At the University of Maryland Medical Center, Drs. Stephen… (Baltimore Sun photo by Jed…)
Since 1980, when a physician at Johns Hopkins Hospital first implanted a defibrillator in a human being, doctors have found that the devices can halt sudden cardiac death in many patients whose hearts have weakened pumping ability, as well as for some who have suffered a heart attack.
But a recent study by researchers at the University of Maryland Medical Center shows that about half of all patients who meet nationally accepted guidelines for treatment with implantable cardioverter-defibrillators, known as ICDs, are not receiving the recommended treatment.
Based on records from 167 cardiology practices across the United States, the study also found that older patients, African-Americans and those without health insurance were less likely than other patients to receive the devices. Heart failure patients treated outside the northeastern U.S. were less likely to be treated in accordance with the guidelines.
"We found that compliance with the national guidelines ranged from wonderful - 100 percent of the time - to complete disregard," said Dr. Mandeep R. Mehra, chief of cardiology at UM Medical Center and lead author of the study.
"At least half of the patients studied were eligible for the devices, but we found that of those, only half were receiving ICDs. Why? That is step No. 2. We need to understand why."
Guidelines for using the device are agreed upon by the American College of Cardiologists, the American Heart Association and the Heart Rhythm Society. They say patients can benefit from ICDs if they have had ventricular arrhythmia before; if they have suffered a heart attack that weakened and scarred the heart; or if they have mild to moderate symptoms of heart failure and weakened heart function.
In the past decade, a growing number of clinical studies have proved that implantation of defibrillators in eligible patients can reduce mortality by about 30 percent, said Dr. Hugh Calkins, professor of medicine and director of electrophysiology at the Johns Hopkins School of Medicine.
The battery-run devices, which are about 2 inches in diameter, are programmed to detect arrhythmia and to restore a normal rhythm by shocking the heart. One in 14 patients implanted with an ICD will suffer a rhythm disorder within two years that will trigger the device, Mehra said.
"We know that about 400,000 individuals [in the U.S.] have sudden cardiac death," Calkins said. "Most people who have a cardiac arrest die - the survival rate is probably less than 10 percent - so the idea is, let's put the ICD in place, and the ICD will give them a shock and prevent death."
In the University of Maryland study, researchers reviewed medical records from 15,381 patients being treated at cardiology practices across the U.S. According to the guidelines for use of ICDs, 7,532 of the patients were eligible for ICD implants, and 311 of them reported medical conditions that prevented them from undergoing the treatment. Of the 7,221 remaining patients, 3,659 - about 50 percent - received the devices. The study, which was published in December in the journal HeartRhythm, was funded by Medtronic Inc., a maker of ICD devices.
"This is an impressive study that confirms a message that we've heard before: That ICDs commonly are not implanted in patients who are indicated for the therapy, and there needs to be greater awareness of this," Calkins said.
Study results showed a link between lower compliance in cases involving older patients, Mehra said. "This may reflect a notion of futility in patients or it may reflect a choice: An older patient may say, 'I don't want this device.' "
Lack of insurance also played a role, as well as geography. Race, too, was a factor. In contrast, Mehra said, cardiology practices in the Northeast complied more frequently with guidelines - as did practices that took a "team approach" to heart failure management, and whose members included specialists in heart failure and heart rhythm.
"This study points to a common problem in medicine: We train doctors who are good at treating a disease, but not at preventing a disease," said Dr. Kenneth Ellenbogen, professor of cardiology at the Virginia Commonwealth University School of Medicine and a spokesman for the American Heart Association. "It shows the importance of looking at the totality of taking care of the patients."
Sometimes, heart failure patients who are informed about the devices refuse treatment, Mehra said. Advanced age might play a role (eligible patients should have more than a year to live, according to the guidelines), as might poor quality of life and complications from additional medical problems. Other patients have concerns about receiving inappropriate shocks from the device.