Glycated hemoglobin, admission blood glucose delta, and associated mortality in patients with acute ST-segment elevation myocardial infarction

Stress hyperglycemia and poor outcomes in patients with ST-elevation myocardial infarction: a systematic review and meta-analysis

Background

Hyperglycemia, characterized by elevated blood glucose levels, is frequently observed in patients with acute coronary syndrome, including ST-elevation myocardial infarction (STEMI). There are conflicting sources regarding the relationship between hyperglycemia and outcomes in STEMI patients. We aimed to compile evidence to assess the association between hyperglycemia and adverse outcomes.

Methods

We conducted a comprehensive search for articles on PubMed and Embase using search strategies which yielded 4,061 articles. After full-text screening, 66 articles were included for systematic review, and 62 articles were further selected for meta-analysis.

Results

The 66 included articles spanned the years 2005-2023. Of these, 45 articles reported admission blood glucose, 13 articles used HbA1c, and 7 articles studied fasting blood glucose. Most studies defined STEMI with primary PCI as their inclusion criteria. Mortality was the most often outcome reported related to hyperglycemia. Overall, 55 (83.3%) studies were at low risk of bias. Both admission and fasting blood glucose were significantly related to short- and long-term mortality after STEMI, with a pooled risk ratio (RR) of 3.02 (95%CI: 2.65-3.45) and 4.47 (95% CI: 2.54-7.87), respectively. HbA1c showed substantial association with long-term mortality (HR 1.69, 95% CI: 1.31-2.18)) with a pooled RR of 1.58 (95% CI 1.26-1.97). In subsequent analyses, admission hyperglycemia was associated with an increased risk of reinfarction (pooled RR 1.69, 95% CI 1.31-2.17), heart failure (pooled RR 1.56, 95% CI: 1.37-1.77), cardiogenic shock (pooled RR 3.68, 95% CI 2.65-5.11), repeat PCI or stent thrombosis (pooled RR 1.99, 95% CI 1.21-3.28), and composite major adverse cardiac and cerebrovascular events (MACCE) (pooled RR 1.99, 95% CI: 1.54-2.58).

Conclusions

Our study demonstrated that hyperglycemia has a strong association with poor outcomes after STEMI. Admission and fasting blood glucose are predictors for short-term outcomes, while HbA1c is more appropriate for predicting longer-term outcomes in STEMI patients.

Systematic Review Registration

PROSPERO 2021 (CRD42021292985).

1,5-Anhydroglucitol as a Marker of Acute Hyperglycemia in Cardiovascular Events

1,5-anhydroglucitol (1,5-AG) is a biomarker of acute hyperglycemia in diabetology and also in cardiodiabetology. It is used to monitor fluctuating glucose levels. 1,5-AG is a monosaccharide that is biochemically similar to D-glucose and originates from the nutrition. The presence of 1,5-AG in blood and tissue is nearly constant due to reabsorption in the renal proximal tubule. In acute hyperglycemia, renal reabsorption is inhibited by glucose and 1,5- AG is excreted in the urine, while its serum level decreases rapidly. 1,5-AG reflects glucose excursions over 1-3 days to 2 weeks. In this regard, low levels of serum 1,5-AG can be a clinical marker of short- term glycemic derangements such as postprandial hyperglycemia, which is an important risk factor for the pathogenesis of coronary artery disease (CAD) as low levels of 1,5-AG reflect severe plaque calcification in CAD and correlate with high-density lipoprotein cholesterol (HDL-C) levels. For these reasons, 1,5-AG may also be a marker for atherosclerosis; in fact an even better marker than HbA1c or fructosamine which are normally used. 1,5-AG may also be a predictor of cardiovascular disease, left ventricular dysfunction after acute coronary syndrome (ACS), and mortality after ACS. This articles reviews the current knowledge on 1,5-AG related to its use as predictor for cardiovascular events.

