A History of Devices As an Alternative to Heart Transplantation

A History of Devices as an Alternative to Heart Transplantation

Garrick C. Stewart, MD, Mandeep R. Mehra, MD*

KEYWORDS Heart failure Cardiomyopathy Cardiac surgery Ventricular assist device

KEY POINTS First conceived 50 years ago as an extension of the heart-lung machine, ventricular assist devices are now in widespread use to treat advanced heart failure. Current ventricular assist devices are being increasingly implanted as lifetime therapy in those ineligible for transplant. Continuous-flow pumps are more durable than first-generation pulsatile flow pumps and offer improved survival, contributing to a widespread acceptance of use of assist devices in the contem- porary era. International registries of mechanical circulatory support devices have contributed to enhanced understanding of patient selection and better patient-device matching. Small, durable next-generation rotary blood pumps, coupled with internal power sources, may 1 day be a viable alternative to cardiac transplantation in selected situations.

INTRODUCTION the next few years, ventricular assist devices (VADs) may become the most common surgical After half a century of clinical development, me- means of supporting the failing circulation, easily chanical circulatory support (MCS) devices have surpassing the frequency of heart transplant. reached maturity and are now in widespread use Only by understanding the evolution of mechanical for the treatment of advanced heart failure (HF). support will we know how best to deploy this The pace of progress has accelerated dramatically remarkable technology. in recent years, creating new challenges in candi- date selection and clinical management, amidst EARLY HISTORY OF MECHANICAL SUPPORT ongoing debate about the cost-effective use of health care resources. With the advent of rotary The modern era of cardiac surgery began in 1953, blood pump technology, device therapy has with the first use of cardiopulmonary bypass dur- emerged as a viable alternative in those ineligible ing a successful atrial septal defect repair.1 for cardiac transplantation. The history of durable Increasingly, complex and daring operations MCS has been interwoven with that of heart trans- were within reach. As a consequence of longer op- plantation. Much of advanced HF care is now erations on sicker patients, MCS devices quickly focused on triaging patients to cardiac transplan- evolved out of a need for prolonged cardiac tation or permanent mechanical support. Within bypass to facilitate resolution of intraoperative

MRM is a consultant with Thoratec, chair of the REVIVE-IT DSMB (a National Heart, Lung, and Blood Institute- sponsored trial with Thoratec as the device sponsor) and editor of the Journal of Heart and Lung Transplan- tation. In addition he consults for Boston Scientific, Medtronic, St. Jude Medical, Baxter, the American Board of Internal Medicine, and the National Institutes of Health. Center for Advanced Heart Disease, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA * Corresponding author. E-mail address: [email protected]

Heart Failure Clin 10 (2014) S1–S12 http://dx.doi.org/10.1016/j.hfc.2013.08.003

myocardial stunning. The heart-lung machine was government bore fruit in 1982. That year at the Uni- the first support device used to bridge a patient to versity of Utah, Dr William DeVries implanted the recovery after postcardiotomy shock. Then, in Jarvik-7 TAH into Barney Clark, a Seattle dentist 1962, Liotta and his team at Baylor College of with chronic HF who volunteered to receive the Medicine in Houston, Texas reported the first clin- pioneering device.8 Designed by Robert Jarvik, ical use of an artificial ventricle in a patient with the Jarvik-7 was the first device implanted for per- cardiogenic shock after aortic valve surgery.2,3 manent circulatory support. The TAH received un- This primitive assist device connected the left precedented media attention, with daily progress atrium to the descending thoracic aorta and con- reports leading network television news. The sisted of a pneumatically driven, tubular displace- Jarvik-7 allowed Barney Clark to survive 112 days ment pump inside a valved conduit to ensure after surgery before dying from sepsis. The second unidirectional flow. The pump provided partial recipient, William Schroeder, survived for 620 days bypass for 4 days after postoperative arrest before after his surgery at the University of Louisville.9 A the patient died from pneumonia and multiorgan bright spotlight shone on the TAH at its debut, system failure. but enthusiasm for long-term use of the device Encouraged by the results of these clinical re- dimmed because of a high incidence of infection, ports as well as convincing large animal experi- pump thrombosis, and stroke. Yet, with few other ments, the National Institutes of Health (NIH) devices available, the Jarvik-7 TAH continued to established the Artificial Heart Program in 1964.4 be used, albeit infrequently, as a temporary means Six entities were contracted to explore the engi- of support before transplantation.10,11 neering feasibility of mechanical heart pumps. In 1983, cardiac transplantation emerged out of These artificial blood pumps were envisioned not its dark years with the approval of cyclosporine by just as a bridge to recovery for acute HF but also the US Food and Drug Administration (FDA).7 as permanent circulatory replacement. By 1966, Improved immunosuppression with this calci- the first pneumatic left VAD (LVAD), then known neurin inhibition led to a sharp decline in allograft as a ventricular bypass pump, was used by DeBa- rejection and dramatic improvements in patient key to support a patient for 10 days after cardiac survival. Now armed with good surgical technique surgery.5 and effective immunosuppression, there was a After the first human heart transplant in 1967 by proliferation of heart transplant programs across Barnard in Cape Town, South Africa, assist devices the United States and an ever-growing cohort of were envisioned as a means to support patients patients with end-stage HF awaiting a donor until a donor organ could be found. In 1969, Cooley organ.12 and colleagues6 reported the first use of a tempo- Confronted with the limitations of the TAH and rary total artificial heart (TAH) as a successful the ascendancy of heart transplant, the MCS com- bridge to transplantation. However, the first gener- munity redoubled efforts to design simpler, single- ation of extracorporeal VADs could remain in place chamber pumps to be implanted in series with the only for a matter of days. These early pumps were failing left ventricle. Component technology for a plagued by faulty control mechanisms, inadequate VAD was easier to engineer and implant than the power supplies, and traumatic blood-pump inter- TAH and allowed the failing native heart to remain faces, which produced hemolysis and thrombosis. in place. Innovation spurred on by the 2-decade Primitive bridging technology, even when success- old commitment of NIH led to the successful ful, then led to a heart transplant that offered limited deployment of the first electric, pulsatile Novacor prospects for longevity. Despite early promise and LVAD as a bridge to transplantation in 1984.13 intense public enthusiasm about transplantation, With both LVAD and TAH in use, in 1984, the inadequate immunosuppressive strategies led Centers for Medicare and Medicaid Services to dismal posttransplant outcomes through the (CMS) defined distinct strategies for mechanical 1970s. Nevertheless, pioneering work on immune support to guide regulatory approval and reim- mechanisms, rejection monitoring, and surgical bursement (Box 1). Over the subsequent decade, technique continued throughout the 1970s at the FDA approved multiple device platforms as a Stanford University and elsewhere, allowing the bridge to transplantation: the Abiomed BVS 5000 heart transplant field to make progress until better in 1992, ThermoCardiosystems pneumatic LVAD immunosuppression could be found.7 in 1994, the electrical Thoratec vented assist de- With few adequate cardiac replacement options vice in 1995, and the Novacor LVAD in 1998.14 available, in the late 1970s, the NIH issued a series Single-chamber pumps could be used to support of initiatives to develop better component tech- the failing left ventricular (LVAD), right ventricle nology for durable assist devices. These pioneer- (right VAD), or both ventricles (biventricular assist ing initiatives between scientists, industry and device), keeping patients alive until orthotopic Download English Version: https://daneshyari.com/en/article/3473366

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