Long-term prognostic value of coronary computed tomography angiography for asymptomatic patients with CAD in type 2 diabetes mellitus

The present study was performed to investigate the prognostic value of coronary computed tomography angiography (CTA) results for asymptomatic patients with coronary artery disease (CAD) in type 2 diabetes mellitus (T2DM). A total of 164 asymptomatic patients with T2DM were enrolled at Weifang Traditional Chinese Hospital (Weifang, China). Coronary plaques and stenosis severity were evaluated after CTA. Structures >1 mm² adjacent to or within the coronary artery lumen that could be clearly separated from the vessel lumen, was scored as a coronary plaque. Stenosis of ≥50% was considered as being obstructive. CAD was defined as the presence of any coronary plaque or a coronary artery calcium (CAC) score of >0. A CAC score of 0 and no coronary plaques was considered to indicate the absence of CAD. A 5-year follow-up was performed to determine the impact of the CTA findings and various clinicopathological characteristics on the prognosis of all participants. The primary end-point was any cardiac event. Event-free survival curves were plotted using the Kaplan-Meier method and compared using the log-rank test. Based on the coronary CTA results, the patients were classified into 3 groups according to the extent of stenosis: Normal coronary arteries, obstructive CAD and non-obstructive CAD. Significant differences in 5-year event-free survival were identified among the groups with normal coronary arteries, non-obstructive CAD and obstructive CAD (P=0.026). Further analysis indicated that the event-free survival rate of patients with 1-vessel CAD was 94.11%, that of patients with 2-vessel CAD was 73.68% and that associated with 3-vessel CAD was 61.54%. Multivariate Cox regression analysis revealed that non-obstructive as well as obstructive CAD diagnosed by coronary CTA are prognostic indicators for asymptomatic T2DM patients [hazard ratio (HR)=11.132, 95% confidence interval (CI): 1.857-66.742, P=0.008; HR=7.792, 95% CI: 1.750-34.698, P=0.007, respectively]. In conclusion, the present study suggests that coronary CTA may predict the prognosis of asymptomatic patients with T2DM.