Adenosine plasma level correlates with homocysteine and uric acid concentrations in patients with coronary artery disease

Uric acid and evaluate the coronary vascular stenosis gensini score correlation research and in gender differences

BACKGROUND AND AIMS

Recent studies have shown that the negative effect of uric acid (UA) on coronary arteries determines the severity of atherosclerotic disease. This study aims to explore the relationship between serum UA level and Gensini score, which reflects the severity of coronary artery disease.

METHODS

A total of 860 patients with suspected coronary heart disease who were admitted to hospital due to angina pectoris or myocardial ischemia related symptoms and received coronary angiography were selected. Based on the findings of the angiography, they were categorized into two groups: the coronary heart disease (CHD) group (n = 625) and the control group (n = 235). The uric acid levels and other clinical data were compared between these groups. Additionally, the prevalence of coronary heart disease and Gensini score were compared between the groups, considering gender-specific quartiles of uric acid levels. The clinical baseline data were analyzed using appropriate statistical methods, and multivariate logistic regression analysis was conducted to identify independent risk factors for coronary heart disease.

RESULTS

Of 860 patients (mean age, 63.97 ± 11.87 years), 528 were men (mean age, 62.06 ± 11.5 years) and 332 were women (mean age, 66.99 ± 10.11 years). The proportion of smoking, diabetes, hypertension, and hyperlipidemia in the coronary heart disease group was higher than that in the control group (P < 0.05). HbA1C, Gensini score, BMI, TG and hsCRP in the coronary heart disease group were higher than those in the control group (P < 0.05), and HDL-C was lower than that in the control group (P < 0.05). There were no significant differences in age, heart rate, Cr, TC and LDL-C between the two groups (P > 0.05).Multivariate logistic regression analysis showed that age, hypertension, hsCRP and SUA levels increased the risk of coronary heart disease, and the difference was statistically significant(OR = 1.034,95%CI 1.016-1.052, P = 0.001; OR = 1.469,95%CI 1.007-2.142, P = 0.046;OR = 1.064,95%CI 1.026-1.105, P = 0.001; OR = 1.011,95%CI 1.008-1.014, P < 0.001).

CONCLUSION

Serum uric acid is positively correlated with Gensini score in patients with coronary heart disease, which is an independent factor for evaluating the degree of coronary artery stenosis and has a predictive effect.

Adropin - A new player in energy regulation predicts long-term prognosis of patients with acute myocardial infarction

Background

As a novel energy homeostasis regulator, Adropin not only plays a vital part in meditating energy metabolism, but also has a certain correlation with atherosclerotic diseases. The purpose of this study was to evaluate the effect of Adropin on the long-term prognosis of patients with acute myocardial infarction (AMI).

Methods

162 recruited patients with AMI were divided into low Adropin group (Adropin<166.3 pg/mL, n = 82) and high Adropin group (Adropin≥166.3 pg/mL, n = 80), according to the mean value of serum Adropin level. Patients were followed up and major adverse cardiac events (MACEs) were recorded. The Kaplan-Meier method and Cox regression model were used to evaluate the survival of patients and the related factors of cardiac events.

Results

Diabetes was more common in low Adropin group than that in high Adropin group (P < 0.05). Patients were followed up for an average of 50.3 ± 19.2 months. MACEs occurred in 37 patients (22.8%), including 6 cardiac deaths (3.7%), 14 recurrent myocardial infarction (8.6%) and 17 rehospitalization of heart failure (10.5%). The incidence of recurrent myocardial infarction in low Adropin group was higher than that in high Adropin group (13.4% vs 3.8%, P < 0.05). There was no significant difference in the overall incidence of MACE, cardiac death and rehospitalization of heart failure between the two groups. Kaplan-Meier method (log rank test) analysis results showed that patients with low Adropin had lower survival rate without recurrent myocardial infarction (log rank P = 0.035).

Conclusion

Low Adropin level was associated with an increased risk of long-term recurrent myocardial infarction in patients with AMI.

