The Effect of Remote Ischemic Preconditioning on Diastolic Function in Coronary Artery Bypass Surgery Between Diabetic and Non-Diabetic Patients

Inclusion Criteria: * All adult patients scheduled for elective isolated on-pump CABG surgery for two- to three-vessel coronary artery disease. * Both males and females will be included. * In the diabetic groups: Type II diabetes currently requiring and adhering to insulin therapy for at least the past 3 months * During cardiopulmonary bypass, the temperature will range from 28-33°C using an esophageal temperature probe. * Antegrade warm cardioplegia will be given by the cardiovascular perfusionist. * Baseline diastolic function will be obtained preoperatively using transthoracic echocardiography done within the six months prior to the surgery Exclusion Criteria: * Combined CABG and valve surgery, emergency CABG. * Type I diabetes, Type 2 diabetes managed with oral hypoglycemic agents without insulin in the past 3 months * Peripheral vascular disease (PVD) affecting the upper limbs. * Acute coronary syndrome (ACS); acute or recent myocardial infarction. * Left ventricular ejection fraction ≤30%. * Serious pulmonary disease necessitating oxygen supplementation or mechanical ventilation. * Renal failure, defined as eGFR \< 30 mL/min/1.73 m² or requiring renal replacement therapy (dialysis). * Liver failure, including Child-Pugh Class B or C cirrhosis, severe hepatocellular dysfunction, or listed for liver transplantation.