Impact of admission glycemic variability, glucose, and glycosylated hemoglobin on major adverse cardiac events after acute myocardial infarction

Abstract

Objective: Dysglycemia is associated with poorer prognosis in patients with acute myocardial infarction (AMI). Whether admission glycemic variability (GV) has important value in prognosis of AMI patients is still unknown. The aim of the study is to investigate the prognostic value of admission GV, glucose, and glycosylated hemoglobin (HbA(1c)) in AMI patients.

Research design and methods: We measured blood glucose, HbA(1c), and GV on admission in 222 consecutive patients with diagnosed AMI. GV, indicated as the mean amplitude of glycemic excursions (MAGE), was determined by a continuous glucose monitoring system. MAGE was categorized as ≥3.9 or <3.9 mmol/L, admission glucose as ≥8.61 or <8.61 mmol/L, and HbA(1c) as ≥6.5 or <6.5%. Participants were followed up prospectively for 12 months. The relationship of admission MAGE, glucose, and HbA(1c) to the major adverse cardiac event (MACE) of AMI patients was analyzed.

Results: In 222 enrolled patients with AMI, the rate of MACE by MAGE category (<3.9 or ≥3.9 mmol/L) was 8.4 and 24.1%, respectively (P = 0.001), by admission glucose category (<8.61 or ≥8.61 mmol/L) was 10.1 and 21.6%, respectively (P = 0.020), and by HbA(1c) category (<6.5 vs. ≥6.5%) was 10.7 versus 18.7%, respectively (P = 0.091). In multivariate analysis, high MAGE level was significantly associated with incidence of MACE (hazard ratio 2.419 [95% CI 1.273-9.100]; P = 0.017) even after adjusting for Global Registry of Acute Coronary Events risk score, but admission glucose and HbA(1c) was not.

Conclusions: Elevated admission GV appears more important than admission glucose and prior long-term abnormal glycometabolic status in predicting 1-year MACE in patients with AMI.

Figures

Figure 1

A: Incidence of MACE after 1-year follow-up in relation to MAGE levels. AMI patients with a higher MAGE level had significantly higher cardiac mortality and incidence of all MACEs (white bars: MAGE level <3.9 mmol/L; black bars: MAGE level ≥3.9 mmol/L). B: Incidence of MACE after 1-year follow-up in relation to admission glucose levels. AMI patients with a higher admission glucose level had significantly higher incidence of all MACEs (white bars: MAGE level <8.61 mmol/L; black bars: MAGE level ≥8.61 mmol/L). C: Incidence of MACE after 1-year follow-up in relation to HbA1c levels. There are no significant differences of adverse cardiovascular events rates between two study groups (all P > 0.05) (white bars: HbA1c level <6.5%; black bars: HbA1c level ≥6.5%).

Figure 2

A: Kaplan-Meier event-free survival curves for freedom from MACE in two patient groups by admission MAGE levels. The event-free survival rate was significantly lower in the high MAGE level patients (log-rank test, P < 0.001) (green dashed line: MAGE level <3.9 mmol/L; blue solid line: MAGE level ≥3.9 mmol/L). B: Kaplan-Meier event-free survival curves for freedom from MACE in two patient groups by admission glucose levels. The event-free survival rate was significantly lower in the high admission glucose level patients (log-rank test, P = 0.011) (green dashed line: MAGE level <8.61 mmol/L; blue solid line: MAGE level ≥8.61 mmol/L). C: Kaplan-Meier event-free survival curves for freedom from MACE in two patient groups by admission HbA1c levels. There is a trend toward lower event-free survival rate in high HbA1c level patients, but the difference is not significant (log-rank test, P = 0.055) (green dashed line: HbA1c level <6.5%; blue solid line: HbA1c level ≥6.5%). (A high-quality color representation of this figure is available in the online issue.)