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Devices & Desires

By Anne Bennett Swingle
Photos Keith Weller

A diagnosis of heart failure once signaled imminent death. Today, specialists are abuzz with pacers, pumps and other implantable mechanisms that have changed the picture for patients with this lethal condition.

Jim McCormick

"I can't plant a tomato garden but I can tend one," says Jim McCormick. He has a bi-ventricular pacemaker implanted in his chest that resynchronizes his heart.

There is no cure for heart failure. Half the people diagnosed with it will be dead within five years. The heart gradually loses its ability to pump blood; the victim feels a deadening fatigue, struggles to breathe, and the lungs become congested with fluid. Luckily for most people with the disease, drug therapy is hugely helpful. But for those who don't respond to drugs or for some unknown reason stop responding there has been little aside from a transplant to make the damaged heart function effectively again.

In most cases, heart failure has a way of creeping up. For Jim McCormick, it all began in 1995 with a series of small, practically symptomless heart attacks. Then came the angioplasty to try to balloon out his constricted coronary vessels, six-way coronary bypass surgery and, five years later, failure of all but one of the bypasses. Finally, McCormick's name went on the transplant list. At first as he waited for a donor heart, different medications kept him going. But inevitably, episodes of heart failure would leave him exhausted, gasping for breath and filling with fluid.

"My body was weakening," he recalls. "The mind was willing, but the body wasn't." Like nearly a third of the people with his disease, McCormick had a heart that was beating out of sync. Its electrical impulse had slowed to one ventricle, and its left and right pumping chambers, built to work together, no longer contracted simultaneously.

Still, Joshua Hare, McCormick's cardiologist, held out hope for this fit-looking 52-year-old former health care executive. Because heart failure is on the rise nationally, as people survive more heart attacks and live longer, cardiac specialists and medical equipment manufacturers are finding better ways of controlling the deadly condition, which now affects an estimated 5.1 million Americans. The result has been a series of implantable devices, some brand new, some improved and some old faithfuls that can benefit a much wider group of patients. And lately, the growing armamentarium for heart failure, which now includes pacers and defibrillators, pumps and splints, socks and newfangled stents, even the artificial heart, has been bolstered by good news. One new device after another has been approved for use, study after study testing cardiac implants reports favorable results.

biventricular pacemaker

For Resynchronization Therapy: Three Pacing Leads. Two leads pace the right atrium and right ventricle. The third lead, which is advanced through the coronary sinus into a venous branch that runs along the free wall of the left ventricle, allows early activation of the left ventricle (otherwise, it would be activated late during conduction).
What Hare had in mind for McCormick was a new device, a bi-ventricular pacemaker that would resynchronize the damaged heart. Unlike the traditional dual-chamber pacemaker, which maintains the heart's rhythm by placing leads carrying an electrical current only in the right atrium and right ventricle, the bi-ventricular pacer also puts a lead on the left ventricle. For the 30 percent of heart patients with conduction delays, this addition improves the coordination between the two beating ventricles as they pump blood throughout the body.

In the last months of 2000, Hopkins joined a multicenter clinical study called companion (Comparison of Medical Therapy, Pacing and Defibrillation in Chronic Heart Failure) to assess how heart-failure patients fared on the bi-ventricular pacemaker in comparison with other kinds of treatment. Every patient in the study, like Jim McCormick, had a heart with an electrical-conduction disturbance-a "dysynchronous" heart. The patients had been divided into three groups. One group would be treated with medication alone; the other two would receive medication plus one of two possible bi-ventricular devices that would keep the heart beating in sync.

What Jim McCormick needed was resynchronization, and he prayed he wouldn't be relegated to the number one group. "I knew there was a chance the bi-ventricular pacing device might not help me," he says, "but if it did, I felt sure it could extend my life until I got a transplant."

On Nov. 27, 2000, McCormick had a physical exam to qualify for the trial. Three days later, he learned he'd made the cut and would be part of the second group. And so, on Dec. 4, he found himself being wheeled into the Hospital's busy electrophysiology lab where electrophysiologist Ronald Berger was preparing to implant a bi-ventricular pacer in him.

