Stephen S. Gottlieb, M.D.
Heart failure is an increasing health problem in the United States. According to the American Heart Association, heart failure affects at least five million Americans, with about 550,000 new cases diagnosed each year. Heart failure is also the leading cause of hospitalization for the Medicare population, and is listed as a cause of death for about 40,000 people a year.
The good news is that new treatments and technologies for heart failure are coming to the forefront at the University of Maryland Medical Center. Cardiac surgeons at the Medical Center recently implanted the experimental Jarvik 2000 heart pump to save the life of Woodrow Snelson, a 63-year-old heart failure patient who is awaiting a heart transplant.
Dr. Stephen Gottlieb, director of the Heart Failure Service and Cardiac Care Unit at the University of Maryland Medical Center, and a professor of medicine at the University of Maryland School of Medicine, discusses the basics of heart failure, this exciting new device and other innovative new treatments.
What is heart failure and what are some symptoms?
Heart failure is the end result of a heart not pumping well, so the heart may not contract adequately. It's a clinical description of the way people feel when their heart doesn't pump adequately. Because the heart doesn't pump enough blood, the organs of the body don't get enough blood and that can cause symptoms. Blood also backs up behind the heart, and that can cause fluid to go into the lungs. It can cause shortness of breath. People with congestive heart failure, in addition to having shortness of breath and being tired, can hold onto fluid and get swelling in their leg or abdomen.
What causes heart failure?
There are a lot of different causes. People who have had heart attacks can develop heart failure. People who have high blood pressure can also have heart failure. Alcohol can cause heart failure. But with some people, we never find out the reason. Coronary artery disease leading to heart attacks can also lead to heart failure, but heart failure can also occur without a person having a heart attack.
What are the two types of heart failure?
Heart failure can be caused by the heart not contracting well and not relaxing well. When we're talking about the majority of treatments for heart failure, we're talking about systolic heart failure -- that is, when heart failure is caused by the heart not contracting well.
Diastolic heart failure is a different disease -- it's the heart not relaxing well. Very often, it's associated with high blood pressure and a thick heart. Treatment is very different. We can treat blood pressure and fluid volume, but there are not really a lot of interventions.
Systolic heart failure is the one we can treat and understand the best. When we talk about medical and surgical interventions for heart failure we're talking about systolic dysfunction.
What new heart failure treatments are being investigated and used at the Medical Center?
One thing we're doing is a telemonitoring program to see if we can keep people out of the hospital by giving them scales and blood pressure cuffs to take home. The results from the scales and cuffs are automatically sent to our server through a modem so that we can follow the patients and pick up changes in weight, blood pressure or rhythm. The whole idea is to prevent hospitalization.
I've been investigating a number of different new medications for heart failure. In particular, we've been concerned about kidney function in people with heart failure. We're looking at drugs that will permit people to get rid of the extra fluid without harming their kidneys. We're also looking at drugs that help the heart to contract better, and these are some investigational drugs.
In addition, we're looking to see if low blood counts (which are often associated with heart failure) can be improved. We want to see if we can increase blood counts and whether that will make patients feel better. We're also looking at the interaction between sleep disturbances and heart failure, and we're investigating ways to prevent sudden death in people with heart failure.
There's a new type of pacemaker that may be helpful for patients to help the heart pump more efficiently. We also do heart transplantation for certain patients.
What about heart pumps (left ventricular assist devices)and other medical
devices for the heart?
In terms of devices there's the Jarvik 2000, a heart pump that is implanted in the left ventricle of the heart. The Jarvik 2000 is very different from other blood pumps used in the past because it's so much smaller. There are other left ventricular assist devices (such as the Novacor), that we use, but this one is just very simple. It's easier to go home with and it's a much less intense operation to put it in. We hope it will have fewer side effects.
Mr. Snelson is the first patient we've used the Jarvik 2000 on here, and the University of Maryland is the first medical center on the East Coast to use the device. So far it's been used in approximately 40 people internationally. At this point, the Jarvik 2000 is used to bridge people over to transplant but the goal is that for some people who can't get a transplant, the device will help their heart to pump more blood and help them lead a normal life.
There's also something called an ACORN CorCap, which is a mesh that gets placed over the heart that at least in animals, looks like it not only prevents the heart from enlarging but actually may improve the function of the heart and have it revert towards normal. We're about to start using that here at the University of Maryland Medical Center. The ACORN is not for people who are going to need a transplant; its purpose is to keep them from needing one.
What are the standard treatments for heart failure?
Most people with heart failure (systolic dysfunction) end up on ACE inhibitors and diuretics, digoxin and beta blockers.
ACE Inhibitors prevent the production of a substance that causes blood vessels to tighten and raises blood pressure. As a result, blood pressure drops and the heart does not have to work as hard to pump blood. ACE Inhibitors also work directly on the heart. Diuretics help reduce the amount of fluid in the body and are useful for patients with fluid retention and hypertension. Digoxin increases the force of the heart's contractions, which help to improve circulation.
Beta blockers block the action of adrenaline, which the body produces under stress. The drugs reduce demand on the heart, slow the heart rate and prevent irregular heartbeats.
We have a lot of experience with beta blockers. I was U.S. principal investigator of a study that showed that it improved survival. They have to be given very carefully and appropriately because they have a very good long-term effect but their immediate effect is not necessarily beneficial, so you start at a low dose and slowly move to a higher dose. It's something people should be on.
Another drug that is sometimes used is spironolactone.
How is heart failure diagnosed?
It's really a symptomatic question. If someone gets short of breath, that's your first indication there might be a problem. When you have that, you want to know what the heart is doing so you have to take pictures of the heart to see what's going on. There are actually blood tests that can help determine whether somebody has heart failure. And in some people, we use cardiac catheterization to see what's going on in the heart.