Incidence and prevalence of unrecognized myocardial infarction in people with diabetes: a substudy of the Rosiglitazone Evaluated for Cardiac Outcomes and Regulation of Glycemia in Diabetes (RECORD) study

Objective: To examine the prevalence and incidence of unrecognized myocardial infarction in a contemporary population with type 2 diabetes.

Research design and methods: We performed a retrospective analysis of the electrocardiograms (ECGs) recorded at baseline and after 2 years for the first 1,004 type 2 diabetic individuals to be randomized in the Rosiglitazone Evaluated for Cardiac Outcomes and Regulation of Glycemia in Diabetes (RECORD) study.

Results: ECGs suitable for analysis were obtained from 669 participants. The prevalence of unrecognized Q-wave myocardial infarction at baseline was 1.9% (n = 13). The incidence of unrecognized Q-wave myocardial infarction at the end of 2 years of follow-up was 1.5/1,000-person-years (n = 2). One-third (13 of 39) of prevalent and one-quarter (2 of 8) of incident myocardial infarctions were unrecognized.

Conclusions: Although the prevalence and incidence of myocardial infarction was low, unrecognized Q-wave myocardial infarctions made up a substantial proportion of all events.