The Association of Coronary Artery Calcification With Subsequent Incidence of Cardiovascular Disease in Type 1 Diabetes: The DCCT/EDIC Trials.

OBJECTIVES: This study sought to determine the relationship between coronary artery calcium (CAC) scores and subsequent cardiovascular disease (CVD) events in DCCT (Diabetes Control and Complications Trial)/EDIC (Epidemiology of Diabetes Interventions and Complications) participants.

BACKGROUND: The CAC score has been validated for improved risk stratification in general populations; however, this association has not been well studied in type 1 diabetes (T1DM).

METHODS: Computed tomography (CT) to measure CAC was performed in 1,205 DCCT/EDIC participants at a mean of 42.8 years of age during EDIC years 7 to 9, after the end of DCCT. This study analyzed the association between CAC and time to the first subsequent CVD event or to the first major adverse cardiac event (MACE), a follow-up of 10 to 13 years. CAC was categorized as: 0, >0 to 100, >100 to 300, or >300 Agatston units.

RESULTS: Of 1,156 participants at risk for subsequent CVD, 105 had an initial CVD event (8.5 per 1,000 patient-years); and of 1,187 participants at risk for MACE, 51 had an initial MACE event (3.9 per 1,000 patient-years). Event rates among those with scores of zero (n = 817 [70.7%]) were very low for CVD (5.6 per 1,000 patient years). CAC scores >100 to 300 (hazard ratio [HR]: 4.17, 5.40) and >300 (HR: 6.06, 6.91) were associated with higher risks of CVD and MACE, respectively, compared to CAC of 0 (p < 0.0001). CAC scores >0 to 100 were nominally associated with CVD (HR: 1.71; p = 0.0415) but not with MACE (HR: 1.11; p = 0.8134). Similar results were observed when also adjusted for mean HbA and conventional CVD risk factors. The increment in the AUC due to CAC was modest.

CONCLUSIONS: CAC scores >100 Agatston units were significantly associated with an increased risk of the subsequent occurrence of CVD and MACE in DCCT/EDIC cohort. (Diabetes Control and Complications Trial [DCCT]; NCT00360815; Epidemiology of Diabetes Interventions and Complications [EDIC]; NCT00360893).