Prognostic significance of the hemoglobin A1c level in non-diabetic patients undergoing percutaneous coronary intervention: a meta-analysis

Hemoglobin A1c levels and 1-year mortality in patients with ST-elevation myocardial infarction undergoing percutaneous coronary intervention

Background: In this study, we investigated whether different levels of hemoglobin A1c (HbA1c) are associated with different short-term and 1-year mortality rates among diabetic patients undergoing percutaneous coronary intervention. Patients & methods: Clinical events including in-hospital, 1-month and 1-year mortality were compared between three groups based on HbA1c levels of patients (I: ≤5.6%, II: 5.7-6.4%, III: ≥6.5%). Results: Among 165 diabetic individuals, patients with abnormal HbA1c levels (≥6.5%) experienced significantly higher hospitalization days (7.65 ± 1.64 days) compared with those with normal HbA1c (4.94 ± 0.97 days) (p < 0.0001). In-hospital mortality was significantly higher in group III (14.5%) and II (5.5%) compared with group I (0%) (p = 0.008). Conclusion: HbA1c levels may be a reliable predictor of short-term clinical events in diabetic patients.

Predictive power of elevated preoperative HbA1c levels for postoperative atrial fibrillation in patients undergoing isolated coronary artery bypass surgery-Many questions to be asked and many answers to be given

The authors performed a detailed retrospective analysis of diabetic patients undergoing isolated coronary artery bypass graft surgery aiming to investigate the association of the preoperative glycosylated hemoglobin with occurrence of postoperative atrial fibrillation. Although statistical analysis showed a weak relationship between HbA1c values of 9.06% or above and postoperative atrial fibrillation (PoAF), they concluded that serum level of HbA1c could not be used as a predictor for the development of PoAF. But there are many questions to be asked and answers to be found.

Effect of high-sensitivity C-reactive protein on the relationship between haemoglobin A1c and cardiovascular events in patients with acute coronary syndrome undergoing percutaneous coronary intervention: a cohort study

BACKGROUND

There are different opinions on haemoglobin A1c (HbA1c) in predicting cardiovascular events after percutaneous coronary intervention (PCI). Some factors may affect the ability of HbA1c to predict cardiovascular events, resulting in this inconsistency. Inflammation is a direct and whole-process participant in atherosclerosis. However, no one has studied the effect of inflammation on the correlation between HbA1c and cardiovascular events. Therefore, we aimed to test the hypothesis that high-sensitivity C-reactive protein (hsCRP) modulates HbA1c-related cardiovascular events in patients with the acute coronary syndrome (ACS) undergoing PCI.

METHODS

This was a retrospective cohort study. We enrolled patients with ACS who were hospitalized for PCI and followed up for 24 months. The primary outcome was the composite of major adverse cardiovascular and cerebrovascular events (MACCEs), including all-cause death, nonfatal myocardial infarction, nonfatal stroke, and unplanned repeat revascularization. We stratified the overall population by HbA1c tertiles and hsCRP median. The relationship between HbA1c, hsCRP, and cardiovascular events was analysed by the Cox proportional hazard regression model.

RESULTS

A total of 2,023 patients were enrolled in this study (age: 59.7±10.03 years old, 78.1% male patients). After the 24-month follow-up, 152 (7.51%) events occurred. Patients with hsCRP >1.21 mg/L had an increased cardiovascular risk compared with patients with hsCRP ≤1.21 mg/L [hazard ratio (HR) 1.58, 95% confidence interval (CI): 1.12-2.24, P=0.010]. We did not observe a significant correlation between HbA1c and cardiovascular events. Furthermore, we stratified patients by hsCRP ≤1.21 or >1.21 mg/L and found that the correlation between HbA1c and cardiovascular events was only significant in patients with hsCRP ≤1.21 mg/L (tertile 2 vs. tertile 1: HR 1.76, 95% CI: 0.79-3.90, P=0.165, tertile 3 vs. tertile 1: HR 3.03, 95% CI: 1.50-6.12, P=0.002; P=0.008 for trend) but not in patients with hsCRP >1.21 mg/L.

CONCLUSIONS

This study showed that hsCRP may affect the relationship between HbA1c and the risk of cardiovascular events in patients with ACS after PCI. This finding suggests that the risk of cardiovascular events may be underestimated when only HbA1c is used as a predictor of cardiovascular risk. HbA1c has a better predictive value in the absence or low levels of inflammation states represented by hsCRP as a predictor of cardiovascular events.

Prediabetes and risk of mortality, diabetes-related complications and comorbidities: umbrella review of meta-analyses of prospective studies

AIMS/HYPOTHESIS

The term prediabetes is used for individuals who have impaired glucose metabolism whose glucose or HbA_1c levels are not yet high enough to be diagnosed as diabetes. Prediabetes may already be associated with an increased risk of chronic 'diabetes-related' complications. This umbrella review aimed to provide a systematic overview of the available evidence from meta-analyses of prospective observational studies on the associations between prediabetes and incident diabetes-related complications in adults and to evaluate their strength and certainty.

METHODS

For this umbrella review, systematic reviews with meta-analyses reporting summary risk estimates for the associations between prediabetes (based on fasting or 2 h postload glucose or on HbA_1c) and incidence of diabetes-related complications, comorbidities and mortality risk were included. PubMed, Web of Science, the Cochrane Library and Epistemonikos were searched up to 17 June 2021. Summary risk estimates were recalculated using a random effects model. The certainty of evidence was evaluated by applying the GRADE tool. This study is registered with PROSPERO, CRD42020153227.

RESULTS

Ninety-five meta-analyses from 16 publications were identified. In the general population, prediabetes was associated with a 6-101% increased risk for all-cause mortality and the incidence of cardiovascular outcomes, CHD, stroke, heart failure, atrial fibrillation and chronic kidney disease, as well as total cancer, total liver cancer, hepatocellular carcinoma, breast cancer and all-cause dementia with moderate certainty of evidence. No associations between prediabetes and incident depressive symptoms and cognitive impairment were observed (with low or very low certainty of evidence). The association with all-cause mortality was stronger for prediabetes defined by impaired glucose tolerance than for prediabetes defined by HbA_1c.

CONCLUSIONS/INTERPRETATION

Prediabetes was positively associated with risk of all-cause mortality and the incidence of cardiovascular outcomes, CHD, stroke, chronic kidney disease, cancer and dementia. Further high-quality studies, particularly on HbA_1c-defined prediabetes and other relevant health outcomes (e. g. neuropathy) are required to support the evidence.