Women Less Likely to Get Heart Defibrillators
TUESDAY Oct. 2, 2007 -- Women are less likely than men to receive implantable defibrillators, and black patients are less likely than white patients to receive the lifesaving heart devices.
Two studies documenting these findings echo previous research, and confirm that little progress has been made in this area of inequity.
"In the mid 1990s, the Institute of Medicine noted that newer technologies and innovative therapies were more likely to be used in men versus women and in whites versus blacks consistently, and recommended that the health-care system needs to figure out how to deliver new therapies more efficiently and equitably," said Dr. Adrian Hernandez, an author of both of the studies, which appear in the Oct. 3 issue of the Journal of the American Medical Association.
"This is a case example where we still haven't done that," added Hernandez, an assistant professor of medicine at the Duke Clinical Research Institute, in Durham, N.C.
"It reconfirms what was found in clinical trials, that the problem still exists," said Dr. Wojciech Zareba, a professor of medicine with the cardiology unit at the University of Rochester (N.Y.) Medical Center. "We do not know the reason for the discrepancy but, in my view, one predominant reason is a lot of education needs to be done among physicians to convince them. People don't know enough and we should have more advertisements during the evening news on sudden cardiac death in women rather than on asthma drugs or breast cancer."
Some 350,000 people in the United States die each year as a result of sudden cardiac death, making it one of the leading causes of death. Although the risk is initially higher in men than in women, that discrepancy disappears after age 85.
Implantable cardioverter-defibrillators (ICDs), introduced about two decades ago, continually monitor heart rhythms and deliver electrical shocks to help control erratic rhythms. The devices have been shown to reduce mortality in those at highest risk for sudden cardiac death. Thanks to pivotal trials, Medicare expanded its coverage of ICDs in 2004.
One trial also found that only a small proportion of women who were eligible received an ICD. But that trial, and others, were conducted before the Medicare expansion.
For the first of the new studies, the researchers looked at the medical records of more than 236,000 Medicare patients from 1999 to 2005. The study had two parts -- one looking at primary prevention (those at risk for sudden cardiac death and cardiac arrest) and one looking at secondary prevention (those who had already had cardiac arrest or sudden cardiac death).
Among patients in the primary prevention component, men were 3.2 times more likely than women to receive an ICD. In the secondary prevention trial, men were 2.4 times more likely to receive an ICD.
White men were more likely than black men to get ICDs and white women were more likely than black women to get them.
The gender discrepancy did not appear to narrow over time.
For the second study, the researchers looked at 13,034 patients with heart failure and left ventricular ejection fraction of 30 percent or less (a measure of how well the heart pumps that indicates the risk for sudden cardiac death) between January 2005 and June 2007. Patients had been admitted to one of 217 hospitals participating in the American Heart Association's "Get With the Guidelines" program. This study only looked at primary prevention.
Overall, just 35.4 percent of patients eligible for ICD therapy had received a device by the time of hospital discharge, but the figure varied by group: 28.2 percent of eligible black women received the therapy, along with 29.8 percent of white women, 33.4 percent of black men and 43.6 percent of white men.
The odds of ICD use were 27 percent lower for black men, 38 percent lower for white women, and 44 percent lower for black women.
The study authors said they weren't sure why these discrepancies exist.
"We're unsure whether there are differences in patient preferences," Hernandez said. "One can imagine that possibly men may ask for defibrillators more often than women or ask to have aggressive therapies more often than women. Alternatively, when offered, women can turn them down more. We don't know."
It's also possible that physicians are more comfortable prescribing the devices for men because clinical trials have been done mostly in men, or they see men who have other risk factors for sudden death more often than women. There could also be system-wide or hospital inequities with women having less than full insurance coverage for ICDs.
In any event, one solution seems clear.
"We need to promote awareness about the use of defibrillators, we need to figure out what are the barriers for use and, specifically, what are barriers for use in women and minorities and how to address these barriers," Hernandez said.
The Heart Rhythm Society has more on ICDs.
Posted: October 2007