The beat goes on: thanks to a new therapy, patients with chronic heart failure are regaining independence, mobility, and quality of life
Patrick Perry
“You know what a million-dollar person feels like?” Josephine Harris of Raleigh, North Carolina, says with a smile. “That’s what I feel like every day I get up.”
Two years ago, however, Harris was not so optimistic. At that time, her health was on a downward spiral. After a mild heart attack in 1995, Harris seemed to be in the hospital more than out, undergoing back-to-back bypass surgeries, angioplasty, and stent placement to open a blocked blood vessel. The 74-year-old was suffering from chronic, debilitating heart failure, and her future looked bleak.
“I was helpless,” she remembers. “The only thing I did was get out of bed. It was awful. I wasn’t able to go anywhere. Moving from my bedroom to my kitchen took a lot. You would think I went a mile.”
When Harris learned of a clinical trial exploring the potential of a new procedure called cardiac resynchronization therapy (CRT) that helps the heart pump more efficiently, she immediately enrolled. In September 2000, Harris received the InSync ICD. A year later, Harris has remained out of the hospital and is resuming an active life: driving, walking, and volunteering at a local senior center.
“This is an old cliche, but this has made my life worth living,” Harris says. “I’m doing things that I didn’t think I would ever do again.”
Chronic heart failure affects about five million people in the United States, the vast majority over age 65. Up to 50 percent of individuals with advanced heart failure develop abnormalities of the heart’s electrical impulses that control the heart’s contractions, leaving cardiac function severely compromised. When the heart fails and becomes weaker, it doesn’t squeeze and pump blood normally. And the way the heart muscle squeezes down may become unsynchronized, which can worsen symptoms–including shortness of breath, fatigue, and swelling of the feet and ankles.
Cardiac resynchronization therapy helps relieve moderate to severe symptoms of severe heart failure, improving quality of life. This is good news for the estimated one million people in the United States with the diagnosis of severe heart failure, all of whom could potentially benefit from this therapy!
To learn more about the benefits of CRT, the Post interviewed one of the principal researchers in the Multicenter InSync Randomized Clinical Evaluation (MIRACLE) trial, Dr. James B. Young from the Cleveland Clinic Foundation.
Q: What is cardiac resynchronization?
A: When the heart fails and becomes weaker, it doesn’t squeeze and pump normally. The heart operates under the same principles as any pump. It fills–called the diastolic cycle of the heart. Then it squeezes, blood is ejected, and the heart empties–called the systolic cycle of the heart. Normally, the heart ejects about one half of the volume in it with each heartbeat; this amount is referred to as a 50 to 60 percent ejection fraction. When the heart becomes weak, it might begin to eject 10 or 20 percent of the volume, so the ejection fraction drops precipitously.
Also in many patients with heart failure, the way that the heart muscle squeezes down is very chaotic and unsynchronized. We have learned that by using pacemakers and pacing leads attached to very specific areas of the heart, we can use the electricity from the pacemaker to resynchronize some of the heart’s contractions and improve the efficiency of the contraction. In this way, we can optimize the way blood flows through the heart and assist the heart in maintaining a more normal beat and contraction.
Q: Does the therapy incorporate a new application for pacemaker technology?
A: Yes, it is a new application for pacemakers. Instead of using one or two wires in this therapy, we use a minimum of three wires to pace the heart. The therapy has additional complexities, including the hardware associated with the pacemaker device, and the wires are placed in a different position than they would ordinarily be placed in patients with slow heartbeats.
Q: Who can benefit from cardiac resynchronization?
A: This therapy is for patients with advanced heart failure. To grade the severity of heart failure, we use a New York Heart Association functional classification. Class I includes individuals who have a weak heart but are not symptomatic, who are capable of doing ordinary daily activities, and are what we call compensated. On the other side of the scale is the class IV patient, who is symptomatic at rest with usually significant short-windedness, fatigue, and has profound problems even getting out of bed and doing ordinary daily activities. Class II and III patients have intermediate symptoms.
The cardiac resynchronization pacing therapies are used in the New York Heart Association’s Class III and IV patients. Patients who are weak, fatigued, and short-winded (generally associated with fluid retention that causes swelling of the extremities and fluid to build up in the abdomen or chest) are the patients at which this therapy is directed.
Q: How many people could potentially benefit from this therapy?
A: In the United States, there are an estimated five million patients with the diagnosis of congestive heart failure. Perhaps one third of those, patients have Class III and IV heart failure. About 20 to 40 percent of these individuals would likely benefit from this therapy. So perhaps a million people could potentially benefit from this type of therapy.
Q: Can you tell us about the findings from the InSync ICD Trial that you presented at the American College of Cardiology in March?
A: The study looked at the combination of a biventricular resynchronization device with an ICD–a cardioverting device. We had previously studied the cardiac resynchronization device in patients who did not require an ICD, a device that could shock malignant arrhythmias back to normal sinus rhythm. A major question: In individuals who needed both an ICD and cardiac resynchronization, could we create a device that does both jobs at the same time?
