CAC scores may predict future CVD events in patients with type 1 diabetes
Coronary artery calcium scores may be effective in predicting future CVD events in patients with type 1 diabetes, with scores over 100 associated with a significantly increased risk, according to findings presented at the American Heart Association Scientific Sessions.
“We know a lot less about cardiovascular risk and cardiovascular risk factors in type 1 diabetes compared to type 2 diabetes,” Matthew J. Budoff, MD, of the UCLA School of Medicine, Los Angeles Biomedical Research Institute, said during a presentation. “We hear more and more about these new therapies that are being applied to type 2 diabetes – every day there’s a big breaking clinical trial.
We really have less information still about type 1. We know that there is increased risk of cardiovascular complications. Coronary artery calcium score is exceptionally well validated in the setting of diabetes. In the last guidelines that addressed diabetes specifically, it was [a Class] IIa recommendation to do calcium scoring in type 2 diabetes with no recommendations given for type 1. The reason is we really didn’t have outcome data for type 1 diabetes until this study.”
To examine the relationship between coronary artery calcium (CAC) scores and subsequent CVD and major adverse cardiovascular events (MACE), researchers used computed tomography (CT) to measure CAC scores in 1,205 patients who were participating in the Diabetes Control and Complications Trial (DCCT) and the Epidemiology of Diabetes Interventions and Complications (EDIC) study between 2001 and 2003 (mean age, 42.8 years; 1,156 at risk of an initial CVD event; 1,187 at risk of an initial MACE event).
CAC scores were measured in Agatston units and categorized as 0, >0 to 100, >100 to 300 or >300.
Researchers looked at CAC scores in relation to the time of the first subsequent CVD or MACE event over 10 to 13 years. Mean follow-up time was 11 years. During this time, 105 participants had an initial CVD event (8.5 per 1,000 patient years) and 51 participants had an initial MACE event (3.9 per 1,000 patient years).
Researchers found that among the 817 participants with a CAC score of 0, the CVD event rate was low (5.6 per 1,000 patient years).
After adjusting for computed tomography scanning site, gender and age, it was determined that CAC scores >100 were associated with an increased risk of CVD and MACE events with approximately 20% of participants with CAC scores >100 suffering a CV event and approximately 30% of participants with CAC scores >300 suffering a CV event during follow-up.
“I would argue that this data plays out very similarly to the general population where a high calcium score is a high risk for CV events,” Budoff said. “In asymptomatic patients, consider measuring coronary artery calcium. These patients were very low risk with a score of 0 – as the score [goes] above 100, advocate for initiating step therapy.” 
Budoff MJ, et al. 166. The Association of Coronary Artery Calcification (CAC) With Subsequent Cardiovascular Disease (CVD) in DCCT/EDIC. Presented at: American Heart Association Scientific Sessions; Nov. 10-12, 2018; Chicago.
Abstract 13133: The Association of Coronary Artery Calcification (CAC) With Subsequent Cardiovascular Disease (CVD) in DCCT/EDIC Matthew J Budoff, Jye-Yu C Backlund, David A Bluemke, Joseph Polak, Ionut Bebu, David Schade, Suzanne Strowig, Philip Raskin. John M Lachin and the DCCT/EDIC Rsch Group
Originally published5 Nov 2018Circulation. 2018;138:A13133
The coronary artery calcium (CAC)-score has been validated to improve risk assessments for future cardiovascular events in general populations; however, this association has not been well-studied in type 1 diabetes (T1D).
To determine the relationship of CAC-scores with subsequent cardiovascular disease (CVD) and major adverse cardiovascular event (MACE) in DCCT/EDIC participants.
Computed tomography (CT) to measure CAC was performed in 1205 DCCT/EDIC participants (mean age of 42.8 years) in 2001-2003. In this study, we analyzed the association between those CAC-scores and the time to the first subsequent CVD and MACE event over the next 13 years. CVD event included non-fatal myocardial infarction or stroke, cardiovascular death, silent myocardial infarction, angina pectoris, congestive heart failure, or revascularization and MACE event included non-fatal MI, non-fatal stroke, or cardiovascular death. Forty-nine participants with a prior CVD including 18 with a prior MACE were excluded, leaving 1156 and 1187 participants who were at risk of an initial CVD and MACE event, respectively. CAC was categorized as: 0, >0–100, >100–300, or >300 Agatston units.
Of 1156 participants studied, 105 had an initial CVD event during the 13-year follow-up period and 51 of 1187 participants had an initial MACE event. CAC-scores >100-300 and >300 were associated with higher risks of both CVD and MACE, compared to CAC=0, adjusting for CT scanning site, gender, and age (p<0.0001). CAC-scores of >0-100 were nominally associated with CVD but not with MACE. The Table shows the event rate and hazard ratio of CVD and MACE by CAC category.
CAC-scores >100 Agatston units were significantly associated with an increased risk of the subsequent occurrence of both CVD and MACE events in the DCCT/EDIC T1D cohort. The robust CVD event prediction observed using CAC in asymptomatic T1D in this study is similar to CAC studies in the general population.
See figure free and also download powerpoint
www red DiabetologNytt