Abstract 13426: Diabetes Severity is Associated with High Risk Plaque by Coronary CT Angiography: The FACTOR-64 Trial

Abstract

PURPOSE: Diabetes mellitus (DM) patients are at high risk for coronary artery disease (CAD), but noninvasive measurement of CAD extent and severity has not previously been available. Non-calcified plaque (NCP), luminal stenosis and positive remodeling measured by coronary CT angiography (CCTA) are related to adverse events. The purpose of this study was to determine the relationship between CAD assessed by CCTA and DM severity in asymptomatic DM subjects of the FACTOR-64 trial.

METHODS: Prospectively evaluated DM patients (N =104, 42% Male, 81% type II, mean age 61±7 yrs), without cardiac symptoms or known CAD, underwent 64-slice CCTA. Proximal coronary segments >2mm in luminal diameter were contoured using Vitrea fX 6.1 software (N=407). Percent atheroma volume (PAV) was total atheroma volume divided by vessel volume. Percentages of calcified (>150HU) and low (<30HU) NCP subtypes were quantified. Type I or II status was patient reported or obtained from the Intermountain Health medical record. Severity of DM was analyzed by diabetes type, duration of DM, 10-year weighted Hemoglobin A1c (HgbA1c), and insulin therapy.

RESULTS: Patients on insulin therapy were younger (59 vs. 64 yrs, p<0.004), yet had longer average diabetes duration (18.7 vs. 9.5 yrs, p<0.001) and poorer glycemic control (HgbA1c 7.6% vs. 6.7%, p<0.001). Insulin users had 10% less low-density NCP (p=0.01), greater PAV (50.6 vs. 47.4, p=0.01), and 12% smaller minimal luminal area (p=0.04). Despite being older (62 vs. 56 years, p=0.002) and having fewer years diabetic (11 vs. 26 years, p<0.001), type II DM patients had 13% greater low-density NCP (p=0.04), 14% less calcified plaque (p=0.04), and greater remodeling index (104 vs. 98%, p=0.03) than type I DM patients. Disease duration was associated with greater % calcified plaque (r=0.22, p=0.045) and lower % low density NCP (r=-0.28, p=0.01). Weighted HgbA1c was associated with greater PAV(r=0.36, p<0.001), larger remodeling index (r=0.25, p=0.01) and smaller minimal luminal area (r= -0.20, p= 0.048).

CONCLUSIONS: High-risk plaque characteristics by CCTA were associated with insulin use, type II status, and increasing HgbA1C. CCTA screening may be useful for enhanced risk stratification in DM patients.