NEW ORLEANS African Americans and women with life-threatening heart rhythm abnormalities are significantly less likely to receive implantable defibrillator devices designed to convert lethal rhythms to normal heart rhythm, according to a new analysis by Duke University Medical Center researchers.
After sifting through 64,936 cases of patients treated under Medicare, the federal health insurance program for Americans over the age of 65, the researchers found that African-American Medicare patients received the devices at one-third the rate of whites, while women received them at less than one-half the rate of men.
This disparity is crucial because past clinical trials have clearly demonstrated that defibrillators are superior to existing medical treatments for these severe cardiac arrhythmias, according to lead investigator, Duke cardiologist Dr. Judy Battle.
Although their analysis was not designed to determine the underlying reasons for this disparity, the researchers believe that it is most likely a combination of factors, including patient preferences and possibly physician bias.
"This is the first study to look at the racial differences in the use of implantable defibrillators, and the results are significant," said Battle, a researcher at the Duke Clinical Research Institute (DCRI). "The data should provide the springboard for continued research into better understanding why these disparities exist and what we can do to close the gap.
"All patients, whether they're black or white, male or female, should be treated equally in receiving this life-saving therapy," she said.
Battle prepared the results of her study for presentation Monday at the 73rd annual scientific sessions of the American Heart Association. The DCRI funded the study.
More than 350,000 deaths occur each year in the United States due to sudden cardiac death, and one of the main causes is ventricular tachyarrhythmia, in which the left lower heart beats too fast. To control these incidents of "lethal rhythms," implantable cardioverter defibrillators (ICD) are placed within a small pocket created in the body to deliver small electrical shocks to the heart whenever the malignant rhythm occurs. In most cases, the ICD returns the heart to its normal rhythm.
Since it has already been documented that African Americans and women do not receive such invasive procedures as cardiac catheterization, angioplasty or coronary artery bypass grafting at the same rates as whites or men, Battle wanted to see if the same trends held true for newer technology such as the ICD use. In her analysis, Battle looked at Medicare patients who received the device in 1991 and 1992. The patients studied were diagnosed with life threatening heart arrhythmias and were seen at hospitals capable of implanting ICDs. Since we were using Medicare data, these low rates of ICD placements in African Americans and women cannot be explained by the differences in socioeconomic status, hospital facilities or access to care," Battle said. "That's why it is so crucial that we follow up on these findings. We know the disparity exists, so now what are we going to do about it?"
Battle and her colleagues are beginning another analysis of Medicare data from 1995 and 1996 to see if the situation is improving. She points out that while Medicare data have advantages in providing a level playing field when comparing patients, they do have limitations. The data are silent on one of the most important aspects of health care the patient-physician interaction.
The reasons may be that patients prefer to take a medicine instead of getting a procedure, or it may be a subconscious bias decision on the part of the physician," she said. "We just don't know. But we want to use this kind of information to move the field forward." Duke researchers have already demonstrated that African Americans with heart disease receive fewer coronary artery bypass surgeries and angioplasties than their white counterparts. Another Duke study, published in May, showed that some first- and second-year medical students already exhibited biases based on patient race and sex.
Joining Battle in her analysis were DCRI colleagues David O. Martin, Dr. Mark A. East, Dr. Lawrence H. Muhlbaier, Judy Stafford, Dr. Jamie Jollis and Dr. Dan Mark.