Study of some components of the influence and formation of blood flow in patients with "slow flow"

BACKGROUND

"Slow flow" is one very important concept in modern fundamental and clinical biomedicine. Slow coronary flow is indicative of delayed filling of the terminal coronary artery vessels, occurring in the absence of significant coronary stenosis. This group patient of patients exhibits a high incidence of disability and represents a significant financial and material burden for the state and the healthcare system in general.

OBJECTIVE

The primary objective of our study was to examine patients with slow coronary flow.

METHODS

We studied the standard parameters recommended by the international health care system (electrocardiography (by Medica QRS-12, Germany), through the electrical activity of a patient's heart by the electrical impulses (beating) of the heart; HC1(Germany); coagulogramma by Coatron M1 (Germany), troponin by AQT 90 (Germany); general blood test we used automatic human counting device HC1(Germany). Also, we investigate the original parameters (non-standard parameters, which we use in this pilot study) that we were first studied for this diagnosis and non-standard parameters.

RESULTS

A general blood test showed that patients with slow flow had a higher blood leukocyte count than the control group, but the amount of hemoglobin was normal, the hematocrit was much higher than in the control group, and the platelet count was close to the lower limit of clinical standards.We obtained details of blood flow by coagulation situation, such as prothrombin time, prothrombin index, international normalized ratio, activated partial thromboplastin time, thrombin time, fibrinogen, and rheological properties such as index of erythrocyte aggregability, index of erythrocyte deformability, plasma viscosity, in silico blood rheological index.

CONCLUSSION

Blood flow can be considered as a superposition of vortices with similar frequencies and wave vectors that change after bifurcations or other obstacles in the vascular network. These factors together determine the conditions for structuring the flow of moving blood. Disruption or alteration of these factors results in slow flow. It has been found that the speed of blood flow in the coronary arteries depends on changes in the number and function of red blood cells. Slow flow is directly influenced by the aggregation and deformation of red blood cells, their number, and plasma viscosity. Consequently, the rheological status plays a crucial role in determining blood flow and its velocity.

Coronary slow flow and angiography-derived index of microcirculatory resistance as prognostic predictors in patients with angina and normal coronary arteries: a retrospective cohort study

BACKGROUND

This study aims to investigate prognostic implications of coronary slow flow (CSF) and angiography-derived index of microcirculatory resistance (caIMR) in patients with angina and normal coronary arteries.

METHODS

A total of 582 patients were enrolled with angiographically normal coronary arteries. caIMR was calculated using a commercial software. Patients were followed up for a median of 45 months. The primary endpoint was defined as major adverse cardiovascular events (MACEs) comprising death, myocardial infarction and readmission for angina or heart failure.

RESULTS

CSF was diagnosed when TIMI grade 2 flow presented in at least one coronary artery. Multivariate analysis indicated TIMI-flow-based determination of CSF was not significantly associated with MACEs [hazard ratio (HR): 2.14; 95% confidence interval (CI): 0.87-5.31; p = 0.099), while caIMR >42 (HR: 2.53; 95% CI: 1.02-6.32; p = 0.047) were independent predictors of MACEs. Incorporation of caIMR improved the area under the curve from 0.587 to 0.642.

CONCLUSIONS

caIMR was an independent prognostic factor of long-term cardiovascular events in patients with CSF. Evaluation of caIMR improved the risk stratification of patients with angiographically-normal coronary arteries.

Understanding the pathogenesis of coronary slow flow: Recent advances

Coronary slow flow is taken to be indicative of delayed filling of terminal vessels of the coronary arteries in the absence of coronary stenosis, as detected using coronary angiography. Patients suffering from coronary slow flow typically experience recurrent chest pain, thereby markedly affecting their quality of life. The etiology and pathogenesis of coronary slow flow, which is gradually attracting clinical attention, have yet to be sufficiently established, although it is currently believed that they may be associated with endothelial dysfunction in the coronary arteries, inflammatory response, abnormalities in microvascular reserve function, subclinical atherosclerosis, blood cell and platelet abnormalities, and genetic factors. In this review, we provide a brief overview of recent progress in research on the pathogenesis of coronary slow flow with a view toward elucidating the possible underlying pathogenesis and identify targets and directions for the treatment of this condition.

Establishment and verification of a nomogram that predicts the risk for coronary slow flow

Background

Coronary slow flow (CSF) has gained significance as a chronic coronary artery disease, but few studies have integrated both biological and anatomical factors for CSF assessment. This study aimed to develop and validate a simple-to-use nomogram for predicting CSF risk by combining biological and anatomical factors.

Methods

In this retrospective case-control study, 1042 patients (614 CSF cases and 428 controls) were randomly assigned to the development and validation cohorts at a 7:3 ratio. Potential predictive factors were identified using least absolute shrinkage and selection operator regression and subsequently utilized in multivariate logistic regression to construct the nomogram. Validation of the nomogram was assessed by discrimination and calibration.

Results

N-terminal pro brain natriuretic peptide, high density lipoprotein cholesterol, hemoglobin, left anterior descending artery diameter, left circumflex artery diameter, and right coronary artery diameter were independent predictors of CSF. The model displayed high discrimination in the development and validation cohorts (C-index 0.771, 95% CI: 0.737-0.805 and 0.805, 95% CI: 0.757-0.853, respectively). The calibration curves for both cohorts showed close alignment between predicted and actual risk estimates, demonstrating improved model calibration. Decision curve analysis suggested high clinical utility for the predictive nomogram.

Conclusion

The constructed nomogram accurately and individually predicts the risk of CSF for patients with suspected CSF and may be considered for use in clinical care.

Analysis of Risk Factors and Construction of a Predictive Model for Readmission in Patients with Coronary Slow Flow Phenomenon

Background

Coronary slow flow phenomenon (CSFP) is a phenomenon in which distal vascular perfusion is delayed on angiography, but coronary arteries are not significantly narrowed and there is no other organic cardiac disease. Patients with CSFP may be repeatedly readmitted to the hospital because of chest pain or other symptoms of precordial discomfort, and there is a risk of adverse events. In order to investigate the risk factors affecting the readmission of CSFP patients, a prediction model was constructed with the aim of identifying patients at risk of readmission at an early stage and providing a reference for further clinical intervention.

Methods

In this study, we collected clinical data from 397 CSFP patients between June 2021 and January 2023 in Xinjiang Medical University Hospital. Telephone follow-up clarified whether the patients were readmitted to the hospital. A predictive model for readmission of CSFP patients was constructed using multifactorial logistic regression. Nomogram was used to visualize the model and bootstrap was used to internally validate the model. ROC, DCA and Calibration curve were plotted to evaluate the calibration and discriminative ability of the column line graphs, respectively. Calibration and resolution of the column line graphs, respectively.

Results

A total of 34 of 397 CSFP patients experienced readmission. Smoking history, creatine kinase isoenzyme-MB, total cholesterol, and left ventricular ejection fraction were the predictors of readmission in patients with CSFP. The area under the curve of the Nomogram model was 0.87, which indicated that the model had good predictive ability and differentiation, and the DCA and Calibration curves also indicated that the model had good consistency and was clinically useful.

Conclusion

A readmission prediction model for patients with CSFP may facilitate early identification of patients at potential risk for readmission and timely interventional therapy to improve patient prognosis.

Association between pan-immune-inflammation value and coronary slow flow phenomenon in patients with angiographically normal coronary arteries

INTRODUCTION

Coronary slow flow phenomenon (CSFP) is characterized by the delayed contrast filling of terminal vessels of coronary arteries in the presence of normal or nearly normal epicardial coronary arteries. Given that inflammation plays a role in cardiovascular disorders, including CSFP, using peripheral blood-derived compound prognostic indexes could be a feasible way to predict the presence of CSFP. Therefore, in the present study, we evaluated the association between pan-immune-inflammation value (PIV) and the CSFP.

METHODS

This single-center, retrospective study was composed of 612 patients aged over 18 years who underwent CAG for suspected stable ischemic heart disease. The association of clinical and laboratory parameters with the CSFP was evaluated with univariate and multivariate analyses.

RESULTS

The median age of the patients was 54 (IQR 46-63) and 61.3% of the patients were male. The 12.6% (84/612) of the patients had CSFP, while the coronary flow was normal in the remaining 87.4% of patients. The PIV levels had moderate success for the prediction of the CSFP (AUC: 0.675, 95% CI: 0.615-0.735, p < 0.001). In multivariate analyses, male gender (OR: 4.858, 95% CI: 2.851-8.277, p < 0.001), presence of diabetes (OR: 2.672, 95% CI: 1.396-5.113, p = 0.003), lower HDL-C values (OR: 2.120, 95% CI: 1.286-3.496, p = 0.003), and higher PIV levels (OR: 2.527, 95% CI: 1.519-4.203, p < 0.001) were associated with a higher risk of CSFP.

CONCLUSION

We demonstrated that a higher risk of CSFP in patients with PIV levels. If supported by prospective evidence, PIV levels could be used as a minimally invasive reflector of CSFP.