Correlation of elevated serum uric acid with coronary artery disease in Xinjiang, China: A retrospective case-control study

Elevated serum uric acid (SUA) levels are associated with coronary artery disease (CAD). However, whether this association is independent of traditional cardiovascular risk factors remains controversial. Our study aimed to determine the concentration of SUA in the presence and severity of CAD in multi-ethnic patients in Xinjiang, China. For this study, 412 consecutive patients with percutaneous coronary intervention (PCI) and 845 individuals with normal coronary angiograms were included in the study. CAD severity was evaluated using the Gensini score index. The SUA concentrations and the levels of various cardiometabolic risk factors were investigated. We assessed the relationship between SUA levels and other cardiometabolic risk factors. Logistic regression was used to evaluate risk factors for PCI patients. SUA levels were significantly elevated in PCI patients compared to those in control subjects (P < .01). With increased UA levels, we found that the risk factors for CAD increased. SUA concentration had a significant positive relationship with total cholesterol (P < .01), triglycerides (P < .01), low-density lipoprotein cholesterol (P < .01), and creatinine (P < .01) in both sexes. In the PCI group, there was no significant correlation between UA levels. SUA levels are not an independent risk factor for CAD. It can be concluded that in Xinjiang, China, SUA is related to multiple risk factors for CAD, but not related to the severity of CAD.

H2S Donors with Cytoprotective Effects in Models of MI/R Injury and Chemotherapy-Induced Cardiotoxicity

Hydrogen sulfide (H2S) is an endogenous signaling molecule that greatly influences several important (patho)physiological processes related to cardiovascular health and disease, including vasodilation, angiogenesis, inflammation, and cellular redox homeostasis. Consequently, H2S supplementation is an emerging area of interest, especially for the treatment of cardiovascular-related diseases. To fully unlock the medicinal properties of hydrogen sulfide, however, the development and refinement of H2S releasing compounds (or donors) are required to augment its bioavailability and to better mimic its natural enzymatic production. Categorizing donors by the biological stimulus that triggers their H2S release, this review highlights the fundamental chemistry and releasing mechanisms of a range of H2S donors that have exhibited promising protective effects in models of myocardial ischemia-reperfusion (MI/R) injury and cancer chemotherapy-induced cardiotoxicity, specifically. Thus, in addition to serving as important investigative tools that further advance our knowledge and understanding of H2S chemical biology, the compounds highlighted in this review have the potential to serve as vital therapeutic agents for the treatment (or prevention) of various cardiomyopathies.

Theophylline in patients with syncope without prodrome, normal heart, and normal electrocardiogram: a propensity-score matched study verified by implantable cardiac monitor

AIMS

Syncope without prodromes in subjects with normal heart and normal electrocardiogram (ECG) is classified as non-classical neurally mediated syncope and is characterized by low adenosine plasma levels (APLs) and frequent asystolic syncope. We assessed the efficacy of theophylline, a non-selective adenosine receptor antagonist, in preventing syncopal events.

METHODS AND RESULTS

Participants received an implantable cardiac monitor, underwent APL measurement, and received oral theophylline at maximum tolerated dose (starting dose 300 mg b.i.d.). They were compared with a historical cohort of untreated patients with implantable cardiac monitor who had the same inclusion criteria and were balanced with the propensity score (PS) method as regard age, sex, lifetime syncopal episodes, APL, and antihypertensive drugs. Primary endpoint was time to first syncopal recurrence at 24 months. There were 76 patients in the theophylline group and 58 in the control group. Syncope recurred in 25 (33%) patients in the theophylline group and in 27 (47%) patients in the control group, with an estimated 2-year recurrence rate of 33% and 60%, respectively, and a hazard ratio of 0.53 [95% confidence interval (CI), 0.30-0.95; P = 0.034]. Most of the benefit of theophylline is derived from reduction of syncope due to asystolic atrioventricular (AV) block (hazard ratio of 0.13; 95% CI, 0.03-0.58; P = 0.008). Thirty (39%) patients discontinued theophylline after a median of 6.4 (interquartile range 1.7-13.8) months due to side effects.

