Oxidative stress parameters in patients with slow coronary flow

Randomised Placebo-Controlled Pilot Trial Evaluating the Anti-Anginal Efficacy of Ticagrelor in Patients with Angina with Nonobstructive Coronary Arteries and Coronary Slow Flow Phenomenon

Background: The coronary slow flow phenomenon (CSFP) is an angiographic finding characterised by the delayed passage of contrast through the coronary arteries, despite the absence of obstructive coronary artery disease (defined as less than 50% narrowing of the vessel lumen). Patients with the CSFP experience recurrent angina, for which there are limited evidence-based therapies. Ticagrelor may serve as an effective anti-anginal therapy for these patients by increasing adenosine levels, which could alleviate coronary microvascular dysfunction and its associated angina due to its vasodilatory properties. This study aimed to determine the anti-anginal efficacy of ticagrelor 90 mg taken twice daily on spontaneous angina episodes in patients with refractory angina (i.e., episodes ≥3/week despite two anti-anginals) and documented CSFP. Methods: In a randomised, double-blind, placebo-controlled, cross-over trial, the anti-anginal efficacy of a 4-week ticagrelor therapy regimen was evaluated in 20 patients with refractory angina (mean age 61.5 ± 10.5 years; 40% women) who had documented slow coronary flow. The primary endpoint was the frequency of angina episodes, recorded using an angina diary. Secondary endpoints included the duration and severity of angina episodes, consumption of short-acting nitrates, and health status evaluations using the Seattle Angina Questionnaire (SAQ) and the Short Form-36 (SF-36) indices. Results: During the four weeks of therapy, ticagrelor did not significantly improve angina symptoms compared to the placebo (placebo 25.7 (16.7)) vs. ticagrelor 19.8 (18.1), p > 0.05). Furthermore, it did not impact other patient-related outcome measures, including angina severity, duration, frequency of prolonged angina episodes, nitrate consumption, or the SAQ/SF-36 health outcome indices. No serious adverse events related to the study drug were observed. Conclusions: In patients with documented CSFP who were unresponsive to standard anti-anginal therapy, ticagrelor did not reduce the frequency of spontaneous angina episodes or the consumption of nitrates. Further confirmation of the potential benefits of this therapy may be obtained through a larger clinical trial.

The expression levels of PPAR-α/γ and UCP1/2 on the slow coronary flow phenomenon; results from a case-control study

PURPOSE

The slow coronary flow (SCF) phenomenon is considered a coronary artery disorder. Because of the critical function of peroxisome proliferator-activated receptors (PPARs) in regulating the oxidative stress and inflammatory reactions in cardiovascular disease, The aim of the current study was to investigate the expression of the genes for uncoupling proteins 1 and 2 (UCP1 and UCP2), peroxisome proliferator-activated receptors and (PPAR- PPAR-), and PPAR- in SCF patients.

METHODS

In this case-control study, coronary angiography examination was used to analyze 35 individuals with SCF and 35 subjects with normal coronary flow (NCF). SCF was diagnosed using the TIMI (thrombolysis in myocardial infarction frame count) method. The SCF phenomenon is thought to be the TIMI > 27. In the peripheral blood mononuclear cells (PBMCs), the messenger ribonucleic acid (mRNA) expression levels of the PPAR-, PPAR-, UCP1, and UCP2 genes were evaluated.

RESULTS

UCP1 and UCP2 expression levels were significantly higher in the SCF group compared to the NCF group (P = 0.034 and P0.001, respectively). The PPAR- and PPAR- levels were found to be significantly lower in the SCF group compared to the NCF group (P = 0.015, P0.001, respectively). According to the results of the logistic regression analysis, high UCP1 and UCP2 levels and low PPAR- and PPAR- levels are each independent predictors of the SCF phenomenon.

CONCLUSION

This research provided evidence about the potential role of PPAR-α, PPAR-γ, UCP1, and UCP2 as biomarkers in SCF. More investigations are suggested to assess the functions of these factors in SCF patients mechanistically.

