ATLANTA -- Diabetic patients would be the most likely candidates for early coronary artery disease (CAD) screening via imaging testing because this patient population is considered at high risk for myocardial infarction or cardiac death, said Gary Heller MD, director of cardiology at Hartford Hospital in Hartford, Conn., during a session yesterday at the American College of Cardiology (ACC) annual conference.
An estimated 21 million American citizens live with diabetes, and an estimated 25 million live with metabolic syndrome, Heller said, and the incidence of diabetes has increased enormously. Controversy about screening asymptomatic type 2 diabetes patients for CAD has also risen. “If you screen for contrary disease, it may be similar to screening for cancer,” said Heller. “There are pluses and minuses to doing that.”
While Heller noted that there are potential benefits of early CAD screening, diagnosis and prognosis of the disease state will only be beneficial to the patient if it allows the physician to modify treatment of the patient with the results of the screening test. “The goals should impact the therapies,” he said.
It would cost a total of $1.3 million to do a SPECT study on each diabetic individual in the U.S., said Heller: “Certainly, SPECT imaging identifies that risk [of CAD]. But there is no difference in the strategy between imaging and not imaging. Routine imaging is not advised.”
However, Heller said that 10 percent of all autopsies conducted on diabetic patients reveal evidence of CAD. This may influence some to screen all asymptomatic patients, but a study completed last year found little benefit to screening asymptomatic type 2 diabetes patients, Heller said. The randomized, prospective study divided 1,000 asymptomatic patients into two groups of 500, with one group receiving screening and the other receiving no screening at all.
Heller said that after screening, it was found that 22 percent received abnormal test results, and 6 percent of the population had high risk findings. Moreover, after a five-year follow-up period, 32 cardiac events had taken place.
While the study found that the outcomes for both groups were similar overall, the researchers found that patients with minor abnormalities did very well. However, among patients with more severe disease, their condition was found to have become more serious, explained Heller.
The duration of diabetes was also found to be a predictor of CAD occurrence, said Heller.
According to Heller, the surprising part of study was that the incidence of abnormal studies went down rather than up after the completion of the follow-up period.
In addition, the research provided data on the medication changes that occurred during the five year period.
“Some patients followed guidelines for ACE inhibitors, aspirin and statins at the completion of the follow up. Physicians began noticing their patients needed to be on appropriate medications, and this is a worldwide trend,” said Heller.