead system) subjects relative to control subjects from the prior FIX-HF-5C (3-lead system) study. Changes in New York Heart Association were a secondary end point. The primary safety end point was a comparison of device-related adverse events between FIX-HF-5C2 and FIX-HF-5C subjects.

Results:

Sixty subjects, 88% male, 66±9 years old with left ventricular ejection fraction 34±6% were included. Baseline characteristics were similar between FIX-HF-5C and FIX-HF-5C2 subjects except that 15% of FIX-HF-5C2 subjects had permanent atrial fibrillation versus 0% in FIX-HF-5C. CCM delivery did not differ significantly between 2- and 3-lead systems (19 892±3472 versus 19 583±4998 CCM signals/day, CI of difference [−1228 to 1847]). The change of peak VO 2 from baseline to 24 weeks was 1.72 (95% Bayesian credible interval, 1.02–2.42) mL/kg per minute greater in the 2-lead device group versus controls. 83.1% of 2-lead subjects compared with 42.7% of controls experienced ≥1 class New York Heart Association improvement ( P <0.001). There were decreased Optimizer-related adverse events with the 2-lead system compared with the 3-lead system (0% versus 8%; P =0.03).

Conclusions:

The 2-lead system effectively delivers comparable amount of CCM signals (including in subjects with atrial fibrillation) as the 3-lead system, is equally safe and improves peak VO 2 and New York Heart Association. Device-related adverse effects are less with the 2-lead system.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03339310

Optimizer Smart in the treatment of moderate-to-severe chronic heart failure

Cardiac contractility modulation, also referred to as CCM™, by the Optimizer Smart device is an innovative intracardiac device-based therapy that has been recently US FDA-approved for the treatment of patients with chronic heart failure, left ventricular ejection fraction (LVEF) between 25 and 45%, QRS <130 ms who remain symptomatic despite optimal medical therapy. Clinical trials demonstrate that CCM therapy is safe and effective in reducing heart failure hospitalization and improving heart failure symptoms, quality of life and functional performance. This novel device-based therapeutic offers benefits to patients who do not otherwise qualify for cardiac resynchronization therapy. CCM expands the indication beyond the traditional LVEF cutoff of 35% to a newer group including patients who fall in midrange LVEF group, up to 45%.

Modulação da Contratilidade Cardíaca

Pacientes com insufi ciência cardíaca (IC) vêm se benefi ciando da terapia elétrica por meio de marcapassos convencionais quando associada à bradicardia e à terapia de ressincronização cardíaca ou com fração de ejeção rebaixada e presença de QRS maior que 150 ms, principalmente na presença de bloqueio de ramo esquerdo. Outros grupos de pacientes com IC apresentam limitações ao tratamento com eletroterapia. No entanto, um conceito antigo tem tomado espaço no tratamento de um grupo de pacientes que fi ca fora das diretrizes nacionais e internacionais para eletroterapia na IC: a modulação da contração cardíaca. Este artigo tem como objetivo apresentar a revisão das evidências científi cas já produzidas e publicadas acerca dessa nova modalidade de tratamento da IC.

Modulation of Heart Contractility

Patients with heart failure (HF) are being benefi ted by electric therapy through conventional pacemakers when associated to bradycardia and cardiac resynchronization therapy or with low ejection fraction and presence of QRS longer than 150 ms, mainly in the presence of left branch block. Other groups of patients with HF present limitations regarding electrotherapy. However, an old concept has gained space in the treatment of patients who are outside the national and international guidelines for electrotherapy in HF: the modulation of heart contractility. This article has the purpose of presenting a review of already produced scientifi c evidence regarding this new modality for HF treatment

Device therapy in heart failure with reduced ejection fraction-cardiac resynchronization therapy and more

In patients with heart failure with reduced ejection fraction (HFrEF), optimal medical treatment includes beta-blockers, ACE inhibitors/angiotensinreceptor-neprilysin inhibitors (ARNI), mineralocorticoid receptor antagonists, and ivabradine when indicated. In device therapy of HFrEF, implantable cardioverter-defibrillators and cardiac resynchronization therapy (CRT) have been established for many years. CRT is the therapy of choice (class I indication) in symptomatic patients with HFrEF and a broad QRS complex with a left bundle branch block (LBBB) morphology. However, the vast majority of heart failure patients show a narrow QRS complex or a non-LBBB morphology. These patients are not candidates for CRT and alternative electrical therapies such as baroreflex activation therapy (BAT) and cardiac contractility modulation (CCM) may be considered. BAT modulates vegetative dysregulation in heart failure. CCM improves contractility, functional capacity, and symptoms. Although a broad data set is available for BAT and CCM, mortality data are still lacking for both methods. This article provides an overview of the device-based therapeutic options for patients with HFrEF.

