Heart failure in pediatric patients is one of the leading causes of mortality in this population. Its management includes medical treatment, circulatory support with VADs, surgical intervention, and heart transplantation. While VADs are a management option for these patients, their use in the pediatric population only increased significantly after the year 2000. Since then, both the technique and the devices have improved considerably, not only altering heart failure management strategies but also significantly enhancing survival rates in these patients. However, their application remains limited due to challenges such as the availability of suitable devices, medium- and long-term complications, and other factors. 

This was a descriptive, retrospective study conducted at Texas Children’s Hospital between May 2008 and September 2022. The authors evaluated the number of VAD implantations rather than the number of patients. The indications for VAD placement included: bridge-to-transplant (for patients already listed for transplantation at the time of device implantation), bridge-to-transplant candidacy (for patients with potentially reversible contraindications to transplantation), bridge-to-decision (as a rescue therapy), bridge-to-recovery, and, occasionally, destination therapy. As part of the hospital’s routine practice, all patients who received a VAD were kept inactive on the heart transplant waitlist for at least three months. During this period, their physical and psychological progress was monitored. If patients showed improvement in left ventricular function or a reduction in the left ventricular end-diastolic volume z-score, they were classified as responders and remained under prolonged surveillance to achieve greater recovery, always with family consent. If the potential for cardiac recovery was deemed minimal, the patient was reactivated on the heart transplant waitlist. 

The overall outcomes of the study were categorized into four groups: heart transplant, device explantationdue to myocardial recovery, ongoing support (or destination therapy), and death. Long-term survival rates were calculated using the Kaplan-Meier method, and follow-up data were censored at the time of death, loss to follow-up, or the end of December 2022. 

A total of 100 events were included. The devices used were HeartWare® in 67% of cases, HeartMate II® in 17%, and HeartMate 3® in 16%. The median age at implantation was 14 years, with a mean weight of 50 kg and a mean body surface area of 1.6 m². The primary diagnosis was cardiomyopathy, which accounted for 58% of cases, followed by congenital heart disease (CHD) in 37% (including single ventricle physiology). 

At six months, 94% of cases showed favorable outcomes: 64 patients underwent heart transplantation, 15 required ongoing support, and 7 were in the recovery phase. A total of 82% of cases were discharged home with VAD support, showing a decrease in bleeding, infection, and cerebrovascular events. At three months, 51% of the cases met the responder criteria. By the end of six months, 88% had successfully completed this period, and only 10 patients required early heart transplantation or died. Survival rates at one, two, and five years were 90%, 86%, and 77%, respectively. Among the 14 deaths, half occurred in-hospital before discharge following VAD implantation, with the main causes being infections and cerebrovascular events. 

Regarding hospital readmissions, 46% of cases required rehospitalization. Among the 82 cases discharged, more than half returned to school or work. One patient married and had a daughter, while six others graduated from high school with VAD support. One of these patients is currently in college and holds the record for the longest follow-up, which spans 11 years. 

The study concluded that the use of VADs is feasible for ambulatory patients in a tertiary pediatric institution. The capacity of implantable devices provides not only a bridge to heart transplantation but also excellent support for other types of bridges or even as destination therapy. 

COMMENTARY: 

This is a single-center study evaluating the prolonged use of VADs in pediatric patients. However, it is not free of limitations, as it presents a retrospective analysis that carries the potential for biases and limitations in data collection. The study does not specify whether delaying the patients’ activation on the heart transplant waitlist for three months had any negative impact. Furthermore, it does not detail the clinical conditions considered for deciding which patients (particularly critically ill ones) should receive circulatory support, nor whether any demographic or social factors were taken into account for device implantation. Additionally, the study fails to define long-term complications associated with the use of these devices and does not specify the causes or costs of readmissions. 

This study involves a substantial series of pediatric patients with VADs and clearly demonstrates that these patients can be safely discharged home and return to their activities. One of the main consequences of progress in diagnosing and managing congenital heart diseases, including patients with single-ventricle physiology, is a significant increase in survival, with many requiring heart transplantation as the definitive treatment for end-stage heart failure. 

Currently, the use of VADs is primarily oriented as a bridge to heart transplantation. However, the scarcity of donor availability is a common problem that necessitates alternative strategies, which come with additional costs and psychological impacts not only on patients but also on their families, which must be taken into consideration. 

For this reason, the use of VADs is becoming increasingly common, and one of the main challenges lies in deciding whether to refer a patient for heart transplantation or instead opt for long-term circulatory support, which could potentially become destination therapy. While it is true that these devices have evolved, becoming safer and easier to manage, adverse effects are not uncommon. These include bleeding (mainly gastrointestinal), infections, thrombus formation, neurological complications, and others. Furthermore, when considering sociodemographic factors related to healthcare access or adherence to prescribed measures, it becomes evident that this decision is not straightforward. 

Access to adequate medical care, convenience, and the cost of follow-up depend heavily on the distribution of qualified centers and the availability of VADs. Consequently, in pediatric populations, this type of therapy is only accessible in developed countries. 

There is no doubt that advances in the diagnosis and management of pediatric cardiology have significantly improved survival rates in these patients. However, the use of VADs in the pediatric population remains far from being widely implemented. Institutional development imbalances and disparities in healthcare resources on an international level greatly restrict access to medical care and overall survival in this population. 

In conclusion, VADs play a crucial role in managing end-stage heart failure, even in pediatric patients. Significant progress has been made in recent years, but the application of these devices in pediatric patients lags behind that of adult patients in many respects. To overcome these challenges, more registries should be established, including the largest possible number of patients, to guide clinical decisions, improve knowledge, and enhance efficiency. 

REFERENCE:

Cho J, Tunuguntla HP, Tume SC, Spinner JA, Bocchini CE, Teruya J, et al. Long-term implantable ventricular assist device support in children. J Thorac Cardiovasc Surg. 2024 Apr;167(4):1417-1426.e1. doi: 10.1016/j.jtcvs.2023.10.048.