Even modest coronary plaque causing no symptoms has a long-term impact on mortality and heart disease in diabetes, an observational study showed.

The adjusted mortality risk was similarly elevated by twofold whether coronary CT angiography showed mild stenosis of less than 50% or obstructive stenosis of 50% or more (hazard ratios 2.0 and 2.1,P=0.003 and P<0.001, respectively), Philipp Blanke, MD, of the University of British Columbia and St. Paul’s Hospital in Vancouver, and colleagues found in the CONFIRM registry.

The mortality risk with nonobstructive coronary artery disease was similar to that of having single-vessel obstructive disease (P=0.42), the researchers reported at the Radiological Society of North America meeting here.

Overall major adverse cardiovascular events (death, myocardial infarction, unstable angina, or late coronary revascularization) showed about double the risk with obstructive disease as with the milder stenosis, but both were significant, with HRs of 10.4 and 4.9, respectively (both P<0.001).

“Coronary computed tomographic angiography in diabetics can be used for long-term prognostication with respect to mortality and major adverse cardiovascular events,” the group concluded.

However, screening of diabetes patients for asymptomatic coronary artery disease with coronary CT angiography to guide management wasn’t any better than simply aggressively targeting risk factors in the FACTOR 64 trial, reported in November at the American Heart Association meeting.

“A lot of patients end up having their first symptom as a heart attack or even death. We would like to be able to identify those patients and treat them before they die or have a heart attack,” said J. Brent Muhlestein, MD, of the FACTOR 64 trial. Muhlestein is from Intermountain Medical Center and the University of Utah in Salt Lake City.

While CT screening wasn’t the solution, “aggressive medical management of all patients significantly reduced the number of adverse events that happened in diabetic patients in both the patients who were in the control arm and also in the scanning arm,” he pointed out to MedPage Today. “We also found that 70% of the patients who did have asymptomatic diabetes also did have some degree of atherosclerosis in their coronary arteries which justifies secondary prevention risk management.”

The Coronary CT Angiography Evaluation For Clinical Outcomes: An International Multicenter (CONFIRM) Registry was designed to look for prognostic value of cardiac CT angiography in coronary artery disease-related events.

Among the more than 40,000 patients with CT angiography data from more than a dozen centers around the world, Blanke’s analysis included the 1,823 with diabetes and at least 5-years of follow-up but no prior clinically-apparent coronary artery disease.