Device Halves Heart Patient Deaths

Pacemaker-like therapy helps heart beat more normally

TUESDAY, Feb. 11, 2003 (HealthDayNews) -- A pacemaker-like device that uses electrical currents to boost the pumping power of patients' weakened hearts halved the short-term death rate from progressive heart failure and reduced hospitalizations by nearly a third, researchers say.

In a new study, published in the Feb. 12 issue of The Journal of the American Medical Association, the Johns Hopkins researchers analyzed four separate trials of the device involving 1,634 patients. All suffered from progressive heart failure, or a steadily weakening heart, causing it to pump less and less effectively.

About half the patients underwent "cardiac resynchronization therapy" (CRT), which relies on a device that makes the heart beat more normally by emitting electrical charges that cause the right and left ventricles to work together more efficiently. A defibrillator component of the device also detects and treats life-threatening heart rhythms.

Hopkins researchers analyzed trials for 809 patients who received CRT and 825 in a control group who did not, with follow-ups at three to six months. Of those who received CRT, 14, or 1.7 percent, died of heart failure, compared with 29, or 3.5 percent, of those who did not receive the therapy, the study found.

CRT also reduced hospitalization for heart failure within three to six months. Of those who received CRT, 13 percent were hospitalized, compared to about 17 percent of those who did not receive the therapy.

Dr. David J. Bradley, a Hopkins cardiology fellow, said the FDA-approved therapy had demonstrated improvements in patients' ability to exercise and had improved the quality of life. But, he said, before the Hopkins study, whether CRT could save lives remained uncertain.

Electrical stimulation of both the left and right ventricles appears to be a key factor in the effectiveness of the therapy, Bradley said.

"When you stimulate both the left and right sides of the heart at the same time, you get the main pumping chamber of the heart pumping more efficiently," he said.

"This study extends the benefits of the technology beyond quality of life and beyond improved exercise capacity to include reduced mortality from heart failure," Bradley said. "It's one more way we can treat a very serious health problem."

CRT differs from more traditional heart failure treatment, in which leads are placed in contact with the right atrium, right ventricle or both to provide electrical currents that help pace the heart so it pumps blood more effectively.

CRT relies on an implanted device consisting of a battery and electronic circuitry, including a pulse generator usually implanted below the collarbone. One lead is placed in the right atrium, and one on each of the right and left ventricles. The left ventricular lead is usually threaded through a coronary vein.

Dr. Robert Bonow, president of the American Heart Association, said the study bodes well for CRT's prospects for sufferers of progressive heart failure.

With advancements in treatment, more and more patients are surviving with weakened hearts, said Bonow, who also is chief of cardiology at Northwestern University Medical School.

"I think it is exciting news and particularly important for people with progressive heart failure," he said. "As we get better and better at treating people with acute heart disease and heart attack, we have more people surviving with weakened hearts. People who might have died in previous decades are now still alive."

And the study shows "overall the very beneficial effect of this therapy for these particular patients," Bonow said. But, he added, more research is needed on longer-term benefits.

Each year, heart failure afflicts nearly 5 million people in the United States, kills about 287,000 and results in almost 1 million hospitalizations, according to the study.

Still, while CRT shows at least short-term promise, the therapy is expensive, with the necessary devices costing $20,000 to $50,000, Bradley said. Further study is needed to determine whether the costs of CRT ultimately would be offset by reduced spending for heart failure hospitalizations, which exceeded $14 billion in 2000.

Bradley also acknowledged that the analysis followed patients for a maximum of six months and that more research would be required to assess longer-term benefits.

Only two of the four trials analyzed by Hopkins researchers had been reported in peer-reviewed medical journals, the study noted, but results of the two unpublished trials had undergone Food and Drug Administration scrutiny.

A major national trial of CRT with numerous participating U.S. institutions, including Hopkins, is tracking patients for about two years, Bradley said. Results are to be presented in April at an American College of Cardiology meeting, he added.

More information

For more about cardiac resynchronization therapy, visit the U.S. Food and Drug Administration. Learn more about heart failure from the American Heart Association.

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