Background: Patients with diabetes are frequently admitted for acute myocardial infarction (AMI) on antihyperglycemic agents but may be discharged without glucose-lowering therapy. We examined the frequency of this practice and evaluated the associated outcomes of readmission and mortality.
Methods and results: We conducted a retrospective study of 24 953 Medicare beneficiaries with diabetes discharged after hospitalization for AMI. We examined the frequency of discontinuation of antihyperglycemic agents on discharge among those patients admitted on a diabetic regimen. The independent association between discharge on versus off antihyperglycemic therapy and outcomes at 1 year was assessed in multivariable Cox proportional hazards models, adjusting for patient, physician, and hospital variables. The primary outcome was time to death within 1 year of discharge; secondary outcomes were time to first rehospitalization within 1 year for AMI, heart failure, and all causes. There were 8751 patients admitted on at least 1 antihyperglycemic agent who met our inclusion/exclusion criteria. Of these, 7581 (86.6%) were discharged on antihyperglycemic therapy and 1170 (13.4%) were discharged off antihyperglycemic therapy. After multivariable analysis, as compared with those whose diabetes therapy was continued at discharge, patients who were not prescribed a glucose-lowering agent had higher 1-year mortality rate (hazard ratio, 1.29; 95% confidence interval, 1.15 to 1.45). Readmission rates did not differ significantly between the 2 groups (hazard ratio, 0.95; 95% confidence interval, 0.87 to 1.03).
Conclusions: In older patients with diabetes after AMI, discontinuation of antihyperglycemic therapy is common and associated with higher mortality rates. The reasons behind this practice as well as the specific effects of hyperglycemia after AMI merit further study.