Abstract 9985: Comprehensive Cardiac Magnetic Resonance Imaging Study for Characterising Remote Myocardial Zone Contractile Function, Perfusion and Fibrosis in Type 2 Diabetes Patients with Prior Myocardial Infarction

Abstract

Background: Type 2 diabetes (T2D) is associated with accelerated increased risk of myocardial infarction (MI). However, ventricular dysfunction has been identified also in T2D patients without prior MI. Objectives: Using cardiac magnetic resonance (CMR), we assessed the effect of established MI on the non-infarcted myocardium’s contractile function, rest and stress myocardial blood flow (MBF) and extra cellular volume fraction (ECV) by comparing remote zone assessments in T2D patients with prior MI (priorMI-DM) to the global assessments in T2D patients with no MI (noMI-DM) and in controls. We also aimed to extrapolate the contributions of infarct size and glycemic control (HBA1c) to cardiac functional changes (global longitudinal strain [GLS] and left ventricular ejection fraction [LVEF]) in T2D. Methods: Age and sex matched 42 priorMI-DM, 47 noMI-DM, and 22 controls underwent CMR (3T). Results: Table-1 shows clinical and CMR data. Both T2D groups showed significant reductions in LVEF and GLS. PriorMI-DM remote zone stress MBF was decreased compared to stress MBF in noMI-DM and controls (remote zone priorMI-DM 1.6±0.6ml/g/min vs global noMI-DM 1.8±0.4ml/g/min vs global control 1.9±0.4ml/g/min, p=0.01). Remote ECV and global ECV were similar in priorMI-DM and were increased compared to noMI-DM and controls. Remote ECV correlated with infarct size (r=0.66, p=0.001). In priorMI-DM, infarct size correlated with GLS (r=0.4, p=0.005) and with LVEF (r=0.2, p=0.03) but not HBA1c. In noMI-DM, there was a significant correlation between HBA1c and GLS (r=0.3, p=0.03). Conclusions: T2D patients exhibit reductions in LVEF and GLS even in the absence of prior MI, suggesting that metabolic factors beyond high prevalence of MI contribute to the cardiac dysfunction in T2D. T2D patients with prior MI show significant increases in ECV in the remote zone, accompanied by reductions in stress MBF, while remote zone contractile function remains preserved.