How to best manage glycemia and non-glycemia during the time of acute myocardial infarction

Abstract

Acute myocardial infarction (AMI) is common in patients with diabetes. Reasons for this are multifactorial, but all relate to a variety of maladaptive responses to acute hyperglycemia. Persistent hyperglycemia is associated with worse left ventricular function and higher mortality during AMI, but intervention data are far from clear. Although there is a theoretical basis for the use of glucose-insulin-potassium infusion during AMI, lack of outcome efficacy (and inability to reach glycemic targets) in recent randomized trials has resulted in little enthusiasm for this strategy. Based on the increasing understanding of the dangers of hypoglycemia, while at the same time appreciating the role of hyperglycemia in AMI patients, goal glucose levels of 140-180 mg/dL using an intravenous insulin infusion while not eating seem reasonable for most patients and hospital systems. Non-glycemic therapy for patients with diabetes and AMI has benefited from more conclusive data, as this population has greater morbidity and mortality than those without diabetes. For ST-elevation myocardial infarction (STEMI), reperfusion therapy with primary percutaneous coronary intervention or fibrinolysis, antithrombotic therapy to prevent acute stent thrombosis following percutaneous coronary intervention or rethrombosis following thrombolysis, and initiation of β-blocker therapy are the current standard of care. Emergency coronary artery bypass graft surgery is reserved for the most critically ill. For those with non-STEMI, initial reperfusion therapy or fibrinolysis is not routinely indicated. Overall, there have been dramatic advances for the treatment of people with AMI and diabetes. The use of continuous glucose monitoring in this population may allow better ability to safely reach glycemic targets, which it is hoped will improve glycemic control.

FIG. 1.

General instructions for University of Washington intravenous insulin infusion protocol. BG, blood glucose; D₅½NS, dextrose 5% in 0.45% NaCl; D₁₀W, dextrose 10% in water; DM, diabetes mellitus; HMC, Harborview Medical Center; ICU, intensive care unit; IV, intravenously; IVF, intravenous fluid; NS, normal saline; s/p CABG, status post-coronary artery bypass graft; SubQ, subcutaneous; T1DM, type 1 diabetes mellitus; TPN, total parenteral nutrition.

FIG. 1.

General instructions for University of Washington intravenous insulin infusion protocol. BG, blood glucose; D₅½NS, dextrose 5% in 0.45% NaCl; D₁₀W, dextrose 10% in water; DM, diabetes mellitus; HMC, Harborview Medical Center; ICU, intensive care unit; IV, intravenously; IVF, intravenous fluid; NS, normal saline; s/p CABG, status post-coronary artery bypass graft; SubQ, subcutaneous; T1DM, type 1 diabetes mellitus; TPN, total parenteral nutrition.

FIG. 2.

Insulin infusion algorithm decision tree used to guide insulin infusion rates at the University of Washington Medical Center. BG, blood glucose; TPN, total parenteral nutrition.

FIG. 3.

Column-based insulin infusion protocols. For individuals who require higher doses, a higher infusion rate can be administered. BG, blood glucose.