Outcomes of Cardiac Contractility Modulation: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Cardiac contractility modulation in patients with heart failure - A review of the literature

Experimental in vivo and in vitro studies showed that electric currents applied during the absolute refractory period can modulate cardiac contractility. In preclinical studies, cardiac contractility modulation (CCM) was found to improve calcium handling, reverse the foetal myocyte gene programming associated with heart failure (HF), and facilitate reverse remodeling. Randomized control trials and observational studies have provided evidence about the safety and efficacy of CCM in patients with HF. Clinically, CCM therapy is indicated to improve the 6-min hall walk, quality of life, and functional status of HF patients who remain symptomatic despite guideline-directed medical treatment without an indication for cardiac resynchronization therapy (CRT) and have a left ventricular ejection fraction (LVEF) ranging from 25 to 45%. Although there are promising results about the role of CCM in HF patients with preserved LVEF (HFpEF), further studies are needed to elucidate the role of CCM therapy in this population. Late gadolinium enhancement (LGE) assessment before CCM implantation has been proposed for guiding the lead placement. Furthermore, the optimal duration of CCM application needs further investigation. This review aims to present the existing evidence regarding the role of CCM therapy in HF patients and identify gaps and challenges that require further studies.

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.

The Year 2022 in Cardiovascular Diseases-Clinics and Practice

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Cardiac Reverse Remodeling in Ischemic Heart Disease with Novel Therapies for Heart Failure with Reduced Ejection Fraction

Despite the improvements in the treatment of coronary artery disease (CAD) and acute myocardial infarction (MI) over the past 20 years, ischemic heart disease (IHD) continues to be the most common cause of heart failure (HF). In clinical trials, over 70% of patients diagnosed with HF had IHD as the underlying cause. Furthermore, IHD predicts a worse outcome for patients with HF, leading to a substantial increase in late morbidity, mortality, and healthcare costs. In recent years, new pharmacological therapies have emerged for the treatment of HF, such as sodium-glucose cotransporter-2 inhibitors, angiotensin receptor-neprilysin inhibitors, selective cardiac myosin activators, and oral soluble guanylate cyclase stimulators, demonstrating clear or potential benefits in patients with HF with reduced ejection fraction. Interventional strategies such as cardiac resynchronization therapy, cardiac contractility modulation, or baroreflex activation therapy might provide additional therapeutic benefits by improving symptoms and promoting reverse remodeling. Furthermore, cardiac regenerative therapies such as stem cell transplantation could become a new therapeutic resource in the management of HF. By analyzing the existing data from the literature, this review aims to evaluate the impact of new HF therapies in patients with IHD in order to gain further insight into the best form of therapeutic management for this large proportion of HF patients.

Matching Imaging and Remodulation Effects: Benefits of Cardiac Contractility Modulation Shown by Global Longitudinal Strain: A Case Report

Cardiac Contractility Modulation (CCM) has been proposed for inpatients affected by heart failure with reduced ejection fraction (HFrEF), with relapsing HF symptoms. We present a case of a patient treated with percutaneous coronary intervention (PCI) in the setting of acute coronary syndrome without persistent ST-segment elevation, with the best medical therapy for decompensated HF. The patient refused the implantable cardioverter-defibrillator (ICD), and to reduce the increasing number of hospitalizations for HF exacerbations, we proposed the use of the cardiac contractility modulation device. After the implant, the patient demonstrated a marked improvement in exercise effort and quality of life (QOL) with a six-minute walk test (SMWT), Minnesota Living with Heart Failure Questionnaire (MLWHFQ), and echocardiographic parameters. At 9 months after discharge, no hospital admissions for HF were recorded. We showed with the speckle tracking imaging how the improvement in global longitudinal strain (GLS) correlates with the remodeling effects on myocardial cells.

SV, Saidova MA, Zhirov IV, Tereshchenko SN. Myocardial remodeling in patients with chronic heart failure and implanted cardiac contractility modulators

Aim. To study the effect of cardiac contractility modulation on reverse remodeling and myocardial function in patients with chronic heart failure (HF) according to echocardiography (EchoCG). Materials and methods. In a group of 40 patients with a combination of chronic HF and atrial fibrillation (AF), the dynamics of standard EchoCG parameters and the effectiveness of myocardial work of the left ventricle (LV) against the background of 12-month therapy of cardiac contractility modulation (CCM) were analyzed. Results. The results obtained indicate a statistically significant positive effect of CCM on LV remodeling parameters and the effectiveness of myocardial work according to EchoCG. Conclusion. Transthoracic echocardiography is the main imaging method and provides great opportunities for evaluating the effectiveness of HF treatment, including non-drug methods such as CCM. Evaluation of LV myocardial function in patients with HF and implanted CCM devices is a promising scientific and practical research method.

Dynamics of Holter electrocardiogram monitoring in patients with chronic heart failure and atrial fibrillation on the background of cardiac contractility modulation

Aim. To evaluate the dynamics of cardiac arrhythmias on the background of cardiac contractility modulation (MCC) in patients with chronic heart failure (CHF) and various forms of atrial fibrillation (AF) on the basis of daily electrocardiogram (ECG) monitoring. Materials and methods. In 100 patients with CHF and AF, the following studies were performed before implantation of the MCC device and after 12 months of follow-up: 12-channel ECG with an estimate of the width of the QRS complex, transthoracic echocardiography (EchoCG), and Holter ECG monitoring. All patients received long-term optimal drug therapy for CHF before surgery. Results. The results obtained indicate that there is no effect of MCC on the development and progression of ventricular arrhythmias in patients with CHF and AF during the year of follow-up, both extrasystole and tachyarrhythmias, regardless of the etiology and LVEF (less than 35% or more than 35%), and a decrease in the frequency of AF paroxysms in patients with CHF during treatment. These results are due to the reverse remodeling of the LV myocardium under the influence of the MCC device. Conclusion. The use of MСС in patients with CHF and AF is a safe method of therapy that does not induce cardiac arrhythmias, including ventricular extrasystole. Large-scale comparative studies are required to evaluate these results.

Possibilities of Evaluating the Dynamics of Left Ventricular Perfusion and Contractility in Patients with Chronic Heart Failure after Implantation of a Heart Contractility Modulator Using Perfusion Single-Photon Emission Computed Tomography

Perfusion scintigraphy and single-photon emission tomography of the myocardium are promising methods for complex assessment of the state of the left ventricle myocardium in patients with chronic heart failure. These methods of nuclear cardiology can be performed in patients with reduced renal function, as well as the presence of implanted devices such as implantable cardioverters-defibrillators, resynchronizing devices and cardiac modulating therapy, which is their undeniable advantage. The reproducibility of the method is ensured bu fully automated calculation of parameters of myocardial perfusion and contractility. To date, there are no data in the literature on the use of nuclear cardiology methods as an imaging technique in patients with cardiac contractility modulation devises. This paper describes the current possibilities and prospects of nuclear medicine methods in patients with chronic heart failure after implantation of a heart contractility modulator.

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.