On Sept. 6, 2002, the University of Maryland Medical Center became just the third medical center in the United States to implant the Jarvik 2000 left ventricular assist device (LVAD) into a patient's heart. This revolutionary blood pump is designed to improve heart functioning in people with severe heart failure awaiting a heart transplant until a donor heart is found.
Robert Jarvik, M.D., inventor of the first permanently implantable artificial heart -- called the Jarvik-7 -- as well as of the Jarvik 2000, assisted University of Maryland Medical Center Chief of Cardiac Surgery Bartley Griffith M.D., during the procedure. In the following interview, Dr. Jarvik talks about the Jarvik 2000, what makes it so unique, why the University of Maryland Medical Center was selected to participate and much more.
Describe the Jarvik 2000 and how it works.
It's a miniature rotary pump, it's electrically powered and is approximately a pacemaker-sized booster pump for the heart. We call it a flowmaker. The Jarvik 2000 boosts the work that the left side of the heart can do. It goes inside the left ventricle, and that's very important because that indicates it's very tiny. It's also silent and it moves with the natural heart as the heart beats. So it doesn't interfere with the motion of the natural heart, and that helps the natural heart recover.
The goal of it is to basically rehabilitate people who are in severe congestive heart failure, rehabilitate them to a normal lifestyle with very free mobility. The important thing to know is that this is not ultimately intended as a bridge to transplant device, even though your first patient there was bridge to transplant and the FDA approval is only for bridge to transplant in the United States. But shortly we'll be starting expanded studies that will use the Jarvik 2000 as what we call a lifetime use device [the Jarvik 2000 is being used that way in Europe].
What are the biggest differences between the Jarvik 2000 and other left ventricular assist devices?
The Jarvik 2000, compared to approved heart assist devices, is much smaller, it's silent, it's simpler, and it acts as a true booster pump for the heart. Some of these other devices essentially take over the whole function of the left side of the heart, whereas the Jarvik 2000's booster pump allows the heart to do part of the work and helps the heart to recover. There have been no serious infections in patients with the Jarvik 2000.
The biggest difference between the Jarvik 2000 and most of the other assist devices is that those are very large, heavy pulsatile devices [which create a pulsing blood flow similar to a natural heart rather than a continuous blood flow, as is the case with the Jarvik 2000]. They have inflow and outflow valves, and they are about 10-20 times as heavy as the Jarvik 2000 device.
The power cables coming out of the other types of devices have air vents, and air flows in and out of them. But with a rotary pump like the Jarvik 2000, it only requires a very small flexible power cable, which is much less subject to infection. We have another type of permanent power cable that we've been using in Europe with the lifetime use patients, which is a type of connector similar to what's used in artificial hearing devices. That general type of connector has been successful for more than 20 years.
How many patients have received the Jarvik 2000 device?
I think your patient was number 42. There have been about 25 in the U.S. and the rest in Europe. The first patient that received it in Europe as a lifetime use device has been living about 2 years and 3 months and is doing well.
Who is the ideal candidate to receive the Jarvik 2000?
In the European studies, many of the patients are lifetime use candidates. In that case, the ideal patient is someone who has chronic heart failure, a person who has been sick for years and is highly incapacitated. But not a patient who has deteriorated so far that they have multi-organ system failure, which complicates their recovery. So we don't treat it as a desperate, last-minute rescue device [as it is being used in U.S. studies].
It's the smallest device available, and it's applicable to teenagers and children. There's a very big difference there because some of the devices are so large they will not fit in most smaller patients, and certainly not children.
The University of Maryland Medical Center is the third U.S. medical center to do this procedure. Why was Maryland selected to take part in this study?
It was because of Dr. Bartley Griffith. We've worked together for a very long time. The first Jarvik-7 heart implant he did was only the seventh patient ever to have a Jarvik-7. That patient was the best man at my wedding, and he lived about 11 years before dying of cancer. So I've worked with Dr. Griffith since then [mid '80s] and he asked if he could participate in this study when he got to the University of Maryland.
Dr. Griffith has been very involved in both total heart and the early research on heart assist devices. He's done a lot, and worked on rotary blood pumps that are like the Jarvik 2000 for many years. The point is, for many years Dr. Griffith has worked with and recognizes the advantages of a true rotary pump, which made the University of Maryland a great candidate for this study.
What role did you play in the Jarvik 2000 procedure performed here?
I was there to assist. I helped prepare the device for implantation, and was a consultant in case any questions arose during the procedure.
What have you learned in the 2-½ years the Jarvik 2000 has been in human trials?
I guess the most important thing we've learned is that the device really can provide stable support long term. We have had no mechanical failures, and our infection rates are very low. And we've shown that patients can lead a very high quality of life. A lot of patients in Europe have gone back to work, are able to travel and in general have had a very good rehabilitation.
What's the current success rate of the Jarvik 2000?
We have narrowed the category of patients since the start of the study - basically patients that either have had heart attacks and lost a lot of their heart muscle and in gradual heart failure for a number of years following a heart attack, or patients who have had idiopathic cardiomyopathy, the primary disease of the heart muscle. If we look at the patients who have had those conditions, and eliminate the humanitarian, last-ditch efforts, to help these other desperately ill people, we have a success rate of 70 percent long-term survival. If we take the whole group of all patients, it's more like 55-60 percent long-term survival. That means patients who are presently alive of all the patients we have ever treated. We think that getting survival rates as high as heart transplants in the first couple of years should be achievable.
The FDA has recently changed its protocol to allow patients who have received the Jarvik 2000 to go home while awaiting a heart transplant rather than having to remain in the hospital. What's the significance of this?
We've just received approval for our U.S. program to permit patients to go home. Until now they've had to wait in the hospital (for a transplant). About 10 of the patients in Europe have gone home, and that's what we think will be the norm. They can be home, go back to work, they can travel it's really quite practical.
What do devices like the Jarvik 2000 mean to patients with heart failure?
I think it's a chance for artificial heart to be as common as a pacemaker, be something that's a routine therapy that reaches a large number of people. The main thing we want people to understand is that this is not just a treatment to save people at the last moment before they die. It's a treatment that, if we can extend it properly and apply it well, should prevent much of the really severe suffering people with congestive heart failure go through the last year or two of their lives.
What's the significance to the University of Maryland Medical Center of being a part of this clinical trial?
We're going to have a limited number of centers that can participate. We think we'll be very successful and help a lot of people, and it will provide options to your patients that otherwise they wouldn't have. It's also an important research area and it leads into a front-line position as this kind of technology evolves and becomes available to a wider group of patients.
What medical facilities and expertise are needed to perform this procedure?
The device was created with the intention that it can be used everywhere. Pacemakers are implanted at more than 1,000 hospitals I think, and thus are able to easily reach the population that needs it. That's our goal with the Jarvik 2000. There are about 800 centers that do basic cardiac surgery, and the goal is for all these centers to have the capability to do this.
Right now, though, there are a much smaller number of places that would qualify, as the trial is limited to those centers that can do the artificial heart surgery and the transplant and provide the necessary follow-up care.
By Chris Lindsley