Relationship between increased systemic immune-inflammation index and coronary slow flow phenomenon

Background

Systemic immune-inflammation index (SII, platelet × neutrophil/lymphocyte ratio), a new marker of inflammation, is associated with adverse cardiovascular events, but its relationship with coronary slow flow phenomenon (CSFP) is unclear. Therefore, we aimed to investigate the relationship between SII and CSFP.

Methods

We enrolled consecutive patients who presented with chest pain, with normal/near-normal coronary angiography findings (n = 89 as CSFP group; n = 167 as control group). The baseline characteristics, laboratory parameters and angiographic characteristics of the two groups were compared.

Results

SII levels were significantly higher in the CSFP group than in the control group (409.7 ± 17.7 vs. 396.7 ± 12.7, p < 0.001). A significant positive correlation between SII and the mean thrombolysis in myocardial infarction frame count (mTFC) was found (r = 0.624, p < 0.001). SII increased with the number of coronary arteries involved in CSFP. In multivariate logistic regression analysis, SII/10 was an independent predictor of CSFP (odds ratio: 1.739, p < 0.001). In addition, the SII level > 404.29 was a predictor of CSFP with 67.4% sensitivity and 71.9% specificity.

Conclusions

SII can predict the occurrence of CSFP.

A novel inflammatory signaling pathway in patients with slow coronary flow: NF-κB/IL-1β/nitric oxide

PURPOSE

The slow coronary flow (SCF) was identified as delayed opacification of epicardial coronary arteries in the absence of stenotic lesion. Metabolic syndrome (MetS), oxidative stress, and inflammation may be possible known insulting factors for the pathogenesis of SCF. This investigation aimed to assess the relationship between some inflammatory markers, oxidative stress parameters and MetS components with SCF phenomenon.

METHODS

A total of 35 patients with SCF and 35 subjects with normal coronary flow (NCF) were included in the study. We assessed some inflammatory markers (IL-1β, IL-18, TNF-α, and NF-κB mRNA expression in peripheral blood mononuclear cells (PBMCs)). Moreover, blood samples of the participants were tested for total antioxidant capacity (TAC), glutathione peroxidase (GPX) and nitric oxide (NO) levels using enzyme-linked immunosorbent assay (ELISA). Diagnosis of MetS was based on the National Cholesterol Education Program's Adult Treatment Panel III report (ATPIII) criteria, 2005. Diagnostic criteria for coronary flow rates of all subjects were documented by thrombolysis in myocardial infarction (TIMI) frame count method.

RESULTS

SCF patients had significantly higher prevalence of MetS (46%, p = 0.048).We found that the level of TAC was significantly higher in the NCF group (p = 0.006). Furthermore, the NO concentration was significantly lower in SCF groups (p = 0.001). A significant incremental difference was detected in IL-1β (fold change 2.82 ± 0.31, p < 0.05) and NF-κB (fold change 4.62 ± 0.32, p < 0.05) mRNA expression in the SCF group when compared with its level in the NCF group. Furthermore, according to logistic regression analysis, there were significant associations between IL-1β, NF-κB expression levels and the incidence of SCF (p < 0.05).

CONCLUSION

Based on the findings of this study, the pathogenesis of the SCF phenomenon may be closely associated with metabolic syndrome and inflammation. The NF-κB/IL-1β/nitric oxide & MetS signaling pathway might be considered as potential therapeutic targets in the management of SCF patients but further researches is required to guarantee these findings.

