Black Heart Disease Patients Die at Higher Rate Than Whites
ORLANDO, FL. -- In the most comprehensive study of its kind, Duke University Medical Center cardiologists found that, years after treatment, black heart patients died at a significantly higher rate than white patients did.
In a group of more than 12,000 patients, the blacks had a 40 percent higher risk of dying than the whites, researchers said in a report prepared for the annual meeting of the American College of Cardiology. This increased mortality is largely due to two factors, Duke researchers conclude: Black patients, about 10 percent of the group, tended to suffer from other diseases, such as hypertension and diabetes, that affected their chances of survival.
Black patients also did not receive the same aggressive treatment for heart disease as the whites did. In fact, the researchers found black patients were 40 percent less likely to receive angioplasty or bypass surgery. These differences in treatment appear to have led to slightly lower survival rates in blacks compared to whites.
"While we can say that, in general, the health status of the black patients in this study was poorer, compared to the whites, and that likely affected their death rates, we can't explain why blacks tended not to receive aggressive therapy," said Duke cardiologist Dr. Eric Peterson in an interview. "These differences in care were not explained by clinical factors or access to medical care."
The study was funded by the federal agency for Health Care Policy and Research as part of the Heart Disease PORT study at Duke. While the study was centered at Duke, Peterson believes a similar problem can be found nationally. He conducted an earlier study of almost 34,000 veterans that found black veterans treated for heart attacks received about half the number of high-technology treatments than whites had. That report was published in 1994 in the Journal of the American Medical Association.
The current study used information from the Duke Databank for Cardiovascular Diseases, which contains clinical records compiled by physicians. It is the largest and most detailed information available nationally on the long-term outcomes of cardiac patients, Peterson said.
He and his colleagues examined the records of 12,402 patients who had significant coronary disease and were seen at Duke from 1984 to 1992. Of this group, 10.2 percent were black. All of the patients received a cardiac catheterization to determine the extent of heart disease, and then were referred to either treatment by medication, angioplasty or by-pass surgery. The researchers found that five years after treatment, 80 percent of the white patients were still living, compared to 73 percent of the black patients. That translates to a 40 percent increased risk of death among blacks, said Peterson.
To determine why this is so, the group looked at several factors: Severity of disease. The researchers looked at whether black patients were diagnosed at a later stage when their disease was more severe. In contrast to expectations, they found that blacks were actually diagnosed more quickly than the white patients after complaining of chest pain or other symptoms, and were found to have equal or less severe coronary blockage. "It's unlikely, therefore, that a late diagnosis can explain differences in outcomes," said Peterson.
The presence of other diseases. The primary differences between the groups of patients is that the blacks tended to have more hypertension and diabetes than the whites, the researchers found. Such "co-morbid" illness impacts long-term survival, Peterson said. After "adjusting" for the sicker status of these patients -- that is, eliminating the effect of the other diseases -- the researchers found the blacks remained 18 percent more likely to die. "Thus, a lot of the differences in survival can be explained by the fact that blacks suffered from other diseases, but that isn't the complete story," said Peterson.
Differences in treatments. As stated, the researchers found that black patients were 40 percent less likely to be referred to angioplasty or bypass surgery. "These differences in care appear to have a small, but real, effect on long-term outcomes of blacks compared to whites," said Peterson.