New Generation Cardiac Contractility Modulation Device-Filling the Gap in Heart Failure Treatment

(1) Background: Heart failure (HF) is a major cause of morbidity and mortality throughout the world. Despite substantial progress in its prevention and treatment, mortality rates remain high. Device therapy for HF mainly includes cardiac resynchronization therapy (CRT) and the use of an implantable cardioverter-defibrillator (ICD). Recently, however, a new device therapy—cardiac contractility modulation (CCM)—became available. (2) Aim: The purpose of this study is to present a first case-series of patients with different clinical patterns of HF with a reduced ejection fraction (HFrEF), supported with the newest generation of CCM devices. (3) Methods and results: Five patients with a left ventricular ejection fraction (LVEF) ≤ 35% and a New York Heart Association (NYHA) class ≥ III were supported with CCM OPTIMIZER^® SMART IPGCCMX10 at our clinic. The patients had a median age of 67 ± 8.03 years (47–80) and were all males—four with ischemic etiology dilated cardiomyopathy. In two cases, CCM was added on top of CRT (non-responders), and, in one patient, CCM was delivered during persistent atrial fibrillation (AF). After 6 months of follow-up, the LVEF increased from 25.4 ± 6.8% to 27 ± 9%, and the six-minute walk distance increased from 310 ± 65.1 m to 466 ± 23.6 m. One patient died 47 days after device implantation. (4) Conclusion: CCM therapy provided with the new model OPTIMIZER^® SMART IPG CCMX10 is safe, feasible, and applicable to a wide range of patients with HF.

Inappropriate Defibrillator Shocks due to Mechanical Inference from an Investigational Device

Cardiac contractility modulation (CCM) is an investigational device-based therapy to enhance ventricular contractility in systolic heart failure patients who are not candidates for cardiac resynchronization therapy (CRT) owing to the absence of wide QRS complexes or who have failed to respond on CRT. The principal mechanism is based on the stimulation of cardiac muscles by nonexcitatory electrical signals to augment the influx of calcium ions into the cardiomyocytes. The majority of patients receiving CCM therapy have concurrent implantable cardioverter defibrillators, and the manufacturer declares both devices can be used in parallel without any interactions. Nevertheless, proper lead positioning of both devices are crucial, and it is mandatory to check device-device interactions during each and every cardiac electronic implantable device-related procedure to prevent adverse outcomes.

Cardiac contractility modulation: a novel approach for the treatment of heart failure

Heart failure is a major health problem worldwide and, despite effective therapies, is expected to grow by almost 50 % over the next 15 years. Five-year mortality remains high at 50 % over 5 years. Because of the economic burden and large impact on quality of life, substantial effort has focused on treatments with multiple medical (beta-blockers, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (ARB), aldosterone antagonists, and combination of ARB/neprilysin blockers, ivabradine) and device therapies (ICD, CRT) which have been implemented to reduce disease burden and mortality. However, in the past decade only two new medical therapies and no devices have been approved by the US FDA for the treatment of heart failure. This review highlights the preclinical and clinical literature, and the implantation procedure, related to a relatively new therapeutic device for heart failure; cardiac contractility modulation (CCM). CCM delivers a biphasic high-voltage bipolar signal to the RV septum during the absolute refractory period, eliciting an acute increase in global contractility, and chronically producing a sustained improvement in quality of life, exercise tolerance, and heart failure symptoms. The technology is used commercially in Europe with nearly 3000 patients implanted worldwide. Indications include patients with reduced EF and normal or slightly prolonged QRS duration, thus filling an important therapeutic gap among the 2/3 of patients with heart failure who do not meet criteria for CRT. The mechanism by which CCM provides benefit can be seen at the cellular level where improved calcium handling (phosphorylation of phospholamban, upregulation of SERCA-2A), reversal of the fetal myocyte gene program associated with heart failure, and reverse remodeling are observed. Recent retrospective studies indicate a long-term mortality benefit. A pivotal randomized controlled study is currently being completed in the USA. CCM appears to be an effective, safe technology for the treatment of heart failure with reduced ejection fraction.

Clinical effects of long-term cardiac contractility modulation (CCM) in subjects with heart failure caused by left ventricular systolic dysfunction

Introduction

Heart failure is a major cause of morbidity and mortality throughout the world. Despite advances in therapy, nearly half of patients receiving guideline-directed medical therapy remain limited by symptoms. Cardiac contractility modulation (CCM) can improve symptoms in this population, but efficacy and safety in prospective studies has been limited to 12 months of follow-up. We report on the first 2 year multi-site evaluation of CCM in patients with heart failure.

