Implications and Treatment of Acute Hyperglycemia in the Setting of Acute Myocardial Infarction

Abstract

A 52-year-old obese male without a prior history of diabetes mellitus (DM) presented with angina and an anterior ST-segment–elevation myocardial infarction (STEMI). Physical examination and chest x-ray were consistent with congestive heart failure. Admission glucose was 230 mg/dL. Coronary angiography revealed an occluded left anterior descending coronary artery, and stenting reestablished TIMI grade 2 flow in that artery within 90 minutes of symptom onset. Left ventricular ejection fraction was 35% with severe anterior hypokinesis. Peak creatine kinase was 600 IU. The next day, fasting glucose was 180 mg/dL. An echocardiogram performed 6 weeks after discharge revealed an ejection fraction of 35% without change in the anterior wall motion. Fasting glucose as an outpatient was 156 mg/dL. The scenario described above is commonly encountered and illustrates how hyperglycemia can affect the outcome of patients with STEMI. Hyperglycemia could have affected the following features of this case: (1) Congestive heart failure was present despite only modest myocardial injury by creatine kinase level; (2) despite successful percutaneous coronary intervention, subnormal coronary perfusion was observed; and (3) left ventricular recovery after STEMI did not occur. Cardiologists need to be cognizant of the hazards associated with hyperglycemia in this setting because these patients will be encountered more frequently as a result of the increasing prevalence of insulin resistance syndromes. Acute hyperglycemia is common in patients with STEMI even in the absence of a history of type 2 DM. Hyperglycemia is encountered in up to 50% of all STEMI patients, whereas previously diagnosed DM is present in only 20% to 25% of STEMI patients.1 The prevalence of type 2 DM or impaired glucose tolerance may be as high as 65% in MI patients without prior DM when oral glucose tolerance testing is performed.2 Elevated …