Predictors of non-obstructive coronary slow flow in poorly controlled type 2 diabetes mellitus: a cross-sectional study

BACKGROUND

Coronary slow flow (CSF) can occur due to various factors, such as inflammation, small vessel disease, endothelial dysfunction, and inadequate glucose control. However, the exact pathological mechanisms behind CSF remain incompletely understood. The objective of this study was to identify the risk factors associated with slow coronary flow in individuals with Type 2 Diabetes Mellitus (T2DM) who have non-obstructive coronary artery disease (CAD) and experience CSF.

METHODS

We conducted a prospective cohort study involving 120 patients with T2DM who were referred for invasive coronary angiography due to typical chest pain or inconclusive results from non-invasive tests for myocardial ischemia. Using a 2 × 2 design, we categorized patients into groups based on their glycemic control (adequate or poor) and the presence of CSF (yes or no), defined by a TIMI frame count > 27. All patients had non-obstructive CAD, characterized by diameter stenosis of less than 40%. We identified many variables associated with CSF.

RESULTS

Our investigation revealed no significant differences in age, sex, family history of coronary artery disease, ECG ischemia abnormalities, or echocardiographic (ECHO) data between the groups. In patients with adequate glycemic control, hypertension increased the risk of CSF by 5.33 times, smoking by 3.2 times, while dyslipidemia decreased the risk by 0.142. Additionally, hematocrit increased the risk by 2.3, and the platelet-to-lymphocyte ratio (PLR) increased the risk by 1.053. Among patients with poor glycemic control, hematocrit increased the risk by 2.63, and the Neutrophil-to-Lymphocyte Ratio (NLR) by 24.6. Notably, NLR was positively correlated with glycemic control parameters in T2DM patients with CSF.

CONCLUSIONS

In T2DM patients with CSF, various factors strongly correlate with glycemic control parameters and can be employed to predict the likelihood of CSF. These factors encompass hypertension, smoking, increased body mass index (BMI), elevated platelet count, hematocrit, NLR, PLR, and C-reactive protein (CRP).

TRIAL REGISTRATION

Registry: ZU-IRB (ZU-IRB#9419-3-4-2022), Registered on: 3 April 2022, Email: IRB_123@medicine.zu.edu.eg.

Triglyceride glucose-body mass index as a novel predictor of slow coronary flow phenomenon in patients with ischemia and nonobstructive coronary arteries (INOCA)

BACKGROUND

The triglyceride glucose-body mass index (TyG-BMI index) has been suggested as a novel predictor of insulin resistance. However, its predictive value for slow coronary flow phenomenon (SCFP) in patients with ischemia and nonobstructive coronary arteries (INOCA) remains unclear.

METHODS

We consecutively recruited 1625 patients with INOCA from February 2019 to February 2023 and divided them into two groups based on thrombolysis in myocardial infarction (TIMI) frame counts (TFCs): the SCFP group (n = 79) and the control group. A 1:2 age-matched case-control study was then performed. The TyG-BMI index was calculated as ln [plasma triglyceride (mg/dL) × fasting blood glucose (mg/dL)/2] × BMI.

RESULTS

TyG-BMI index in the SCFP group (218.3 ± 25.2 vs 201.0 ± 26.5, P < .001) was significantly higher than in the normal controls. TyG-BMI index also increased with the number of coronary arteries involved in the SCFP. Multivariate logistic regression analysis showed that TyG-BMI, BMI, and TG were independent predictors for SCFP. Receiver operating characteristic (ROC) curve analysis showed that when the TyG-BMI index was above 206.7, the sensitivity and specificity were 88.6% and 68.5%, respectively, with an AUC of 0.809 (95% CI: 0.756-0.863, P = .027). Combined BMI with TG, the TyG-BMI index had a better predictive value for SCFP than BMI and TG (P < .001).

CONCLUSION

The TyG-BMI index was an independent predictor for SCFP in INOCA patients, and it had a better predictive value than BMI and TG.

Coronary slow flow and its correlation with reduced left ventricle global longitudinal strain: a case-control study

BACKGROUND

Coronary slow flow (CSF) often links to inflammation and endothelial function disturbance. While conventional ejection fraction measurements fall short in identifying myocardial dysfunction, left ventricular global longitudinal strain (LV GLS) has shown superior efficacy in this regard. Our study aimed to explore subclinical left ventricular systolic dysfunction by assessing LV GLS in patients diagnosed with coronary slow flow (CSF).

METHODS

The study included sixty patients with CSF and sixty control individuals without CSF. Coronary angiography employed the Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) to identify CSF. LV GLS values were evaluated and compared between the two groups.

RESULTS

Significantly reduced LV GLS was evident in the CSF group compared to the control group (- 16.18 ± 1.25 vs. - 19.34 ± 1.33, p < 0.001). A notable correlation (r = 0.492, p < 0.001) between LV GLS and TFC was observed in the CSF group. Multivariate logistic regression analysis highlighted reduced LV-GLS (OR 2.2, 95% CI 1.57-3.09, p < 0.001) and smoking (OR 11.55, 95% CI 3.24-41.2, p < 0.001) as significant predictors for CSF presence. The receiver operating characteristic curve established that an LV GLS value of ≥ - 17.8% accurately predicted the presence of CSF (AUC: 0.958, 95% CI: 0.924-0.991, p < 0.001) with 90% specificity and 91.7% sensitivity.

CONCLUSION

Our study indicates that reduced LV GLS is associated with CSF presence, offering a valuable means to early detect subclinical left ventricular systolic dysfunction in high-risk patients susceptible to heart failure.

TRIAL REGISTRATION

ZU-IRB#7038/12-7-2021 Registered 12 July 2021, email: IRB_123@medicine.zu.edu.eg.

Changes of left atrial morphology and function evaluated with four-dimensional automated left atrial quantification echocardiography in patients with coronary slow flow phenomenon and preserved left ventricular ejection fraction

BACKGROUND

Coronary slow flow phenomenon (CSFP) can cause left ventricular diastolic dysfunction (LVDD). In multiple studies, the left atrial (LA) strain has been reported to be an excellent parameter for assessing LVDD. The 4-dimensional automated LA quantification (4D Auto LAQ) dedicated to the LA was recently available. Our study aimed to evaluate subclinical changes in LA morphology and function with 4D Auto LAQ in patients with CSFP and preserved left ventricular ejection fraction (LVEF).

METHODS

Forty-eight patients with CSFP confirmed with coronary angiography and 46 age and gender-matched controls with normal coronary flow were enrolled. The thrombolysis in myocardial infarction frame count (TFC) method was used to record coronary blood flow velocities for each major coronary artery. LA volume, LA longitudinal and circumferential strains during each of the three LA phases (reservoir, conduit, and contraction), LA total emptying fraction (LATEF), LA active emptying fraction (LAAEF), and LA passive emptying fraction (LAPEF) were quantified with 4D Auto LAQ analysis.

RESULTS

Compared with controls, LA longitudinal reservoir strain (LASr), LA longitudinal strain during the conduit phase (LAScd), LA contraction strain (LASct), LA conduit circumferential strain (LAScd-c), LATEF, LAPEF decreased significantly in individuals with CSFP. Of the 4D- LAQ parameters, only LASr [odds ratio (OR): 0.773, P < 0.001] and LATEF [OR: 0.762, P < 0.001] were associated with CSFP in multivariate analysis. A LASr ≤23.00% can differentiate CSFP from controls [sensitivity, 66.7%; specificity, 93.5%; area under the curve (AUC), 0.823; P < 0.001]. A LASr of ≤19.00% could predict the elevation of LV filling pressure in the CSFP cohort [sensitivity, 76.9%; specificity, 74.3%; area under the curve (AUC), 0.792; P < 0.001]. LASr was the only index to demonstrate significant changes compared to controls in single-vessel CSFP. Compared to the right coronary artery (RCA) and left circumflex (LCX), TFC of the left anterior descending (LAD) artery was the only independent variable of LASr (Standardized Coefficients: -0.386, P = 0.037).

CONCLUSIONS

Impairment of LA reservoir function reflected by changes in LASr and LATEF can be seen in patients with CSFP. LASr could predict the elevation of LV filling pressure in CSFP individuals. LASr is more sensitive than LATEF in detecting LA reservoir dysfunction in single-vessel CSFP. CSFP in LAD exerts a more prominent influence on LASr than RCA or LCX.

Relationship between quantitative epicardial adipose tissue based on coronary computed tomography angiography and coronary slow flow

BACKGROUND

The purpose of this study was to explore the relationship between quantitative epicardial adipose tissue (EAT) based on coronary computed tomography angiography (CCTA) and coronary slow flow (CSF).

METHODS

A total of 85 patients with < 40% coronary stenosis on diagnostic coronary angiography were included in this retrospective study between January 2020 and December 2021. A semi-automatic method was developed for EAT quantification on CCTA images. According to the thrombolysis in myocardial infarction flow grade, the patients were divided into CSF group (n = 39) and normal coronary flow group (n = 46). Multivariate logistic regression was used to explore the relationship between EAT and CSF. Receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of EAT in CSF.

RESULTS

EAT volume in the CSF group was significantly higher than that of the normal coronary flow group (128.83± 21.59 mL vs. 101.87± 18.56 mL, P < 0.001). There was no significant difference in epicardial fat attenuation index between the two groups (P > 0.05). Multivariate logistic regression analysis showed that EAT volume was independently related to CSF [odds ratio (OR) = 4.82, 95% confidence interval (CI): 3.06-7.27, P < 0.001]. The area under ROC curve for EAT volume in identifying CSF was 0.86 (95% CI: 0.77-0.95). The optimal cutoff value of 118.46 mL yielded a sensitivity of 0.80 and a specificity of 0.94.

