Search

Background Intensive glycemic control is generally recommended for diabetic patients to reduce complications. However, the role of glycemic control in the mortality in diabetic patients with acute myocardial infarction (AMI) remained unclear. Methods We selected diabetic patients who measured HbA1c more than 3 times after AMI among 10,719 patients enrolled in the multicenter AMI registry. Patients (n = 1384) were categorized into five groups: according to mean HbA1c level: ≤ 6.5%, > 6.5 to ≤ 7.0%, > 7.0 to ≤ 7.5%, > 7.5 to ≤ 8.0% and > 8.0%. The primary endpoint was all-cause mortality. Results During a median follow-up of 6.2 years, the patients with a mean HbA1c of 6.5 to 7.0% had the lowest all-cause mortality. Compared to patients with mean HbA1c of 6.5 to 7.0%, the risk of all-cause mortality increased in subjects with mean HbA1c ≤ 6.5% (adjusted hazard ratio [HR] 2.00, 95% confidence interval [CI] 1.02–3.95) and in those with mean HbA1c > 8.0% (adjusted HR 3.35, 95% CI 1.78–6.29). In the subgroup analysis by age, the J-curve relationship between mean HbA1c and all-cause mortality was accentuated in elderly patients (age ≥ 65 years), while there was no difference in all-cause mortality across the HbA1c groups in younger patients (age Conclusions The less strict glycemic control in diabetic patients with AMI would be optimal for preventing mortality, especially in elderly patients.

Additional file 1: Table S1. Hazard ratios and 95% CIs of cardiovascular mortality according to the glycated hemoglobin level. Table S2. Hazard ratios and 95% CIs of the composite of cardiovascular mortality, myocardial infarction, and stroke according to the glycated hemoglobin level. Table S3. Baseline characteristics of the patients according to age. Table S4. Baseline characteristics of the patients according to the glycated hemoglobin level after excluding individuals who died in the first 1 years after the last HbA1c measurement. Table S5. Hazard ratios and 95% CIs of mortality according to the glycated hemoglobin level in patients after excluding individuals who died in the first 1 year after the last HbA1c measurement. Table S6. Hazard ratios and 95% CIs of mortality according to the glycated hemoglobin level in patients after exclusion according to age. Table S7. Baseline characteristics of diabetic patients who were excluded from this study and included in this study. Figure S1. Cubic spline curve showing the hazard of all-cause mortality according to mean HbA1c.