Jarvik 2015 ventricular assist device supports child with end-stage heart failure

In a medical milestone that is drawing attention from pediatric heart specialists around the world, a surgical and intensive care team at the Children’s Hospital Affiliated to Zhejiang University School of Medicine in Hangzhou, China, has reported the successful use of the Jarvik 2015 ventricular assist device in a child suffering from dilated cardiomyopathy and end-stage heart failure. The case, published as a research letter in the World Journal of Pediatrics, documents one of the first applications of this miniaturized implantable blood pump in China and offers a rare detailed account of the technical, anticoagulation and ethical challenges involved in keeping a small child alive while waiting for a donor heart.

Dilated cardiomyopathy is a disease in which the heart muscle becomes enlarged and weakened, losing its ability to pump blood efficiently. In adults, mechanical circulatory support has become a well-established bridge to transplantation, but in small children the options have long been painfully limited. The Jarvik 2015 was designed specifically to close that gap. It is a miniaturized, implantable, continuous-flow axial pump that weighs roughly 12 grams and measures about the size of an AA battery, small enough to fit within the thorax of a young child while generating sufficient flow to sustain the systemic circulation.

The device operates on an axial-flow principle: an impeller suspended within a compact housing spins at high rotational speed, drawing blood from the left ventricular apex and expelling it into the ascending aorta. Unlike pulsatile devices of earlier generations, which used bulky chambers and mechanical valves to replicate the natural heartbeat, continuous-flow pumps like the Jarvik 2015 provide steady perfusion. This design reduces the number of moving parts in contact with blood, lowers the risk of mechanical failure, and permits implantation through a less extensive surgical approach, a critical advantage when the patient’s chest is only a fraction of the size of an adult’s.

The Hangzhou team, led by corresponding author Qiang Shu of the Department of Cardiac Surgery, with Ru Lin of the Department of Heart Failure and Mechanical Circulatory Support serving as a lead author, described the meticulous planning and multidisciplinary coordination that the implantation demanded. The effort spanned cardiac surgery, cardiovascular medicine, cardiac intensive care, anesthesiology, ultrasound imaging and perfusion services, and it drew on international expertise. Adachi Iki of the Congenital Heart Surgery program at Baylor College of Medicine and Texas Children’s Hospital in Houston contributed guidance, and the team received device-handling training from Antonio Amodeo, Surgical Director of the Heart Failure Unit at Bambino Gesù Children’s Hospital in Rome, whose group performed the first human implantation of a miniaturized axial-flow ventricular assist device in a child in 2020.

The clinical course, however, was not without complications, and it is in the team’s handling of these setbacks that the report carries its greatest scientific value. One of the central challenges in ventricular assist device therapy, particularly in children, is the management of antithrombotic therapy. The surfaces of any artificial pump activate the coagulation cascade, creating a persistent risk of pump thrombosis, the formation of clots within the device that can impair or completely stop blood flow. At the same time, aggressive anticoagulation exposes the patient to bleeding, including hemorrhagic stroke, which remains one of the most feared complications of pediatric mechanical circulatory support. Prior research, including the work of Rosenthal and colleagues at Stanford on modified anti-thrombotic guidelines, has shown that standardized protocols can significantly reduce stroke rates in children supported by ventricular assist devices, and the Hangzhou team acknowledged guidance from Christopher S. Almond of Stanford University School of Medicine specifically in the treatment of pump thrombosis in this child.

The recognition and management of pump thrombosis in a pediatric patient requires constant vigilance. Surveillance depends on trends in lactate dehydrogenase and plasma-free hemoglobin, markers of hemolysis that rise when red blood cells are sheared across obstructed pump surfaces, along with echocardiographic assessment of pump function and power consumption data from the device controller. Because the child in this case was among the first in China to receive the Jarvik 2015, the team had to interpret these signals without the accumulated local experience that larger Western centers enjoy, relying instead on protocols refined during the PumpKIN trial, the international pediatric trial of the Jarvik 2015 that has been the backbone of the device’s clinical development for nearly a decade.

