Many physicians still conceptualize Left Ventricular Assist Devices (LVADs) as they were back in the early 1990s, unaware of design innovations and broadened indications that can immediately benefit their patients.
The developmental lineage of LVADs goes back to early heart-lung bypass machines and experiments in the late 1950s, during which artificial hearts were implanted in dogs. There has been considerable work since then on both total artificial hearts and heart assist devices, and the physicians at NewYork-Presbyterian Hospital have played a major role in the research and development of this technology.
LVAD design in particular has made tremendous advances over the last decade, in particular by significantly reducing size. NewYork-Presbyterian Hospital/Columbia University Medical Center has participated in feasibility trials for several years and has been active in the development of the HeartMate II (Thoratec), an LVAD device, designed to provide as much as a decade of circulatory support, which has recently received FDA approval. MORE...
Many physicians still conceptualize Left Ventricular Assist Devices (LVADs) as they were back in the early 1990s, unaware of design innovations and broadened indications that can immediately benefit their patients.
The developmental lineage of LVADs goes back to early heart-lung bypass machines and experiments in the late 1950s, during which artificial hearts were implanted in dogs. There has been considerable work since then on both total artificial hearts and heart assist devices, and the physicians at NewYork-Presbyterian Hospital have played a major role in the research and development of this technology.
LVAD design in particular has made tremendous advances over the last decade, in particular by significantly reducing size. NewYork-Presbyterian Hospital/Columbia University Medical Center has participated in feasibility trials for several years and has been active in the development of the HeartMate II (Thoratec), an LVAD device, designed to provide as much as a decade of circulatory support, which has recently received FDA approval.
In addition to improved LVAD design elements, the opportunities for using an LVAD have recently expanded. There are now three presentations for which an LVAD might be used. The original indication was as a ‘bridge to transplant,' representing perhaps 85% of all LVAD procedures in the United States. "This is for patients already in the queue waiting for a heart transplant, but who for reasons of size, blood type, scarcity, etc., need a heart assist device because they are getting worse while they are waiting," explained Jonathan M. Chen, MD, Director of Pediatric Cardiovascular Surgery at NewYork-Presbyterian Hospital/Weill Cornell Medical Center, and Associate Professor of Cardiothoracic Surgery at Weill Cornell Medical College. NewYork-Presbyterian/ Cornell has recently begun its own LVAD program, whose development is being assisted by the considerable LVAD experience at NewYork-Presbyterian/Columbia.
Another category of LVAD use, accounting for less than 5% of procedures, is termed ‘bridge to recovery,' of which there are two subcategories. "The first is the acute cardiac failure patient, such as those suffering acute myocardial infarction or myocarditis," explained Yoshifumi Naka, MD, the Director of Cardiac Transplantation and Director of the Mechanical Circulatory Support Programs at both NewYork-Presbyterian Hospital/Columbia University Medical Center and NewYork-Presbyterian Hospital/Weill Cornell Medical Center. "These patients eventually recover their native heart function, at which we explant the devices." The second subcategory is the chronic heart failure patient, a minority of whom can recover heart function.
The final category of LVAD use is ‘destination therapy,' employed in patients who are not transplant-eligible but have advanced heart failure. "Reasons for not transplanting include age," Dr. Naka explained, noting that NewYork-Presbyterian/Columbia offers heart transplants up through age 72. "Let's say you have a 73-year-old patient with severe heart failure who is not actively dying but is not doing well. Those patients' prognoses are miserable, with a one-year survival of about 25% without an LVAD. Prognosis is actually less than any solid tumor." Implanting the LVAD can boost survival and enhance quality of life, an important finding that was demonstrated in the landmark REMATCH (Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart failure) trial (NEJM 2001;345:1435).
Destination therapy amounts to about 10% of LVAD procedures, but that may not be enough. "If you do the math, there should be a lot of people out there who are candidates for destination therapy," said Dr. Chen. "Unfortunately, this message hasn't gotten out to the public and some physicians are not as familiar as they should be with it."
Those interested in learning more about LVAD design innovations and details of LVAD implantation should view this webcast, which includes commentary from these and other experts at NewYork-Presbyterian Hospital.
