CHICAGO – Acute myocardial infarction patients who have diabetes are less likely to present with an ST-elevation MI, yet they run a significantly increased risk for in-hospital death, compared with nondiabetic MI patients.
Moreover, MI patients with diabetes are more likely to experience in-hospital stroke, recurrent MI, and heart failure or pulmonary edema, according to Dr. Quang T. Bui of Harbor-UCLA Medical Center, Los Angeles.
Dr. Bui presented an analysis of 232,927 patients presenting with acute MI to 823 hospitals participating in the National Registry of Myocardial Infarction (NRMI) 4-5. A history of diabetes was noted in 31%.
The in-hospital mortality rate was 10.1% in diabetic patients and 8.3% in nondiabetic patients. In-hospital strokes occurred in 1.4% of diabetics compared with 1.0% of nondiabetic patients. The in-hospital rate of recurrent MI was 1.5% in the diabetic patients and 1.3% in those without diabetes.
Diabetes patients hospitalized for MI had an 18% greater risk of in-hospital mortality than did nondiabetic patients. They also had a 30% greater risk of in-hospital stroke, a 14% increased risk of in-hospital recurrent MI, and a 57% greater risk of developing in-hospital heart failure or pulmonary edema.
An ST-elevation MI occurred in 31% of diabetic patients and 40% of nondiabetic patients. Anterior/septal MI occurred in 14.7% of diabetic MI patients and 18.9% of those without diabetes. However, 11.5% of MI patients with diabetes were Killup class III/IV, compared with 6.5% of those without diabetes.
A history of previous MI was present in 31% of diabetic patients compared with 22% of those without diabetes. The diabetic group also had significantly higher rates of background hypercholesterolemia, hypertension, renal dysfunction, previous revascularization, and prior stroke.
Preadmission use of cardiovascular risk-reducing medications was more common among the diabetic MI patients. Yet the use of these agents was actually low given that diabetes is a well-recognized risk factor for cardiovascular disease, Dr. Bui observed. Less than half of diabetic MI patients were on an ACE inhibitor or an angiotensin receptor blocker prior to their hospitalization for an MI. About 30% were taking a beta-blocker. A similar proportion of patients used a statin or other lipid-lowering agent.
Health care planners will be particularly interested in the NRMI 4-5 finding that the mean hospital length of stay was 6.5 days in acute MI patients with diabetes, compared with 5.2 days in those without a history of diabetes, Dr. Bui noted. Diabetes patients with a history of MI were hospitalized for about 20 hours longer than were nondiabetic patients with a prior MI. And diabetes patients without a prior MI were hospitalized for 14 hours longer than were nondiabetic patients with a history of MI, Dr. Bui said.
The NRMI project is funded by Genentech. Dr. Bui reported having no financial conflicts.