Prospective randomised study of intensive insulin treatment on long term survival after acute myocardial infarction in patients with diabetes mellitus

TLDR

Diabetes is common in acute myocardial infarction patients and is linked to poor short‑ and long‑term outcomes, largely due to inadequate metabolic control that can be improved with insulin therapy. The study aimed to determine whether intensive insulin treatment—starting with an insulin‑glucose infusion followed by multidose insulin—improves prognosis in diabetic patients with acute myocardial infarction. Patients were randomized to standard care plus a 24‑hour insulin‑glucose infusion and subsequent multidose insulin versus standard care alone; 620 participants (306 intensive, 314 control) were followed for long‑term all‑cause mortality. Intensive insulin therapy lowered long‑term mortality by 11 % (relative risk 0.72, 95 % CI 0.55–0.92, P = 0.011), especially in those without prior insulin use and low cardiovascular risk, equating to one life saved per nine treated over a mean 3.4‑year follow‑up.

Abstract

<h3>Abstract</h3> <b>Objectives:</b> To test the hypothesis that intensive metabolic treatment with insulin-glucose infusion followed by multidose insulin treatment in patients with diabetes mellitus and acute myocardial infarction improves the prognosis. <b>Design:</b> Patients with diabetes mellitus and acute myocardial infarction were randomly allocated standard treatment plus insulin-glucose infusion for at least 24 hours followed by multidose insulin treatment or standard treatment (controls). <b>Subjects:</b> 620 patients were recruited, of whom 306 received intensive insulin treatment and 314 served as controls. <b>Main outcome measure:</b> Long term all cause mortality. <b>Results:</b> The mean (range) follow up was 3.4 (1.6-5.6) years. There were 102 (33%) deaths in the treatment group compared with 138 (44%) deaths in the control group (relative risk (95% confidence interval) 0.72 (0.55 to 0.92); P=0.011).The effect was most pronounced among the predefined group that included 272 patients without previous insulin treatment and at a low cardiovascular risk (0.49 (0.30 to 0.80); P=0.004). <b>Conclusion:</b> Insulin-glucose infusion followed by intensive subcutaneous insulin in diabetic patients with acute myocardial infarction improves long term survival, and the effect seen at one year continues for at least 3.5 years, with an absolute reduction in mortality of 11%. This means that one life was saved for nine treated patients. The effect was most apparent in patients who had not previously received insulin treatment and who were at a low cardiovascular risk. <h3>Key messages</h3> Diabetes mellitus is common among patients with acute myocardial infarction Diabetic patients with myocardial infarction have a poor short and long term prognosis Poor metabolic control is common among diabetic patients with myocardial infarction Improved metabolic control by means of acute insulin-glucose infusion followed by long term intensive insulin treatment improves long term prognosis among these patients