The InSync ICD device, in fact, is a two-in-one device–a cardioverter and a biventricular pacing system. Patients at risk for sudden cardiac death (who would benefit from an lCD and have significant congestive heart failure with dysynchrony or chaotic contractile patterns) were studied in the InSync ICD trial. We found that study participants’ symptoms and quality of life were significantly improved. They were also able to exercise more on maximal stress tests. In addition, certain parameters on their echocardiograms suggested that the therapy actually improved symptoms of heart failure syndrome. Specifically, the heart was contracting more efficiently. Finally, having a biventricular resynchronization pacing system in place did not adversely affect the ICD. The ICD could, in fact, detect potentially malignant arrhythmias and fire when needed. The trial confirmed the hypothesis that this combined therapy in appropriate patients was safe and effective. This singular device allows us, in appropriately selected patients, to address a broad spectrum of individuals with heart failure.
Q: Is this an outpatient procedure or major surgery?
A: Most electrophysiologists admit patients to the hospital on the day of the procedure. After the procedure, the patient stays overnight and is then discharged the next morning if everything goes well. The procedure is not terribly invasive and is done in the cardiac catheterization laboratory. It is not done under general anesthesia.
Q: When will the study findings be published?
A: Some of these results have been presented to the FDA circulatory device panel. We will publish perhaps in 6 to 12 months after analyzing the data, all of which is not in yet.
Q: Medications have been the main therapy to address this condition for many years. Is this a radical new approach to treatment?
A: That is correct.
Q: Do you foresee a dramatic improvement of life in this patient population?
A: We use the Minnesota Living With Heart Failure Metric, a heart-failure-specific quality-of-life measurement. It demonstrated that the point scale change was an improvement of almost 20 points. When you compare that with observations made in drug-treatment trials, for example, this improvement is certainly equivalent to anything that any medication has been able to achieve. The improvement, in fact, effects a highly significant change in quality of life.
These heart-failure patients are pretty ill, however. As any study would show, the statistics look at a group and, on balance, that was what the improvement was–almost 20 points in that particular metric.
There are patients who had very dramatic improvements. We have seen many patients go from New York Heart Association Class III or IV symptoms down to Class I symptoms. For those patients, that is a very, very dramatic improvement. More patients improved than did not. There are some patients who had no improvements.
Q: Are there associated risks?
A: Yes. As with any invasive procedure in the arteries and veins, you can create damage. You can cause bleeding and blood loss. You can predispose the patient to infection. Both complications were seen in this trial. They were not, however, very frequent or significant. The procedure can be done safely. The patients, on balance, experienced more benefits than risks.
Q: How exactly does this therapy improve heart function?
A: It improves the function in several ways. First, it increases the efficiency of contraction, so it resynchronizes the ventricle. Second, it improves the way the blood flows into the heart by resynchronizing the contraction and relaxation patterns of the heart. Blood flows into the heart more efficiently, so it improves something called diastolic dysfunction. It also decreases mitral regurgitation, on balance, when we look at all the biventricular patient studies, so it decreases the inefficiencies that are created by leaking valves.
Q: Earlier, we spoke about ejection fraction. Does the therapy improve ejection fraction?
A: Yes, it does. This therapy in both the InSync trial and the InSync ICD trial demonstrated ejection fraction improvement.
Q: How does the pacemaker used in resynchronization therapy differ from pacemakers used conventionally?
A: The device had to have at least three ports so it could attach to three separate leads, instead of attaching to just one or two leads. The leads are placed in the right atrium, the right ventricle, and into veins that come out from the left ventricle. The most significant distinguishing characteristic of this unit is a third wire that comes from the left ventricle. We pace both sides of the heart, not just one side as one would with standard pacing therapy.
Q: Have studies demonstrated significant reduction in mortality because of this therapy?
A: Yes. If you look at the observation in InSync, the study without the ICD component to the device, the reduction in hospitalizations for heart failure and mortality was statistically significant at a p value of .02. If you look at the InSync ICD trials, the reduction in hospitalizations for heart failure and mortality had a p value of .07, so there was a significant trend for the InSync ICD. And there was a significant reduction in morbidity in the InSync trial.
Even though these studies were not designed as morbidity/mortality trials, I think that there is a substantial amount of data available that suggests morbidity and mortality are beneficially impacted.
We do have one ongoing study called the Companion Trial, which is using a slightly different device, one made by Guidant. The InSync ICD system is produced by Medtronic. The Companion Trial is a larger study, having three different arms in it–an arm of just medical therapy, an arm of just cardiac resynchronization, and an arm of a combined cardiac resynchronization-ICD device. Its primary endpoint is hospitalization and deaths. We hope that study will give us some insight into the impact on mortality.
Q: Are you still enrolling for the trial?
A: For the Companion Trial, yes. We will also be enrolling for another trial looking at mortality rates. Actually, many trials are up and going, and people can take advantage of them.
Q: If our readers are interested in participating in these trials, how can they learn more about them?
A: People can call the Cleveland Clinic and route through my office. We are one of the centers for all of these studies. My office number is 216-444-2270. We can get them to the right spot.
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