Increased red cell distribution width in patients with slow coronary flow syndrome

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.

Hematological Changes during Seven Days of Hospitalization in Patients with Acute Myocardial Infarction

BACKGROUND

Acute myocardial infarction is a major cause of mortality worldwide, and atherosclerotic plaque formation is the main pathophysiological mechanism, which results in chronic inflammation that induces erythrocyte maturation and may cause an increase in the red cell distribution width (RDW) index.

OBJECTIVE

Evaluate the role of the anisocytosis index in patients with acute myocardial infarction in both types of infarctions as a predictor of severity.

METHODS

Patients were included in the study according to the inclusion/exclusion criteria, following the hospital routine based on their clinical and laboratory history. Statistical analyzes were performed according to each variable. All conclusions were drawn considering the significance level of 5%.

RESULTS

During the follow-up period, in the 349 patients analyzed, the mortality rate was associated with the variables RDW (CV) and RDW (SD), in those patients who died, an increase was noted, as demonstrated in the multivariate model, for the effects of an acute ST elevation myocardial infarction and the RDW, adjusted for confounding factors (p-value = 0.03 and 0.04). In contrast, the total number of erythrocytes (p-value = 0.00) and hemoglobin (p-value = 0.03) showed a decrease during severe patients' hospitalization.

CONCLUSION

The anisocytosis index was a predictive factor of mortality and can be used as an indicator of worse prognosis in patients with acute myocardial infarction.

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.

Red Cell Distribution Width as a Marker of Periprocedural Myocardial Infarction in Patients with Elective Percutaneous Coronary Intervention

We aimed to investigate whether red cell distribution width (RDW) was associated with periprocedural myocardial infarction (PMI) in patients undergoing elective percutaneous coronary intervention (PCI). Among 1723 consecutive patients undergoing elective PCI, a total of 230 (13.3%) met the diagnostic criteria of PMI. The high RDW (≥ 12.6%) group tended to have PMI (15.4% vs. 11.2%, P = 0.010). RDW was an independent predictor of PMI whether as a categorical variable (adjusted odds ratio = 1.442, 95% confidence interval = 1.088 to 1.911, P = 0.011) or a continuous variable (adjusted odds ratio = 1.236, 95% confidence interval = 1.079 to 1.415, P = 0.002). High RDW was also significantly associated with increased risk of major adverse cardiovascular events (MACE) during follow-up. However, anemia was not independently associated with PMI or MACE in the current study. In conclusion, RDW showed strong and independent association with PMI in patients undergoing elective PCI.

Predictive value of red cell distribution width on left atrial thrombus or left atrial spontaneous echo contrast in patients with non-valvular atrial fibrillation

OBJECTIVE

To evaluate the predictive value of red cell distribution width (RDW) on left atrial thrombus (LAT) or left atrial spontaneous echo contrast (LASEC) in patients with non-valvular atrial fibrillation (AF).

METHODS

We reviewed 692 patients who were diagnosed as non-valvular AF and underwent transesophageal echocardiography (TEE) in Guangdong Cardiovascular Institute from April 2014 to December 2015. The baseline clinical characteristics, laboratory test of blood routine, electrocardiograph measurements were analyzed.

RESULTS

Eighty-four patients were examined with LAT/LASEC under TEE. The mean RDW level was significantly higher in LAT/LASEC patients compared with the non-LAT/LASEC patients (13.59% ± 1.07% vs. 14.34% ± 1.34%; P < 0.001). Receiver-operating characteristic curve analysis was performed and indicated the best RDW cut point was 13.16%. Furthermore, multivariate logistic regression analysis indicated that RDW level > 13.16% could be an independent risk factor for LAT/LASEC in patients with AF.

CONCLUSION

Elevated RDW level is associated with the presence of LAT/LASEC and could be with moderate predictive value for LAT/LASEC in patients with non-valvular AF.

[Regression analysis of red cell distribution width and mean platelet volume in patients with acute myocardial infarction]

OBJECTIVE

To investigate clinical implications of changes in red cell distribution width (RDW) and mean platelet volume (MPV) in patients with acute myocardial infarction.