The Beneficial Effects of Saffron Extract on Potential Oxidative Stress in Cardiovascular Diseases

Saffron is commonly used in traditional medicines and precious perfumes. It contains pharmacologically active compounds with notably potent antioxidant activity. Saffron has a variety of active components, including crocin, crocetin, and safranal. Oxidative stress plays an important role in many cardiovascular diseases, and its uncontrolled chain reaction is related to myocardial injury. Numerous studies have confirmed that saffron exact exhibits protective effects on the myocardium and might be beneficial in the treatment of cardiovascular disease. In view of the role of oxidative stress in cardiovascular disease, people have shown considerable interest in the potential role of saffron extract as a treatment for a range of cardiovascular diseases. This review analyzed the use of saffron in the treatment of cardiovascular diseases through antioxidant stress from four aspects: antiatherosclerosis, antimyocardial ischemia, anti-ischemia reperfusion injury, and improvement in drug-induced cardiotoxicity, particularly anthracycline-induced. Although data is limited in humans with only two clinically relevant studies, the results of preclinical studies regarding the antioxidant stress effects of saffron are promising and warrant further research in clinical trials. This review summarized the protective effect of saffron in cardiovascular diseases and drug-induced cardiotoxicity. It will facilitate pharmacological research and development and promote utilization of saffron.

Evaluation of homocystein and asymmetric dimethyl arginine levels in patients with coronary slow flow phenomenon

Background

Previous studies have demonstrated that homocysteine and asymmetric dimethyl arginine (ADMA) levels were strongly associated with cardiovascular diseases including coronary artery disease. The aim of this study was to investigate the role of plasma homocysteine and ADMA levels in the pathogenesis of coronary slow flow (CSF) phenomenon.

Methods

Twenty-three patients with CSF and 25 controls with normal coronary flow were included in this study. The quantitative measurement of coronary blood flow was performed using the thrombolysis in myocardial infarction frame count method. Plasma homocysteine and ADMA levels were determined using enzymatic assays from venous blood samples.

Results

The patients with CSF had significantly higher plasma homocysteine levels than controls (16.2 ± 7.6 vs. 12.2 ± 2.2 μM/L; p = 0.023). The uric acid levels were significantly higher in CSF group than controls (5.4 ± 1.1 vs. 4.6 ± 0.9 mg/dl; p = 0.011). Plasma ADMA levels were also higher in the CSF group; however, this was not statistically significant (0.6 ± 0.1 vs. 0.5 ± 0.2 μM/L; p = 0.475).

Conclusions

Increased homocysteine and uric acid levels may play an important role in the pathogenesis of CSF. Further large scale studies are required to determine the relationship between ADMA levels and CSF.

Oxidant-Antioxidant balance in patients with coronary slow flow

OBJECTIVE

Recent studies have focused on the probable role of oxidative stress in cardiovascular diseases. We aimed to assess the oxidant/antioxidant biomarkers in coronary slow flow (CSF).

METHODS

The study included 51 subjects with CSF and age and sex matched 32 controls. Detailed anamnesis of the patients in the study was taken and routine physical examinations were performed. Routine biochemical blood tests were analyzed. Total oxidative status (TOS), oxidative stress index (OSI) and lipid hydroxyperoxide (LOOH) levels as oxidant biomarkers; paraoxonase (PON1), ceruloplasmin (CP), free sulphydryl (SH) groups, and total antioxidant capacity (TAS) levels as antioxidant biomarkers were studied.

RESULTS

Baseline demographic characteristics of the study population did not differ significantly between groups.TOS, OSI and LOOH concentrations were higher in study group than in control group. However, there was no significant difference detected in levels of TAS, PON1, SH and CP. Multivariate logistic regression analysis revealed that TOS, hsCRP and smoking were indepedent risk factors of CSF.

CONCLUSIONS

Although there was not any significant difference in antioxidant biomarkers (TAS, PON1, SH and CP) in CSF patients, we detected increased TOS, OSI and LOOH levels which have oxidant properties. These data supported the possible involvement of oxidative stress in pathogenesis of CSF as previous studies reported.