CONCLUSION

Theophylline was effective in preventing recurrences in patients with syncope without prodromes, normal heart, and normal ECG. The benefit was greater in patients with syncope due to asystolic AV block.

CLINICALTRIALS.GOV IDENTIFIER

NCT03803215.

Distinct Prognostic Role of Serum Uric Acid Levels for Predicting All-Cause Mortality Among Chinese Adults Aged 45~75 Years With and Without Diabetes

Introduction

The current study sought to explore the effect of baseline serum uric acid (SUA) on the risk of all-cause mortality among Chinese adults aged 45~75 years and to determine its interaction relationship with diabetes.

Methods

The study was designed as a community-based cohort of 4467 adults aged between 45~75 years included in a 6-years follow-up period from 2009 to 2015 years by the China Health and Nutrition Survey (CHNS). Baseline SUA levels were grouped into quartiles and its association on all-cause mortality was explored using multivariate Cox proportional hazards models. Stratified analyses were performed to explore the associations of SUA quartiles with all-cause mortality among diabetic and non-diabetic individuals.

Results

A total of 141 deaths (5.3 per 1000 person-years) were recorded During a follow-up of 26431 person-years. Out of the 141 deaths, 28 deaths (10.1 per 1000 person-years) were reported in the diabetic groups and 113 deaths (4.8 per 1000 person-years) were recorded in the non-diabetic group. An increased risk of all-cause mortality was observed for participants in the first and fourth quartiles compared with the second SUA quartile, (Q1 SUA: aHR=2.1, 95% CI 1.1~4.1; Q4 SUA: aHR=2.1, 95% CI 1.1~4.0). Stratification of participants by diabetes status showed a U-shaped association for non-diabetic individuals. Whereas, declined eGFR, rather than SUA, was an independent risk factor for all-cause mortality in diabetic individuals (aHR=0.7, 95% CI 0.6~1.0).

Conclusion

Our study proved that the prognostic role of SUA for predicting all-cause death might be regulated by diabetes. Both low and high SUA levels were associated with increased mortality, supporting a U-shaped association only in non-diabetic individuals. Whereas, renal dysfunction rather than SUA was an independent risk factor for all-cause mortality. Further studies should be conducted to determine the SUA levels at which intervention should be conducted and explore target follow-up strategies to prevent progression leading to poor prognosis.

Hyperhomocysteinemia and Cardiovascular Disease: Is the Adenosinergic System the Missing Link?

The influence of hyperhomocysteinemia (HHCy) on cardiovascular disease (CVD) remains unclear. HHCy is associated with inflammation and atherosclerosis, and it is an independent risk factor for CVD, stroke and myocardial infarction. However, homocysteine (HCy)-lowering therapy does not affect the inflammatory state of CVD patients, and it has little influence on cardiovascular risk. The HCy degradation product hydrogen sulfide (H2S) is a cardioprotector. Previous research proposed a positive role of H2S in the cardiovascular system, and we discuss some recent data suggesting that HHCy worsens CVD by increasing the production of H2S, which decreases the expression of adenosine A2A receptors on the surface of immune and cardiovascular cells to cause inflammation and ischemia, respectively.

Recent advances in the role of the adenosinergic system in coronary artery disease

Adenosine is an endogenous nucleoside that plays a major role in the physiology and physiopathology of the coronary artery system, mainly by activating its A2A receptors (A2AR). Adenosine is released by myocardial, endothelial, and immune cells during hypoxia, ischaemia, or inflammation, each condition being present in coronary artery disease (CAD). While activation of A2AR improves coronary blood circulation and leads to anti-inflammatory effects, down-regulation of A2AR has many deleterious effects during CAD. A decrease in the level and/or activity of A2AR leads to: (i) lack of vasodilation, which decreases blood flow, leading to a decrease in myocardial oxygenation and tissue hypoxia; (ii) an increase in the immune response, favouring inflammation; and (iii) platelet aggregation, which therefore participates, in part, in the formation of a fibrin-platelet thrombus after the rupture or erosion of the plaque, leading to the occurrence of acute coronary syndrome. Inflammation contributes to the development of atherosclerosis, leading to myocardial ischaemia, which in turn leads to tissue hypoxia. Therefore, a vicious circle is created that maintains and aggravates CAD. In some cases, studying the adenosinergic profile can help assess the severity of CAD. In fact, inducible ischaemia in CAD patients, as assessed by exercise stress test or fractional flow reserve, is associated with the presence of a reserve of A2AR called spare receptors. The purpose of this review is to present emerging experimental evidence supporting the existence of this adaptive adenosinergic response to ischaemia or inflammation in CAD. We believe that we have achieved a breakthrough in the understanding and modelling of spare A2AR, based upon a new concept allowing for a new and non-invasive CAD management.

