The influence of admission glucose on epicardial and microvascular flow after primary angioplasty:

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).

Role of plasma glucose level on myocardial perfusion in ST-segment elevation myocardial infarction patients

AIMS

Hyperglycemia is frequent in patients with ST elevation myocardial infarction (STEMI) and is associated with adverse outcome. Aim of our study was to evaluate the correlation between admission plasma glucose level (PGL) and coronary arteries flow velocity.

METHODS

We enrolled 149 STEMI patients successfully treated with primary percutaneous coronary intervention (pPCI). The study population was divided into two groups based on PGL (< or >140 mg/dl) and on history of diabetes, and the groups compared in terms of corrected TIMI frame count (cTFC).

RESULTS

Hyperglycemic patients had a significantly higher cTFC in both the culprit (p < 0.0001) and non-culprit vessel (p: 0.0002); diabetes history impairs as well cTFC of the culprit (p < 0.0001) and non-culprit vessel (p: 0.0001). Within the subpopulation of diabetic patients hyperglycemic ones showed higher cTFC in both the culprit (p 0.0013) and non-culprit vessel (p: 0.0006). Moreover in the whole population cTFC values of both arteries increase linearly with the increment of admission PGL.

CONCLUSIONS

Admission PGL affects coronary flow of both culprit and non-culprit vessel. The impairment of coronary flow is also demonstrated in known diabetic patients, suggesting to consider hyperglycemia an additional risk factor. We finally demonstrated for the first time a positive linear relationship between PGL and cTFC.

Hyperglycemia in acute coronary syndromes: from mechanisms to prognostic implications

Hyperglycemia is a frequent condition in patients with acute coronary syndromes (ACS). Hyperglycemia during ACS is caused by an inflammatory and adrenergic response to ischemic stress, when catecholamines are released and glycogenolysis induced. Although the involved pathophysiological mechanisms have not yet been fully elucidated, it is believed that hyperglycemia is associated with an increase in free fat acids (which induce cardiac arrhythmias), insulin resistance, chemical inactivation of nitric oxide and the production of oxygen reactive species (with consequent microvascular and endothelial dysfunction), a prothrombotic state, and vascular inflammation. It is also related to myocardial metabolic disorders, leading to thrombosis, extension of the damaged area, reduced collateral circulation, and ischemic preconditioning. In the last few years, several observational studies demonstrated that hyperglycemia in ACS is a powerful predictor of survival, increasing the risk of immediate and long-term complications in patients both with and without previously known diabetes mellitus. Glucose management strategies in ACS may improve outcomes in patients with hyperglycemia, perhaps by reducing inflammatory and clotting mediators, by improving endothelial function and fibrinolysis and by reducing infarct size. Recent clinical trials of insulin in ACS have resulted in varying levels of benefit, but the clinical benefit of an aggressive treatment with insulin is yet unproved.

Admission glucose and left ventricular systolic function in non-diabetic patients with acute myocardial infarction

Carbohydrate metabolism disorder in patients hospitalized due to acute ST-segment elevation myocardial infarction (STEMI) is associated with poor outcome. The association is even stronger in non-diabetic patients compared to the diabetics. Poor outcome of patients with elevated parameters of carbohydrate metabolism may be associated with negative impact of these disorders on left ventricular (LV) function. The aim of the study was to determine the impact of admission glycemia on LV systolic function in acute phase and 6 months after myocardial infarction in STEMI patients treated with primary angioplasty, without carbohydrate disorders. The study group consisted of 52 patients (9 female, 43 male) aged 35-74 years, admitted to the Department of Cardiology and Internal Medicine, Collegium Medicum in Bydgoszcz, due to the first STEMI treated with primary coronary angioplasty with stent implantation, without diabetes in anamnesis and carbohydrate metabolism disorders diagnosed during hospitalization. Echocardiography was performed in all patients in acute phase and 6 months after MI. Plasma glucose were measured at hospital admission. In the subgroup with glycemia ≥7.1 mmol/l, in comparison to patients with glycemia <7.1 mmol/l, significantly lower ejection fraction (EF) was observed in acute phase of MI (44.4 ± 5.4 vs. 47.8 ± 6.3 %, p = 0.04) and trend to lower EF 6 months after MI [47.2 ± 6.5 vs. 50.3 ± 6.3 %, p = 0.08 (ns)]. Higher admission glycemia in patients with STEMI and without carbohydrate metabolism disturbances, may be a marker of poorer prognosis resulting from lower LV ejection fraction in the acute phase and in the long-term follow-up.

