Newly Discovered Abnormal Glucose Tolerance in Patients With Acute Myocardial Infarction and Cardiovascular Outcomes: A Meta-analysis

BACKGROUND The prevalence of unrecognized abnormal glucose tolerance (AGT) and the incidence of recurrent cardiovascular (CV) events in patients with acute myocardial infarction (MI) has not been systematically evaluated. PURPOSE The purposes of this study were to define the prevalence of newly discovered AGT and examine the risk of recurrent major adverse cardiac events (MACE) and mortality in patients with acute MI. DATA SOURCES Medline, Embase, Cochrane Library, and Google Scholar were searched for relevant articles. STUDY SELECTION Inclusion criteria included prospective studies in patients with acute MI without known history of diabetes; AGT diagnosed using fasting plasma glucose, 2-h oral glucose tolerance test, or HbA1c; and incidence of MACE and/or all-cause mortality in newly discovered AGT. DATA EXTRACTION Two investigators extracted the data. Pooled prevalence, incidence rate ratios, and hazard ratios (HRs) were calculated using random-effects models. DATA SYNTHESIS In 19 studies (n = 41,509, median follow-up 3.1 years), prevalence of newly discovered AGT was 48.4% (95% CI 40.2–56.6). Prediabetes had a higher mortality risk than normal glucose tolerance (NGT) (HR 1.36 [95% CI 1.13–1.63], P < 0.001) and MACE (1.42 [1.20–1.68], P < 0.001). Newly diagnosed diabetes had higher mortality risk than NGT (1.74 [1.48–2.05], P < 0.001) and MACE (1.54 [1.23–1.93], P < 0.001). LIMITATIONS This is not a meta-analysis of individual patient data. Time-to-event analysis and covariate-adjusted analysis cannot be conducted to examine heterogeneity reliably. Few studies reported CV death and heart failure hospitalizations. CONCLUSIONS Patients with acute MI have a high prevalence of newly discovered AGT. Aggressive risk reduction strategies in this population, especially in those with prediabetes, are warranted.