Adenosine and Its Receptors: An Expected Tool for the Diagnosis and Treatment of Coronary Artery and Ischemic Heart Diseases

Adenosine is an endogenous nucleoside which strongly impacts the cardiovascular system. Adenosine is released mostly by endothelial cells and myocytes during ischemia or hypoxia and greatly regulates the cardiovascular system via four specific G-protein-coupled receptors named A₁R, A_2AR, A_2BR, and A₃R. Among them, A₂ subtypes are strongly expressed in coronary tissues, and their activation increases coronary blood flow via the production of cAMP in smooth muscle cells. A_2A receptor modulators are an opportunity for intense research by the pharmaceutical industry to develop new cardiovascular therapies. Most innovative therapies are mediated by the modulation of adenosine release and/or the activation of the A_2A receptor subtypes. This review aims to focus on the specific exploration of the adenosine plasma level and its relationship with the A_2A receptor, which seems a promising biomarker for a diagnostic and/or a therapeutic tool for the screening and management of coronary artery disease. Finally, a recent class of selective adenosine receptor ligands has emerged, and A_2A receptor agonists/antagonists are useful tools to improve the management of patients suffering from coronary artery disease.

Homocysteine concentration and adenosine A2A receptor production by peripheral blood mononuclear cells in coronary artery disease patients

Hyperhomocysteinemia is associated with coronary artery disease (CAD). The mechanistic aspects of this relationship are unclear. In CAD patients, homocysteine (HCy) concentration correlates with plasma level of adenosine that controls the coronary circulation via the activation of adenosine A_2A receptors (A_2AR). We addressed in CAD patients the relationship between HCy and A_2AR production, and in cellulo the effect of HCy on A_2AR function. 46 patients with CAD and 20 control healthy subjects were included. We evaluated A_2AR production by peripheral blood mononuclear cells using Western blotting. We studied in cellulo (CEM human T cells) the effect of HCy on A_2A R production as well as on basal and stimulated cAMP production following A_2A R activation by an agonist‐like monoclonal antibody. HCy concentration was higher in CAD patients vs controls (median, range: 16.6 [7‐45] vs 8 [5‐12] µM, P < 0.001). A_2A R production was lower in patients vs controls (1.1[0.62‐1.6] vs 1.53[0.7‐1.9] arbitrary units, P < 0.001). We observed a negative correlation between HCy concentration and A_2A R production (r = −0.43; P < 0.0001), with decreased A_2A R production above 25 µM HCy. In cellulo, HCy inhibited A_2AR production, as well as basal and stimulated cAMP production. In conclusion, HCy is negatively associated with A_2A R production in CAD patients, as well as with A_2A R and cAMP production in cellulo. The decrease in A_2A R production and function, which is known to hamper coronary blood flow and promote inflammation, may support CAD pathogenesis.

