Incremental prognostic value of ischemic score quantified by stress dynamic CT myocardial perfusion in patients with and without diabetes mellitus

This study aimed to assess the incremental prognostic value of ischemic score quantified by stress dynamic CT myocardial perfusion imaging (CT-MPI) in patients with and without diabetes mellitus (DM). 331 patients (92 patients with DM) with suspected coronary artery disease (CAD) who underwent coronary computed tomography angiography (CCTA) and CT-MPI were included. Major adverse cardiovascular events (MACE) included cardiac death, acute coronary syndrome (ACS), late revascularization, and hospitalizations attributable to heart failure. Ischemic score was assessed based on reduced myocardial blood flow across 16 segments. An ischemic perfusion defect (IPD) was identified as ischemic score ≥ 4. During a median follow-up of 15 (9, 40) months, 49 patients (14.8%) experienced MACE. IPD was an independent predictor for the development of MACE in both DM (HR: 11.64, p = 0.019) and non-DM patient groups (HR: 8.66, p = 0.004). Adding IPD to clinical risk factors and CCTA characteristics increased the C-index for predicting MACE from 0.72 to 0.80 in DM patients (p = 0.005) and from 0.76 to 0.83 in non-DM patients (p = 0.006). IPD quantified by stress dynamic CT-MPI had incremental prognostic value over traditional clinical risk factors and anatomic parameters in both DM and non-DM patients.