Elderly male heart patients are two to three times more likely than females to receive implanted devices that shock a malfunctioning heart back into normal rhythms, and white men are about a third more likely than black men to receive them, researchers reported today.
Overall, only about a third of patients who are eligible for the potentially lifesaving implanted cardioverter defibrillators are actually getting them, according to a pair of studies in the Journal of the American Medical Assn.
The devices, known as ICDs, “save lives, so the sex difference in treatment rates is worrisome,” said Lesley H. Curtis, a health economist at Duke University Medical Center and lead author of one of the studies.
“We don’t know why the difference exists, but we do know that this is bad news for women,” added a co-author, Dr. Kevin A. Schulman of Duke, an internist and health policy expert.
As many as 450,000 Americans die each year when the electrical signals that initiate heartbeats become erratic, interfering with the organ’s ability to pump blood through the body. ICDs monitor the electrical impulses and, when they become irregular, shock the heart back into normal rhythms.
Clinical trials have shown that the devices, which are about the size of a pack of cigarettes and cost $30,000 to $40,000 to implant, can prolong life in 31% to 50% of patients who receive them.
Previous research has shown a disparity between use of the devices in men and women but suggested that the gap was closing. Today’s study, however, indicates it is getting wider.
“What it is showing . . . is that we are not identifying women with heart disease,” said Dr. Jeffrey S. Goodman, a cardiologist at Cedars-Sinai Medical Center who was not involved in the research.
“One thing that is very obvious is that, overall, we are underutilizing them in patients who meet the criteria,” he said. “Only 35% to 40% of people who meet the criteria are receiving appropriate therapy.”
In one study, Curtis and her colleagues studied a 5% sample of Medicare patients whose average age was 75.
One group of 136,421 patients had been diagnosed with a heart attack along with heart failure or cardiomyopathy, either of which left them susceptible to arrhythmia. A second group of 99,663 patients had suffered either a cardiac arrest or cardiac arrhythmia.
In the first group, 32.3 out of every 1,000 men had received an ICD, compared with only 8.6 out of every 1,000 women. Yet the risk of death in the first year after enrollment in the study was the same in the group who received ICDs as in the group who did not -- perhaps because of their advanced age.
In this case, “the bad news may not be for women and minorities, but for white men who are undergoing a procedure that . . . has not been shown to save their lives,” wrote Dr. Rita F. Redberg of UC San Francisco in an editorial accompanying the studies.
The outcomes were better for the group that had already suffered an arrhythmia: The risk of death in the following year was 35% lower among those who received ICDs. Still, men were more likely to get the device: They were implanted in 102.2 out of every 1,000 men, compared with 38.4 out of every 1,000 women.
In the second study, Dr. Adrian F. Hernandez and a different team at Duke studied 13,034 patients with heart failure at 217 hospitals participating in a voluntary American Heart Assn. project to increase adherence to guidelines for treatment of the disorder.
They found that African American men were 73% as likely to receive an ICD as white men, white women were 62% as likely and African American women were 56% as likely. Overall, only 35% of eligible patients received the devices.
Hernandez, a cardiologist, said the disparity may be even greater in other hospitals that are not part of the American Heart Assn. project.
Dr. Wojciech Zareba, a cardiologist at the University of Rochester Medical Center who was not involved in either study, said it is “not surprising” that there are gender disparities. Even though heart problems are the single largest cause of death for women, females “represent only 25% of coronary patients, not 50% as you would expect.”
But Dr. Nieca Goldberg, who directs the NYU Women’s Heart Program, said there may be a good reason for the gender disparity.
“Women who have heart failure have better heart muscle function than men, so many do not require a defibrillator,” she said. “This is not about gender, but about levels of heart function.”
The studies were funded by the National Institutes of Health. All of the physicians reported receiving lecture fees or grants from companies that manufacture the devices.