Glycated hemoglobin and long-term prognosis in patients with suspected stable angina pectoris without diabetes mellitus: a prospective cohort study

Even chained acylcarnitines predict long-term cardiovascular prognosis in patients with chest pain and non-obstructive coronary artery disease

Background

Acylcarnitines are essential for mitochondrial fatty acid oxidation. Earlier studies suggest that impaired energy metabolism may be implicated in the pathogenesis of microvascular angina. We explored metabolites from the carnitine pathway as predictors of cardiovascular disease (CVD) - and all-cause mortality among patients with non-obstructive coronary artery disease (NOCAD).

Methods

A total of 1046 patients with suspected stable coronary syndrome underwent coronary angiography during 2000–2004, with findings of NOCAD. Serum levels of 8 selected carnitine metabolites were analyzed through liquid chromatography tandem mass spectrometry. Associations with CVD- and all-cause mortality were assessed by multivariable Cox regression models.

Results

Median age at inclusion was 57 years. 51.5% were men. During median (25th- 75th percentiles), 14.1 (13.2–15.4) years of follow-up, 5.7% of the participants died from CVD and the incidence of all-cause mortality was 17.3%. Serum acetyl, octanoyl- and palmitoylcarnitine predicted CVD mortality with multivariable HR and 95% CI (per SD increment log transformed) of 1.36 (1.01–1.83), 1.49 (1.15–1.93) and 2.07 (1.49–2.85), p ≤ 0.04, respectively. Higher serum acetyl- and palmitoylcarnitines were also associated with increased risk of all-cause mortality (HR (95% CI): 1.27 (1.01–1.50), and 1.51 (1.26–1.81), p ≤ 0.007. Baseline levels of the precursors trimethyllysine and ƴ-butyrobetaine, carnitine or the odd chained propionylcarnitine and (iso)valerylcarnitine were not associated with adverse outcomes.

Conclusion

Elevated serum even-chained acylcarnitines predicted adverse long-term prognosis in NOCAD. The strongest risk estimates were observed for palmitoylcarnitine, which predicted both CVD- and all-cause mortality after extensive multivariable adjustments. Underlying pathomechanisms should be further elucidated.

Atherogenic index of plasma predicts coronary artery disease severity and major adverse cardiac events in absence of conventional risk factors

BACKGROUND

Various overlapping risk factors lead to coronary artery disease (CAD). The atherogenic index of plasma (AIP) is a marker for CAD severity and progression. However, little is known about its contribution to the residual risk of CAD observed in the absence of all typical risk factors.

METHODS

A prospective cohort study of 366 Indian patients undergoing coronary computed tomography (CT) angiography and diagnosed with stable CAD. Diabetes, hypertension, hypercholesterolemia, smoking, previous CAD, alcohol or lipid-lowering medication intake, renal, liver or thyroid dysfunction were exclusion criteria. Coronary stenosis was graded using the CAD-reporting and data system (CAD-RADS™) system. Lipid profile, HbA1c, uric acid, highly sensitive C-reactive protein (hsCRP) and anthropometric measurements were taken. AIP, triglyceride/high-density lipoprotein cholesterol (HDLc) and total cholesterol (Tc)/HDLc ratios were calculated. Independent predictors of CAD severity and the occurrence of major adverse cardiac events (MACE) during 2.57 (0.52) years of follow-up were identified using logistic regression and Cox proportional hazards regression.

RESULTS

Sixty patients experienced a MACE during a cumulative 887.03 person-years. HbA1c, uric acid, hsCRP, Tc/HDLc and AIP were independent predictors of severe coronary lesions (CAD-RADS 4,5) on multivariate analysis with odds ratio 4.52 (2.37-8.61), 1.41 (1.08-1.84), 1.33 (1.09-1.62), 1.76 (1.27-2.44) and 1.29 (1.11-1.50), respectively. Only AIP and Tc/HDLc were independent predictors of MACE with hazard ratios of 1.41 (1.20-1.65) and 1.78 (1.33-2.39) besides patient age and CAD severity.

CONCLUSION

AIP is associated with both the severity of CAD and the occurrence of MACE within 3 years. It could serve as an effective marker of residual risk of CAD in patients devoid of traditional risk factors. Lipid-profile ratios, such as AIP are cost-effective and accessible parameters suitable for low and middle-income settings.

Effects of prediabetes on long-term clinical outcomes of patients with acute myocardial infarction who underwent PCI using new-generation drug-eluting stents

AIMS

We investigated the 2-year clinical outcomes of patients with acute myocardial infarction (AMI) and prediabetes after new-generation drug-eluting stents implantation.

