Cardiac Imaging No Better Than Optimal Drug Therapy to Prevent Heart Disease in Diabetes

High-quality diabetes care is more important than cardiac imaging for asymptomatic diabetes patients at high cardiac risk, according to newly published results of the FACTOR-64 Randomized Clinical Trial.

Researchers examined whether the use of advanced coronary computed tomographic angiography (CCTA) screening would result in significant long-term reduction in death, myocardial infarction, and hospitalization for 900 patients with type 1 or type 2 diabetes of at least 3 to 5 years’ duration and without symptoms of coronary artery disease (CAD).

“Although CCTA screening demonstrated a marked diversity of CAD burden that was related to cardiovascular risk and led to more aggressive treatment recommendations for lipids, blood pressure, and glucose control in 70% of patients, which resulted in significant improvements in statin use and intensity, lipid fractions, and blood pressure levels, there was no advantage in reducing death and coronary heart disease outcomes,” wrote the researchers, led by Brent Muhlestein, MD, director of cardiovascular research at the Intermountain Medical Center Heart Institute, Salt Lake City, Utah.

“The question was whether screening for the presence of silent heart disease in these patients would be helpful,” he said. “However, although the screenings did lead to recommended changes of treatment, including surgery in some cases, it didn’t benefit the patients enough to support a change in the current recommended standards of care.”

The FACTOR-64 study is significant because diabetes is the most important risk factor for heart disease, the researchers point out. Patients with diabetes often develop severe, but asymptomatic heart disease. The combination of aggressive, asymptomatic heart disease has made it the most common cause of death in patients with diabetes.

The patients in the study were randomly assigned to undergo screenings or pursue standard diabetes management, which consisted of continued care from the patient’s Intermountain Healthcare physician. For those found to have asymptomatic coronary disease, aggressive treatment recommendations were provided beyond standard diabetes management, with the goal of preventing future cardiac events.

After 4 years of follow-up, the occurrence of deaths, heart attacks, and episodes of unstable angina did not differ significantly between those who were screened (6.2%) and those who were not (7.6%).

Muhlestein believes one element that may have affected the overall results is that patients enrolled in Intermountain Healthcare’s Diabetes Management program received excellent diabetes management and support.

He noted that CCTA is an accurate, non-invasive imaging technology, however, it does involve additional expense and some radiation exposure.

“Previous studies have shown that CCTA screening is nearly as good as standard invasive heart catheterization in defining coronary arteries. Because of this, we hoped this new technology would help us identify heart disease in high-risk patients who don’t have symptoms, and thereby allow us to better care for them. However, it turned out that the excellent standard of care offered to diabetic patients is just as effective,” Muhlestein said.

The researchers presented their findings at the 2014 American Heart Association Scientific Session in Chicago on November 17, 2014, and also published their results online in the November 17 issue of the Journal of the American Medical Association.

References:

Muhlestein JB, Lappe DL, Lima JAC, et al. Effect of screening for coronary artery disease using CT angiography on mortality and cardiac events in high-risk patients with diabetes. The FACTOR-64 Randomized Clinical Trial. JAMA. 2014;312(21):2234-2243. doi:10.1001/jama.2014.15825.