Objective: Diabetes mellitus (DM) has been associated with an elevated, short-term risk of death after myocardial infarction (MI). Among the studies of DM, however, few studies have included elderly subjects. The purpose of the present investigation was to determine if non-insulin-treated DM (NIRxDM) and insulin-treated DM (IRxDM) were associated with specific comorbid conditions, clinical findings on arrival, and MI characteristics, as well as a higher 30-day mortality rate in elderly patients with acute MI.
Design: The study design was a retrospective medical record review and secondary data analysis of previously collected data from the Cooperative Cardiovascular Project.
Setting: Study setting was Connecticut from June 1, 1992, through February 28, 1993.
Patients: Subjects included the entire Medicare population (n = 2050), aged 65 years or older who were hospitalized for acute MI.
Outcome measures: Mortality rate at 30 days after MI was measured.
Results: A history of DM was observed in 29% of the study population. DM status was associated with previous comorbid conditions, poorer functional status, higher body mass index, heart failure on arrival, non-Q-wave MI, and development of atrial fibrillation and oliguria during hospitalization. Patients with DM were less likely to have chest pain on arrival to the hospital. Diabetic status was not a significant predictor of short-term mortality; at 30 days after MI, 17% (n = 242) of the subjects without DM, 19% (n = 71) of those with NIRxDM, and 18% (n = 39) of the subjects with IRxDM died (P = .460). After adjustment for other prognostic factors, it was noted that MI characteristics present on hospital arrival predicted mortality at 30 days in both patients with NIRxDM and patients with IRxDM.
Conclusions: The slightly, but not significantly, increased mortality risk in patients with DM should not minimize the importance of monitoring DM in the acute MI setting. Hospitalization for MI provides an opportunity to provide aggressive lipid and blood pressure management, optimize blood glucose, control heart failure, and institute other secondary preventive interventions in the elderly population with DM.