METHODS

A total of 11,962 patients with AMI were classified into normoglycemia (group A; 3,080), prediabetes (group B; 3,709), and diabetes (group C; 5,173) groups. The primary outcomes were the patient-oriented composite outcomes (POCOs) defined as all-cause death, recurrent myocardial infarction (Re-MI), and any repeat revascularization. Secondary outcomes were the individual components of POCOs and stent thrombosis (ST).

RESULTS

POCOs in groups B and C were significantly higher than those in group A. Cardiac death (adjusted hazard ratio [aHR]: 1.957, 95% confidence interval [CI]: 1.126-3.402; p = 0.017) and any repeat revascularization (aHR: 1.597, 95% CI: 1.052-2.424; p = 0.028) rates were significantly higher in group B than in group A. Re-MI (aHR: 1.884, 95% CI: 1.201-2.954; p = 0.006) and death or MI (aHR: 1.438, 95% CI: 1.098-1.884; p = 0.008) were significantly higher in group C than in group B.

CONCLUSIONS

In this study, prediabetes showed bad clinical outcomes post AMI. However, larger randomized controlled studies including ethnically diverse population are needed to confirm these harmful cardiovascular effects of prediabetes in the future.

Glucose-lowering therapy and cardiovascular outcomes in patients with type 2 diabetes mellitus and acute coronary syndrome

Diabetes is a common comorbidity in patients hospitalized for an acute coronary syndrome event, and prevalence is increasing. Among patients hospitalized with acute myocardial infarction, diabetes can be an independent predictor of mortality and new cardiovascular events; both short- and long-term outcomes are worse for patients with diabetes relative to those without, and undiagnosed diabetes is associated with greater mortality. The impact of glycemic control on cardiovascular outcomes and the best approach to treat hyperglycemia upon hospital admission for acute coronary syndrome in patients with or without known diabetes remain open questions. This review assesses available evidence for hyperglycemia management at the time of admission for acute coronary syndrome and, thereafter, finds that (1) admission plasma glucose plays a role in predicting adverse events, especially in patients with unknown diabetes; (2) glycated haemoglobin is a likely predictor of events in patients with unknown diabetes; and (3) hypoglycemia at the time of acute myocardial infarction hospital admission is an important predictor for mortality in patients with and without diabetes. Whether glucose-targeted insulin and glucose infusion have advantages over glucose-insulin-potassium infusion remains controversial. Evidence for the effect of novel glucose-lowering agents used at the time of an acute cardiovascular event is limited and requires more dedicated studies.

Plasma Amino Acids and Incident Type 2 Diabetes in Patients With Coronary Artery Disease

OBJECTIVE

Altered plasma amino acid levels have been implicated as markers of risk for incident type 2 diabetes; however, amino acids are also related to established diabetes risk factors. Therefore, potential for confounding and the impact from competing risks require evaluation.

RESEARCH DESIGN AND METHODS

We prospectively followed 2,519 individuals with coronary artery disease but without diabetes. Mixed Gaussian modeling identified potential for confounding. Confounding, defined as a change in effect estimate (≥10%), was investigated by comparing amino acid-incident diabetes risk in a Cox model containing age and sex with that in models adjusted for potential confounders (BMI, estimated glomerular filtration rate, HDL cholesterol, triacylglycerol, C-reactive protein), which were further adjusted for plasma glucose, competing risks, and multiple comparisons (false discovery rate = 0.05, Benjamini-Hochberg method). Finally, component-wise likelihood-based boosting analysis including amino acids and confounders was performed and adjusted for competing risks in order to identify an optimal submodel for predicting incident diabetes.

RESULTS

The mean age of the source population was 61.9 years; 72% were men. During a median follow-up of 10.3 years, 267 incident cases of diabetes were identified. In age- and sex-adjusted models, several amino acids, including the branched-chain amino acids, significantly predicted incident diabetes. Adjustment for confounders, however, attenuated associations. Further adjustment for glucose and multiple comparisons rendered only arginine significant (hazard ratio/1 SD 1.21 [95% CI 1.07-1.37]). The optimal submodel included arginine and asparagine.

CONCLUSIONS

Adjustment for relevant clinical factors attenuated the amino acid-incident diabetes risk. Although these findings do not preclude the potential pathogenic role of other amino acids, they suggest that plasma arginine is independently associated with incident diabetes. Both arginine and asparagine were identified in an optimal model for predicting new-onset type 2 diabetes.

