As part of a larger randomized , single-blind , interventional efficacy study on the effects of hyperinsulinemic glucose control in cardiac surgery ( NCT@ ) , consenting patients were randomly assigned to receive combined administration of insulin and glucose , titrated to preserve normoglycemia ( @-@ @ mmol L ( -@ ) ; experimental group ) , or standard metabolic care ( blood glucose @-@ mmol L ( -@ ) ; control group ) , during open heart surgery .