Both Diabetes Duration and Cumulative Hyperglycemic Exposure Promote Myocardial Fibrosis and Increase Coronary Microvascular Resistance Evaluated by Comprehensive Myocardial CT Perfusion

Background: Diabetes cardiomyopathy is raising attention recently, however, there is few clinical study to evaluate changes in the early stage before clinical signs appear. The present study investigated the risk of diabetes duration and cumulative hyperglycemic exposure (CHE) to myocardial extracellular volume (ECV), a marker of myocardial fibrosis, and coronary microvascular resistance (CMVR) assessed by dynamic myocardial CT perfusion (DMCTP). Material and Methods: We assessed 192 patients who had undergone DMCTP from April 2016 to October 2017. Patients with significant coronary stenosis and previous stent intervention were excluded. ECV of myocardium was calculated from CT delay enhancement subtraction image. CMVR was derived from the diastolic pressure gradient divided by myocardial blood flow. We defined HbA1c debt as sum of elevated HbA1c in recent 10 years as the indicator of CHE. The impacts of diabetes duration and HbA1c debt to ECV and CMVR were analyzed by multivariable analysis. Results: Diabetic patients showed significant increase of ECV (30.4±4.4% vs. 25.9±3.8%, p