The Effects of Plant-Derived Oleanolic Acid on Selected Parameters of Glucose Homeostasis in a Diet-Induced Pre-Diabetic Rat Model

Prolonged exposure to high energy diets has been implicated in the development of pre-diabetes, a long-lasting condition that precedes type 2 diabetes mellitus (T2DM). A combination of pharmacological and dietary interventions is used to prevent the progression of pre-diabetes to T2DM. However, poor patient compliance leads to negligence of the dietary intervention and thus reduced drug efficiency. Oleanolic acid (OA) has been reported to possess anti-diabetic effects in type 1 diabetic rats. However, the effects of this compound on pre-diabetes have not yet been established. Consequently, this study sought to evaluate the effects OA on a diet-induced pre-diabetes rat model. Pre-diabetic male Sprague Dawley rats were treated with OA in both the presence and absence of dietary intervention for a period of 12 weeks. The administration of OA with and without dietary intervention resulted in significantly improved glucose homeostasis through reduced caloric intake, body weights, plasma ghrelin concentration and glycated haemoglobin by comparison to the pre-diabetic control. These results suggest that OA may be used to manage pre-diabetes as it was able to restore glucose homeostasis and prevented the progression to overt type 2 diabetes.

Glycosylated haemoglobin and coronary atherosclerosis in non-diabetic patients: is it a prognostic factor?

BACKGROUND

Some studies aimed to evaluate the relationship between HbA1c and coronary artery disease (CAD). However, it is well known that long-term glycometabolic disorders put the heart at risk for CAD. Considering the inconsistencies between previous studies, this study aimed to investigate the relationship between HbA1c and coronary artery atherosclerosis.

METHODS

A cross-sectional study was conducted on 411 non-diabetic patients who underwent their first coronary angiography between November 2013 and December 2014 in Baqiyatallah Hospital. Blood samples were taken before angiography. Coronary angiograms were reported and reviewed by two cardiologists according to the Gensini score. They were not aware about the patients' HbA1c level. Severity of CAD was determined through ascertaining the prevalence of multi-vessel disease, extent of CAD (single-, two- or three-vessel disease or left main stem stenosis (>50%)). Data analysis was performed by using SPSS software.

RESULTS

A total of 411 patients (252 men and 159 women) were evaluated. Angiography was normal in 67 patients (16.3%), 30.7% had single-vessel disease (SVD), and 29.1%, 20.7% and 3.2% had two-, three- and multivessel disease, respectively. Based on the ROC curve, the HbA1c was able to differentiate between patients with and without coronary atherosclerosis (p < .001, cut-off point = 5.45). The cut-off points for differentiation of severe CAD and patients with 75-100% stenosis of coronary artery were 5.55 (p < .001) and 5.65 (p < .001), respectively.

CONCLUSIONS

The present study demonstrated that HbA1c might be an independent diagnostic factor in non-diabetic patients with severe coronary atherosclerosis.

The kynurenine:tryptophan ratio as a predictor of incident type 2 diabetes mellitus in individuals with coronary artery disease

AIMS/HYPOTHESIS

The tryptophan metabolite kynurenine has potent immune modulatory and vasoactive properties. Experimental data implicate kynurenine in obesity-related morbidities. Epidemiological studies are, however, sparse. We evaluated associations of the plasma and urine kynurenine:tryptophan ratio (KTR) to incident type 2 diabetes.

METHODS

We followed 2519 individuals with coronary artery disease (CAD; 73.1% men) without diabetes at baseline for a median of 7.6 years, during which 173 (6.9%) new incidences of type 2 diabetes were identified. Multivariate Cox regression analyses were applied to investigate the prospective relationships of plasma and urine KTR with new onset type 2 diabetes.

RESULTS

At inclusion, mean (SD) age was 61.3 (10.4) years, BMI was 25.9 (3.71) kg/m2 and median (interquartile range) HbA1c was 5.6% (5.0%-6.0%) (38 [31-42] mmol/mol). Plasma KTR was not significantly related to type 2 diabetes risk. By contrast, urine KTR showed a strong positive association. Comparing quartile 4 with quartile 1, the HRs (95% CIs) were 2.59 (1.56, 4.30) and 2.35 (1.39, 3.96) in the age- and sex-adjusted and multivariate models, respectively.

CONCLUSIONS/INTERPRETATION

Urine KTR is a strong predictor of incident type 2 diabetes in individuals with CAD. Potential clinical implications and possible pathogenic roles of renal kynurenine excretion in type 2 diabetes development should be further elucidated.