Hyperuricemia and Hypertension, Coronary Artery Disease, Kidney Disease: From Concept to Practice

Since the publication of the Framingham Heart Study, which suggested that uric acid should no longer be associated with coronary heart disease after additional adjustment for cardiovascular disease risk factors, the number of publications challenging this statement has dramatically increased. The aim of this paper was to review and discuss the most recent studies addressing the possible relation between sustained elevated serum uric acid levels and the onset or worsening of cardiovascular and renal diseases. Original studies involving American teenagers clearly showed that serum uric acid levels were directly correlated with systolic and diastolic pressures, which has been confirmed in adult cohorts revealing a 2.21-fold increased risk of hypertension. Several studies involving patients with coronary artery disease support a role for serum uric acid level as a marker and/or predictor for future cardiovascular mortality and long-term adverse events in patients with coronary artery disease. Retrospective analyses have shown an inverse relationship between serum uric acid levels and renal function, and even a mild hyperuricemia has been shown to be associated with chronic kidney disease in patients with type 2 diabetes. Interventional studies, although of small size, showed that uric acid (UA)-lowering therapies induced a reduction of blood pressure in teenagers and a protective effect on renal function. Taken together, these studies support a role for high serum uric acid levels (>6 mg/dL or 60 mg/L) in hypertension-associated morbidities and should bring awareness to physicians with regards to patients with chronic hyperuricemia.

Serum adenosine deaminase activity and coronary artery disease: a retrospective case-control study based on 9929 participants

Background:

Adenosine deaminase (ADA) regulates purine metabolism through the conversion of adenosine to uric acid (UA). Adenosine and UA are closely associated with cardiovascular events, but the correlation between serum ADA activity and coronary artery disease (CAD) has not been defined.

Methods:

We performed a hospital-based retrospective case-control study that included a total of 5212 patients with CAD and 4717 sex- and age-matched controls. The serum activity of ADA was determined by peroxidase assays in an automatic biochemistry analyzer.

Results:

Serum ADA activity in the CAD group (10.08 ± 3.57 U/l) was significantly lower than that of the control group (11.71 ± 4.20 U/l, p < 0.001). After adjusting for conventional factors, serum ADA activity negatively correlated with the presence of CAD (odds ratio = 0.852, 95% confidence interval: 0.839–0.865, p < 0.001). Among the patients with CAD, serum ADA activity was lowest in patients with myocardial infarction (MI; 9.77 ± 3.80 U/l). Diabetes mellitus and hypertension increased the serum ADA activity in CAD patients.

Conclusions:

Serum ADA activity is significantly attenuated in patients with CAD, particularly in MI. We propose a mechanism by which the body maintains adenosine levels to protect the cardiovascular system in the event of CAD.

Uric acid levels are associated with endothelial dysfunction and severity of coronary atherosclerosis during a first episode of acute coronary syndrome

The role of serum uric acid in coronary artery disease has been extensively investigated. It was suggested that serum uric acid level (SUA) is an independent predictor of endothelial dysfunction and related to coronary artery lesions. However, the relationship between SUA and severity of coronary atherosclerosis evaluated via endothelial dysfunction using peripheral arterial tone (PAT) and the reactive hyperhemia index (RHI) has not been investigated during a first episode of acute coronary syndrome (ACS). The aim of our study was to address this point. We prospectively enrolled 80 patients with a first episode of ACS in a single-center observational study. All patients underwent coronary angiography, evaluation of endothelial function via the RHI, and SUA measurement. The severity of the coronary artery lesion was assessed angiographically, and patients were classified in three groups based on the extent of disease and Gensini and SYNTAX scores. Endothelial function was considered abnormal if RHI < 1.67. We identified a linear correlation between SUA and RHI (R² = 0.66 P < 0.001). In multivariable analyses, SUA remained associated with RHI, even after adjustment for traditional cardiovascular risk factors and renal function. SUA was associated with severity of coronary artery disease. SUA is associated with severity of coronary atherosclerosis in patients with asymptomatic hyperuricemia. This inexpensive, readily measured biological parameter may be useful to monitor ACS patients.

