ST/T wave changes during acute coronary syndrome presentation in patients with the coronary slow flow phenomenon

Analysis of correlative factors of female coronary slow-flow phenomenon: A retrospective study

The coronary slow-flow phenomenon (CSFP) is a manifestation of coronary artery disease wherein coronary angiography reveals no apparent stenosis; however, there is a delay in blood flow perfusion. Given its increased occurrence in male patients, with the majority of subjects in previous studies being male, this study aimed to explore whether distinct risk factors are present in female patients with CSFP. This single-center retrospective study focused on female patients diagnosed with CSFP by using coronary angiography. Eligible patients meeting the predefined inclusion and exclusion criteria were divided into the study group (presenting with CSFP) and control group (displaying normal epicardial coronary arteries). Comparative analyses of clinical and diagnostic data were performed. Ninety-two patients with CSFP and an equal number of controls were enrolled in this study. Patients with CSFP exhibited a higher prevalence of smokers (P = .017) and a heightened incidence of diabetes mellitus (DM) (P = .007). Significantly elevated levels of total cholesterol (TC) (P = .034) and free fatty acids (FFA) (P = .016) were observed in the CSFP group compared to those in the control group. Additionally, patients with CSFP displayed lower levels of apolipoprotein E (ApoE) (P = .092), free thyroxine (FT4) (P = .001), and total thyroxine (TT4) (P = .025). Logistic regression analysis indicated that smoking (P = .019), FFA (P < .001), ApoE (P = .015), and FT4 (P < .001) were independent risk factors for CSFP, accounting for confounding factors. Additionally, the area under the ROC curve (AUC) of the combined effect of smoking, ApoE, FT4, and FFA on CSFP was 0.793 (95% CI: 0.729-0.857, P < .01). In addition to the established risk factors for smoking, diabetes, and hyperlipidemia, female patients with CSFP exhibited significant differences in apoE, FFA, FT4, and TT4 levels compared to the control group. Smoking, FFA, and FT4 levels emerged as independent risk factors for CSFP.

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.

The MAPH Score Predicts Coronary Slow Flow. A Retrospective Case-Controlled Study

AIM

The MAPH score is a new score that combines mean platelet volume (MPV), hematocrit, and total protein, which are markers of whole blood viscosity (WBV). We aimed to investigate the relationship between the MAPH score and the coronary slow flow phenomenon (CSF).

MATERIAL AND METHODS

A total of 201 patients were included in the study. 105 had CSF and 96 had normal coronary flow (NCF). Coronary flow was measured by the Thrombolysis in Myocardial Infarction frame count (TFC) method. The patients' MPV, age, hematocrit, and total protein were recorded. High (HSR) and low shear rates (LSR) were calculated, based on total protein and hematocrit values. Cut-off values for CSF were determined using the Youden's index, and the score was determined as 0 or 1 according to the cut-off values. The sum of these scores was the MAPH score.

RESULTS

The mean age of the patients included in the study was 51.1±7.9 (n=201, 54.2 % male). Hyperlipidemia, DM, and HT rates of both groups were similar, but the mean age of the CSF group was higher (p=0.773; p=0.549; p=0.848; p <0.001, respectively). Total protein, MPV, hematocrit, HSR and LSR were higher in the CSF group (p< 0.001, for all values). Comparative receiver operating characteristic (ROC) curve analysis showed that the performance of the MAPH score in predicting CSF is better than the performance of these parameters separately.

CONCLUSION

A new score, the MAPH score, may be used to identify the presence of CSF.

Cut-off value for interleukin-34 as an additional potential inflammatory biomarker for estimation of slow coronary flow risk

BACKGROUND

Inflammatory markers may provide insights into the underlying mechanisms of slow coronary flow (SCF), including subclinical atherosclerosis and endothelial dysfunction. Interleukin-34 (IL-34), known for its role in immuno-inflammatory diseases, might hold significance in SCF. We aimed to explore the potential association between IL-34 and SCF in patients undergoing diagnostic elective coronary angiography.

METHODS

This observational, cross-sectional study enrolled 256 participants: 124 with SCF and 132 with normal coronary flow (NCF). All participants had undergone outpatient coronary angiography for suspected coronary artery disease. SCF assessment employed the TIMI frame count (TFC) for quantifying coronary flow rate.

