Evaluating coronary artery calcium in addition to traditional Framingham Risk Score factors may better predict CVD mortality in patients with type 2 diabetes, new data from the community-based Diabetes Heart Study indicate.
To investigate the association between coronary artery calcium (CAC) and CVD mortality, researchers followed 1,123 participants aged 34 to 86 years with type 2 diabetes for an average of 7.4 years. At baseline, they stratified participants into three groups according to CAC scores as measured by CT: 0 to 9, 100 to 299, 300 to 999 and ≥1,000.
CVD-related death occurred in 8% of all participants during follow-up, according to the data, with incidence of CVD mortality appearing increased across higher CAC categories (P<.0001). A multivariate analysis adjusted for age, sex, race, smoking, total and HDL cholesterol, systolic BP and antihypertensive medication yielded ORs of 2.93 (95% CI, 0.74-19.55) for CAC scores from 10 to 99, 3.17 (95% CI, 0.7-22.22) for CAC scores from 100 to 299, 4.41 (95% CI, 1.15-22.22) for CAC scores from 300 to 999 and 11.23 (95% CI, 3.24-71) for CAC scores ≥1,000, as compared with CAC scores from 0 to 9.
The researchers also compared areas under the curve (AUC) with and without CAC, as well as net reclassification improvement with use of Framingham Risk Score plus CAC vs. Framingham Risk Score alone. Results showed that AUC for prediction of CVD mortality increased from 0.7 to 0.75 (P=.0001) with the addition of CAC. Net reclassification improvement was 0.13 for the entire study cohort (95% CI, 0.07-0.19), according to study results.
“Our observations challenge accepted medical knowledge that all people with diabetes have the same risk,” senior study researcher Donald Bowden, PhD, professor of biochemistry at Wake Forest Baptist, said in a press release. “People at very high risk are 11 times more likely to die from cardiovascular diseases as compared to those at low risk. Diagnosing a more precise risk level should help doctors provide more effective treatments and hopefully improve outcomes.
“Based on our study, we think that CAC should b e added to the Framingham tool as the standard of care for all people with diabetes,” Bowden said.
Disclosure: The researchers report no relevant financial disclosures.