Successful explantation of children from the Berlin Heart EXCOR® ventricular assist device: A systematic review

BACKGROUND

The Berlin Heart EXCOR® (BHE) can bridge children with severe heart failure to transplantation, but some are successfully weaned and spared transplantation. This study seeks to identify characteristics of children amenable to successful explantation with BHE support.

METHODS

Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 guidelines were used. Five databases were screened for original, English articles measuring BHE support in patients <18 years old based on title and abstract. Exclusion criteria were applied: full-text availability, <10 total pediatric BHE patients, zero successful explantations from BHE, nonprimary literature, adult and pediatric results that could not be separated, and studies with overlapping patient information. Studies were analyzed with descriptive statistics.

RESULTS

From 41 857 potential studies, 14 were analyzed with data from 58 hospitals on four continents from 1990 to 2020. There were 984 BHE patients. The most common diagnosis was dilated cardiomyopathy (n = 318, 32.3%), followed by congenital heart disease (n = 249, 25.3%). There were 85 (8.6%) children explanted with favorable outcomes. The underlying diagnosis was known in 44 (51.8%) cases: 14 (8.4%) of 166 cardiomyopathies, 17 (48.6%) of 35 myocarditis, and 12 (16.7%) of 72 with congenital heart disease were explanted. When the type of support was known, the rate of LVAD patients explanted was 21.3% (n = 19/89) and 2.4% (n = 1/42) of BiVAD patients were explanted.

CONCLUSION

Explantation from BHE is not uncommon at 8.6%, but significant variation exists in the explantation data reported. Myocarditis and LVAD support may be populations suitable for weaning. Standardization of reporting measures and prospective registries may help identify patients suitable for this alternative to transplant and help develop weaning protocols.

HeartMate 3 Explantation Using Felt Plug for Ventriculotomy Occlusion

Left ventricular assist devices (LVAD) can be utilized for heart failure patients as a bridge to transplant, bridge to destination, or bridge to recovery. Given the lack of a universally accepted consensus for assessing myocardial recovery, techniques and strategies in LVAD explantation also vary. In addition, the incidence of LVAD explantation remains relatively low, and surgical techniques of explantation continue to be areas of interest. Our approach using a felt-plug Dacron technique is an effective way to preserve left ventricular geometry and cardiac function.

Complications in children with ventricular assist devices: systematic review and meta-analyses

Heart failure is a significant cause of mortality in children with cardiovascular diseases. Treatment of heart failure depends on patients' symptoms, age, and severity of their condition, with heart transplantation required when other treatments are unsuccessful. However, due to lack of fitting donor organs, many patients are left untreated, or their transplant is delayed. In these patients, ventricular assist devices (VADs) are used to bridge to heart transplant. However, VAD support presents various complications in patients. The aim of this study was to compile, review, and analyse the studies reporting risk factors and aetiologies of complications of VAD support in children. Random effect risk ratios (RR) with 95% confidence intervals were calculated to analyse relative risk of thrombosis (RR = 3.53 [1.04, 12.06] I² = 0% P = 0.04), neurological problems (RR = 0.95 [0.29, 3.15] I² = 53% P = 0.93), infection (RR = 0.31 [0.05, 2.03] I² = 86% P = 0.22), bleeding (RR = 2.57 [0.76, 8.66] I² = 0% P = 0.13), and mortality (RR = 2.20 [1.36, 3.55] I² = 0% P = 0.001) under pulsatile-flow and continuous-flow VAD support, relative risk of mortality (RR = 0.45 [0.15, 1.37] I² = 36% P = 0.16) under left VAD and biVAD support, relative risk of thrombosis (RR = 1.72 [0.46, 6.44] I² = 0% P = 0.42), infection (RR = 1.77 [0.10, 32.24] I² = 46% P = 0.70) and mortality (RR = 0.92 [0.14, 6.28] I² = 45% P = 0.93) in children with body surface area < 1.2 m² and > 1.2 m² under VAD support, relative risk of mortality in children supported with VAD and diagnosed with cardiomyopathy and congenital heart diseases (RR = 1.31 [0.10, 16.61] I² = 73% P = 0.84), and cardiomyopathy and myocarditis (RR = 0.91 [0.13, 6.24] I² = 58% P = 0.92). Meta-analyses results show that further research is necessary to reduce complications under VAD support.

2019 EACTS Expert Consensus on long-term mechanical circulatory support

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.

Improved 6 Minute Walk Distance and Brain-Type Natriuretic Peptide After Continuous-Flow Ventricular Assist Device Placement in Children

Despite increasing continuous-flow ventricular assist device (CF-VAD) use in children, minimal data exist regarding the functional recovery and rehabilitation potential after device placement. We hypothesized that after CF-VAD implantation, children would demonstrate a time-limited improvement in 6 minute walk distance (6MWD) and brain-type natriuretic peptide (BNP). A retrospective cohort study of 27 patients was conducted, those <18 years of age at a tertiary-care center during the study period. Seventy-four percent were male; median age was 12.7 years. Six minute walk distance and BNP were evaluated within 365 days of implantation. Associations were examined before and after 90 days postimplantation because a plateau in both values was seen after 90 days. Data included 92 6MWD and 341 BNP values. In the first 90 days, 6MWD increased by 12 percent predicted (%P) per 30 days (P < 0.01); with no significant change thereafter, increasing 0.6 %P per 30 days (P = 0.482). In the first 90 days, BNP decreased by 59% per 30 days (P < 0.01); with no significant change thereafter, increasing 1.2% per 30 days (P = 0.561). Six minute walk distance and BNP improved after CF-VAD implantation, with a significant improvement only in the first 90 days. Routine use of 6MWD and BNP can help in assessment of functional recovery in children after CF-VAD placement.