Methods

One hundred and forty-three subjects with heart failure and reduced ejection fraction were followed via clinical registry for 24 months recording NYHA class, MLWHFQ score, 6 min walk distance, LVEF, and peak VO₂ at baseline and 6 month intervals as clinically indicated. Serious adverse events, and all cause as well as cardiovascular mortality were recorded. Data are presented stratified by LVEF (all subjects, LVEF <35%, LVEF ≥35%).

Results

One hundred and six subjects from 24 sites completed the 24 month follow-up. Baseline parameters were similar among LVEF groups. NYHA and MLWHFQ improved in all 3 groups at each time point. LVEF in the entire cohort improved 2.5, 2.9, 5.0, and 4.9% at 6, 12, 18, and 24 months, respectively. Insufficient numbers of subjects had follow-up data for 6 min walk or peak VO₂ assessment, precluding comparative analysis. Serious adverse events (n = 193) were observed in 91 subjects and similarly distributed between groups with LVEF <35% and LVEF ≥35%, and similar to other device trials for heart failure. Eighteen deaths (7 cardiovascularly related) over 2 years. Overall survival at 2 years was 86.4% (95% confidence intervals: 79.3, 91.2%).

Conclusion

Cardiac contractility modulation provides safe and effective long-term symptomatic and functional improvement in heart failure. These benefits were independent of baseline LVEF and were associated with a safety profile similar to published device trials.

Cardiac contractility modulation in heart failure patients: Randomized comparison of signal delivery through one vs. two ventricular leads

BACKGROUND

Cardiac contractility modulation (CCM) is an electrical stimulation treatment for symptomatic heart failure (HF) patients. The procedure involves implantation of two ventricular leads for delivery of CCM impulses. The purpose of this study is to compare the efficacy and safety of CCM when the signal is delivered through one vs. two ventricular leads.

METHODS

This prospective blinded randomized trial enrolled 48 patients. Eligible subjects had symptoms despite optimal HF medications, left ventricular ejection fraction <40% and peakVO₂≥9ml O₂/kg/min. All patients received a CCM system with two ventricular leads, and were randomized to CCM active through both or just one ventricular lead; 25 patients were randomized to receive signal delivery through two leads (Group A) and 23 patients to signal delivery through one lead (Group B). The study compared the mean changes from baseline to 6 months follow-up in peakVO₂, New York Heart Association (NYHA) classification, and quality of life (by MLWHFQ).

RESULTS

Following 6 months, similar and significant (p<0.05) improvements from baseline in NYHA (-0.7±0.5 vs. -0.9±0.7) and MLWHFQ (-14±20 vs. -16±22) were observed in Group A and in Group B. PeakVO₂ showed improvement trends in both groups (0.34±1.52 vs. 0.10±2.21ml/kg/min; p=ns). No patient died. Serious adverse event rates (20 events in 10 subjects) were not different between groups. No statistically significant difference was found in any of the study endpoints.

CONCLUSIONS

The efficacy and safety of CCM in this study were similar when the signal was delivered through either one or two ventricular leads. These results support the potential use of a single ventricular lead for delivery of CCM.

Post-extrasystolic Potentiation: Link between Ca(2+) Homeostasis and Heart Failure?

Post-extrasystolic potentiation (PESP) describes the phenomenon of increased contractility of the beat following an extrasystole and has been attributed to changes in Ca(2+) homeostasis. While this effect has long been regarded to be a normal physiological phenomenon, a number of reports describe an enhanced potentiation of the post-extrasystolic beat in heart failure patients. The exact mechanism of this increased PESP is unknown, but disruption of normal Ca(2+) handling in heart failure may be the underlying cause. The use of PESP as a prognostic marker or therapeutic intervention have recently regained new attention, however, the value of the application of PESP in the clinic is still under debate. In this review, the mechanism of PESP with regard to Ca(2+) in the normal and failing heart will be discussed and the possible diagnostic and therapeutic role of this phenomenon will be explored.

New Management Strategies in Heart Failure

Despite >100 clinical trials, only 2 new drugs had been approved by the US Food and Drug Administration for the treatment of chronic heart failure in more than a decade: the aldosterone antagonist eplerenone in 2003 and a fixed dose combination of hydralazine-isosorbide dinitrate in 2005. In contrast, 2015 has witnessed the Food and Drug Administration approval of 2 new drugs, both for the treatment of chronic heart failure with reduced ejection fraction: ivabradine and another combination drug, sacubitril/valsartan or LCZ696. Seemingly overnight, a range of therapeutic possibilities, evoking new physiological mechanisms, promise great hope for a disease that often carries a prognosis worse than many forms of cancer. Importantly, the newly available therapies represent a culmination of basic and translational research that actually spans many decades. This review will summarize newer drugs currently being used in the treatment of heart failure, as well as newer strategies increasingly explored for their utility during the stages of the heart failure syndrome.