RESULTS

SCF patients exhibited significantly elevated TFC in all three major coronary arteries compared to controls (p < 0.05). IL-34 displayed a noteworthy positive correlation with average TFC [for all participants: r = 0.514, p < 0.001; for SCF patients: r = 0.526, p < 0.001; for normal controls: r = -0.288, p > 0.05]. Similarly, high-sensitivity C-reactive protein (hsCRP) showed a significant and positive relationship with average TFC [for all participants: r = 0.504, p < 0.001; for SCF patients: r = 0.558, p < 0.001; for normal controls: r = -0.148, p > 0.05]. SCF patients presented coronary arteries of larger size compared to controls.

CONCLUSION

Mean coronary diameter and IL-34 emerged as independent predictors of SCF. Additionally, hsCRP, mean coronary diameter, and IL-34 exhibited a positive correlation with mean TFC values. IL-34 appears to be a more effective indicator than hsCRP in SCF patients.

Prognostic implication of coronary slow flow assessed by cTFC in patients with myocardial infarction with Non-obstructive coronary arteries

BACKGROUND

Coronary slow flow (CSF) is common and linked to worse cardiovascular events and life-threatening arrhythmias. However, the clinical implication of CSF among myocardial infarction with the non-obstructive coronary artery (MINOCA) has never been studied. We aimed to evaluate the impact of CSF on the MINOCA population.

METHODS

Patients diagnosed with MINOCA were consecutively selected. The corrected TIMI frame count (cTFC) was used to evaluate the coronary flow. CSF was defined as cTFC greater than 27 frames per second (FPS) in any of the three coronary arteries. Major adverse cardiovascular events (MACE) are the primary endpoint. Cox regression analysis was used to evaluate the association between CSF and MACE.

RESULTS

A total of 158 patients with MINOCA were enrolled, of which 54 (34.2%) patients had CSF. Forty incidents of MACE occurred during the median 28 months of follow-up. The MACE incidence was higher among patients who presented with CSF than the normal coronary flow patients (35.2% vs. 20.2%, p = 0.040). In the Kaplan-Meier analysis, CSF patients had significantly higher rates of MACE (log-rank P = 0.034). Multivariate Cox regression analysis showed that CSF was an independent predictor linked to an increased hazard of MACE (adjusted HR, 2.76; 95% CI, 1.34-5.67; P = 0.006).

CONCLUSION

The presence of CSF is associated with a higher risk of adverse events and is an independent predictor of clinical outcomes among patients with MINOCA. This result suggests that CSF might serve as a robust tool to stratify MINOCA patients.

Endothelial nitric oxide synthase Asp298Glu (894G/T) gene polymorphism as a possible risk factor for the coronary slow flow phenomenon among Iranians

Background

Mounting evidence indicates an association between endothelial dysfunction and the coronary slow flow phenomenon (CSFP). In the present study, we aimed to evaluate the possible role of endothelial nitric oxide synthase (eNOS) 894G/T and interleukin-1β (IL-1β) 315C/T polymorphisms as possible risk factors for CSFP.

Methods

This prospective study enrolled patients with CSFP and individuals with normal coronary arteries. Genotypes were assessed using regular polymerase chain reaction and direct Sanger-sequencing techniques.

Results

The study population consisted of 267 individuals: 180 patients with CSFP (49 women [27.2%]) at a median age of 55 (48–62) years and 87 controls with normal coronary arteries (56 women [64.4%]) at a median age of 47 (41–58) years. The allelic distribution of eNOS 894G/T was significantly associated with CSFP (odds ratio [OR], 1.58; 95% confidence interval (CI), 1.04–2.42; P = 0.03). This polymorphism increased the risk of CSFP under the dominant model (OR 1.73; 95% CI I.02–2.95; P = 0.04). However, the allelic frequencies (1.05; 95% CI 0.68–1.59; P = 0.83) and genotypic frequencies (0.88; 95% CI 0.52–1.49; P = 0.63) of the IL-1β 315C/T polymorphism were not associated with the incidence of CSFP in the Iranian population.

Conclusions

The CSFP and control groups were statistically different regarding the eNOS 894G/T polymorphism. Our findings also demonstrated that the IL-1β 315C/T polymorphism was not a risk factor for CSFP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02736-0.

