A study recently completed at the UR Medical Center will enable more patients with heart problems to receive improved cardiac treatment. The research, published in the March 21 issue of the New England Journal of Medicine, proved the effectiveness of using implantable cardioverter defibrillators (ICDs) as a preventative treatment to hinder sudden deaths due to fatal heart rhythm.
“It’s like having your own personal coronary care unit,” said Dr. Arthur Moss, professor of medicine and cardiology at UR, who designed and directed the five-year study.
Moss coordinated the gathering and analysis of information from 76 research centers all over the world, two of which are located in Rochester. The study split 1,232 qualifying patients into two groups, one with ICDs, the other without. Both groups also received their regular drug treatments. The patient death rate in the ICD group was 14.2 percent, which was 31 percent lower than the death rate in the group without ICDs, a significant improvement.
Currently, half of all deaths from heart attacks occur suddenly due to fatal heart rhythm, which could be prevented by an ICD. However, until now, only patients with the most severe heart conditions were prescribed this device ? only about 80,000 implantations were done per year. But the ICD could benefit an estimated three to four million people in the U.S. who are currently at risk from sudden death due to cardiac problems, as well as 400,000 new sufferers annually.
The results of the study indicate that the treatment is extremely effective. “We now have a way of preventing a major cause of death in heart disease,” said Moss. As a result of the study, the device, which is manufactured by the Guidant Corporation, is now going through an expedited Food and Drug Administration review.
ICDs have been used selectively for two decades, with one most famously implanted in Vice President Dick Cheney, but FDA approval will make the Guidant version of the device more popular and significantly broaden the scope of its application. ICDs are also manufactured by two other corporations, Medtronic Inc. and St. Jude Medical Inc., but they do not have FDA approval.
“UR has played a major role in this landmark study,” said Moss. He was assisted in designing the study by Dr. William Hall, a UR biostatistics professor.
Dr. David Oakes, professor and chairman of the UR biostatistics department, chaired the Data Safety Monitoring Board, an independent group which monitored the study and made recommendations.
Dr. Moss saw the life-saving potential of ICD technology six years ago and, with a group of colleagues, approached the Guidant Corporation with a request to evaluate it in a formal study. Guidant agreed, granting $7 million to fund the research.
“There is no effective drug at this time to prevent sudden death [from heart malfunction],” said Moss. “A clinical trial [of the ICD] was really necessary.”
The ICD is a sophisticated pager-sized device that is implanted under the patient’s collarbone and connected to the heart by four leads. The ICD monitors and records the heart activity of the patient, using electrical pulses to pacify dangerous heart rhythms. The implantation procedure is an hour long and done under local anesthetic, with almost no recovery time required.
“It has the ability to track the heart rhythm and convert it to a regular rhythm by a properly timed stimulus or a shock. It has the ability to pace [the heart rhythm], and it stores [information about] the rhythms and the episodes,” Moss said.
This information can be retrieved wirelessly and analyzed, and the ICD can be reprogrammed in the same fashion.
The analysis reported that no fatal side effects occurred as a result of the device. “The numbers [of complications] were very, very small, less than 0.2 percent of the patients,” said Moss. “The infection rate was very low.
“We looked at the adverse effects, and there’s less of them than with drug therapy,” Moss continued.
However, the development of new or worsened heart conditions in the ICD group was slightly higher than in the control group. Moss attributed it to the fact that patients in that group lived longer and thus had more time to develop more severe conditions. He concluded that the device does not worsen heart problems and is safe.
Uzilov can be reached at auzilov@campustimes.org.