CONCLUSIONS

Increased EAT volume based on CCTA is strongly associated with CSF. This preliminary finding paves the way for future and larger studies aimed to definitively recognize the diagnostic value of EAT in CSF.

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.

Long-Term Change in Flow Rates in Patients with Coronary Slow Flow

INTRODUCTION

Coronary slow flow (CSF) is a condition characterized by impaired blood flow rates in the coronary arteries. It can result in severe cardiovascular outcomes. There is no sufficient evidence regarding the certain etiology and reversibility of slow flow patterns and changes in frame counts with long-term management.

METHODS

We retrospectively enrolled 48 patients with chronic coronary syndrome and CSF who underwent a second angiography. A corrected coronary frame rate (CFR) >27 was defined as CSF. We created 3 groups according to the change in CSF status as the improved, not changed, and worsened groups. We compared the CFR and CSF status of the patients between the first and second angiographies within a median of 2.6 years.

RESULTS

We determined a nonsignificant change in cCFR in left anterior descending (LAD) artery (34.4 [18.9] vs. 31.59 [10.3], p = 0.35), circumflex (Cx) artery (42.84 [12.56] vs. 40.66 [13.2], p = 0.35), and right coronary artery (RCA) (57.80 [30.13] vs. 50.32 [19.5], p = 0.11). In the comparison of CSF status of LAD (75% vs. 63%, p = 0.27), Cx (96% vs. 83%, p = 0.09), RCA (94% vs. 94%, p = 1.0) between first and second angiographies, there was no significant change. In the comparison of the 3 groups according to the improvement of CSF status, there was no significant difference in demographic features, change in laboratory parameters, and time between the groups.

CONCLUSION

There was no significant change in the median CFR and CSF status in the overall group between the two angiographies after 3 years.

Evaluation of the relationship between clinical and laboratory risk factors in atherosclerosis patients with coronary slow flow: a case-control analysis

BACKGROUND

Coronary slow flow (CSF) is an angiographic entity distinguished by the delayed filling of the epicardial coronary arteries in the lack of significant obstructive artery disease. The pathological causes are still unknown. This study aimed to elucidate the relationship between clinical and laboratory-related risk factors in atherosclerosis patients diagnosed with CSF.

RESULTS

The research encompassed a study group of 142 individuals, with a mean age of 52.47 ± 10.62, and a male representation of 47.7%. A thorough statistical analysis was conducted, indicating that there were no noteworthy variations in age, gender, smoking history, hematocrit, blood sugar, and HDL levels between the groups of cases and controls (P > 0.05). Subsequent analysis of the data indicated that there were significant differences in history of hypertension, LDL, and BMI measurements between the groups of subjects who were designated as cases and those who were designated as controls. Our study revealed that male gender, a history of hypertension, and BMI were identified as independent predictors of CSF (P < 0.05).

CONCLUSIONS

After modeling regression, we were able to conclude that male gender, BMI, and history of hypertension are reliable predictors of slow coronary flow. These findings add to our growing understanding of the complex interplay between clinical and laboratory risk factors in the development and progression of CSF.

Homocysteine levels in patients with coronary slow flow phenomenon: A meta-analysis

BACKGROUND

With the development of coronary angiography, more and more attention has been paid to coronary slow flow phenomenon (CSFP). Recent studies have found that the correlation between homocysteine (Hcy) levels and CSFP was contradictory, so we conducted this meta-analysis to investigate the correlation.

METHODS

By March 2022, studies that meet the research requirements were identified by searching multiple databases including Embase, Web of Science, and PubMed. We included studies evaluating the correlation between Hcy levels and CSFP. Random or fixed effect meta-analyses were performed according to heterogeneity among included studies. A leave-out method and subgroup analyses were conducted to determine the source of heterogeneity.

RESULTS

Thirteen studies involving 625 CSFP and 550 subjects were included. After pooling data from each study, Hcy levels were higher in the CSFP groups (standard mean difference [SMD], 1.45; 95% CI, 0.94 to 1.96, P < .00001) than in the control group. In the meta-analysis, there was significant heterogeneity (I2 = 93%), which was further explored through leave-out method and and subgroup analyses. Specifically, pooling data from studies with a mean thrombolysis in myocardial infarction (TIMI) frame count ≥ 46 (SMD, 1.31; 95% CI, 1.00 to 1.63, P < .00001) resulted in no heterogeneity (0%), indicating that the TIMI frame count ≥ 46 was the source of heterogeneity.

CONCLUSIONS

Our study found that elevated Hcy levels are strongly associated with CSFP. More importantly, the association was stronger in CSFP patients with mean TIMI frame count ≥ 46.

Thromboembolic risk scores in patients with non-obstructive coronary architecture with and without coronary slow flow: A case-control study

AIM

Coronary slow flow phenomenon (CSFP) detected on coronary angiography (CA) has been related to poor prognosis. We sought to examine the relationship between thromboembolic risk scores, routinely used in cardiology practice, and CSFP.

METHODS

This single-center, retrospective, case-control study comprised 505 individuals suffering from angina and had verified ischemia between January 2021 and January 2022. Demographic and laboratory parameters were obtained from the hospital database. The following risk scores were calculated; CHA₂DS₂-VASc, M-CHA₂DS₂-VASc, CHA₂DS₂-VASc-HS, R₂-CHA₂DS₂-VASc, M-R₂-CHA₂DS₂-VASc, ATRIA, M-ATRIA, M-ATRIA-HSV. The overall population was divided into two groups; coronary slow flow and coronary normal flow. Multivariable logistic regression was performed to compare risk scores between patients with and without CSFP. Pairwise comparisons were then undertaken to test performance in determining CSFP.

RESULTS

The mean age was 51.7 ± 10.7 years, of whom 63.2% were male. CSFP was detected in 222 patients. Those with CSFP had higher rates of male gender, diabetes, smoking, hyperlipidemia, and vascular disease. All scores were higher in CSFP patients. Multivariable logistic regression analysis found that CHA₂DS₂-VASc-HS score was the most powerful determinant of CSFP among all risk schemes (for each one-point increase in score OR = 1.90, p < 0.001; for score of 2-3 OR = 5.20, p < 0.001; for score of >4 OR = 13.89, p < 0.001). Also, the CHA₂DS₂-VASc-HS score provided the best discriminative performance, with a cut-off value of ≥2 in identifying CSFP (AUC = 0.759, p < 0.001).

CONCLUSION

We showed that thromboembolic risk scores may be associated with CSFP in patients with non-obstructive coronary architecture who underwent CA. The CHA₂DS₂-VASc-HS score had the best discriminative ability.

Predictors of Long-Term Mortality in Patients with Stable Angina Pectoris and Coronary Slow Flow

Background and Objectives: Coronary slow flow (CSF) is an angiographic phenomenon characterized by the slow progression of an injected contrast agent during diagnostic coronary angiography in the absence of significant stenosis. Although CSF is a common angiographic finding, the long-term outcomes and mortality rates are still unknown. This study aimed to investigate the underlying causes of mortality over a 10-year period in patients diagnosed with stable angina pectoris (SAP) and CSF. Materials and Methods: This study included patients with SAP who underwent coronary angiography from 1 January 2012 to 31 December 2012. All patients displayed CSF despite having angiographically normal coronary arteries. Hypertension (HT), diabetes mellitus (DM), hyperlipidaemia, medication compliance, comorbidities, and laboratory data were recorded at the time of angiography. Thrombolysis in myocardial infarction (TIMI) frame count (TFC) was calculated for each patient. The cardiovascular (CV) and non-CV causes of long-term mortality were assessed. Results: A total of 137 patients with CSF (93 males; mean age: 52.2 ± 9.36 years) were included in this study. Twenty-one patients (15.3%) died within 10 years of follow-up. Nine (7.2%) and 12 (9.4%) patients died of non-CV and CV causes, respectively. Total mortality in patients with CSF was associated with age, HT, discontinuation of medications, and high-density lipoprotein cholesterol (HDL-C) levels. The mean TFC was associated with CV mortality. Conclusion: Patients with CSF exhibited a notable increase in cardiovascular-related and overall mortality rates after 10 years of follow-up. HT, discontinuation of medications, HDL-C levels, and mean TFC were associated with mortality in patients with CSF.

The Systemic Immune-Inflammation Index May Predict the Coronary Slow Flow Better Than High-Sensitivity C-Reactive Protein in Patients Undergoing Elective Coronary Angiography

Methods

A total of 197 patients (102 patients with CSF; 95 patients with normal coronary flow) were included in this retrospective study. Clinical and angiographic characteristics of patients were obtained from hospital records.

Results

Patients with CSF had higher SII, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte (PLR), and high-sensitivity C-reactive protein (hsCRP) levels compared with the control group. Body mass index (p=0.022, OR 1.151, 95% CI 1.121–1.299), low-density lipoprotein (p=0.018, OR 1.028, 95% CI 1.005–1.052), hsCRP (p=0.044, OR 1.161, 95% CI 1.004–1.343), and SII (p < 0.001, OR 1.015, 95% CI 1.003–1.026) were independent predictors of CSF in the multivariable analysis. The optimal cutoff value of SII in predicting CSF was >877 in ROC curve analysis (p < 0.001, AUC = 0.892, 95% CI 0.848–0.936). This cutoff value of SII predicted the CSF with a sensitivity of 71.5% and specificity of 92.4%. Spearman correlation analysis showed a positive correlation between the mean TFC value and PLR, NLR, hsCRP, and SII.

