Abstract 9342: Risk Stratification in a Diabetic Population With Metabolic Syndrome Using Coronary Calcium Scores: Diabetes Heart Study
Introduction: Patients with diabetes and metabolic syndrome (MetS) have increased all cause mortality, in part due to increased cardiovascular disease. In this high risk group it remains unclear whether coronary artery calcium (CAC) scores provide additional information about risk for total mortality independent of conventional risk factors.
Methods: 1109 participants, ages 34–86, with diabetes and MetS in the Diabetes Heart Study (DHS) were followed for an average of 7.4 years. Subjects were separated into five groups based on CAC scores derived from baseline CT scans, CAC (0–9, 10–99, 100–299, 300–999, and ≥ 1000). Logistic regression was performed with and without adjustment for age, gender, race, smoking and low density lipoprotein (LDL) to examine the association between CAC group and all cause mortality. Natural splines for the continuous measure of CAC were fit to estimate the relationship between observed CAC and the risk of mortality.
Results: Overall, 9.4% (104/1109) of participants died during follow-up. In univariate analysis, the ORs (95%CI, p-values)) for all cause mortality using CAC 0–9 as reference group were CAC 10–99: 5.47 (0.66–44.33, p = 0.11); CAC 100–299: 11.6 (1.43–93.9, p = 0.02); CAC 300–999: 18.4 (2.43–139.45, p = 0.005); CAC ≥1000: 39.0 (5.37–282.91, p = 0.0003). Similar results were observed in fully adjusted model, CAC 10–99: 3.86 (0.46–32.57, p=0.2); CAC 100–299: 6.69 (0.79–56.90, p=0.08); CAC 300–999: 12.57 (1.63–96.98, p=0.02); CAC ≥ 1000: 23.61 (3.15–176.71, p=0.002). Using spline regression, the estimated risk (95% CI) of mortality for CAC=0 was 2.1% (1.1%, 3.9%) and risk increased nearly linearly plateauing at a CAC level of ≥ 1000 with a risk of 15.5% (7.9%, 28.2%).
Conclusion: In this cohort of diabetics with MetS at high risk for death, CAC was shown to be a strong independent predictor of mortality. Participants with low or no CAC were at low risk (0.3% annual mortality). The risk of mortality increased with increasing levels of CAC with a plateau at about CAC ≥ 1000, which defined a population at very high risk (2.1% annual mortality). More research is warranted to determine the potential utility of CAC scans for risk stratification in this high risk patient population.
- © 2010 by American Heart Association, Inc.