Elective percutaneous coronary intervention: the relationship between preprocedural blood glucose levels and periprocedural myocardial injury

Regardless of the diabetic status of patients with coronary artery disease, hyperglycemia and hypoglycemia are adversely associated with cardiovascular events. The relationship between glucose levels and increased mortality risk in acute myocardial infarction has been shown through various glucose metrics; however, there is a dearth of multivariate analysis of the relationship between elective coronary angioplasty and preprocedural blood glucose levels. We evaluated the relationship between preprocedural blood glucose levels and myocardial injury in 1,012 consecutive patients who underwent elective percutaneous coronary angioplasty. The patients were classified into 4 glycemic groups on the basis of blood glucose levels measured immediately before the procedure: hypoglycemic, euglycemic, mildly hyperglycemic, and hyperglycemic. Samples for troponin I and creatine kinase-MB fraction were collected before each procedure and at 8, 16, and 24 hours after each procedure. Bivariate analysis revealed that postprocedural troponin I levels were significantly higher in the hyperglycemic group (P=0.027). Although postprocedural levels of creatine kinase-MB fraction rose insignificantly in the hypoglycemic patients, our results showed that these patients were more likely to have postprocedural levels 2 to 5 times the upper limit of normal (P=0.013). We tentatively conclude that abnormally low preprocedural plasma glucose levels-together with a recent history of smoking-are associated with an increased incidence of periprocedural myocardial injury in patients undergoing elective percutaneous coronary intervention.