Impact of hyperglycemia at admission in patients with acute ST-segment elevation myocardial infarction as assessed by contrast-enhanced MRI

BACKGROUND

Blood glucose level at admission in ST-segment elevation myocardial infarction (STEMI) is a predictor of heart failure and mortality. This study was performed to investigate the impact of hyperglycemia at admission in non-diabetic patients on infarct size, microvascular obstruction, and long-term outcome using contrast-enhanced magnetic resonance imaging (CMR) in patients with acute STEMI.

METHODS

One hundred and seven consecutive patients (84 males; mean age 59.4 years ± 11.3 years) with a first acute STEMI successfully treated by primary PCI were included. Admission hyperglycemia was defined as blood glucose above 7.8 mmol/l. CMR was performed 3.6 days ± 1.9 days after admission on a 1.5-tesla MR system. The imaging protocol included single-shot steady-state free precession (SSFP) cine sequences for assessing segmental and global left ventricular (LV) function and microvascular obstruction (MVO)/late gadolinium enhancement (LGE) imaging immediately and 10 min after the administration of 0.2 mmol gadodiamide/kg of body weight using an inversion-recovery SSFP (IR-SSFP) sequence. A receiver operating characteristics analysis was used to detect the best cut-off point of microvascular obstruction that predicted myocardial infarction and death during follow-up.

RESULTS

Of 107 patients, 37 (35%) had hyperglycemia on admission. Compared to normoglycemic patients, patients with admission hyperglycemia had a lower LV ejection fraction (38.6 ± 13.7% vs. 47.5 ± 12.2%, p < 0.001), greater ESV (88.8 ± 41.8 ml vs. 72.3 ml ± 35.1 ml, p = 0.01), greater infarct size (LGE% 21.1 ± 14.9% vs. 9.8 ± 8.7%, p < 0.001), and greater MVO (MVO% 9.6 ± 9.9% vs. 2.5 ± 4.3%, p < 0.001). Admission hyperglycemia was an independent predictor of the presence and extent of microvascular obstruction. Microvascular obstruction as a percentage of left ventricular mass was the only variable independently related to clinical outcome in a Cox proportional hazard model (Wald 18.78, HR 1.155, p < 0.001).

CONCLUSION

Hyperglycemia at admission in STEMI patients who are successfully treated by PCI is independently associated with the presence and extent of microvascular obstruction on contrast-enhanced CMR. Thus, microvascular obstruction as assessed by CMR may be a mechanism that relates admission hyperglycemia in acute STEMI to worse outcome.

Influence of abnormal glucose metabolism on coronary microvascular function after a recent myocardial infarction

OBJECTIVES

This study sought to assess the association between abnormal glucose metabolism and abnormal coronary flow reserve (CFR) in patients with a recent acute myocardial infarction (AMI).

BACKGROUND

Mortality and morbidity after AMI is high among patients with abnormal glucose metabolism, which may be related to abnormal microcirculation.

METHODS

We studied 183 patients with a first AMI. In 161 patients with no history of diabetes mellitus (DM), an oral glucose tolerance test was performed, and patients were categorized according to World Health Organization criteria for whole blood glucose into 3 groups. After coronary angiography and revascularization, a comprehensive transthoracic echocardiogram and noninvasive assessment of CFR was performed in the distal part of left descending artery, as an indicator of microvascular function. Adenosine was administered by intravenous infusion (140 microg/kg/min) to obtain the hyperemic flow profiles. The CFR was defined as the ratio of hyperemic to baseline peak diastolic coronary flow velocities.

RESULTS

Median CFR was 1.9 (interquartile range [IQR] 1.4 to 2.4], and 109 (60%) patients had a CFR <or=2. The lowest CFR was seen in patients with a history of DM (1.4 [IQR 1.4 to 1.7], n = 22) and in patients with newly diagnosed DM (1.6 [IQR 1.3 to 2], n = 39), whereas CFR did not differ in patients with abnormal glucose tolerance (2.1 [IQR 1.4 to 2.6], n = 58) and in patients with normal glucose tolerance (2.2 [IQR 1.7 to 2.6], n = 62). In a stepwise logistic regression model adjusting for age, sex, site and size of AMI, heart rate, risk factors of the metabolic syndrome, degree of angiographic evidence of coronary artery disease, and medical therapy, newly diagnosed DM (odds ratio: 3.0) and a history of DM (odds ratio: 9.9) remained significant predictors of CFR <2, whereas impaired glucose tolerance was not.

CONCLUSIONS

CFR is decreased in patients with known or newly diagnosed DM even after adjustment of possible confounders, whereas CFR in patients with impaired glucose tolerance seems less affected. (Coronary Flow Reserve and Glucometabolic State [CFRGS]; NCT00845468).