David Lederman was born and raised in Bogata, Colombia. After moving to the United States in 1966, Lederman studied engineering at Cornell University, obtaining his Bachelor's degree, Master's degree and Ph. D by 1973.

Lederman returned to Bogota, where he was an assistant professor at the University of Los Andes. He became the Director of the University's Biomedical research division before returning to the U.S. in 1974.

As a senior and primary investigator for a series of NIH studies, Lederman became involved in the development and evaluation of artificial heart pumps. Since 1981, Lederman has served as CEO and Chairman of the board of ABIOMED, Inc. in Danvers, MA.

A prolific author, Lederman has given lectures about his research all over the world. He lives on north of Boston with his and two children.

2.12.01 Joel Bartz asked:
I am a 22-year-old male who has had three open heart surgeries. I have a St. Jude valve in the aortic position. It clicks, louder when I am tired. I was wondering if the valve used in your hearts will be or are available for use in a human heart.

Lederman's response:
The St. Jude valve selected by your physician to replace your aortic valve is, in my opinion, the most durable and reliable mechanical valve available today. The plastic valves used in the AbioCor implantable heart are not available for replacement of human heart valves. While some day these plastic valves may be configured as prosthetic valves, it will take a very large amount of testing and clinical experience over many many years to demonstrate the level of reliability for long term use achieved by the patient-tested St. Jude valve.

2.12.01 Ryan Dunkleyasked:
I was wondering how you match the heart rate needed by the patient with the heart rate of the artificial heart? If a person gets excited and his pace quickens, how does the artificial heart adapt to it?

Lederman's response:
The natural heart responds to demand via several physiological mechanisms. Some of these, like the sympathetic and parasympathetic systems (the so-called "fight or fright" mechanisms), do not have an equivalent mechanism to control the beat rate of the AbioCor. However, other physiological mechanisms in our bodies, like baroreceptors (pressure sensors in some of our vessels) send signals to the natural heart to increase or decrease the beat rate depending upon the "filling pressures" (the pressure of the blood returning to the heart). The AbioCor has built-in pressure transducers that, like the baroreceptors, measure the filling pressures and send signals to the AbioCor electronic control system (an implanted computer) causing the AbioCor to beat faster or slower according to demand (the so-called "Starling response"). In summary, the AbioCor will adjust its rate automatically according to physiologic demand, but it will take a few seconds longer than the natural heart.

2.12.01 Peggy asked:
Can the Abiomed artificial heart device help someone that with congestive heart failure?

Lederman's response:
There are several degrees of congestive heart failure. The majority of patients respond well to drug therapies. However, there is a category of patients who are in end-stage congestive heart failure (designated NY Class IV), whose hearts are in severe failure and chronically deteriorating despite use of all available drugs. When the natural heart is not able to pump sufficient amount of blood to maintain life, despite maximum use of available therapies, the AbioCor implantable heart would be indicated. However, the AbioCor is not yet available for clinical use. It recently received FDA approval to begin initial tests in a small number of patients.

2.12.01 John Teague asked:
Do the artificial hearts feel pain? If not, how would a recipient know if his or her heart were failing?

Lederman's response:
Pain is a signal sounded by the brain when it senses trouble anywhere in the body. In order to feel pain, the nerves that sense trouble at a site (due to injury or disease) convey messages to the brain. The brain, in turn, evaluates the message and sends a signal ("pain") indicating that something hurts and where. This signal persists until the problem is resolved. The AbioCor implantable heart cannot "feel pain" because there are no nerves connected directly to provide a direct pathway to the brain. However, if the AbioCor implantable heart were to cause any kind of trouble to another organ, the nerves (if intact) connected to the affected organ provide a pathway to the brain for it to send an alarm in the form of pain signals.

2.12.01 Cynthia Serrano asked:
You mentioned that the heart pumps were being tested in cows. I was wondering if the pumps in the cows were in anyway different (size-wise) from what would be transplanted in humans? What is the longest life-span of a cow with this new device implanted in it?

Lederman's response:
The size of the AbioCor implantable units tested in growing calves is the same as those to be implanted in large adult humans. However, the orientation of the inflow and outflow conduits is different in order to match the different anatomies. As the technology is further developed based on clinical tests, the plan is to produce next generation devices that include one smaller sized-AbioCor for use with smaller adults. The durability and reliability of the AbioCor is tested in the laboratory under simulated bench conditions. The longest that the AbioCor can be tested in cows is approximately 3 months because, unlike adult humans, these animals outgrow the fix-sized device and its maximum output.

2.12.01 Courtney Pearson asked:
Has the Abiomed Heart been tested in humans yet?

Lederman's response:
No. The AbioCor was only recently approved by the FDA to begin human tests, in a limited number of very sick patients with no other alternative.

2.12.01 Diane asked:
Have you researched the neurological complications from damage to red blood cells? I understand that researchers are looking at the relationship between neurological complications associated with extended blood oxygenation procedures during heart bypass surgeries, due to damage to red blood cells by the "mechanical" components of oxygenators. Will your new device, with it's many visible moving mechanical parts be able to avoid those complications?

Lederman's response:
For the past 50 years, many studies have sought to understand the neurological effects of "heart-lung" bypass machines (used temporarily during heart operations where the heart is stopped and both the circulation and the oxygenation of the blood are carried out with external pumps and machines) The "oxygenators" appear to be the primary source of concern today due to the formation of cell aggregates, not limited to the destruction of red cells. With regards to the AbioCor implantable heart, it replaces only the pumping function of the natural ventricles. Since the lungs stay in place, no artificial oxygenator is needed. As with any device that pumps blood, ABIOMED' s design has focused on minimizing any potential damage to cells, not only red cells. Neurological function can be impaired if a thrombus, (consisting predominantly of platelets and white cells) is formed on any synthetic surface because the flowing blood can dislodge it and carry it to a natural vessel where it can obstruct the flow. ABIOMED has researched this field extensively, as part of the efforts that led to the development of the AbioCor heart.

2.12.01 Peter Backus asked:
What are the primary risk factors that concern you most about your upcoming human trials?

Lederman's response:
Yours is indeed a very difficult question to answer. The AbioCor design has evolved over the past two decades of research and development to answer any questions and concerns that have been raised. But have we asked all the important questions? We think so. For ethical reasons, we will start with very sick patients who have less than one month to live and no other alternative. We are reasonably comfortable that we can select patients who, except for their hearts, are otherwise in reasonably good physiological shape. But we must treat the whole patient, not only their heart. Complications may arise that we could not have anticipated and for this reason we are only allowed by the FDA to start out with limited and very controlled clinical trials.