Adenosine 5'-Triphosphate Metabolism in Red Blood Cells as a Potential Biomarker for Post-Exercise Hypotension and a Drug Target for Cardiovascular Protection

The importance of adenosine and ATP in regulating many biological functions has long been recognized, especially for their effects on the cardiovascular system, which may be used for management of hypertension and cardiometabolic diseases. In response to ischemia and cardiovascular injury, ATP is broken down to release adenosine. The effect of adenosine is very short lived because it is rapidly taken up by erythrocytes (RBCs), myocardial and endothelial cells, and also rapidly catabolized to oxypurine metabolites. Intracellular adenosine is phosphorylated back to adenine nucleotides via a salvage pathway. Extracellular and intracellular ATP is broken down rapidly to ADP and AMP, and finally to adenosine by 5′-nucleotidase. These metabolic events are known to occur in the myocardium, endothelium as well as in RBCs. Exercise has been shown to increase metabolism of ATP in RBCs, which may be an important mechanism for post-exercise hypotension and cardiovascular protection. The post-exercise effect was greater in hypertensive than in normotensive rats. The review summarizes current evidence in support of ATP metabolism in the RBC as a potential surrogate biomarker for cardiovascular protection and toxicities. It also discusses the opportunities, challenges, and obstacles of exploiting ATP metabolism in RBCs as a target for drug development and precision medicine.

Uric acid levels are associated with endothelial dysfunction and severity of coronary atherosclerosis during a first episode of acute coronary syndrome

The role of serum uric acid in coronary artery disease has been extensively investigated. It was suggested that serum uric acid level (SUA) is an independent predictor of endothelial dysfunction and related to coronary artery lesions. However, the relationship between SUA and severity of coronary atherosclerosis evaluated via endothelial dysfunction using peripheral arterial tone (PAT) and the reactive hyperhemia index (RHI) has not been investigated during a first episode of acute coronary syndrome (ACS). The aim of our study was to address this point. We prospectively enrolled 80 patients with a first episode of ACS in a single-center observational study. All patients underwent coronary angiography, evaluation of endothelial function via the RHI, and SUA measurement. The severity of the coronary artery lesion was assessed angiographically, and patients were classified in three groups based on the extent of disease and Gensini and SYNTAX scores. Endothelial function was considered abnormal if RHI < 1.67. We identified a linear correlation between SUA and RHI (R² = 0.66 P < 0.001). In multivariable analyses, SUA remained associated with RHI, even after adjustment for traditional cardiovascular risk factors and renal function. SUA was associated with severity of coronary artery disease. SUA is associated with severity of coronary atherosclerosis in patients with asymptomatic hyperuricemia. This inexpensive, readily measured biological parameter may be useful to monitor ACS patients.

Purinergic Signaling in the Cardiovascular System

There is nervous control of the heart by ATP as a cotransmitter in sympathetic, parasympathetic, and sensory-motor nerves, as well as in intracardiac neurons. Centers in the brain control heart activities and vagal cardiovascular reflexes involve purines. Adenine nucleotides and nucleosides act on purinoceptors on cardiomyocytes, AV and SA nodes, cardiac fibroblasts, and coronary blood vessels. Vascular tone is controlled by a dual mechanism. ATP, released from perivascular sympathetic nerves, causes vasoconstriction largely via P2X1 receptors. Endothelial cells release ATP in response to changes in blood flow (via shear stress) or hypoxia, to act on P2 receptors on endothelial cells to produce nitric oxide, endothelium-derived hyperpolarizing factor, or prostaglandins to cause vasodilation. ATP is also released from sensory-motor nerves during antidromic reflex activity, to produce relaxation of some blood vessels. Purinergic signaling is involved in the physiology of erythrocytes, platelets, and leukocytes. ATP is released from erythrocytes and platelets, and purinoceptors and ectonucleotidases are expressed by these cells. P1, P2Y₁, P2Y₁₂, and P2X1 receptors are expressed on platelets, which mediate platelet aggregation and shape change. Long-term (trophic) actions of purine and pyrimidine nucleosides and nucleotides promote migration and proliferation of vascular smooth muscle and endothelial cells via P1 and P2Y receptors during angiogenesis, vessel remodeling during restenosis after angioplasty and atherosclerosis. The involvement of purinergic signaling in cardiovascular pathophysiology and its therapeutic potential are discussed, including heart failure, infarction, arrhythmias, syncope, cardiomyopathy, angina, heart transplantation and coronary bypass grafts, coronary artery disease, diabetic cardiomyopathy, hypertension, ischemia, thrombosis, diabetes mellitus, and migraine.