WHAT IS STRESS HYPERGLYCEMIA? A SUGGESTION FOR AN IMPROVEMENT OF ITS DEFINITION

CONTEXT

Stress hyperglycemia has been studied in numerous critical illnesses for several decades. Despite the extensive accumulation of knowledge about this topic, the definition of stress hyperglycemia is not updated since 2007.

SUBJECTS AND METHODS

We performed a narrative review about stress hyperglycemia in acute myocardial infarction (AMI), aiming to improve its current definition and to give evidence supporting this.

RESULTS

The definition of stress hyperglycemia in 2021 we recommend is: "SH is a high ABGly in an AMI patient irrespective of DM status. It can be calculated as e.g., "stress hyperglycemia ratio" or "admission glucose delta"/"glycemic gap". This definition may serve to start a consensus document of the experts in the field. The evidence accumulates supporting the possibility to recognize stress hyperglycemia also in AMI patients with diabetes mellitus (DM) by calculating glycemia during the previous 2-3 months using glycated hemoglobin. Moreover, it is now obvious that 2007 definition of stress hyperglycemia did not take into account the necessity to separate cut-offs for the subgroups with vs. without DM.

CONCLUSIONS

We demonstrated the insufficiency of the current 2007 definition of stress hyperglycemia, provided evidence-based recommendation for the improvement and suggested the need for a consensus of the experts on this topic. In order to optimize the treatment of stress hyperglycemia in numerous critical illnesses, we ought to have its universal definition (as we already have the universal definition of AMI).

Prevalence and clinical characteristics of prediabetes and diabetes mellitus in young patients with ST-segment elevation myocardial infarction

BACKGROUND

Only few data on the prevalence of DM in young patients with ST-elevation myocardial infarction (STEMI) exist. Aim of the present study was to analyse this prevalence, its association to other cardiovascular risk factors and its impact on severity of CAD. In a substudy, consecutive HbA1c measurements in each patient were evaluated.

METHODS

All patients ≤ 45 years old, admitted with STEMI to an overregional German Heart Centre and treated with primary coronary intervention between 2006 and 2019, entered analysis. Since 2015 HbA1c measurements were performed to detect unknown dysglycaemia.

RESULTS

Out of 776 young patients of the total cohort, 88 patients (11.4%) had a DM, while 688 (88.6%) did not. Diabetics were more likely to be obese (BMI ≥ 30 kg/m², OR 2.4, 95%CI 1.4-4.0, p < 0.01) and very obese (BMI ≥ 40 kg/m², OR 5.1, 95%CI 2.1-12.2, p < 0.01). In diabetics, a higher likelihood of subacute STEMI (OR 2.2, 95% CI 1.1-4.5, p < 0.05) and more advanced CAD (OR 1.6, 95% CI 1.0-2.6, p < 0.05) compared to non-diabetics was observed. 208 patients were included in the substudy with HbA1c measurements. Out of those, 26 patients (12%) had known DM, while 17 patients (8%) had newly diagnosed DM and 49 patients (24%) preDM. The combined prevalence of any type of dysglycaemia was 44%.

CONCLUSION

DM in young patients with STEMI was associated with (severe) obesity, a higher likelihood of subacute STEMI and more advanced CAD compared to non-diabetics. Measurement of HbA1c in every consecutive STEMI-patient increased the rate of detected dysglycaemias more than three times higher than in general population.

Single prognostic cut-off value for admission glycemia in acute myocardial infarction has been used although high-risk stems from hyperglycemia as well as from hypoglycemia (a narrative review)

All original articles and meta-analysis use the single cut-off value to distinguish high-risk hyperglycemic from other acute myocardial infarction (AMI) patients. The mortality rate is 3.9 times higher in non-diabetic AMI patients with admission glycemia ≥6.1mmol compared to normoglycemic non-diabetic AMI patients. On the other hand, admission hypoglycemia in AMI is an important predictor of mortality. Because both admission hypo- and hyperglycemia correspond to higher in-hospital mortality, this graph is recognized as "J or U shaped curve". The review suggests two cut-off values for admission glycemia for risk assessment in AMI instead of single one because hypoglycemia as well as hyperglycemia represents a high-risk factor.