Conclusions

SII may be used as a better indicator for the prediction of CSF than hsCRP.

Evaluation of index of cardio-electrophysiological balance in patients with coronary slow flow

BACKGROUND

Coronary slow flow (CSF) is defined as the late progression of applied contrast through coronary arteries. The cardiac electrophysiological balance index (iCEB) reflects the balance between ventricular depolarisation and repolarisation and provides more information about ventricular arrhythmogenesis (VA) than other electrocardiography (ECG) parameters (QT, corrected QT [QTc], etc.).

AIM

We aimed to evaluate iCEB in patients with CSF.

METHODS

We divided the study population into two groups as CSF and control. The CSF group consisted of 100 patients (33 female, 67 male, mean age 52.2 ± 2.6), while the control group consisted of the same number of age and sex-matched patients (35 female, 65 male, mean age 51.7 ± 1.4). ECG parameters of the study population (QRS duration, QT, T wave peak-to-end (Tp-e) intervals, iCEB (QT/QRS), and iCEBc (heart rate QTc/QRS) rates were calculated and compared between CSF and control groups.

RESULTS

Intervals (QT and QTc intervals) and Tp-e/QTc ratio were greater in the CSF group compared with controls [422.1 ± 12.8 vs. 349.4 ± 14.3 bpm, respectively, p  <  .001; 457.0 ± 12.2 vs. 378.1 ± 12.3 bpm, respectively, p < .001, and 0.19 vs. 0.12, respectively, p  <  .001]. ICEB and iCEBc were significantly greater than controls [(4.9 ± 0.4 vs. 4.2 ± 0.4, respectively, p < .001), (5.7 ± 0.3 vs. 4.4 ± 0.3, respectively, p < .001)].

CONCLUSIONS

ICEB and iCEBc were significantly increased in patients with CSF. This may suggest that CSF may predispose to malign arrhythmias.

Slow Coronary Blood Flow: Pathogenesis and Clinical Implications

Coronary slow flow (CSF) phenomenon, also known as cardiac syndrome Y, is defined as the delayed opacification of the coronary vasculature at the distal level. Different hypotheses and theories have been postulated about its substrate and mechanism, such as microvascular and endothelial dysfunction. Several studies have confirmed that CSF is a cause of ischaemia detected by non-invasive testing. Clinically, it can present as angina pectoris, acute coronary syndrome and sudden cardiac death. It has an incidence of 1–5% in patients undergoing coronary angiography and has been most frequently found in young men who are smokers with metabolic syndrome. There are no established treatments for CSF and further studies are still necessary.

The Effect of Chronic Inhouse Biomass Fuel Smoke Exposure on Coronary Slow Flow Phenomenon in Women Living in the Eastern Region of Turkey

Objective:

Biomass fuel (BMF) is still widely used in rural areas for cooking and heating worldwide. BMF smoke inhalation is a prominent cause of respiratory and cardiovascular disease. The slow coronary flow (SCF) phenomenon is known as the delayed opacification of distal coronary arteries on a coronary angiogram. SCF is known to be related to cardiovascular morbidity and mortality. Thus, we aimed to investigate the relationship between exposure to BMF and SCF in women in this study.

Methods:

A total of 457 consecutive women who underwent coronary angiography were retrospectively enrolled in this study. Patients were divided into two groups according to the use of BMF during their lives, from birth to older ages, as biomass exposure group (BEG) and non-exposure group. The presence of SCF was calculated based on thrombolysis in myocardial infarction frame count.

Results:

Two hundred fifty nine patients were in the BEG, whereas 198 patients were in the non-exposure group. The prevalence of SCF was higher in the BEG compared to the non-exposure group (47.9% vs. 13.1%, respectively, p<0.001). The presence of biomass exposure, body mass index, white blood cell count, low-density lipoprotein cholesterol, C-reactive protein, serum creatinine, and hypertension were independent predictors of SCF. The optimal cutoff point of biomass exposure time in years to detect the presence of SCF was 30 years (Area under the curve: 0.71, sensitivity: 0.65, specifity: 0.71).

Conclusions:

Exposure to indoor BMF was associated with a SCF phenomenon in women.

Angiographic profile and outcomes in persistent non-valvular atrial fibrillation: A study from tertiary care center in North India

Background

The relationship of atrial fibrillation (AF) with coronary artery disease (CAD) is well established, yet it is often missed. There is evidence of myocardial ischemia on stress imaging in AF patients in the absence of obstructive CAD. In this prospective cohort, we studied the angiographic profiles of non-valvular AF patients.

Methods

The study was a nonrandomized, prospective, single-center observational study of consecutive patients of persistent non-valvular AF. Patients symptomatic for AF despite optimal medical therapy for 3 months were recruited and all underwent coronary angiograms (CAG). Patients with prior history of CAD were excluded.

Results

A total of 70 patients were followed for a mean duration of 12 ± 1.4 months. The mean age of the study group was 66.07 (±11.49) years. Hypertension was the commonest comorbidity seen in 74% patients. Obstructive CAD was present in 32 (46%) patients, non-obstructive (<50% stenosis) CAD in 17 (24%) patients and normal coronaries in 21 (30%) patients. Overall 49 (70%) patients had evidence of CAD. Amongst patients without obstructive CAD, slow flow was seen in 16 (42%) patients. Lower baseline ejection fraction, lower haemoglobin & albumin levels and higher creatinine levels was associated with increased mortality. In patients without obstructive CAD, hospitalizations for fast ventricular rate were significantly increased in those having slow flow on CAG (p = 0.005).

Conclusions

Majority (70%) of our patients had evidence of atherosclerotic CAD on CAG. A large proportion of patients without obstructive CAD had slow flow on CAG.

•

Coexistent coronary artery disease is common in symptomatic non-valvular atrial fibrillation (AF).

•

Revascularization was needed in 35.7% of patients.

•

Lower ejection fraction, haemoglobin and serum albumin levels correlated with worse outcomes.

•

Coronary slow-flow is highly prevalent in AF patients (42%) and has a bearing of future events.

•

Hospitalizations for fast ventricular rate were significantly increased in those having slow flow.

Plasma atherogenic indices are independent predictors of slow coronary flow

Background

Although the pathophysiology of coronary slow flow (CSF) has not been fully elucidated, emerging data increasingly support potential role for subclinical diffuse atherosclerosis in the etiology of CSF. We aimed to investigate relationship between atherogenic indices and CSF.

Methods

130 patients with CSF diagnosed according to Thrombolysis in Myocardial Infarction (TIMI)-frame count (TFC) method and 130 controls who had normal coronary flow (NCF) were included in this retrospective study. Atherogenic indices (atherogenic index of plasma [AIP], Castelli risk indices I and II [CRI-I and II]) were calculated using conventional lipid parameters.

Results

The logistic regression analyses demonstrated that AIP (OR, 5.463; 95% confidence interval [CI], 1.357–21.991; p = 0.017) and CRI-II (OR, 1.624; 95% CI, 1.138–2.319; p = 0.008) were independent predictors of CSF. Receiver operating characteristic analysis showed that the optimal cutoff value to predict the occurrence of CSF was 0.66 for AIP (sensitivity, 59%; specificity, 73%; area under curve [AUC], 0.695; p < 0.001) and 3.27 for CRI-II (sensitivity, 60%; specificity, 79%; AUC, 0.726; p < 0.001).

Conclusions

AIP and CRI-II levels were independent predictors of CSF. Prospective studies in larger cohorts of patients may elucidate the role of atherogenic dyslipidemia in the pathophysiology of CSF.

Echocardiographic Evaluation of Left and Right Ventricular Function in Patients with Coronary Slow Flow Syndrome: A Comparative Study

The Coronary Slow Flow Phenomenon is a syndrome of normal coronary anatomy and delayed progression of contrast medium through the coronary vessels. This research attempts to analyze and compare the systolic and diastolic function of the left and right ventricle in primary Slow Flow and Normal Coronary Flow.Two groups of primary Slow Coronary Flow (33 people) and Normal Coronary Flow (11 people) were included and the systolic and diastolic function of the ventricles was analyzed and compared between them.In the control group 18% of patients had mild and in the case group 24.2% mild, and 3.1% had moderate left ventricular diastolic dysfunction (P >0.05). The frequency distribution of the left and right ventricular systolic dysfunction was similar in the two groups.There was no statistically significant difference between two groups and in the association of cardiac dysfunction, it may be reasonable to investigate other causes.

LncRNA NEAT1 Promote Inflammatory Responses in Coronary Slow Flow Through Regulating miR-148b-3p/ICAM-1 Axis

Background

Coronary slow flow (CSF) is an angiographic phenomenon characterized by delayed coronary opacification with normal or near-normal epicardial coronary arteries. The pathogenesis of CSF is closely related to inflammatory response. Accumulating evidence shows that long non-coding RNAs (lncRNAs) play an important role in cardiovascular disease. However, the mechanism underlying the influence of the lncRNA nuclear enriched abundant transcripts 1 (NEAT1) on CSF is still unknown.