Evaluation of the relationship between aspartate aminotransferase/alanine aminotransferase ratio and coronary slow-flow phenomenon

Aim: To assess the correlation between the ratio of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and slow coronary flow (SCF). Methods: A total of 119 patients with SCF and 121 age- and sex-matched patients with normal coronary flow were included in this retrospective cross-sectional study. Thrombolysis in myocardial infarction frame count of angiography images was marked by two interventionalists. In addition to AST and ALT levels, complete blood count; kidney, liver and thyroid function tests; age; sex; medication and medical history were recorded. Results: Significant spikes in AST/ALT ratio were discovered in the SCF group compared with the normal coronary flow group (p < 0.001). Thrombolysis in myocardial infarction frame count values were significantly higher in all coronaries for the SCF group compared with the normal coronary flow group (p < 0.001). Thrombolysis in myocardial infarction frame count values of the left anterior descending artery (r = 0.258; p < 0.001), left circumflex artery (r = 0.297; p < 0.001) and right coronary artery (r = 0.195; p = 0.002) were positively correlated with AST/ALT ratio. Conclusion: AST/ALT ratio is significantly correlated with SCF; therefore, this ratio may have predictive value.

Long-term outcomes of the modest stent expansion strategy for the culprit lesion of acute myocardial infarction

Slow flow during primary percutaneous coronary intervention (PCI) is a common complication. Our group showed that the stent (or post-balloon) diameter-to-vessel diameter ratio was inversely associated with slow flow phenomenon. We advocated the utility of modest stent expansion strategy, which was defined as the stent (or post-balloon) diameter-to-culprit vessel diameter ratio < 0.71, for prevention of slow flow phenomenon. This study aimed to compare the long-term outcomes in patients with acute myocardial infarction (AMI) between the modest stent expansion strategy and the aggressive stent expansion strategy (the stent diameter-to-culprit vessel diameter ratio ≥ 0.71). We included 584 AMI patients, which were divided 177 patients in the modest stent expansion group and 146 patients in the aggressive stent expansion group. The primary endpoint was major adverse cardiac events (MACE), which was defined as a composite of cardiac death, ischemia driven target vessel revascularization, and stent thrombosis. The slow flow after stent deployment was more frequently observed in the aggressive stent expansion group (24.0%) than in the modest stent expansion group (4.0%) (P < 0.001). The Kaplan-Meier curves revealed that MACE was comparable between the two groups (P = 0.64). The multivariate COX hazard model showed the non-significant association between the modest stent expansion strategy and MACE (vs. aggressive stent expansion: hazard ratio 1.005, 95% confidence interval 0.619-3.242, P = 0.41). In conclusion, the modest stent expansion strategy was not associated with long-term MACE. Therefore, the modest stent expansion strategy may be a good choice for the culprit lesion of AMI.

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.

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.

Assessment of Coronary Slow Flow, Cystatin C, and Body Mass Index in Female Candidates for Diagnostic Coronary Artery Angiography

Introduction: Evidence indicates that the associations between coronary slow flow (CSF), cystatin C (Cys C), and body mass index (BMI) are unclear. Therefore, the purpose of our study was to determine the association among the above-mentioned parameters in female patients. Methods: This was a descriptive-analytical study and the participants were those who were referred to the Shohada Cardiovascular Center of Urmia in 2015-2016. The participants were measured by a quantitative method under angiography (corrected TIMI frame count, CTFC) for CSF assessment, followed by evaluating physiological indices and the serum Cys C by the enzyme-linked immunosorbent assay. Finally, Pearson correlation coefficient test was used to analyze the correlations among CTFC, Cys C, and BMI, and a significance level of P < 0.05 was used for this test. Results: Sixty-six female patients (mean age: 57.01±8.25 years) took part in this study. The correlations among Cys C with CTFC, and BMI (r=-0.189, P=0.128 and r=0.044, P=0.724, respectively) and BMI with CTFC (r=-0.178, P=0.153) were not meaningful in female patients’ who were candidates for angiography. Conclusion: In general, the results suggested that serum Cys C cannot be considered as a predictive biomarker for the prognostic stratification of CSF and BMI in female patients aged 34-73 years who were candidates for angiography.

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.

Atorvastatin improves coronary flow and endothelial function in patients with coronary slow flow

The underlying mechanisms behind the effect of atorvastatin on patients with coronary slow flow (CSF) remain largely unknown. To investigate the possible underlying molecular mechanisms 108 patients were divided into atorvastatin group and control group. Coronary flow was quantified according to corrected TIMI frame count (CTFC). Serum high sensitivity C-reactive protein (hs-CRP), lipids, ET-1, interleukin (IL)-6, NO, circulating endothelial progenitor cell (cEPC) count, adhesion, migration and proliferation were measured in pretreatment and post-treatment. After respective treatment, the atorvastatin group had significantly decreased levels of TC, TG, LDL-C, hs-CRP, ET-1 and IL-6 and increased NO compared to the control group. The atorvastatin group had a more significant improvement of CTFC, effective rate, cEPC number, EPC adhesion, migration and proliferation compared to the control group. In conclusion, atorvastatin can be used in treatment of CSF by suppressing inflammation and improving endothelial function.

