Routinely screening patients with diabetes for asymptomatic coronary artery disease (CAD) failed to improve outcomes, results published online Nov. 17 in JAMA showed.
The FACTOR-64 study group theorized that because diabetes mellitus is a risk factor for CAD and is a cause of death for patients with diabetes, routinely screening asymptomatic patients using coronary CT angiography (CCTA) might allow physicians to intervene and reduce the likelihood of adverse events. They designed FACTOR-64 as a randomized, controlled clinical trial to test the idea.
The trial enrolled and randomized high-risk patients between 2007 and 2013 with a history of type 1 or 2 diabetes and no documented atherosclerotic disease who were treated in the Intermountain Healthcare system in Utah. Patients either received standard diabetes care (448 patients) or underwent CCTA screening (452 patients). Physicians received recommendations on subsequent medical management based on the CCTA results.
The primary endpoint was the composite of all-cause mortality, nonfatal MI or hospitalization for unstable angina with at least two years of follow-up.
The intervention and control groups were well matched and on average participants had a diagnosis of diabetes for 12 years. The mean follow-up to a first primary event was four years. In the CCTA group, 11 percent of patients were found to have severe CAD and 12 percent moderate CAD.
Lead author Joseph B. Muhlestein, MD, of the Intermountain Medical Center Heart Institute in Murray, and colleagues found no significant difference in the primary event rates between of the groups (6.2 percent for CCTA and 7.6 percent for standard care). The composite of ischemic major adverse cardiovascular events was also similar (4.4 percent vs. 3.8 percent, respectively).
“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 percent 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,” Muhlestein et al wrote.
Based on the findings, they did not recommend routine CCTA screening for CAD in asymptomatic patients with diabetes.
They observed that the annual event rate, at 2 percent, was low in both groups. They credited the system’s diabetes prevention and management program, which was initiated in 1997 and fully running by 2005, for the good outcomes. Without that quality of care, the differences between the CCTA and control groups may have been greater, they proposed.
The results were presented simultaneously at the American Heart Association scientific session in Chicago.