Patients and Methods

Forty CSF patients and forty control subjects were included in the study and underwent coronary angiography, Seattle angina questionnaire (SAQ) and echocardiography. The plasma levels of the inflammatory factors soluble intercellular adhesion molecule-1 (sICAM-1), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) were determined by ELISA. The expression levels of NEAT1, miR-148b-3p and ICAM-1 in cells were measured by qRT-PCR or Western blotting. Cell proliferation was measured by 5‐Ethynyl‐2ʹ‐deoxyuridine (EdU) and Cell Counting Kit-8 (CCK-8) assay. Cell apoptosis was detected by apoptosis assay. The relationship between NEAT1 and miR-148b-3p was verified by luciferase reporter gene assay, RNA immunoprecipitation (RIP) assay and avidin-biotin pull-down assay. The relationship between ICAM-1 and miR-148b-3p was verified by luciferase reporter gene assay and avidin-biotin pull-down assay.

Results

This study showed that plasma sICAM-1, miR-148b-3p, and NEAT1 as independent predictors of a CSF diagnosis. Furthermore, plasma NEAT1 level showed superior diagnostic ability for CSF compared with sICAM-1 and miR-148b-3p. It was also shown that high expression of NEAT1 in oxygen-glucose deprivation (OGD)-treated human umbilical vein endothelial cells (HUVECs) functions as a competing endogenous RNA (ceRNA). By specifically binding miR-148b-3p, it weakened the negative regulatory effects of miR-148b-3p on the ICAM-1 target gene leading to upregulated expression of ICAM-1. This interaction was also shown to inhibit HUVEC proliferation and enhance apoptosis.

Conclusion

This study demonstrated for the first time the important mechanism of action of the NEAT1/miR-148b-3p/ICAM-1 axis in the progression of CSF disease, and indicated the potential of NEAT1, miR-148b-3p, and ICAM-1 as a new target for the diagnosis and treatment of CSF.

Slow Flow Phenomenon Impairs the Prognosis of Coronary Artery Ectasia as Well as Coronary Atherosclerosis

Introduction:

Coronary artery ectasia (CAE) is one of the uncommon cardiovascular disorders and its prognosis is still debated.

Objective:

We aimed to review long-term follow-up data in patients with CAE and to evaluate the prognosis of CAE patients with coronary slow flow phenomenon (CSFP).

Methods:

This study had a prospective design and 143 patients with CAE were included. The angiographic and demographic characteristics were reviewed in detail. The patients were categorized, based on concomitant coronary artery stenosis detected by angiography, as CCAE group (n=87, ≥30% luminal stenosis) and ICAE group (n=56, <30% luminal stenosis) and also categorized by the coronary flow as CSFP group (n=51) and normal flow coronary ectasia - NCEA group (n=92). All patients were re-evaluated at 6-month intervals. Follow-up data, cardiovascular (CV) mortality, hospitalization and major adverse cardiac events (MACE) were collected. The level of statistical significance was set at 5%.

Results:

Patients were followed up for an average of 56.9±7.4 months. During the follow-up, statistically significant differences were found in hospitalization, CV mortality and MACE between the CCAE and ICAE groups (P=0.038, P=0.003, P=0.001, respectively). The CSFP and NCEA groups were also compared. There was a statistical difference with respect to hospitalization between the CFSP and NCEA groups (P=0.001), but no difference was observed in terms of MACE and CV mortality (P=0.793 and P=0.279).

Conclusion:

CSFP accompanying CAE may be a predictor of hospitalization. Significant atherosclerotic plaques coexisting with CAE may be predictive for MACE.

Echocardiographic and laboratory findings in coronary slow flow phenomenon: cross-sectional study and review

Background

Coronary sow-flow phenomenon (CSFP) is defined as slow passage of the contrast injected into the coronary arteries without distal obstruction of the vessel.

Methods

The present study was a cross-sectional, descriptive-analytical study performed at the Seyed-al-Shohada Heart Center during 2018–2019. The eligible patients based on the inclusion and exclusion criteria were divided into the study group showing the CSFP and the control group with normal epicardial coronary arteries.

Results

The study included 124 patients. 67.9% of the study group and 39.4% of the control group were male patients (p-value = 0.001), and the mean patient age was 52.18 ± 12.55 and 51.77 ± 10.36 years in the study and control groups, respectively (p-value = 0.18). The study group had a significantly higher BMI than the control group (p < 0.05) and also a higher prevalence of smoking and hypertension. The variables of ALC, Hct, Plt, MPV, RDW, Cr, triglyceride, TC, and LDL, were higher in the study group. Given the echocardiographic findings, the mean E wave was significantly lower in the study group, while the control group had a significantly higher GLS (p-value = 0.01). Also, left anterior descending artery was the most common artery involved with CSFP.

Conclusion

The CSFP was significantly more common in men, smokers, hypertensive patients, and patients with high BMI. Moreover, these patients had significantly higher platelet count, MPV, LDL, and FBS. Some other laboratory variables were also higher in these patients. Given the echocardiographic findings, mild diastolic dysfunction and low GLS were also observed in the study group.

Comparison of the Outcomes between Coronary No-Reflow and Slow-Flow Phenomenon in Non-STEMI Patients

BACKGROUND

Coronary slow-flow phenomenon (CSFP) and coronary no-reflow phenomenon (CNP) are associated with increased risk of major cardiovascular adverse events (MACE).

OBJECTIVES

This study aimed to evaluate and compare the one-year clinical follow-up outcomes among patients with CNP and CSFP who underwent percutaneous coronary interventions (PCI) in non-ST elevation myocardial infarction (NSTEMI).

METHODS

This study included a total of 858 patients who were diagnosed with NSTEMI and underwent PCI within 24 h of symptom onset. The patients were divided into two groups, the CSFP group (n=221) and the CNP group (n=25), regarding the angiographic characteristics of thrombolysis in myocardial infarction (TIMI) flow of the infarct-related artery. Patients were followed for one-year. A p-value of <0.05 was considered significant.

RESULTS

CNP was observed in 2.91%, and CSFP was observed in 25.75% of the patients. Clinical endpoints analyzed that stroke was significantly higher in the CNP group than in the CSFP group (6 (24%) vs. 6 (2.70%), p<0.001) and MACE was significantly higher in the CNP group than in the CSFP group (11 (44%) vs. 51 (23.10%), p=0.022). Forward conditional logistic regression analysis demonstrated that body mass index (BMI) (OR=1.11, 95%CI: 1.00-1.24, p=0.038) and baseline heart rate (HR) (OR=0.923, 95%CI: 0.88-0.96, p<0.001) were the independent predictors of CNP in NSTEMI.

CONCLUSION

CNP patients have worse clinical outcomes and a higher risk of stroke compared with CSFP patients in NSTEMI. (Arq Bras Cardiol. 2021; 116(5):856-864).

Atorvastatin improves the proliferation and migration of endothelial progenitor cells via the miR-221/VEGFA axis

The present study was aimed at investigating the detailed functions of atorvastatin, a lipid-lowering agent, in the pathogenesis of coronary slow flow (CSF), a clinical disease characterized by delayed angiographic coronary opacity without obstructive coronary disease. In the present study, we successfully identified isolated endothelial progenitor cells (EPCs) from the peripheral blood of patients with CSF. Their vascular endothelial growth factor-A (VEGFA) protein levels were determined using immunoblotting analyses. We determined cell viability using MTT assays, cell migration capacity using Transwell assays, and the angiogenic capacity using a tube formation assay. The target association between miR-221 and VEGFA was validated with a luciferase reporter assay. Atorvastatin treatment increased EPC VEGFA protein levels, proliferation, migration, and angiogenesis. miR-221 expression was down-regulated after atorvastatin treatment; miR-221 overexpression exerted an opposing effect to atorvastatin treatment on VEGFA protein, EPC proliferation, migration, and angiogenesis. The protective effects of atorvastatin treatment on VEGFA protein and EPCs could be significantly suppressed by miR-221 overexpression. miR-221 directly bound the VEGFA 3'UTR to inhibit its expression. In conclusion, atorvastatin improves the cell proliferation, migration, and angiogenesis of EPCs via the miR-221/VEGFA axis. Thus, atorvastatin could be a potent agent against CSF, pending further in vivo and clinical investigations.

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 effect of coronary slow flow on left atrial structure and function

The coronary slow flow phenomenon (CSFP) is common in coronary angiography, however its impact on left atrial (LA) function is still controversial. This study aims to evaluate the LA structure and function of patients with CSFP using two-dimensional speckle tracking echocardiography (2D-STE). Consecutive patients scheduled for coronary angiography from January 2016 to September 2017 were enrolled in this study. Patients’ demographic data, clinical histories, laboratory and angiographic findings were collected and recorded. Diagnostic criteria for CSFP is based on Beltrame et al. proposed in 2012. Meanwhile 139 patients who have no significant stenosis (≤ 40%) and normal blood flow were selected as control. All patients received an echocardiographic examination 24 h before coronary angiography. LA structure and function were measured with echocardiography and 2D-STE. Our results showed that among the 1,954 patients who had received coronary angiography, 512 patients were included in the analysis after the exclusion criteria was implemented. Of those, 101 patients met the CSFP criteria (5.5%). CSFP is mainly seen in LAD (~ 70%). There was no statistical difference in baseline characteristics between the CSFP group and control group, except for a higher proportion of smokers in the CSFP group (P = 0.001). The percentage of monocytes is an independent risk factor for the occurrence of CSFP (P = 0.036) after binary logistic regression analysis. The LA global longitudinal strain (LA-GLS, represents reservoir functions) decreased and LA strain rate at late diastole (LA-SRa, represents booster function) increased in patients with CSFP compared to the control group (P < 0.05). Correlation test of continuous variables by Pearson test suggested that LA-GLS was negatively correlated with TIMI frame count (TFC). We concluded that the percentage of monocytes is an independent risk factor for the CSFP; the LA reservoir and booster functions were impaired in patients with CSFP; LA-GLS is negatively correlated with TFC.