The PumpKIN trial, formally titled the Pediatric Pulse, Kinetics and Hemodynamics study, grew out of the National Heart, Lung, and Blood Institute’s contract program to develop a miniaturized pediatric continuous-flow pump. Baldwin, Adachi and colleagues described its design in 2017, and Adachi updated its status in 2018. A prospective multicenter feasibility study published in the Journal of Heart and Lung Transplantation in 2024 by Almond, Davies, Adachi and colleagues demonstrated the device’s feasibility in smaller children with heart failure, and compassionate-use reports published in the ASAIO Journal by Spinner and colleagues have documented individual cases in which the device served as a bridge to transplant when no other option existed. The Hangzhou case adds to this growing body of experience and, importantly, extends it to a Chinese clinical context, where the regulatory, financial and logistical barriers to obtaining such devices have historically been formidable.

Indeed, the report highlights a dimension of pediatric mechanical circulatory support that rarely appears in the technical literature: the economics of keeping a child alive on an implanted heart pump. The authors thank the Zhejiang Women and Children’s Foundation and the Future Smile Charitable Foundation, whose fundraising enabled many generous individuals in the community to contribute financially to the child’s medical treatment and care. Implantable ventricular assist devices for children are extraordinarily expensive, and in the absence of robust insurance coverage or clinical trial sponsorship, charitable funding can be the deciding factor between a viable bridge to transplantation and no treatment at all. The case therefore stands as both a scientific advance and a social one, demonstrating a pathway through which a single child in end-stage heart failure could access technology available in only a handful of centers worldwide.

The underlying disease that brought the child to surgery, dilated cardiomyopathy, remains one of the most common indications for heart transplantation in children. When medical therapy with inotropes, diuretics and neurohormonal agents fails, the options narrow to extracorporeal membrane oxygenation, paracorporeal pulsatile devices such as the Berlin Heart EXCOR, or, increasingly, implantable continuous-flow pumps. Extracorporeal membrane oxygenation is intended only for short-term stabilization, and the Berlin Heart, while effective, confines children to bedside support with substantial stroke and infection risks. The Jarvik 2015 occupies a different niche: because it is fully implantable, children supported with it can potentially be extubated, mobilized, rehabilitated and even, in some centers, discharged home while awaiting a donor heart, transforming the waiting period from an intensive care ordeal into something approaching a tolerable childhood.

The concept of bridging is central to the field. Data from adult programs have shown that some patients supported with left ventricular assist devices experience myocardial recovery sufficient for device deactivation, as documented in case reports of LVAD deactivation after cardiac function recovers, and pediatric teams hope similar bridges to recovery may one day be possible. For now, however, the realistic goal in end-stage pediatric dilated cardiomyopathy is a bridge to transplantation, and every successful case strengthens the argument that children too small for adult-sized devices deserve access to purpose-built technology. The miniaturized pediatric continuous-flow device has already been shown, in a report by Adachi, Spinner, Tunuguntla, Elias and Heinle published in 2019, to achieve a successful bridge to heart transplant, and each additional documented implantation refines the collective understanding of patient selection, implantation technique and postoperative management.

The ethical framework surrounding the Hangzhou case was similarly thorough. The clinical research project was approved by the Hospital Ethics Board and Hospital Academic Committee of the Children’s Hospital Affiliated to Zhejiang University School of Medicine and by the National Health Commission of the People’s Republic of China under trial authorization number 2022-IEC-019. Written informed consent for publication was obtained in accordance with applicable ethical guidelines, and the authors declared no competing interests, noting explicitly that the affiliation of one author with an artificial heart technology company did not constitute a conflict for this study. Qiang Shu, a member of the World Journal of Pediatrics editorial board, was recused from the journal’s review of the manuscript, which was handled by another editor through the standard peer review process.

For the global pediatric cardiology and cardiac surgery community, the significance of this report lies less in any single technical maneuver than in the proof it provides that complex, high-stakes pediatric mechanical circulatory support can be successfully exported beyond the small circle of centers that pioneered it. The Jarvik 2015’s journey, from design concept through the PumpKIN trial framework, through the first human implantation in Rome, through compassionate use cases in North America and now through a documented implantation and management experience in Hangzhou, reflects the slow, deliberate accumulation of evidence required to make a new therapy standard of care. Every additional case contributes to the anticoagulation algorithms, the troubleshooting protocols and the surgical techniques that will determine whether children everywhere with end-stage heart failure gain access to a viable bridge to a new heart. The child in Hangzhou, supported by a pump the size of a battery and an international network of expertise, embodies that progress.