Recognition of incident diabetes mellitus during an acute myocardial infarction

Background - Diabetes mellitus (DM) is common in patients hospitalized with an acute myocardial infarction (AMI), representing in some cases the first opportunity to recognize and treat DM. We report the incidence of new DM and its recognition among patients with AMI. Methods and Results - Patients in a 24-site US AMI registry (2005-08) had glycosylated hemoglobin assessed at a core laboratory, with results blinded to clinicians and local clinical measurements left to the discretion of the treating providers. Among 2854 AMI patients without known DM on admission, 287 patients (10%) met criteria for previously unknown DM, defined by a core laboratory glycosylated hemoglobin of ≥6.5%. Among these, 186 (65%) were unrecognized by treating clinicians, receiving neither DM education, glucose-lowering medications at discharge, nor documentation of DM in the chart (median glycosylated hemoglobin of unrecognized patients, 6.7%; range, 6.5-12.3%). Six months after discharge, only 5% of those not recognized as having DM during hospitalization had been initiated on glucose-lowering medications versus 66% of those recognized (P<0.001). Conclusions - Underlying DM that has not been previously diagnosed is common among AMI patients, affecting 1 in 10 patients, yet is recognized by the care team only one third of the time. Given its frequency and therapeutic implications, including but extending beyond the initiation of glucose-lowering treatment, consideration should be given to screening all AMI patients for DM during hospitalization. Inexpensive, ubiquitous, and endorsed as an acceptable screen for DM, glycosylated hemoglobin testing should be considered for this purpose.