Objectives: This study tested the impact of intensive metabolic treatment with insulin on transient myocardial ischaemia detected with continuous 12-lead ST-segment monitoring during non-ST segment elevation acute coronary syndromes in type 2 diabetic patients.
Methods and results: The study included 57 type 2 diabetic patients with non-ST segment elevation acute coronary syndromes.Twenty-eight patients randomized to conventional treatment plus intensive insulin therapy (group A) and twenty-nine to conventional therapy only (group B). Group A patients received insulin by infusion for 48 hours according to a predefined protocol aiming to maintain normoglycaemia. Group B patients received standard coronary care unit treatment. The ST-segment monitoring was performed for 48 hours in the coronary care unit. The two groups were comparable in terms of medical history, clinical and biochemical data. Three patients from both groups were excluded from the analysis because there was objective evidence for evolution in persistent ST-segment elevation acute myocardial infarction. Six patients (24%) from group A vs. twelve from group B (46.2%) had evidence of transient ischaemia (p = 0.098). Group A patients showed significantly lower values in the mean number [group A vs. group B: 0.4 +/- 0.8 vs. 2 +/- 3.1, p < 0.01] and total duration of ST-episodes [group A vs. group B: 2.4 +/- 5.1 vs. 21.2 +/- 31 min, p < 0.01]. Multivariate analysis revealed that the mean plasma glucose during the study period was a powerful predictor of the presence (b:0.377,p < 0.01), the number (b:0.523,p < 0.001) and the total duration (b: 0.686, p < 0.001) of ST-episodes, respectively. CONCLUSIONS; Intensive insulin treatment considerably decreases the number and the total duration of ST-episodes in type 2 diabetic patients suffering from non-ST segment elevation acute coronary syndromes.