Changes over Time in Hemoglobin A1C (HbA1C) Levels Predict Long-Term Survival Following Acute Myocardial Infarction among Patients with Diabetes Mellitus.

Ygal Plakht,Arthur Shiyovich,Harel Gilutz

doi:10.3390/jcm10153232

Abstract

Frequent fluctuations of hemoglobin A1c (HbA1C) values predict patient outcomes. However, data regarding prognoses depending on the long-term changes in HbA1C among patients after acute myocardial infarction (AMI) are scarce. We evaluated the prognostic significance of HbA1C levels and changes among diabetic patients (n = 4066) after non-fatal AMI. All the results of HbA1C tests up to the 10-year follow-up were obtained. The changes (∆) of HbA1C were calculated in each patient. The time intervals of ∆HbA1C values were classified as rapid (<one year) and slow (≥one year) changes. The outcome was all-cause mortality. The highest mortality rates of 53.8% and 35.5% were found in the HbA1C < 5.5–7% and ∆HbA1C = −2.5–(−2%) categories. A U-shaped association was observed between HbA1C and mortality: adjOR = 1.887 and adjOR = 1.302 for HbA1C < 5.5% and ≥8.0%, respectively, as compared with 5.5–6.5% (p < 0.001). Additionally, ∆HbA1C was associated with the outcome (U-shaped): adjOR = 2.376 and adjOR = 1.340 for the groups of <−2.5% and ≥2.5% ∆HbA1C, respectively, as compared to minimal ∆HbA1C (±0.5%) (p < 0.001). A rapid increase in HbA1C (but not decrease) was associated with a greater risk of mortality. HbA1C values and their changes are significant prognostic markers for long-term mortality among AMI-DM patients. ∆HbA1C and its timing, in addition to absolute HbA1C values, should be monitored.

Highlights

The global burden of diabetes mellitus (DM), a major cardiovascular risk factor, has increased dramatically throughout the last two decades [1,2]
Patients who died were older and more likely to be women, with higher rates of prior Acute myocardial infarction (AMI), prior coronary artery bypass graft (CABG), congestive heart failure, renal failure and peripheral arterial disease than the survivors. They had an increased rate of DM-associated target-organ complications compared with the survivors
These patients had a lower rate of dyslipidemia, obesity, smoking and family history of early coronary artery disease (CAD) than the survivors

Summary

Introduction

The global burden of diabetes mellitus (DM), a major cardiovascular risk factor, has increased dramatically throughout the last two decades [1,2]. DM is a significant risk factor for short- and long-term morbidity and mortality among patients presenting with AMI [8,9]. Glucose and glycated hemoglobin (HbA1C ) levels upon admission with AMI were associated with long-term mortality among patients with and without DM [10]. Glycemic variability emerged as an additional and possibly even superior predictor of diabetic complications than mean HbA1C , with frequent fluctuations independently associated with poor prognosis. Lee et al recently reported that long-term mean HbA1C was significantly associated with long-term survival following AMI [22]. Data regarding long-term HbA1C changes following AMI and the association with the survival of these patients are scarce. This study aimed to evaluate the prognostic significance of HbA1C and its changes among patients with DM with non-fatal AMI

Objectives

Methods

Results