Incremental effect and risk association of obstructive coronary artery disease on microvascular myocardial ischemia in T2DM patients evaluated via CT myocardial perfusion

Abstract

Objective Microvascular myocardial ischemia (MMI) in patients with T2DM may be influenced by the presence of concomitant obstructive coronary artery disease (OCAD). Our investigation focused on assessing the impact of OCAD on MMI and delineating the prognostic relevance of MMI. Methods This study included four groups: (1) control group without OCAD (n = 125), (2) control group with OCAD (n = 99); (3) T2DM patients without OCAD (n = 100); (4) T2DM patients with OCAD (n = 93). All patients received dynamic computed tomography myocardial perfusion imaging (CT–MPI) as well as coronary computed tomography angiography (CCTA). Univariate and multivariate linear regression analyses were performed to identify independent determinants of clinical characteristics and perfusion metrics related to MMI. Major adverse cardiovascular events (MACEs) were documented, and the prognostic significance of CT–MPI compared with clinical variables was assessed. Results The myocardial blood flow (MBF) stepwise reduced from the control (OCAD−), T2DM (OCAD−), control (OCAD+) to T2DM (OCAD+) group (p < 0.05). Independent associations were observed between global MBF and OCAD or T2DM (OCAD: p < 0.05, R2 = 0.154; T2DM: β = −11.96, p < 0.001, R2 = 0.101). A significant association was observed between OCAD and global MBF in the circumstance of T2DM (R2 = 0.176). An independent association was observed between the global MBF and MACEs (p < 0.05). Conclusion Dynamic CT–MPI combined with CCTA demonstrated that the presence of OCAD in T2DM patients is associated with a greater occurrence of MMI. MBF emerged as a robust predictor of cardiovascular outcomes in this population.