August 29, 2005
Race, sex differences persist in cardiac care, study shows
BY holly Korschun
Despite a decade of initiatives to remedy health disparities in cardiovascular medicine, at least some aspects of the treatment of U.S. patients hospitalized for heart attacks continue to vary according to sex and race, according to a study by Emory researchers in collaboration with Yale University and other centers. The results, reported in the New England Journal of Medicine, found a pattern of less-intensive treatment offered to women and black heart-attack patients.
When a patient has a heart attack, clearing blocked arteries and restoring blood flow as quickly as possible can mean the difference between life and death. While heart-attack care improved over the past decade, the study found that disparities in the use of medications and diagnostic procedures remained consistent.
Investigators studied the records of 598,911 white and black patients treated for heart attacks between 1994 and 2002 at 658 hospitals participating in the National Registry of Myocardial Infarction, sponsored by the Genentech Corp. They examined differences by sex and race in the use of reperfusion therapy (the use of a drug or invasive catheter procedure to open an artery blocked by a clot), coronary angiography (a diagnostic procedure used to identify blockages in the heart’s circulation), aspirin and beta-blocker therapy. In order to eliminate differences attributable to other patient illnesses, they included only patients who were ideal candidates for therapy.
Although observed differences in the use of medications (such as aspirin and beta-blockers) among white, black, male and female patients decreased after accounting for other characteristics associated with sex and race, the study found that rates of reperfusion therapy, coronary angiography and in-hospital death after heart attack varied according to race and sex.
The rate of treatments went progressively down in white women, black men and black women compared with white men, with black women found to have the lowest use of interventions. For example, black women with the appropriate indications for therapy had 10 percent lower rates of reperfusion therapy and 24 percent lower rates of angiography compared to white men. Black women also had the highest in-hospital mortality rates—11 percent higher than white men—among the four
sex and race groups. In contrast, differences in treatment and mortality between white women and white men were generally small.
Although a number of studies have shown disparities in cardiovascular treatment, this study was unique in that the researchers were looking for changes in disparities over time. They were surprised to discover that differences by sex and race were essentially unchanged between 1994 and 2002, indicating there was no lessening of treatment gaps in recent years.
“Lower rates of treatment in patients who are clinically appropriate for treatment are troubling and raise obvious concerns about under-treatment,” said Viola Vaccarino, associate professor of medicine (cardiology) in the School of Medicine, associate professor of epidemiology in the Rollins School of Public Health and leader of the multi-institutional study. “These differences in treatment are particularly concerning for use of reperfusion therapy and cardiac catheterization because race and sex differences in treatment were not explained by patient age, risk factors or other clinical characteristics that might differ between patients.
“Simply put,” Vaccarino continued, “we could not determine the reasons for these differences.”
The reasons for the persisting differences may reflect some unmeasured characteristics of the patients or of the health care system that have not changed over time, the authors report. For example, women and black patients with heart attacks may have less typical symptoms leading to delayed diagnosis and delayed treatment. Patients’ socioeconomic status may also play a role, perhaps leading to lower access to specialist care, or admission to centers of poorer quality.
Nanette Wenger, professor of medicine (cardiology) in the School of Medicine and a co-author, said the findings underscore the complexity of the issue.
“Although race and sex differences in the use of drug therapy were attributable to other patient factors, race and sex differences in use of procedures persisted even after accounting for these factors, and the question is: Why?” Wenger said. “What is it about procedures that results in race and sex differences in treatment that we don’t see with drugs? And while we have some hypotheses, the answer is really, we don’t know.”