Association of the lymphocyte-to-monocyte ratio, mean diameter of coronary arteries, and uric acid level with coronary slow flow in isolated coronary artery ectasia

Background

The pathophysiology of isolated coronary artery ectasia (CAE) with the coronary slow flow (CSF) phenomenon is still unclear. The purpose of this study was to investigate the risk factors for isolated CAE complicated with CSF.

Methods

A total of 126 patients with isolated CAE were selected retrospectively. The patients were grouped into the no CSF (NCSF) group (n = 55) and the CSF group (n = 71) according to the corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC). Data on demographics, laboratory measurements, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDd), CTFC and diameters of three coronary arteries were collected.

Results

The proportions of males (84.5% vs. 61.8%, p = 0.004) and patients with a smoking history (63.4% vs. 43.6%, p = 0.021) were higher in the CSF group than in the NCSF group. The neutrophil-to-lymphocyte ratio (NLR) (2.08(1.68–3.21) vs. 1.89 ± 0.58, p = 0.001), mean diameter of coronary arteries (mean D) (5.50 ± 0.85 vs. 5.18 ± 0.91, p < 0.001), and uric acid (URIC) level (370.78 ± 109.79 vs. 329.15 ± 79.71, p = 0.019) were significantly higher in the CSF group, while the lymphocyte-to-monocyte ratio (LMR) (4.81 ± 1.66 vs. 5.96 ± 1.75, p < 0.001) and albumin (ALB) level (44.13 ± 4.10 vs. 45.69 ± 4.11, p = 0.036) were lower. Multivariable logistic analysis showed that the LMR (odds ratio: 0.614, 95% CI: 0.464–0.814, p = 0.001), mean D (odds ratio: 2.643, 95% CI: 1.54–4.51, p < 0.001) and URIC level (odds ratio: 1.006, 95% CI: 1.001–1.012, p = 0.018) were independent predictors of CSF in CAE.

Conclusions

The LMR was a negative independent predictor of CSF in isolated CAE, while URIC level and mean D were positive independent predictors.

Slow Coronary Flow: Pathophysiology, Clinical Implications, and Therapeutic Management

Coronary slow flow (CSF) is an angiographic phenomenon with specific epidemiologic characteristics, associated clinical presentation, and prognosis. Although patients with CSF are diagnosed as having "normal coronary arteries," it seems appropriate to consider CSF as a distinct disease entity requiring specific treatment. The patient with CSF is usually male, smoker, obese, with a constellation of risk factors suggestive of metabolic syndrome. Unstable angina is the most common clinical presentation, with recurrent episodes of chest pain at rest associated with electrocardiographic changes often requiring readmission and reevaluation. Regarding definition and diagnosis, interventionists should first exclude possible "secondary" causes of CSF, use objective means for definition and then differentiate from other similar conditions such as microvascular angina. Although the phenomenon is generally benign, patients with CSF are severely symptomatic with recurrent episodes of chest pain and poor quality of life. Furthermore, acute presentation of the phenomenon is commonly life-threatening with ventricular tachyarrhythmias, conduction abnormalities, or cardiogenic shock. Acute treatment of CSF includes, but is not restricted to, intracoronary infusion of dipyridamole, adenosine, or atropine. Chronic management of patients with CSF encompasses dipyridamole, diltiazem, nebivolol, telmisartan, and/or atorvastatin associated with amelioration of angina symptoms, improved quality of life, and good prognosis.

Prevalence and predictors of slow coronary flow phenomenon in Kermanshah province

Introduction: This study was conducted to investigate prevalence and predictors of slow coronary flow phenomenon (SCF) phenomenon. Methods: This cross-sectional study was performed at Imam Ali Cardiovascular Hospital affiliated with the Kermanshah University of Medical Sciences (KUMS), Kermanshah province, Iran. From March 2017 to March 2019, all the patients who underwent coronary angiography were enrolled in this study. Data were obtained using a checklist developed based on the study's aims. Independent samples t tests and chi- square test (or Fisher exact test) were used to assess the differences between subgroups. Multiple logistic regression model was applied to evaluate independent predictors of SCF phenomenon. Results: In this study, 172 (1.43%) patients with SCF phenomenon were identified. Patients with SCF were more likely to be obese (27.58±3.28 vs. 24.12±3.26, P <0.001), hyperlipidemic (44.2 vs. 31.7, P <0.001), hypertensive (53.5 vs. 39.1, P <0.001), and smoker (37.2 vs. 27.2, P =0.006). Mean ejection fraction (EF) (51.91±6.33 vs. 55.15±9.64, P <0.001) was significantly lower in the patients with SCF compared to the healthy controls with normal epicardial coronary arteries. Mean level of serum triglycerides (162.26±45.94 vs. 145.29±35.62, P <0.001) was significantly higher in the patients with SCF. Left anterior descending artery was the most common involved coronary artery (n = 159, 92.4%), followed by left circumflex artery (n = 50, 29.1%) and right coronary artery (n = 47, 27.4%). Body mass index (BMI) (OR 1.78, 95% CI 1.04-2.15, P <0.001) and hypertension (OR 1.59, CI 1.30-5.67, P =0.003) were independent predictors of SCF phenomenon. Conclusion: The prevalence of SCF in our study was not different from the most other previous reports. BMI and hypertension independently predicted the presence of SCF phenomenon.

Determination of Myocardial Scar Tissue in Coronary Slow Flow Phenomenon and The Relationship Between Amount of Scar Tissue and Nt-ProBNP

Fundamento

A fisiopatologia e o prognóstico não estão claramente determinados nos pacientes com fenômeno do fluxo coronário lento (FCL). Esses pacientes apresentam várias condições clínicas, que variam desde quadro assintomático até internação hospitalar com morte cardíaca súbita.

Objetivos

Nosso objetivo foi avaliar os achados da ressonância magnética cardíaca (RMC) com o realce tardio pelo gadolínio (RTG), como um indicador de fibrose miocárdica. Também buscamos determinar a relação entre a presença de fibrose miocárdica e os níveis de NT-proBNP em pacientes com FCL na artéria coronária descendente anterior esquerda (DAE).

Métodos

Ao todo, 35 pacientes, entre 31 e 75 anos de idade, foram incluídos. Os pacientes estudados (n=19) apresentaram artérias coronárias epicárdicas normais na angiografia, mas tinham FCL na DAE. O grupo controle de pacientes (n=16) apresentou artérias coronárias epicárdicas normais e níveis de escore TIMI normais na angiografia. Em ambos os grupos, os pacientes foram examinados com RMC para a detecção de presença de fibrose miocárdica. Além disso, níveis plasmáticos de NT-proBNP foram medidos. Valores de p < 0,05 foram considerados significativos.

Resultados

A taxa de fibrose miocárdica foi significativamente maior na RMC para os pacientes com FCL (p=0.018). Uma quantidade variável de tecido cicatricial foi detectada no ápice ventricular esquerdo em 7 pacientes e nas regiões inferior e inferolateral em 3 pacientes. Não foram observadas diferenças nos níveis de NT-proBNP nos pacientes com FCL. Entretanto, os níveis de NT-proBNP foram maiores nos pacientes com FCL, que apresentaram fibrose miocárdica na RMC (p=0.022).

Conclusões

Em suma, o RTG na RMC mostrou que a cicatriz miocárdica isquêmica pode estar presente nos pacientes com FCL. Esses resultados indicam que o FCL pode nem sempre ser inofensivo. (Arq Bras Cardiol. 2020; 114(3):540-551)

Establishing normal reference value of carotid ultrafast pulse wave velocity and evaluating changes on coronary slow flow

Pulse wave velocity (PWV) measured by ultrafast ultrasound imaging can early evaluate arteriosclerosis. The study aimed to establish normal reference range for ufPWV in healthy adults and explore its influencing factors, and evaluate the ufPWV changes on coronary slow flow (CSF). ufPWV at the beginning and end of systole (ufPWV-BS and ufPWV-ES, respectively) was measured in healthy adults (201 cases). CSF was diagnosed based on thrombolysis in myocardial infarction (TIMI) frame count during coronary angiography. ufPWV-BS and ufPWV-ES were compared between CSF (50 cases) and control groups (50 healthy age-, body mass index-, and blood pressure-matched adults). In healthy adults, average ufPWV-BS and ufPWV-ES was 5.36 ± 1.27 m/s and 6.99 ± 1.93 m/s, respectively. ufPWV-BS and ufPWV-ES positively correlated with age, body mass index, and blood pressure. ufPWV-BS and ufPWV-ES in the CSF group were higher than in the control group (ufPWV-BS, 6.05 ± 1.07 vs. 5.26 ± 0.89 m/s, P < 0.001; ufPWV-ES, 9.07 ± 1.84 vs. 6.84 ± 1.08 m/s, P < 0.001). Receiver operating characteristic curves showed that ufPWV-ES was more sensitive than ufPWV-BS. The normal reference range of ufPWV for healthy adults was established. Age, body mass index, and blood pressure were the main influencing factors. ufPWV was increased in the patients with CSF. The findings indicated that, in addition to reflecting atherosclerosis, ufPWV might also provide a basis for the noninvasive evaluation of microvascular impairment in the patients with CSF.