METHODS

A total of 127 patients (90 men and 37 women) were enrolled in this analysis, including 66 with acute myocardial infarction (AMI) and 61 with unstable angina (UA). The patients' baseline demographic and clinical data were compared between the two groups including age, hypertension, diabetes, smoking, BMI, blood biochemical profiles, cardiac functions and platelet and red blood cell parameters. The patients were further divided into subgroups according to the RDW 50% cumulative frequency, and the MPV, P-LCR, hsCRP, NT-proBNP, RBC, Dimer and MCV were compared. The correlations between platelet and erythrocyte test results were evaluated in both the AMI and UA patients. Regression analysis was performed to identify the factors affecting the RDW in the AMI group and a regression model was established.

RESULTS

The platelet and red blood cell test results, P-LCR, MPV, and RDW differed significantly between AMI and UA groups (P<0.01 or 0.05). Correlation analysis showed a significant positive correlation between RDW and MPV in AMI group (r=0.34, P<0.01). Between the subgroups with different RDW 50% cumulative frequencies, MPV, P-LCR, hsCRP, D-Dimer, and NT-proBNP all differed significantly (P<0.05 or 0.01). In AMI group, with RDW as the dependent variable, we established a multivariate regression model of RDW=0.19MPV+10.83.

CONCLUSION

RDW and MPV are closely correlated in patients with AMI. In multiple regression analysis, MPV can explain the changes in RDW in patients with AMI.

Clinical and laboratory predictors of coronary slow flow in coronary angiography

Background:

The coronary slow-flow phenomenon (CSFP) is a multifactorial angiographic finding with no established pathogenesis.

Objective:

To investigate the role of clinical profile and laboratory findings in patients with CSFP.

Methods:

We prospectively recruited 69 patients with angiographically diagnosed CSFP and compared them with 88 patients with normal coronary flow. Demographic information, comorbidities and laboratory analysis, including complete blood count with differential, lipid profile and serum biochemical analysis, were documented and compared in univariate and multivariate analyses.

Results:

Patients with CSFP were more likely to be male and active smokers. Total cholesterol, triglyceride, hemoglobin and hematocrit, platelet count, mean platelet volume, platelet distribution width and red cell distribution width (RDW) were all higher in patients with CSFP. In multivariate regression analysis, including smoking, total cholesterol, hematocrit, fasting blood glucose and red cell distribution width, except fasting blood glucose, all variables were independently associated with CSFP. Receiver operating characteristic curve analysis revealed a cut-off point of 13.05% for RDW with a sensitivity of 74.6% and a specificity of 77.3% (p<0.001, AUC = 0.802) A cut-off value of 11.35% for PDW had a 89.9% sensitivity and 98.9% specificity for the prediction of CSFP (p<0.001, AUC = 0.970)

Conclusion:

The changes of circulating blood cell components in patients with CSFP may be indicative of underlying inflammation and endothelial dysfunction that should be investigated in experimental studies.

High aortic pulse-wave velocity may be responsible for elevated red blood cell distribution width in overweight and obese people: a community-based, cross-sectional study

Background:

Obesity and overweight are risk factors for atherosclerosis. Red blood cell distribution width (RDW) is associated with subclinical cardiac diseases. The aim of this study was to investigate the association between RDW and aortic stiffness in overweight or obese subjects.

Methods:

A total of 101 overweight or obese subjects without overt cardiovascular disorders, and 48 healthy controls were enrolled. RDW, aortic pulse-wave velocity (PWV) and augmentation index 75 (Aix75) were evaluated. The case subjects were divided into two sub-groups according to PWV values; ≥ 10 m/s in group I, and < 10 m/s in group II. Bivariate correlation and multiple regression analyses (stepwise) were performed.

