Diabetic patients with chest pain who have more than one other common risk factor for heart attack should be considered for direct admission for a complete cardiac work-up, bypassing a period of Chest Pain Unit (CPU) observation, according to a new analysis by Duke University Medical Center researchers.
Since it is known that diabetic patients have higher rates of heart disease, have worse outcomes and expend more health care resources than heart patients without diabetes, cardiologists have long debated the most effective and efficient way of treating them when they first come to the hospital with chest pain, especially those who arrive without obvious evidence of a heart attack.
Duke University Medical Center researchers believe they are getting closer to an answer that not only has implications for how these patients ultimately fare, but also for the expenditure of health care resources.
"We found that diabetic patients assigned to chest pain units for observation who have more than one other traditional heart disease risk factor may be better served by being admitted directly to the hospital for a full cardiac work-up or care, bypassing the period of observation and testing in a chest pain unit," said Carlos Sanchez, a fourth-year Duke medical student working at the Duke Clinical Research Institute (DCRI).
"More than 8 million Americans come to emergency rooms with chest pain, but only 10 to 15 percent are actually having a heart attack," Sanchez continued. "We are always looking to improve our ability to evaluate the risk for the other chest pain patients, and the diabetic patients within that group have always been a difficult group to �risk stratify.'"
Sanchez prepared the results of the Duke analysis for presentation at the 74th annual scientific sessions of the American Heart Association in Anaheim, Calif.
The Duke researchers studied the results of 1,005 patients in the CHECKMATE trial, the results of which were first presented in 2000. The trial compared the prognostic abilities of three different biochemical markers of heart muscle damage in low- to moderate-risk patients in CPUs at six different institutions.
For the current investigation, the researchers analyzed the course of treatment and outcomes of the 722 patients who were deemed to be low risk. Of those, 109 (15 percent) had diabetes.
The analysis revealed that diabetic patients had more than twice the risk of short-term death or heart attack (8.3 percent vs. 3.2 percent); were admitted to the hospital from the CPU earlier (after 8.9 hours versus 13.3 hours) and twice as often (40.4 percent vs. 22.7 percent) as non-diabetic patients, and were twice as likely to have more than one coronary artery afflicted with disease (44.4 percent vs. 18.4 percent).
"Our analysis suggests that because of the likely adverse outcomes these patients suffer and their higher resource use, less may be gained by the traditional observation and monitoring that occurs in chest pain units," said Duke cardiologist Dr. Kristin Newby, the senior member of the research team.
In addition to diabetes, other important predictors of worse outcome for heart patients include the status of a major biochemical marker known as troponin; being a male over age 55, or a female over 65; abnormal electrocardiograms (EKG) or previous history of cardiac event.
"It appears that if a diabetic patient has only one or none of those other risk factors, they have about the same short-term risk as a similar non-diabetic patient," Sanchez said. "However, with two or more of the factors, these patients are clearly at higher risk and should receive more aggressive attention."
Chest pain units are usually located within emergency departments or on cardiology units of hospitals. They are supported 24 hours a day by emergency physicians or cardiologists who can quickly conduct the necessary tests needed to differentiate patients who are truly having a heart attack from those who are not.
Earlier Duke studies have demonstrated the value of CPUs in speeding the diagnosis of chest pain patients and in better determining the potential for future heart attacks. These CPUs can save health care dollars, the researchers say, because up to 85 percent of chest pain patients are not having a heart attack. As a precaution, many hospitals without CPUs routinely admit these chest pain patients for days of tests they may not need.
However, after several hours of monitoring in a CPU, doctors often know whether a patient needs hospitalization or can safely be sent home.
The CHECKMATE trial involved CPUs in the following centers: Duke; the University of Cincinnati; Carolinas Medical Center, Charlotte, N.C.; St Luke's Medical Center, Milwaukee; Stanford University Medical Center, Palo Alto, Calif.; and St. Luke's Roosevelt Hospital, N.Y. The Duke analysis of the CHECKMATE data was supported by the DCRI.
Duke University Medical Center
