Demographics
Of 93 patients consenting to participate in ABCD-2, 56
patients had no contraindications to the imaging procedures
and consented to perform both CCTA and ICA.
In eight patients CT angiography was not performed, because
of calcium score >1000, rendering 48 patients eligible
for analysis. The patient population studied was
obese (mean BMI 29.6 kg/m2) and middle-aged (mean
age 64 years) with a long history of T2DM (mean duration
15.6 years), not at optimal glycemic control (mean
HbA1c 7.4 %). The majority were males (75 %). Further
characteristics are given in Table 1.
Imaging assessments
In total 99 % (588 out of 594) of coronary segments with a
luminal diameter ≥1 mm from the full patient population
were eligible for analysis with CCTA. Only 6 segments
were non-interpretable, mainly because of severe artifacts
from pacemaker electrodes. Mean Agatston score was
269, but ranged from 0 to 976 and this did not correlate
with neither diabetes duration (r = 0.05, p = 0.75) or
HbA1c (r = -0.14, p = 0.35). Image quality and degree of
calcifications are detailed in Table 2. In analyzing the 588
segments, CCTA had a sensitivity of 90 % (9 of 10) and a
specificity of 96 % (557 of 578) for detection of coronary
stenosis ≥50 % using ICA as gold standard (Table 3). The
positive predictive value was 30 % (9 of 30) and the negative
predictive value 99 % (556 of 557). Degree of stenosis
per segment analysis and maximum degree of any stenosis