Intensive treatment of hyperglycemia in the acute phase of myocardial infarction: the tenuous balance between effectiveness and safety – a systematic review and meta-analysis of randomized clinical trials

Abstract

SUMMARY INTRODUCTION In acute myocardial infarction (AMI), each 18 mg/dl (1 mmol/L) increment is associated with a 3% increase in mortality rates. All strategies applied for reducing blood glucose to this date, however, have not presented encouraging results. METHODOLOGY We searched the Medline (PubMed) and Cochrane Library databases for randomized clinical trials (RCTs) from 1995 to 2017 that used the intensive strategy or GIK therapy for blood glucose control during the acute stage of the AMI. We included eight studies. In order to identify the effects of GIK or insulin therapy, we calculated a overall risk ratio (RR) with meta-analysis of fixed and random effects models. A two-tail p-value of < 0.05 was considered statistically significant. RESULTS A total of 28,151 patients were included: 1,379 intensively treated with insulin, 13,031 in GIK group, and 13,741 in the control group. The total mortality was 10.5% (n=2,961) and the RR of 1.03 [95%CI 0.96–1.10]; I2 = 31%; p = 0.41 for the combined intensive insulin plus GIK groups in comparison with the control group. In meta-regression analyses, intense reductions in blood glucose (> 36 mg/dL) in relation to the estimated average blood glucose (estimated by HbA1c) were associated with higher mortality, whereas lower reductions in blood glucose (< 36 mg/dL) were not associated with mortality. The lowering of blood glucose in the acute phase of MI compared with the average blood glucose was more effective around 18 mg/dL. CONCLUSION This meta-analysis suggests that there may be a tenuous line between the effectiveness and safety of reducing blood glucose in the acute phase of MI. The targets must not exceed a reduction greater than 36 mg/dL in relation to estimated average blood glucose.

High admission glucose levels predict worse short-term clinical outcome in non-diabetic patients with acute myocardial infraction: a retrospective observational study

“…Patients with AMI and undiagnosed diabetes, even if their blood glucose levels are elevated on admission, do not receive sufficient attention and adequate medical treatment in most cases. Early positive glycemic therapy is thought to improve the clinical outcome, but several clinical studies have shown that mortality rates do not improve [29]. This finding may be related to failure of controlling blood glucose levels according to the protocol or a stratified analysis strategy was not used for diabetic and non-diabetic patients [30].…”