The role of urotensin II and atherosclerotic risk factors in patients with slow coronary flow

BACKGROUND

Slow coronary flow (SCF) is an angiographic finding characterized with delayed opacification of epicardial coronary arteries without obstructive coronary disease. Urotensin II (UII) is an important vascular peptide, which has an important role in hypertension, coronary artery disease, and vascular remodeling in addition to potent vasoconstrictor effect.

OBJECTIVES

We investigated UII levels, hypertension, and other atherosclerotic risk factors in patients with SCF, a variety of coronary artery disease.

METHODS

We enrolled 14 patients with SCF and 29 subjects with normal coronary arteries without SCF. We compared the UII levels and the atherosclerotic risk factors between patients with SCF and control subjects with normal coronary flow.

RESULTS

UII concentrations were significantly higher in patients with SCF compared to controls (711.0 ± 19.4 vs. 701.5 ± 27.2 ng/mL, p = 0.006). We detected a positive correlation between SCF and age (r = 0.476, p = 0.001), BMI (r = 0.404, p = .002), UII concentrations (r = 0.422, p = 0.006), and hypertension (r = 0.594, p = 0.001).

CONCLUSION

We identified increased UII levels in patients with SCF. We think that UII concentrations may be informative on SCF pathogenesis due to relationship with inflammation, atherosclerosis, and vascular remodeling.

Association between soluble lectin-like oxidized low-density lipoprotein receptor 1 levels and coronary slow flow phenomenon

INTRODUCTION

The coronary slow flow phenomenon (CSFP) has been associated with myocardial ischemia, myocardial infarction, life-threatening arrhythmias, sudden cardiac death and increased cardiovascular mortality similar to coronary artery disease (CAD). Possible underlying mechanisms of CSFP are endothelial dysfunction, chronic inflammation, microvascular dysfunction and diffuse atherosclerosis. Soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) seems to play an important role in the pathogenesis of atherosclerosis. We hypothesized that sLOX-1 might be associated with CSFP, and aimed to research the relationship between sLOX-1 and CSFP.

MATERIAL AND METHODS

Forty patients with angiographically proven CSFP and 43 patients with a normal coronary flow pattern (NCFP) were included in this study. Coronary blood flow was measured according to the Thrombolysis In Myocardial Infarction (TIMI) frame count method. sLOX-1 levels were measured in all study subjects.

RESULTS

Serum levels of sLOX-1 were significantly higher in the CSFP group than the NCFP group (1061.80 ±422.20 ng/ml vs. 500.043 ±282.97 ng/ml, p < 0.001, respectively). Multivariate logistic regression analysis including sLOX-1, MPV, GGT and uric acid levels revealed a significant association between sLOX-1 levels and CSFP (Exp (B)/OR: 1.006, 95% CI: 1.002-1.010, p = 0.001).

CONCLUSIONS

The present study demonstrated that serum sLOX-1 levels were significantly higher in patients with CSFP and there was a strong association between high sLOX-1 levels and CSFP. High serum sLOX-1 levels may have an important role in the pathogenesis of CSFP. Future studies are needed to confirm these results.

Association of Monocyte-to-HDL Cholesterol Ratio with Slow Coronary Flow is Linked to Systemic Inflammation

BACKGROUND

Previous studies proposed that both inflammation, oxidative stress, and impaired endothelial dysfunction have a significant role in occurrence of slow coronary flow (SCF). monocyte-to-high density lipoprotein cholesterol ratio (MHR) is a recently emerged indicator of inflammation and oxidative stress, which have been studied only in patients with chronic kidney disease.

HYPOTHESIS

We aimed to assess the relationship between MHR and SCF.

METHODS

Patients who had angiographically normal coronary arteries were enrolled in this retrospective study (n = 253 as SCF group and n = 176 as control group). Patients who had corrected thrombolysis in myocardial infarction frame counts (cTFCs) above the normal cutoffs were defined as with SCF.

RESULTS

The MHR and high-sensitivity C-reactive protein (hsCRP) were significantly higher in the SCF group. In correlation analysis, MHR has a significantly positive correlation with cTFC and serum hsCRP levels (P < .001). In multivariate logistic regression analysis, MHR was found as independently associated with the presence of SCF (odds ratio: 1.24, P < .001).