Increased plasma lipoprotein-associated phospholipase A2 levels are associated with coronary slow flow

OBJECTIVE

Coronary slow flow (CSF) is characterized by delayed opacification of distal epicardial coronary arteries without significant coronary stenosis. In addition, The changes of lipoprotein-associated phospholipase A2 (Lp-PLA₂) as a significant predictive factor for CSF remain controversial. The study aims to investigate the association between plasma Lp-PLA₂ and CSF.

METHODS

In this retrospective study, 170 consecutive patients who underwent coronary angiography were enrolled in Beijing Anzhen Hospital from January 2017 to September 2019, and were divided into CSF group and normal control groups. According to coronary blood flow rate measured by the thrombolysis in myocardial infarction frame count (TFC) method, CSF was defined as TFC > 27. Serum Lp-PLA₂ levels were measured in an enzyme-linked immunosorbent assay.

RESULTS

Lp-PLA₂ levels were higher in the CSF group than in the control group (288.6 ± 50.3 versus 141.9 ± 49.7, P < 0.001) and were significantly correlated with the mean coronary artery thrombolysis in myocardial infarction (TIMI) frame count (r = 0.790, P<0.001). Logistic regression analysis showed that high Lp-PLA₂ was independently associated with CSF after adjustment for conventional risk factors (OR = 1.040, CI = 1.022-1.059, P<0.001). Male sex (OR = 2.192, CI = 1.161-4.140, P = 0.016) and hypertension (OR = 1.965, CI = 1.034-3.736, P = 0.039) were also CSF risk factors. Receiver-operating characteristic curve (ROC) analysis showed that Lp-PLA₂ levels can predict CSF severity; the predictive power was higher than the other risk factors.

CONCLUSION

Our study demonstrated that patients with CSF had higher circulating levels of Lp-PLA₂ than normal controls. After adjustment for potential confounders, increased Lp-PLA₂ was independently associated with presence of CSF.

Ventricular Dysfunction in Patients with Coronary Slow-Flow Phenomenon: A Single-center Case-control Study

Background:

Coronary slow-flow phenomenon (CSFP), characterized by delayed distal vessel opacification of contrast, in the absence of significant epicardial coronary stenosis, has effects on exercise capacity and clinical outcomes. The aim of this study was to explore the systolic and diastolic function of patients with CSFP and to compare it with a group of controls with normal coronary anatomy and flow.

Materials and Methods:

In this case–control study, 45 consecutive CSFP patients and 45 age-, body mass index-, and presentation season-matched controls with normal coronary arteries and normal coronary flows were enrolled from Seyyedoshohada Heart Center from March 2015 to March 2016. A transthoracic echocardiography was done by a blinded echocardiographer using both conventional and tissue Doppler imaging techniques.

Results:

Patients with CSFP were more likely to be male (P = 0.006) and smoker (P = 0.02) compared to controls. Other risk factors were not different between the two groups. There were no differences between groups in terms of the peak early (E) and late (A) diastolic velocities, deceleration time, early (E’) and late (A’) peak diastolic velocities at the mitral annulus, and the systolic mitral annular velocity (S’). Global longitudinal strain and peak systolic strain rates was lower in patients with CSFP compared to controls (−16.7% ±2.4% vs. −18.9% ±1.6%, P < 0.001 and 1.10 ± 0.1 vs. 1.24 ± 0.3, P = 0.008, respectively).

Conclusion:

Patients with CSFP showed signs of the left ventricular systolic dysfunction in tissue Doppler echocardiography, which underlines the importance of close follow-up in these patients. Patients with CSFP should be screened for ventricular function preferably by tissue Doppler echocardiography.

Plasma Choline as a Diagnostic Biomarker in Slow Coronary Flow

Aim

The slow coronary flow (SCF) phenomenon was characterized by delayed perfusion of epicardial arteries, and no obvious coronary artery lesion in coronary angiography. The prognosis of patients with slow coronary flow was poor. However, there is lack of rapid, simple, and accurate method for SCF diagnosis. This study aimed to explore the utility of plasma choline as a diagnostic biomarker for SCF.

Methods

Patients with coronary artery stenosis <40% evaluated by the coronary angiogram method were recruited in this study and were grouped into normal coronary flow (NCF) and SCF by thrombolysis in myocardial infarction frame count (TFC). Plasma choline concentrations of patients with NCF and SCF were quantified by Ultra Performance Liquid Chromatography Tandem Mass Spectrometry. Correlation analysis was performed between plasma choline concentration and TFC. Receiver operating characteristic (ROC) curve analysis with or without confounding factor adjustment was applied to predict the diagnostic power of plasma choline in SCF.

Results

Forty-four patients with SCF and 21 patients with NCF were included in this study. TFC in LAD, LCX, and RCA and mean TFC were significantly higher in patients with SCF in comparison with patients with NCF (32.67 ± 8.37 vs. 20.66 ± 3.41, P  <  0.01). Plasma choline level was obviously higher in patients with SCF when compared with patients with NCF (754.65 ± 238.18 vs. 635.79 ± 108.25, P=0.007). Plasma choline level had significantly positive correlation with Mean TFC (r = 0.364, P=0.002). Receiver operating characteristic (ROC) analysis showed that choline with or without confounding factor adjustment had an AUC score of 0.65 and 0.77, respectively.

Conclusions

TFC were closely related with plasma choline level, and plasma choline can be a suitable and stable diagnostic biomarker for SCF.

Association between impaired cutaneous microvascular endothelial function and lectin-like oxidized low-density lipoprotein receptor-1 in patients with coronary slow flow

OBJECTIVE

Although increasing studies indicate coronary slow flow (CSF) is a systemic microvascular disorder, whether there is impaired cutaneous microvascular endothelial function in CSF patients remains unclear. This study was designed to test the hypothesis that the cutaneous microvascular endothelial function of CSF patients is impaired and correlates with lectin-like oxidized low-density lipoprotein receptor-1(LOX-1).

METHODS

39 patients with CSF and 45 controls with normal coronary flow were enrolled. Velocity of coronary flow was quantitatively identified by thrombolysis in myocardial infarction frame count (TFC) method. LSCI system was used to assess subjects' cutaneous blood flow at rest and during PORH. Serum soluble LOX-1(sLOX-1) level was measured in all study subjects.

RESULTS

PORH-induced vasodilation was significantly reduced in CSF group in comparison with control group (0.26 ± 0.10 vs 0.35 ± 0.07 APU/mmHg, P < 0.001) and negatively correlated with the mean TFC for three coronary arteries (r = -0.385, P = 0.016). Serum sLOX-1 level in CSF group was significantly increased (582.93 ± 74.89 vs 483.64 ± 51.38 pg/ml, P < 0.001) and positively correlated with mean TFC(r = 0.467, P = 0.003).PORH response amplitudes had a significantly negative relationship with serum sLOX-1 level in CSF patients (r = -0.588, P < 0.001).

CONCLUSION

These data suggest that cutaneous microvascular endothelial function is impaired in patients with CSF, which is closely associated with increased LOX-1 expression.

Value of exercise stress electrocardiography for stratification of exercise capacity and left ventricular systolic and diastolic function on coronary slow flow: case-control study

Background

Coronary slow flow phenomenon (CSFP) is an angiographic entity characterized by delayed coronary opacification in absence of evident obstructive lesion in the epicardial coronary artery. However, whether patients with CSFP exhibit differing responses to exercise is still not known. This study aimed to evaluate results of exercise stress electrocardiography (ExECG) and left ventricular (LV) function during exercise, and study the value of ExECG for stratification of exercise capacity and LV function in patients with CSFP.

Methods

Thirty patients with CSFP and 24 controls were enrolled in the study. Diagnosis of CSFP was made by Thrombolysis in Myocardial Infarction frame count. ExECG and LV function measured by echocardiography at rest, during exercise and recovery phase were evaluated.

Results

Negative ExECG was found in 24 (80%) patients with CSFP. At rest, LV global longitudinal strain (GLS) decreased and mitral average E/e’ increased in patients with CSFP compared with controls; however, there were no differences in these parameters between CSFP patients with negative ExECG and patients with positive ExECG. During exercise, CSFP patients with negative ExECG and controls had significantly increased LV GLS and decreased mitral average E/e’, but CSFP patients with positive ExECG had significantly decreased LV GLS and increased mitral average E/e’.

Conclusions

About 80% patients with CSFP exhibited negative ExECG. CSFP patients with negative ExECG exhibited improved LV function but CSFP patients with positive ExECG exhibited impaired LV function during exercise. ExECG may aid in the stratification of exercise capacity and LV function in patients with CSFP.