Results

RDW and PWV were considerably increased in the case groups compared with the controls. RDW was significantly increased in group I compared with group II and the controls [median 12.0 m/s, interquartile range (IQR): 10.5–17.5; median 11.7 m/s, IQR: 10.2–14.2, and median 11.4 m/s, IQR: 9.6–15.5, p < 0.05, respectively]. Resting heart rate and age were higher in group I than group II (81 ± 11 vs 74 ± 12 beats/min and 41 ± 120 vs 36 ± 9 years, respectively, p < 0.05). Regression analyses revealed that while log-RDW, age and resting heart rate were independent predictors for aortic PWV, log-RDW was the most important predictor in the final model.

Conclusions:

RDW, resting heart rate and age independently predicted arterial stiffness, and RDW may be useful to provide an early recognition of subclinical atherosclerosis in overweight and obese individuals.

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.

Serum YKL-40 is increased in patients with slow coronary flow

OBJECTIVES

There is accumulating evidence that inflammation plays a major role in the development of the slow coronary flow (SCF) phenomenon. YKL-40 has been suggested to be a potential biomarker of inflammation. In this study, we aimed to study YKL-40 as it relates to SCF.

MATERIALS AND METHODS

Patients who underwent coronary angiography before and had angiographically normal coronary arteries of varying coronary flow rates without any atherosclerotic lesion were enrolled in this study. Patients who had thrombolysis in myocardial infarction frame counts (TFC) above the normal cutoffs were considered to have SCF and those within normal limits were considered to have normal coronary flow (NCF). The YKL-40 levels and biochemical profiles of all patients were studied and analyzed.

RESULTS

There were 41 patients in the SCF group and 209 patients in the NCF group. Compared with the NCF patients, SCF patients had higher serum high-sensitivity C-reactive protein (hs-CRP) (P=0.0003) and YKL-40 (P=0.0007) levels. A positive correlation was detected between the YKL-40 levels and hs-CRP (r=0.7021, P<0.001), and the mean TFC (r=0.4038, P=0.0088) in SCF patients.

CONCLUSION

Our study showed that YKL-40 levels are higher and correlated positively with TFC and hs-CRP in SCF patients. This finding suggests that YKL-40 may be a useful marker and predictor for SCF.

Predictors of slow flow in angiographically normal coronary arteries

INTRODUCTION

Slow coronary flow (SCF) is a well-known angiographic finding; however, the pathophysiology of SCF remains only partially understood. In this study, we have examined the risk factors of slow coronary flow.

METHODS

Seventy patients with angiographically proven SCF were studied along with 60 control participants. Patients were divided into 2 groups based on the angiographic findings as with or without SCF. In both groups, clinical information was collected and laboratory parameters were measured and compared.

RESULTS

Patients with SCF had higher serum uric acid, creatinine and hemoglobin levels. They also more commonly had a history of smoking. On the other hand, C-reactive protein and hematologic parameters such as mean platelet volume (MPV), red cell distribution width (RDW), and neutrophil to lymphocyte (N/L) ratio did not differ significantly between the two groups. In the logistic regression analysis, only uric acid (odds ratio [OR]=1.583, 95% confidence interval [CI]=1.011-2.349, P=0.034) was found as an independent correlate of SCF.

CONCLUSIONS

This study demonstrates that serum uric acid level is significantly correlated with SCF and may play a role in the development of the condition. These findings provide impetus for additional studies to confirm these results and treatment of SCF.

Red cell distribution width as a predictor of left atrial spontaneous echo contrast in echocardiography

