CCTA plaque data improve heart disease risk assessment in diabetics

Heart plaque data from coronary CT angiography (CCTA) exams boost heart disease risk assessment in diabetic patients compared with assessing obstructive stenosis alone, according to research published October 28 in the Journal of Thoracic Imaging.

The findings could improve patient care, wrote a team led by Dr. Christian Tesche of Munich University Clinic in Germany.

"[Our results] portend improved risk stratification in both patients with and without diabetes," Tesche and colleagues noted.

CCTA is often used to evaluate for heart disease and to quantify plaque, the group wrote. Diabetes is a known risk factor for heart disease, with increased morbidity and mortality rates, but typical risk scores recommended by professional medical societies can be tricky to apply to diabetic patients.

"[Conventional] risk scores ... are often challenging to apply effectively in patients with diabetes and do not necessarily meet the required prevention care of cardiovascular disease in this specific patient population," Tesche and colleagues explained.

Since there has been little investigation about how CT data such as plaque scores may interact with major adverse cardiovascular events in diabetic patients, the authors investigated the prognostic value of plaque information taken from coronary CTA exams in patients with and without diabetes. For the purposes of the study, major cardiovascular events included death; heart attack; bypass surgery, angiography, or stenting; stroke; or hospitalization due to heart failure.

The study included 64 patients with diabetes and suspected coronary artery disease who underwent CCTA; they were matched to 297 patients without diabetes by age, sex, cardiovascular risk factors, and whether they were taking statins or antithrombotic medicines.

The authors assessed the study cohort for any major cardiac incidents, CCTA risk scores, and plaque measures. Patients were tracked for a median of 5.4 years.

At this five-year follow-up, 31 patients (8.6%) had experienced a major cardiac episode. Patients with diabetes had higher CCTA risk scores and plaque measures compared to those who did not have diabetes. And the team found the following measures were predictive of cardiac events in diabetic patients:

• Segment stenosis score (hazard ratio, 1.20, p < 0.001)
• Low-attenuation plaque (hazard ratio, 3.47, p = 0.05)

In nondiabetic patients, segment stenosis score (hazard ratio, 1.92, p < 0.001), Agatston score (hazard ratio, 1.0009, p = 0.04), and low-attenuation plaque (hazard ratio, 4.15, p = 0.04) were associated with major cardiac events.

The results fill a knowledge gap about how CCTA findings may predict heart trouble in patients with diabetes, according to the authors.

"[Our] study demonstrates that the presence of diabetes is associated with a significantly higher extent of coronary artery disease and plaque features, which have independent predictive values for major adverse cardiac events," they concluded.