Over the past decade, an estimated 30,000 ventricular assist devices have been implanted in patients with failing hearts around the world. Commonly known as the heart pump, the device circulates blood throughout the body.
These life-saving electromechanical pumps, also called mechanical circulatory support devices, are the brainchild of a handful of pioneering heart surgeons from the Texas Medical Center. Of them, O.H. “Bud” Frazier, MD, Chief of Transplant Services at Baylor St. Luke's, Professor of Surgery at Baylor College of Medicine, and Chief of the Center for Cardiac Support at the Texas Heart Institute, has been globally recognized as the leader in the development of left ventricular assist devices (LVADs), the most widely used heart pump in the world.
Bedside Teaching Rounds
This month, Dr. Frazier launched his bedside teaching rounds on LVADs for students, interns, residents, fellows, nurse practitioners, and physician assistants. They are also geared toward anyone working in cardiology, cardiac surgery, anesthesia, critical care, perfusion, circulatory support, nursing, and any other medical fields that interact with patients with LVADs. The rounds are held on the third Tuesday of each month from 3-4 p.m. on 8 Cooley A at Baylor St. Luke`s.
“Dr. Frazier is the world's foremost expert on LVADs and the pioneer who invented and popularized these devices,” said Jeffrey A. Morgan, MD, Chief of the Division of Cardiothoracic Transplant and Circulatory Support at Baylor College of Medicine and the Texas Heart Institute. “These teaching rounds are highly valuable to all practitioners who care for patients with LVADs. They will learn the history of LVADs, the associated preclinical lab work, their mechanisms of action, and postoperative management of the patients.”
Mechanical circulatory support devices are used to assist or replace the pumping action of a heart. They serve as either a “bridge-to-transplant” transitional device for those waiting for a transplant or a “destination therapy” permanent device for those who are not candidates for transplant.
Dr. Frazier's continuous-flow pump design is a revolution from the older pulsatile variety made to generate pulsated blood flow by mimicking the healthy human heart that beats 100,000 times every 24 hours. The new generation of nonpulsatile pump produces a continuous flow of blood and is much smaller and more durable without the parts and workload to produce frequent pulses.
“The physiology of continuous-flow pumps that we use today is totally different from that of the devices developed to imitate normal physiology, such as artificial heart valves and pacemakers,” he said. “My goal is to help our clinicians understand the heart pump's unique physiology, how it works, and how best to work with patients with such devices so they receive the right care.”
Blazing His Own Trail
A protégé of world-renowned heart surgeons Denton Cooley, MD, and Michael DeBakey, MD, Dr. Frazier blazed his own trail to become a luminary in clinical practice, research, and teaching. He has performed more than 1,300 heart transplants and implanted about 1,000 LVADs, outnumbering any other surgeon in the world. The development of LVADs – the continuous-flow pump in particular – has been Dr. Frazier's most significant contribution to the medical industry.
When describing his passion for developing heart pumps, Dr. Frazier never forgets his experience as a medical student in the 1960s when he was with a team operating on an Italian heart patient. During the operation, Dr. Frazier kept massaging the young man's heart to keep him alive. At one point, the man had eye contact with Dr. Frazier and reached out to touch Dr. Frazier. But the team couldn't save his life. That experience deeply affected Dr. Frazier, planting a seed for a mission he would embark on after his return from Vietnam where he had served in the U.S. Army as a flight surgeon.
Over the next four decades, Dr. Frazier would achieve numerous milestones in his scientific advances. Among them, in 1986, he performed the world&'s first implantation of HeartMate I, a pneumatically powered LVAD that has become the most widely used implantable LVAD in the world. In 2000, Dr. Frazier implanted the Jarvik 2000 LVAD, a continuous-flow pump widely used as long-term support for patients who may not be candidates for transplant.
More recently in 2011, Dr. Frazier, along with Bill Cohn, MD, Professor of Surgery at Baylor College of Medicine and Director of the Texas Heart Institute Center for Technology and Innovation, implanted the first total heart replacement with two continuous-flow pumps inside a human patient.
“These devices extend the patients' lifespan and enhance the quality of their lives,” Dr. Frazier said. “It's amazing to think some 30,000 pumps have been used in people around the world the past 10 years and they were all developed here. About 160 hospitals in the U.S. have performed heart pump implantations.”
The size and durability of the continuous-flow pump remain the main challenges researchers continue to tackle in development, he noted.
“But for clinicians, their priority now is to gain a deep understanding of the LVADs so they can better care for our patients.”