Abstract 10484: Cardiac Adaptation to Acute Haemodynamic Stress in Patients with Type 2 Diabetes

Abstract

Background: Due to varying cardiac workloads, efficient demand-supply matching is crucial for maintaining normal cardiac function. Cardiac metabolism is profoundly affected by changes in cardiac workload. There is scarcity of non-invasive studies evaluating how the heart adapts to hemodynamic stress in type 2 diabetes (T2D) patients. Objectives: Using cardiovascular magnetic resonance (CMR) and 31 Phosphorus MR spectroscopy ( 31 P-MRS) we assessed changes in cardiac energetics, perfusion, strain, systolic and diastolic function in response to increases in cardiac workload with dobutamine stress in T2D patients and healthy volunteers (HV). Methods: 24 T2D patients and 18 matched HV were recruited. Participants with ischemic heart disease were excluded. Results: Table-1 shows clinical and CMR/ 31 P-MRS data. Compared to HV, T2D patients showed reductions in left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) at rest, and a blunted increase in LVEF and GLS during stress. Diastolic function was impaired in T2D with lower mitral in-flow E/A ratio compared to HV at rest, which was further reduced during stress in both groups. Stress myocardial blood flow was lower in T2D patients.Compared to HV, rest phosphocreatinine (PCr)/ATP ratio was 17% lower in T2D patients, with a further 8% reduction during stress. However, there was a more pronounced reduction in the PCr/ATP with stress in HV (33% relative reduction), although stress PCr/ATP remained numerically higher in HV compared to T2D patients. Conclusions: T2D is associated with blunted ability of the myocardium to significantly increase contractile function from rest to stress. Moreover, T2D patients show exacerbated reductions in myocardial energetics and diastolic function during stress. Although reductions in myocardial energetics and diastolic function in response to acute stress were also detected in HV, these assessments remained higher in HV at stress compared to T2D patients.