An overlooked parameter in coronary slow flow phenomenon: whole blood viscosity

Aims: We aimed to assess the relationship between coronary slow flow phenomenon (CSFP) and whole blood viscosity (WBV). Materials & methods: Two hundred patients with CSFP and 200 subjects with normal coronary arteries as control group were enrolled. WBV was calculated from hematocrit and plasma protein concentration at low shear rate (LSR) (0.5 s-1) and high shear rate (HSR) (208 s-1) by a validated equation. Results: CSFP patients had significantly higher WBV for LSR and HSR. The mean corrected TIMI frame count was highest in the highest tertile group for both shear rates. Corrected TIMI frame count revealed a significant relationship with WBV for LSR (r = 0.562) and HSR (r = 0.611). At multivariate analysis, WBV at LSR and HSR were independent predictors of CSFP. Conclusion: WBV seemed to have a significant and an independent predictor of CSFP.

The association of serum albumin with coronary slow flow

BACKGROUND

A number of inflammatory markers such as high-sensitivity C-reactive protein (Hs-CRP), interleukin-6 (IL-6), and fibrinogen have been shown to be associated with coronary slow flow (CSF). Our aim was to investigate the relationship between albumin, a long-acting negative acute-phase protein, and CSF.

METHODS

A total of 106 patients with angiographically proven slow coronary flow and 57 control subjects with normal coronary flow were included in the study. Serum levels of Hs-CRP and albumin were measured. CSF was defined by Thrombolysis In Myocardial Infarction (TIMI) frame count (TFC) method.

RESULTS

Serum albumin (s-albumin) was significantly lower in the CSF group (3.79 ± 0.3 vs 4.17 ± 0.3, p < 0.001), whereas Hs-CRP level was significantly higher in the CSF group compared with the controls (1.22 ± 0.79 vs 0.76 ± 0.44, p < 0.001). S-albumin and Hs-CRP were correlated with the mean TFC in the whole study population (r= - 0.574, p < 0.001; r = 0.376, p < 0.001, respectively). Hs-CRP and low s-albumin were found to be significant predictors of CSF in the multivariate analysis. The comparison of receiver-operating characteristics curves for s-albumin and Hs-CRP demonstrated that s-albumin was the strongest predictor of CSF.

CONCLUSIONS

We found that s-albumin levels decreased and Hs-CRP levels increased in patients with CSF. S-albumin was also found to have superior predictive value than Hs-CRP for diagnosing CSF. S-albumin, an inexpensive and easily measurable laboratory variable, may be a useful predictor of CSF, especially when other reasons which alter its serum levels were excluded.

The coronary slow flow phenomenon: characteristics, mechanisms and implications

The coronary slow flow phenomenon (CSFP) is an important, angiographic entity characterized by delayed progression of the injected contrast medium through the coronary tree. It is a frequent finding, typically observed in patients presenting with acute coronary syndromes. Although it is well known to interventional cardiologists for approximately four decades, the pathogenic mechanisms remain unclear. The clinical implications are significant, with over 80% of patients experiencing recurrent chest pain, resulting in considerable impairment in quality of life. This article will address in detail the characteristics, possible mechanisms, and clinical implications of this entity to provide further insight into its clinical significance and management strategies.

Association Between Serum Cystatin C Levels and Coronary Slow Flow

We assessed the association between serum cystatin C (CysC) levels and coronary slow flow (CSF) phenomenon in patients who underwent coronary angiography. A total of 210 patients (mean age 55.6 ± 10.9 years; 100 females) were included. Patients were divided into 3 groups, (patients with CSF [group 2], with coronary artery disease [CAD; group 3], and without CAD [group 1]). Serum CysC levels in patients with CSF were significantly lower than those with and without CAD (912.5 ± 135.6, 820.4 ± 104.2, and 1343.4 ± 236.6 ng/mL in groups 1, 2, and 3, respectively; P < .001). Serum CysC levels correlated with the number of vessels with CSF and mean corrected thrombolysis in myocardial infarction frame count (Spearman correlation coefficient [ rs] = .192, P < .001 and rs = .261, P < .001 respectively). In conclusion, patients with CSF have lower CysC levels; this could be a useful biomarker of CSF involvement in patients who undergo diagnostic coronary angiography.