Abstract 13133: Coronary Artery Calcium and Cardiovascular Events in Diabetes: Implications for Primary Prevention Therapies: The Multi-Ethnic Study of Atherosclerosis (MESA)

Abstract

Background: Patients with Diabetes Mellitus (DM) are at an increased risk for cardiovascular disease (CVD); however, not all individuals with DM carry the same elevated risk. We sought to evaluate whether coronary artery calcium (CAC) could further risk stratify individuals with DM and identify those expected to derive the most and least benefit from primary prevention aspirin and statin therapy.

Methods: A total of 478 MESA participants (men and women aged 45-84 years free of clinical CVD) had diabetes at the baseline exam (fasting glucose ≥ 126mg/dL or currently taking insulin or oral hypoglycemic medication) and were not taking aspirin or statin. CVD event rates and multivariable-adjusted hazard ratios were compared after stratification by CAC score (0, 1-100, and > 100); 5-year number needed to treat (NNT) was calculated for both aspirin and statin by applying the established benefit for each respective treatment (rate reduction 10% for aspirin and 37% for statin) to the event rates within each CAC score group.

Results: Over median follow-up of 7.6 years (IQR 7.2 - 7.8) there were 63 (13.2%) incident CVD events. Individuals with CAC 0 (n=213, 44.5%) had an event rate of 7.70 per 1,000 person-years, whereas those with CAC 1-100 (n=137, 28.7%) and CAC > 100 (n=128, 26.8%) had event rates of 24.09 and 41.14 per 1,000 person-years respectively. After multivariable adjustment, the presence of CAC was associated with a significant increase in the risk of CVD events (Table). For CVD, the predicted 5-year NNT with aspirin was 278 for CAC 0, 93 for CAC 1-100, and 57 for CAC > 100. The 5-year NNT with statin was 75, 25, and 15 for CAC 0, 1-100, and > 100 respectively.

Conclusion: Although as a group, patients with DM have an increased risk of CVD, as individuals, the risk of CVD is heterogeneous. CAC can further risk stratify this cohort of individuals traditionally classified as high risk, and may be used to identify individuals who are most and least likely to benefit from primary preventive therapies.