Titanium Plug Closure after HeartWare Ventricular Assist Device Explantation in a 15-Year-Old Girl: First U.S. Experience

We describe the case of a teenage girl with anthracycline-induced cardiomyopathy who received a HeartWare ventricular assist device and underwent successful device explantation after cardiac recovery. During device support, the patient's cardiac function returned to normal. Twelve months after implantation, we explanted the device via repeat median sternotomy. To close the hole in the left ventricular apex and preserve the sewing ring in case future device support is needed, we used a German-manufactured titanium plug, developed specifically for this purpose. To our knowledge, this is the first use of this plug in the United States. The patient recovered uneventfully and was discharged from the hospital on postoperative day 11. Left ventricular biopsy specimens at explantation revealed the resolution of previous degenerative sarcomeric changes. Our patient did well clinically; however, recurrent late anthracycline cardiotoxicity might subsequently cause her cardiac function to deteriorate. In this event, our use of the titanium plug to preserve the left ventricular sewing ring would enable easier device replacement than would other explantation options.

Current Status of Pediatric Ventricular Assist Device Support

The last decade has witnessed significant advancement in the field of ventricular assist device (VAD) support. Although device options for pediatric patients were previously severely limited because of body size constraints, this frustrating situation has gradually been changing, owing to ongoing device miniaturization. Recognition of the superiority of VAD support compared with conventional extracorporeal membrane oxygenation support has spurred enthusiasm for VAD support in children. In this article, we discuss the current status of pediatric VAD support; where do we stand now and where will we be heading? Because this field is rapidly changing, it is anticipated that this article will provide a general overview of what is currently occurring in the field of pediatric VAD support.

Now how do we get them home? Outpatient care of pediatric patients on mechanical circulatory support

The last five yr have been monumental for the pediatric heart failure community. In the US, the most notable has been the FDA approval of the first pediatric specific device (Berlin Heart EXCOR(®) ; Berlin Heart, Inc., Berlin, Germany). Subsequently, the field of heart failure has gained a great deal of knowledge regarding the nuances of MCS in children. Despite FDA approval in the US, the Berlin EXCOR(®) is only currently indicated for in-hospital use. Due to the limitations with discharge and the positive in- hospital experiences with the Berlin EXCOR(®) , there has been an increased interest in the implantation of adult durable devices into children. While many institutions have focused their intial efforts on the first phase of care within the hospital, they are now ready to tackle the challenge of how to safely transition children to the community setting.

Clinical management of patients with acute heart failure

Acute heart failure is a common and serious complication of congenital and acquired heart disease, and it is associated with significant morbidity, mortality, and costs. When a patient is admitted to the hospital with acute heart failure, there are several important goals for the hospital admission, including maintaining adequate perfusion, establishing the underlying aetiology for the heart failure, patient and family education, and discharge from the hospital in a stable condition. The pathway to home discharge is variable and may include inotropic therapy, mechanical circulatory support, and/or heart transplantation. This review will cover the epidemiology, presentation, and management of acute heart failure in children.

Current approaches to device implantation in pediatric and congenital heart disease patients

The pediatric ventricular assist device (VAD) has recently shown substantial improvements in survival as a bridge to heart transplant for patients with end-stage heart failure. Since that time, its use has become much more frequent. With increasing utilization, additional questions have arisen including patient selection, timing of VAD implantation and device selection. These challenges are amplified by the uniqueness of each patient, the recent abundance of literature surrounding VAD use as well as the technological advancements in the devices themselves. Ideal strategies for device placement must be sought, for not only improved patient care, but also for optimal resource utilization. Here, we review the most relevant literature to highlight some of the challenges facing the heart failure specialist, and any physician, who will care for a child with a VAD.

Pediatric ventricular assist devices

The field of pediatric mechanical circulatory support with ventricular assist devices has lagged significantly behind that of adult patients. However, there is increasing attention on the emerging field of pediatric ventricular assist device support. In this review, part of the Pediatric Cardiac Intensive Care Society/Extracorporeal Life Support Organization Joint Consensus Statement on Mechanical Circulatory Support, we discuss several important aspects of pediatric ventricular assist device, focusing on biomechanics and selection of the most appropriate device.

Mechanical circulatory support in children: bridge to transplant versus recovery

The number of children and adolescents suffering from heart failure is increasing dramatically. Some of these patients will progress to need advanced therapies in the form of mechanical circulatory support (MCS). Over the past few years, increased attention has been focused on clinical use of existing devices as well the development of pediatric-specific ventricular assist devices (VADs). As in adult populations, these devices offer unique opportunities to successfully support children as a bridge-to-transplant, but increasing data suggest that bridge-to-recovery and bridge-to-destination are also viable options in select pediatric populations. Herein, we will review existing approaches as well describe future potential MCS options.