Much of the early work on bi-ventricular pacing was led at Hopkins by David Kass, a heart failure basic researcher who also is in the Department of Biomedical Engineering. Berger was part of Kass's team of researchers. Back in the mid-1990s, he and Kass were doing all sorts of experiments with standard pacemakers, trying to figure out how to pace the left ventricle. Their most significant study confirmed that bi-ventricular pacing improves the heart's efficiency. "We showed how the cardiac muscle uses less oxygen with the pacing despite the fact that it's pumping more blood," Berger says.

Still, for all its glory, the bi-ventricular pacer remains technically challenging for the electrophysiologist. For a long time, Berger was the only one at Hopkins who could put the device into a patient. Even today, he does more than 90 percent of the implants. The procedure, which is done with sedation and a local anesthetic, is not particularly risky, but the cardiologist must stand for long periods, often in awkward positions, clad in a weighty lead vest and wrap-around skirt that acts as a barrier to the radiation emitting from the imaging devices.

Joshua Hare, right, with fellow cardiologist Ron Berger.

Joshua Hare, right, with fellow cardiologist Ron Berger.
On that December morning more than a year and a half ago, as Berger set to work on Hopkins' first subject in companion, he tucked the device under McCormick's skin in the upper chest, just below his shoulder. Berger likes to tackle the toughest part-putting the third lead on the left ventricle-first. And so, he inserted a sheath equipped with a tiny guide wire into McCormick's neck and directly into his giant left subclavian vein. Then he maneuvered it down through the superior vena cava, into the right atrium and into the coronary sinus, the big vein of the heart's own circulation system. Berger had marked this spot with a catheter he'd put into the groin from below and directed up through the big femoral vein. And now, with the sheath he'd inserted from above, he nailed it.

As the dilated, baggy heart thumped away, Berger began traveling along the wispy streets and alleys that come off the coronary sinus, dodging dead ends, navigating hairpin turns, heading for a branch that would take him as far out to the side as possible. And because negotiating these turns is the hardest part of the procedure, his eyes almost never left the monitor which showed him in vivid images how far he'd progressed into the heart. Reaching a destination he deemed suitable, Berger inserted the lead into the sheath and over the guide wire and poked it all the way out to the left ventricle outpost. Then he pulled out first the guide wire and then the delivery sheath, leaving the lead in place on the ventricle. Finally, he positioned the two other leads in the right atrium and right ventricle. The pacing could now begin.
"These new pacers benefit only a small group of heart-failure patients," Hare says. "But even though they now are FDA-approved, we know far less about them than we do about drugs. What we do know is that they make patients feel better."

McCormick stands as living testimony to that. Immediately after the procedure, in the recovery room, he already felt "strangely refreshed." Today, a year and a half later, his name remains on the transplant list, but "I have a certain quality of life," he says. "I can't plant a tomato garden, but I can tend one. I can't cut the yard, but I can pull a few weeds. I can't talk for hours, but I can still enjoy the company of friends." As part of companion, McCormick comes for quarterly checkups-he considers it a duty. He hopes that aside from prolonging his life, the device "can teach doctors something about how to help others like me who are waiting for a new heart."
That waiting, of course, remains one of the biggest problems of all. The generally accepted medical therapy for the late stages of heart failure is a transplant. But of the approximately 56,000 people annually who need a new organ, only about 2,000 will be lucky enough to receive the call telling them a donor heart has become available. Most of the rest will die. That's why cardiac specialists have begun resting their hopes on the idea of a workable artificial heart.

Some 125,000 Americans a year could be candidates for an implantable artificial heart. The new AbioCor replacement heart, currently in several small, FDA-authorized clinical trials and first implanted in a patient in Louisville, KY., in the summer of 2001, is a small battery-driven pump about the size of a grapefruit and weighing two pounds. How soon the AbioCor becomes available on an experimental basis at Hopkins, however, will depend on the manufacturer and what modifications it chooses to make. "I expect to be putting it in as soon as we get it," says Edward Kasper, medical director of the heart failure/heart transplant program. "But that could be two years from now, or as early as the fall."