Red cell distribution width (RDW) represents the heterogeneity of red blood cells (anisocytosis). Spontaneous echo contrast (SEC) is thought to be a manifestation of red cell aggregation and it has been linked to the development of thromboemboli. The aim of this study was to evaluate the association between RDW levels and the presence of left atrial SEC (LASEC). One-hundred and 72 patients who underwent transesophageal echocardiography for various indications were enrolled in the study. All patients were categorized into 2 groups according to the presence of LASEC and into 4 groups according to the severity of LASEC. The baseline clinical characteristics, echocardiographic measurements, and laboratory findings, including RDW, were compared between the groups. The RDW (%) level was higher in the LASEC group (14.95 ± 1.32) compared with the non-LASEC group (12.20 ± 1.45; P = 0.0001). When the relationship between RDW and SEC was evaluated according to the increasing grade of SEC, a significant positive correlation was found (r = 0.645, P < 0.0001). In the ROC analysis, an RDW level >13.8% had 70% sensitivity and 89.2% specificity in predicting LASEC (area under the curve = 0.834, P < 0.0001, 95% CI 0.656-0.773). In multivariate analysis, RDW levels >13.8% and the presence of atrial fibrillation were independently associated with LASEC (odds ratio [OR] 1.697; 95% confidence interval [CI] 1.198-2.085; P = 0.001 and OR 1.586; 95% CI 1.195-2.098; P = 0.003, respectively]. Elevated RDW value is associated with the presence and the severity of SEC. RDW may be a useful marker and independent predictor for the presence of SEC.

Interleukin-10 promotor -592A/C polymorphism is associated with slow coronary flow in Han Chinese

An accumulating body of evidence suggests that slow coronary flow (SCF) phenomenon seems to be an early-form of atherosclerosis and low-grade inflammation plays a major role in the atherosclerotic vascular processes. Interleukin (IL)-10 is a multifunctional cytokine involved in both innate and adaptive immune response. The aim of the present study is to investigate the association of IL-10 gene -592A/C polymorphism with SCF in Han Chinese. 250 patients who underwent coronary angiography and had angiographically normal coronary arteries of varying coronary flow rates without any atherosclerotic lesion were enrolled in this study. Patients who had thrombolysis in myocardial infarction frame counts (TFC) above the normal cutoffs were considered to have SCF and those within normal limits were considered to have normal coronary flow (NCF). The PCR-based restriction fragment length polymorphism (PCR-RFLP) technique was used to assess the genotypes frequencies. The distribution of the IL-10 -592A/C genotypes (AA, AC, and CC) was 46.34%, 41.46%, and 12.20% in the NCF group, and 66.51%, 28.71%, and 4.78% in SCF subjects, respectively (P = 0.0280). The frequency of the A allele in the SCF group was significantly higher than that in the NCF group (80.86% vs. 67.07%, P = 0.0054). Compared with the CC genotype, the AA genotype had increased risk of SCF in both unadjusted and adjusted analyses. In SCF patients, the average serum IL-10 levels in AA genotype were statistically lower than in AC + CC genotype (P = 0.0000). These findings suggest that IL-10 -592A/C polymorphism is associated with SCF and the A allele has increased risk for SCF in Han Chinese.

Significance of red cell distribution width measurement for the patients with isolated coronary artery ectasia

BACKGROUND

Red cell distribution width (RDW) has been recognized as a novel marker for several cardiovascular diseases. The aim of this study was to evaluate the association between RDW levels and the presence of isolated coronary artery ectasia (CAE).

METHODS

We studied 414 subjects including 113 patients with isolated CAE (Group A), 144 patients with coronary artery disease (CAD, group B) and 157 angiographically normal controls (group C). Baseline clinical characteristics and laboratory findings including RDW were compared among three groups.

RESULTS

The levels of RDW were significantly higher in group A and B compared with that in group C (12.97 ± 1.4 and 12.88 ± 1.0 vs 12.34 ± 0.9, p = 0.020) while no difference was found between CAE and CAD (p = 0.17). Additionally, the levels of CRP were also higher in patients with CAE and CAD compared with normal controls (0.26 ± 0.14 mg/L, 0.31 ± 0.27 mg/L vs 0.20 ± 0.06 mg/L, p = 0.04). The multivariate analysis indicated that RDW and CRP were the independent variables most strongly associated with the presence of isolated CAE and CAD. There was a positive correlation between levels of RDW and CRP in patients with isolated CAE (γ=0.532, p = 0.001).

CONCLUSIONS

Our data suggested that RDW may be a useful marker and independent predictor for the presence of isolated CAE.