Impact of Long-term Glycosylated Hemoglobin in Patients with Acute Myocardial Infarction: a retrospective cohort study

Abstract

Little clinical evidence supports the strict implementation of glycemic control for diabetic patients with AMI. We aimed to demonstrate the effect of long-term glycemic control on mortality in patients with diabetes mellitus after acute myocardial infarction (AMI). Eight hundred and twenty-four consecutive diabetic patients were divided into three groups according to the mean hemoglobin (HbA1c) value: <6% (group A), ≥6% to <7.5% (group B), and ≥7.5% (group C). The best long-term mortality outcome was observed in Group B, followed by groups C and A. Groups B and C were further compared in-depth because the baseline characteristics of group A differed significantly. A Cox regression analysis indicated that Group C was associated with an adjusted hazard ratio (HR) of 1.55 [95% confidence interval (CI): 1.02-2.34, P = 0.038]. An inverse probability of treatment weight analysis was performed to compare groups B and C. Group C had significantly higher mortality, compared to group B (adjusted HR: 1.58; 95% CI: 1.21-2.06, P < 0.001). In conclusion, Glycemic status was associated with the long-term survival outcome in diabetic patients after AMI. However, further study is needed to prove whether HbA1c-targeted glycemic control can effectively improve survival after AMI.

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1

Flow chart of the establishment of the study population. A total of 824 patients with diabetes mellitus and acute myocardial infarction were analyzed.

Figure 2

Glycated hemoglobin (HbA1c) levels after acute myocardial infarction and the association of this variable with prognosis. HbA1c was measured continuously throughout the follow-up period (A). The adjusted hazard ratio according to the individual mean HbA1C level for each patient, illustrated by a J-shaped restricted cubic spline curve for all-cause mortality (B). Patients were classified into three groups according to the mean HbA1c levels: <6.0%, ≥6% to <7.5%, and ≥7.5%; each group maintained a constant HbA1c level throughout the follow-up period. The size of the circle indicates the number of patients included at each time point, and the linear lines indicate the average and standard deviation (C). The cumulative 5-year survival rate differed significantly between the three groups (D).

Figure 3

Prognosis of patients with acute myocardial infarction according to glycated hemoglobin (HbA1c) level in the inverse propensity treatment weight (IPTW) cohort. Kaplan–Meier curves were used to compare groups B (HbA1c level: ≥6% to

Figure 4

Subgroup analysis. A comparison of unadjusted hazard ratios of all-cause mortality revealed an unfavorable effect of a glycated hemoglobin (HbA1c) level >7.5% in most subgroup analyses.