Glycosylated hemoglobin levels and clinical outcomes in nondiabetic patients with coronary artery disease: A meta-analysis

A number of studies assessed the prognostic value of HbA1c level in nondiabetic patients with coronary artery disease (CAD). The purpose of this meta-analysis was to assess the association between the HbA1c level and clinical outcomes.We searched PubMed, EMBASE, MEDLINE, and the Cochrane Library from their inception to 10 April 2016. Studies evaluated the outcomes according to HbA1c levels in CAD patients without diabetes mellitus were eligible.Twenty studies involving 22,428 patients were included. In nondiabetic patients with CAD, a high HbA1c level was associated with a higher rate of long-term death (odds ratio 1.76, 95% confidence interval 1.44-2.16, P < .001), and myocardial infarction (MI, odds ratio 1.69, 95% confidence interval 1.07-2.67, P = .026), but not a higher rate of early deaths (odds ratio 1.08, 95% confidence interval 0.92-1.27, P = .359). These findings for death remained the same after sensitivity analyses and the trim and fill method, but the risk difference for MI became nonsignificant after adjustment for potential publication bias.Elevated HbA1c level increased the risks of long-term mortality and MI, but not the risk for early deaths in nondiabetic patients with CAD. High-quality large-scale studies with less bias are needed to confirm these findings.

Management standards for stable coronary artery disease in India

Coronary artery disease (CAD) is one of the important causes of cardiovascular morbidity and mortality globally, giving rise to more than 7 million deaths annually. An increasing burden of CAD in India is a major cause of concern with angina being the leading manifestation. Stable coronary artery disease (SCAD) is characterised by episodes of transient central chest pain (angina pectoris), often triggered by exercise, emotion or other forms of stress, generally triggered by a reversible mismatch between myocardial oxygen demand and supply resulting in myocardial ischemia or hypoxia. A stabilised, frequently asymptomatic phase following an acute coronary syndrome (ACS) is also classified as SCAD. This definition of SCAD also encompasses vasospastic and microvascular angina under the common umbrella.

Significance of HbA1c Test in Diagnosis and Prognosis of Diabetic Patients

Diabetes is a global endemic with rapidly increasing prevalence in both developing and developed countries. The American Diabetes Association has recommended glycated hemoglobin (HbA1c) as a possible substitute to fasting blood glucose for diagnosis of diabetes. HbA1c is an important indicator of long-term glycemic control with the ability to reflect the cumulative glycemic history of the preceding two to three months. HbA1c not only provides a reliable measure of chronic hyperglycemia but also correlates well with the risk of long-term diabetes complications. Elevated HbA1c has also been regarded as an independent risk factor for coronary heart disease and stroke in subjects with or without diabetes. The valuable information provided by a single HbA1c test has rendered it as a reliable biomarker for the diagnosis and prognosis of diabetes. This review highlights the role of HbA1c in diagnosis and prognosis of diabetes patients.

Independent association between glycated hemoglobin and arterial stiffness in healthy men

Aims/Introduction

Materials and Methods

Results

Conclusions

Hemoglobin A1c Level Is Not Related to the Severity of Atherosclerosis in Patients with Acute Coronary Syndrome

BACKGROUND

The relationship between hemoglobin A1c (HbA1c) levels and the extent of coronary artery stenosis in patients with acute coronary syndrome (ACS) remains uncertain. The present study aimed to assess the correlation of HbA1c level with angiographic coronary atherosclerosis.

METHODS

292 consecutive ACS patients were enrolled and stratified into three groups according to HbA1c levels (group 1: < 6.0%, n = 137; group 2: 6.0-6.4%, n = 67; group 3: ≥ 6.5%, n = 88). The severity of coronary arteriosclerosis was assessed by Gensini score. The relationship between HbA1c and Gensini score was analyzed by multiple variables analysis.

RESULTS

HbA1c level was not associated with the severity of CAD assessed by Gensini score in patients with ACS, even after the adjustment for other risk factors. However, NT-proBNP, ApoA1 and LVEF levels were independent predictors for CAD severity. Moreover, HbA1c level was not associated with the risk of high Gensini score (> 40) by logistic regression analysis. Diabetes mellitus (DM) and LVEF levels were two independent risk factors for high Gensini score.

CONCLUSIONS

HbA1c level is not a significant and independent marker for the severity of angiography in ACS patients, even in high-risk patients.