Evaluation of homocysteine in the diagnosis and prognosis of coronary slow flow syndrome

Aim: To identify the exact molecular markers related to coronary slow flow syndrome (CSFS) and its prognosis. Patients & methods: Data from 54 patients with CSFS diagnosed by coronary angiography and 101 normal control patients were collected and analyzed. Results: Logistic regression analysis confirmed that homocysteine (Hcy; odds ratio: 1.107; 95% CI: 1.018-1.205; p = 0.018) was associated with CSFS. Receiver-operating characteristic curve analysis identified an Hcy value of 17.1 μmol/l as an effective cut-off point for predicting CSFS. Cox survival analysis showed a relationship between high admission Hcy level (odds ratio: 1.19; 95% CI = 1.05-1.34; p = 0.005) and recurrent angina. Conclusion: Our results showed positive correlations of Hcy with CSFS and cardiac events.

Relationship of serum salusin beta levels with coronary slow flow

OBJECTIVE

The pathophysiology of coronary slow flow (CSF) has not been clarified. Salusin-β is released predominantly from the atheroma plaques and influences the pathophysiologic processes of atherosclerosis. Therefore, this study aimed to determine serum salusin-β levels in CSF and its correlation with CSF.

METHODS

The study included 39 patients with CSF, and the control group (n=42) consisted of consecutive subjects with normal coronary arteriogram. We measured salusin-β and thrombolysis in myocardial infarction frame count (TFC).

RESULTS

Age, body mass index (BMI), systolic blood pressure, diabetes, hyperlipidemia, and smoking rates were similar (p values>0.05) in both groups. High sensitive C-reactive protein (2.80±1.2 vs. 2.21±1.2 mg/dL, p=0.011), salusin-β [1205 (330-2092) vs. 162 (29-676), pg/ml, p<0.001], corrected TFC of left anterior descending coronary artery (29±9 vs. 19.7±3.7, p<0.001), circumflex artery TFC (25±10 vs. 15±3.2, p<0.001), right coronary artery TFC (28±7.1 vs. 13±3.3, p<0.001), and mean TFC (28±4.4 vs. 16±3.7, p<0.001) were significantly higher in the CSF group. In univariate and multivariate regression analysis, only BMI (unstandardized β±SE=0.178±0.08, p=0.036) and salusin-β levels (unstandardized β±SE=0.006±0.01, p<0.001) were determined as predictors of CSF. There was a good correlation between serum salusin-β and mean TFC values (r=0.564; p<0.001).

CONCLUSION

There is an association between serum salusin-β levels and CSF.

Factors Associated with Sub-intimal Coronary Artery Dissection in MINOCA Patients with Delayed Washout at Coronary Angiography – Protocol for an Observational, OCT-based Study

Background: Myocardial infarction (MI) with no obstructive coronary arteries (MINOCA) is a special form of the acute coronary syndrome. The heterogeneous pathophysiology of MINOCA is not well elucidated and includes cardiac and non-cardiac causes. Slow flow phenomenon on coronary angiography can be associated with several possible causes of MINOCA confirmed by optical coherence tomography (OCT). Therefore, the aim of this study is to assess the underlying mechanism of the delayed washout phenomenon on coronary angiography and the potential role of subintimal coronary artery dissection (SD) in the setting of an acute MI.

Methods and design: This clinical prospective, descriptive research will enroll patients diagnosed with acute MI (STEMI or NSTEMI) identified by coronary angiography, followed by OCT imaging of the coronary arteries at the Emergency Clinical County Hospital of Târgu Mureş, Romania. The enrolled patients will be separated into two groups based on OCT examination, patients with SD and patients with no SD.

Conclusion: The underlying mechanisms of MINOCA with delayed washout phenomenon on coronary angiography is still poorly understood. Modern invasive imaging techniques are capable to assess the microstructure of the coronary artery wall and are able to offer the much needed information to elucidate the pathophysiological changes which ultimately cause the acute event. The current study offers a new, complex – clinical, invasive and noninvasive imaging, as well as biomarker-based – approach, which may lead to a better understanding and treatment of this pathology.

Evaluation of left atrial volume and function in patients with coronary slow flow phenomenon using real-time three-dimensional echocardiography

This study aimed to evaluate the left atrial (LA) volume and phasic functions using real-time three-dimensional echocardiography (RT3DE) in coronary slow flow phenomenon (CSFP) patients with preserved left ventricular ejection fraction (LVEF). 56 patients with CSFP (36 males, 20 females) and 48 controls with normal coronary flow (27 males, 21 females) were prospectively enrolled. Comprehensive transthoracic echocardiographic examination and RT3DE for the assessment of LA dynamics were performed in all participants. LA maximum, minimum, and pre-atrial contraction volumes (LAV-max, LAV-min, and LAV-preA) were obtained for every subject. Conventional echocardiographic parameters, except for isovolumetric relaxation time and transmitral deceleration time, did not differ in two groups. RT3DE demonstrated higher LAV-max, LAV-min, LAV-preA, indexed LAV-max (LAVi-max), LA total emptying volume, and LA active emptying volume and fraction for CSFP patients compared with controls (all P < 0.05). In addition, LA total emptying fraction and LA passive emptying fraction were found to be lower in CSFP patients than in controls (all P < 0.05). Moreover, there were positive correlations between mean thrombolysis in myocardial infarction frame count values and LAV-max, LAV-min, LAV-preA, LAVi-max, and LA total and active emptying volumes. CSFP was associated with enlarged LA volumes, impaired LA reservoir and conduit function and enhanced contractile function. Evaluation of LA dynamics using RT3DE could facilitate recognition of subtle myocardial alterations related with CSFP.

Relationship Between the Reciprocal Change in Inflammation-Related Biomarkers (Fibrinogen-to-Albumin and hsCRP-to-Albumin Ratios) and the Presence and Severity of Coronary Slow Flow

Inflammation has been implicated in the pathogenesis of endothelial dysfunction, atherosclerosis, and microvascular coronary dysfunction. In this context, it is thought that fibrinogen, high-sensitive C-reactive protein (hsCRP), and albumin may be associated with the pathogenesis of coronary slow flow (CSF). We aimed to evaluate the ratios of fibrinogen-to-albumin and hsCRP-to-albumin in patients with CSF compared to patients with angiographically normal coronary arteries and stable coronary artery disease (CAD). In all, 65 patients with CSF, 65 patients with newly diagnosed stable CAD, and 65 control participants with angiographically normal coronary arteries were included. The coronary flow rates of all patients were determined by the Thrombolysis in Myocardial Infarction frame count method. Fibrinogen, hsCRP, and albumin levels were analyzed in all patients, and the fibrinogen-to-albumin and hsCRP-to-albumin ratios were calculated. The baseline characteristics of the 3 groups were similar. The plasma albumin level was significantly lower, whereas the fibrinogen and the hsCRP levels were significantly higher, in the CSF and CAD groups compared to the controls. The fibrinogen-to-albumin and hsCRP-to-albumin ratios were significantly higher in both the CSF and the CAD groups compared to the control group. The hsCRP-to-albumin ratio was positively correlated with the mean Thrombolysis in Myocardial Infarction frame count in the whole study population. According to the receiver–operating characteristic analysis, the efficacies of the fibrinogen-to-albumin and hsCRP-to-albumin ratios in predicting CSF were significant. The fibrinogen-to-albumin and hsCRP-to-albumin ratios, which were increased by a reciprocal change, suggest that inflammation may play a role in the pathogenesis of CSF.

Clinical Profile and Outcome in Patients with Coronary Slow Flow Phenomenon

The coronary slow flow phenomenon (CSFP) is a poorly recognized clinical entity characterized by delayed distal vessel opacification in the absence of epicardial coronary stenosis and presently lack of specific data on the clinical profile and outcome. We investigated a cohort of 429 patients who fulfilled the criteria for CSFP to explore the clinical feature, outcome, and risk factor of prognosis. Two teams (clinical center and core lab) were blind to patient data for the assessment of coronary angiograph using corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC). The study cohort consisted of 429 patients (294 men, 68.5%), aged from 30 to 78 years (mean, 54 years). Two hundred patients (46.6%) out of 429 patients had a history of hypertension, 72 (16.8%) had diabetes mellitus, and 222 (51.7%) had dyslipidemia. All the rates of agreement between two teams in evaluating whether normal flow (CTFC ≤ 27 frames) or slow flow (CTFC > 27 frames) were moderate (0.40 < κ < 0.75) for the three arteries. Follow-up (mean, 3.8 years) was done for 421 patients (98.1%). The major adverse cardiovascular events (MACE) occurred in 39 patients (9.3%) out of 421 patients. Multivariate analysis showed that the risk of MACE approximately doubles with age >50 years (hazard ratio (HR) = 2.2, 95% CI: 1.0 to 4.9, and P=0.042), hypertension (HR = 2.1, 95% CI: 1.1 to 4.2, and P=0.021), and dyslipidemia (HR = 2.0, 95% CI: 1.0 to 3.9, and P=0.042). CSFP affects predominantly patients at middle age and above but can occur in any age group; CSFP should be more concerned, particularly in patients >50 years old with hypertension and dyslipidemia.