Still, the fact is, most end-stage heart failure patients don't need a whole heart. What they do need is a decent left ventricle. By definition, heart failure is a condition in which the heart loses its ability to pump, and of all the heart's four chambers, the left ventricle has been assigned the toughest pumping task of all: it's the chamber that pushes blood out to the entire body. So, it stands to reason that the heart pump known as a left-ventricle-assist device (LVAD) should be able to help a patient in end-stage heart failure stay alive until a donor heart becomes available. And quite soon, these LVADs may be able to do even more.

Sixty-one-year-old Steve Riddle hails from a family with a long history of heart problems. His own massive heart attack arrived in 1993. By March 2001, after he had gone through bouts of pneumonia, persistent arrhythmia and a serious case of hyperthyroidism, Riddle's cardiologist at Johns Hopkins Bayview, David Meyerson, referred him to Kasper. Kasper gave him a defibrillator and put him on the transplant list.

By April 2001, Riddle lay near death. His blood pressure read just 50 over 40. Mary Ann Albaugh, a nurse who specializes in ventricular assist devices, told him: "You can die, or we can put you on an LVAD."

Rosa Riddle helps her husband dress as the LVAD remains inside him.

Rosa Riddle helps her husband dress as the LVAD remains inside him.
About the size and shape of a portable CD player and weighing three and a half pounds, the LVAD is a vented electric pump. When surgically inserted into the abdomen of a heart-failure patient, it is able to help a damaged heart drive blood through the body. The pump is affixed with a Dacron tube that enters the left ventricle. Blood from the ventricle drains through the tube and into the pump, which sends it into the ascending aorta and then to the rest of the body. Another tube extending from the pump to the outside of the body attaches to a battery pack. Patients carry the packs in shoulder holsters and wear a beeper-sized control system on a belt. (The LVAD emits a constant ticking noise, a source of some consternation in banks, airports and other public places.)

LVADs, of late, have been proving their mettle. A landmark study published last November found that they kept heart-failure patients alive longer than optimal medical therapy and offer them an improved quality of life. They may even be able to provide an acceptable alternative therapy for heart-failure patients who aren't candidates for transplantation.

Fortunately for Riddle, his ample torso easily accommodated the LVAD. Once he was fitted with the device, he did well for a full year. "We went on errands, picnics in the park. He even went fishing," his wife Rosa recalls. Then, early in the afternoon last March 26, while Rosa and he were sitting in the den of their Columbia, Md., home, the LVAD's alarm went off, meaning that the pump had either slowed or stopped. Steve's feeble heart may have actually pumped on its own for the minute or two it took him to change the batteries and check the alarm. Nothing helped. The pump refused to pump, and Steve passed out.

Rosa grabbed for the hand pump that Albaugh had taught her to use. Panic-stricken, she pumped and nudged her husband, pumped and nudged, calling Steve's name over and over. Gradually, he came to, and as Rosa continued to pump, Steve even dialed 911 and lucidly gave the dispatcher the vital information. All the way into the Hopkins emergency department, the EMTs pumped Steve. At Hopkins, doctors discovered the LVAD had an electrical problem.

"I never thought this would happen," Rosa says bitterly. For her and Steve, the big hurdle to get through had been finding a donor heart. The mechanical failure had been an unanticipated roadblock.

The only safe place now for Riddle and his malfunctioning device was a hospital bed. Four months, as his name stood at the top of the transplant list, he lay tethered to a pneumatic pump that required round-the-clock surveillance. But coming up with a donor heart that matched Riddle's substantial size was not easy. By July, cardiologists were thinking about implanting a second LVAD. But Riddle held out, praying a heart would come through. On the night of July 13, cardiac surgeon Peter Greene walked into his room."We've got a heart," he said. "Do you want it?" Early the next morning, Greene began the transplant.