CONCLUSION

Higher MHR which indicates an enhanced inflammation and oxidative stress was significantly and independently associated with the presence of SCF. Besides, MHR was positively correlated with serum hsCRP level as a conventional marker for systemic inflammation.

Plasma lipoprotein(a) levels in patients with slow coronary flow

Introduction

Slow coronary flow (SCF) is a microvascular disorder characterized by delayed opacification of coronary vessels with normal coronary angiogram. It may be due to endothelial dysfunction and diffuse atherosclerosis. Lipoprotein(a) [Lp(a)] is related to cardiovascular events. Plasma Lp(a) levels have not been studied previously in SCF patients.

Aim

We investigated plasma Lp(a) and fibrinogen levels, and their relation to coronary flow rate in patients with SCF.

Material and methods

This cross-sectional study included 50 patients with SCF and 30 age- and sex-matched controls who had normal coronary arteries and normal flow. Coronary flow rates of patients and controls were counted with the thrombolysis in myocardial infarction (TIMI) frame count. Plasma Lp(a) and fibrinogen levels were measured in SCF patients and controls, with routine biochemical tests.

Results

There were no significant differences between the two groups with respect to plasma Lp(a) (21 mg/dl vs. 14 mg/dl, p = 0.11) and fibrinogen (278 mg/dl vs. 291 mg/dl, p = 0.48) levels. The TIMI frame count was not correlated with plasma Lp(a) (r = 0.13, p = 0.25) or fibrinogen (r = –0.14, p = 0.28) levels.

Conclusions

Our results show that there is no significant association between SCF and Lp(a) and fibrinogen levels.

Clinical analysis of the risk factors of slow coronary flow

Slow coronary flow (SCF) phenomenon is a coronary microvascular disorder characterized by the delayed passage of contrast in the absence of obstructive epicardial coronary disease, and is an important clinical entity because it may be the cause of precordial pain when the body is at rest and/or during exercise. Although clinical and pathological features of SCF have been previously described, its etiopathogenesis remains unclear. The present study aims to investigate the risk factors of slow coronary flow, in order to provide the foundation for further exploration of potential mechanisms of SCF. A total of 47 consecutive patients with documented slow coronary flow, and 33 patients with normal coronary flow--as defined by TIMI frame count (TFC)--were recruited for this study. Clinical information was collected, and biochemical indicators including high-sensitivity C-reactive protein (hs-CRP), and a marker of systemic inflammation were detected. Logistic regression analysis was performed for statistical analysis. SCF patients had a higher level of serum uric acid (323.2 ± 79.3 vs. 282.8 ± 82.4 μmol/l, p = 0.03), 2-h postprandial blood glucose (8.6 ± 2.7 vs. 7.5 ± 1.8 mmol/l, p = 0.04), platelet count (165.9 ± 51.6 × 10(3) vs. 127.0 ± 32.0 × 10(3) cells/μl, p = 0.0003) and hs-CRP (3.4 ± 0.8 vs. 2.0 ± 0.9 mg/l, p < 0.0001) than those of patients in the control group. No marked differences in other variables were observed between the two groups. Logistic regression showed serum uric acid level (χ(2) = 3.84, β = 0.007, p = 0.049), 2-h postprandial blood glucose (χ(2) = 5.02, β = 0.277, p = 0.025) and blood platelet count (χ(2) = 12.16, β = 0.026, p = 0.001) were independent predictors of SCF. When hs-CRP was included in the multivariate model, hs-CRP (χ(2) = 21.19, β = 1.90, p < 0.0001) was the only independent predictor of SCF. These findings suggested that an elevation of serum uric acid level, 2-h postprandial blood glucose, and blood platelet count might be the causes of SCF, and inflammation was likely to be implicated in the causal pathway leading to SCF.