Coronary computed tomography angiography as a screening tool for moderate-high risk asymptomatic type 2 diabetes mellitus patients

Abstract

Background: There are few data on the clinical significance of coronary computed tomography angiography (CCTA) in asymptomatic type 2 diabetes mellitus (T2DM) patients. We performed a retrospective study to evaluate coronary heart disease (CHD) screening in asymptomatic patients with T2DM using CCTA and CHD risk stratification prediction.

Materials and methods: Data from 141 T2DM patients (58 ± 8 years, 57% males) without known symptoms suggestive of CHD who underwent CCTA were retrospectively analyzed. The patients were classified into three subgroups based on United Kingdom prospective diabetes study (UKPDS) CHD risk stratification prediction. Seventy-four patients without diabetes mellitus and CHD who underwent CCTA successively were chosen as the control group. The segment involvement score (SIS), segment stenosis score (SSS), stenosis coefficient (SC), severe proximal plaque (SPP) positive ratio and CCTA-adapted Leaman score (CT-LeSc) based on CCTA data were evaluated and compared among the groups.

Results: Compared with the patients in the control group, patients in the moderate-high risk DM groups had higher scores on the SIS, SSS, SC, CT-LeSc, and a higher SPP positive ratio (all p-values < 0.001), and no difference was observed between the low-risk group and the control group (p = 0.136, p = 0.088, p = 0.0.067, p = 0.225, p = 1.000, respectively). Compared with patients in the control group, the patients in the moderate-high risk DM groups had increased odds of SIS > 3 [odds ratio (OR) = 6.557, p < 0.001; OR = 4.455, p < 0.001, respectively], SSS > 5 (OR = 5.727, p < 0.001; OR = 5.144, p < 0.001, respectively), CT-LeSc > 8.7 (OR = 3.780, p = 0.001; OR = 2.804, p = 0.007, respectively), and obstructive stenosis (OR = 7.233, p < 0.001; OR = 5.787, p < 0.001, respectively).

Conclusion: The moderate-high CHD risk patients had increased odds of obstructive coronary artery stenosis, and the distribution of coronary artery stenosis was more extensive and more severe in that group compared to the patients without diabetes mellitus and CHD. CHD can be effectively screened in moderate-high risk asymptomatic T2DM patients using CCTA.

Keywords: United Kingdom prospective diabetes study; coronary computed tomography angiography (CCTA); coronary heart disease; risk stratification prediction; type 2 diabetes mellitus.

FIGURE 1

A flow diagram of the study.

FIGURE 2

A case example of 55-years-old man with T2DM for 10 years. (A) The MIP of coronary tree with blood pool removal shows right dominance and six non-obstructive stenosis segments in LAD, D1, LCx, and RCA. (B) The straightened MPR of LAD shows a mixed plaque with mild lumen stenosis in LM. The CT-LeSc = 5 × 1.5 × 0.615 (weighting for localization × type of plaque × stenosis severity) = 4.61. (C) The straightened MPR of LAD shows mixed plaques with mild lumen stenosis in proximal and mid LAD, a calcified plaque with mild lumen stenosis in D1. The CT-LeSc = 3.23 (3.5 × 1.5 × 0.615), 2.31 (2.5 × 1.5 × 0.615), 0.62 (1 × 1 × 0.615), respectively. (D) The straightened MPR of LCx show a calcified plaque with mild lumen stenosis in proximal LCx. The CT-LeSc = 0.92 (1.5 × 1 × 0.615). (E) The straightened MPR of RCA show a calcified plaque with mild lumen stenosis in proximal RCA. The CT-LeSc = 0.62 (1 × 1 × 0.615). The total CT-LeSc of this patient = 4.61 + 3.23 + 2.31 + 0.62 + 0.92 + 0.62 = 12.31. There are six segment coronary plaques, so the SIS of this patient is 6. Mild lumen stenosis is found in all 6 plaques with score 1 of SSS, the SSS of this patient is 6. The SC = SSS÷SIS = 1. There is no severe proximal plaque in the proximal of LAD, LCx, and RCA, so the SPP is negative. MIP, maximum density projection; MPR, multiplanar reconstruction; LAD, left anterior descending; LM, left main; D1, 1st diagonal; LCx, left circumflex; RCA, right coronary artery; CT-LeSc, CCTA-adapted Leaman score; SIS, segment involvement score; SSS, segment stenosis score; SC, stenosis coefficient; SPP, severe proximal plaque.

FIGURE 3

The proportion of obstructive stenosis plaque (A) and plaque composition proportion (B) in the control group and DM subgroups.

FIGURE 4

The difference in the CCTA stenosis scores among the control group and DM subgroups. SIS (A), SSS (B), SC (C), and CT-LeSc (D). SIS, segment involvement score; SSS, segment stenosis score; SC, stenosis coefficient; CT-LeSc, CCTA-adapted Leaman score. *p-value < 0.05.

FIGURE 5

The SPP-positive ratio of the control group and DM subgroups.

FIGURE 6

The SIS > 3, SSS > 5, CT-LeSc > 8.7, and obstructive stenosis odds ratio (95% CI) of the DM group and subgroups. SIS, segment involvement score; SSS, segment stenosis score; SC, stenosis coefficient; CT-LeSc, CCTA-adapted Leaman score. The control group was used as the reference group.