AR: CTA uncovers CAD in young diabetics
Lipid-lowering therapy has been employed as a strategy to reduce cardiovascular events in adults with diabetes older than age 40, but few data support its use in younger patients. Meanwhile, newer technologies have curbed radiation exposure associated with CTA.
Paul M. Madaj, MD, from the Los Angeles Biomedical Research Institute at University of California-Los Angeles, and colleagues designed a prospective study to evaluate coronary artery calcium (CAC) and coronary CTA in young adults with diabetes to determine the earliest objective evidence of arteriosclerosis eligible for primary prevention.
The study population was comprised of 25 patients presenting with type 1 diabetes and 15 with type 2 disease for five years or longer.
All patients underwent CAC scoring and CTA on a 64-slice CT system. Average radiation exposure was 2.48 mSv.
Image datasets were postprocessed using various reconstruction algorithms and reviewed by a single reviewer blinded to patient characteristics. Stenosis severity was assessed according to the following scale: no stenosis; <29 percent stenosis; 30 to 49 percent stenosis; 50 to 69 percent stenosis; 70 to 100 percent stenosis. Each plaque was assigned a severity score ranging from 1 (small) to 3 (large), and all interpretable segments were summed to devise the total plaque severity score.
The researchers found abnormal scans in 23 persons, noncalcified in 14 and calcified-mixed plaque in nine. Plaque prevalence by CTA was more pronounced in persons with type 2 diabetes vs. type 1 diabetes, at 80 percent and 44 percent, respectively. A total of 53 percent of patients with type 2 disease had positive CAC scores compared with 4 percent of type 1 patients.
These findings mirror earlier studies, which had demonstrated that plaque is more common and greater in amount in persons with diabetes, according to Madaj and colleagues, who added that these plaques often form at a young age and are undetected and asymptomatic for years. The challenge may be larger in patients with type 2 disease as silent ischemia may be a considerable challenge in this population.
A significant fraction of young adults with diabetes have identifiable plaque that can be detected with minimal radiation exposure via CTA, the researchers concluded. CAC did not exclude early arteriosclerosis in this population, and coronary CTA provided earlier identification as one-third of this group had isolated noncalcified plaque.
Finally, a positive CTA result allows physicians to consider earlier initiation of primary CAD prevention, rather than waiting until age 40, added Madaj et al.