Surgeon John Conte with two of the LVADs currently in use. The one on the right is like the one that sustained Steven Riddle.

Surgeon John Conte with two of the LVADs currently in use. The one on the right is like the one that sustained Steven Riddle.
As problematic as Steve Riddle's LVAD had been, it did what it was supposed to: it kept him alive for 15 months until he got a transplant, a Hopkins record. Today, he is at home, learning to live again. Even in the time since Riddle first got his LVAD, these devices have been enormously improved. The new generation of LVADs are quieter and simpler and contain continuous-flow pumps. They are also smaller (weighing less than four ounces), and fit into more patients. Most important, these new VADs, which are set to enter clinical trials early this fall at Hopkins, will act as more that just stand-ins until a transplant becomes available.

"We are on the precipice of some big advances," says Conte, who's surgical director of the heart failure/heart transplant program. "Once the problems of the earlier devices are corrected-and that's just a matter of time-VADs will become permanent for some patients-alternatives and not bridges to transplant. When LVADs become fully implantable, Conte says, they may be more cost effective than transplants. "Down the road, they may even render heart transplants a thing of the past."
There will be a price to pay if more physicians begin implanting LVADs or one of the new pacing devices in patients. Each of these devices costs tens of thousands of dollars. An LVAD like the one Riddle had, for example, goes for around $50,000. Such costs are fueled by a number of sources-the desperate hopes of dying patients, commercial interests of medical equipment manufacturers, institutions striving to offer the latest in medical technology and, perhaps most of all, by physicians laboring to keep dying patients alive. "We are not at the point yet where we can cure congestive heart failure, even though we've made great strides," says cardiologist Hare. "These devices offer tremendous opportunities for stabilizing patients and preventing them from dying. For that we feel extremely lucky."


Some of the research in this article has corporate ties. For full disclosure information, call the Office of Policy Coordination at 410-223-1608.


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Stents of a New Stripe

Alan Heldman in the Cath Lab.

Alan Heldman in the Cath Lab.

Most people don't think of clogged coronary arteries as having anything to do with heart failure. But, in fact, cardiologists say that the earliest stage of the condition occurs when fat deposits begin to seriously block the blood flow to the heart. And so, they have come up with inventive ways to keep the vital coronary blood vessels open. What's been a challenge is to keep them from clogging up again.

Not long ago, stents, the tiny mesh tubes that scaffold vessels, were the new, new thing. But because they can scar the inside of the blood vessel, stents didn't turn out to be as great as everyone had hoped. In about 20 percent of patients, the scarring causes the narrowing to reappear-restenosis. For a couple of years, interventionalists have used radiation inside the stents to clear up the scarring. And now, a new type of coronary-artery stent delivers a drug to prevent reblockage and promises to prevent restenosis altogether.

Much of the early work on these so-called drug-eluting stents was done by Hopkins interventional cardiologist Alan Heldman and researchers at the Gerontology Research Center of the National Institute on Aging, located on the Johns Hopkins Bayview campus. Using paclitaxel, the active ingredient in the drug Taxol®, the scientists tried to affix the drug to the stent in several different ways. Ultimately, they settled on what Heldman describes as the simplest approach: "We just got the bare-naked drug on the bare-naked stent."

Heldman's report, presented in 1997 to the American Heart Association and published in Circulation in 2001, was one of the earliest to show that drug-coated stents inhibited restenosis in pig arteries. Last spring, one of these drug-eluting stents was approved for use in Europe. And now, Heldman says it's just a matter of time before they are approved in the United States.
"These stents will make it possible for us to offer patients treated with angioplasty much better long-term results, " says Heldman. "It still is technically difficult to get the stents into some places, and if you have to use nine stents to fix one patient's heart, it becomes very complicated. For all those reasons, it's foolish to think that bypass surgery will be dead anytime soon. But for many patients these new stents will do the job."

-ABS

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