Effects of sarpogrelate on blood viscosity.

The objective of the present study was to evaluate the effects and safety of sarpogrelate hydrochloride (sarpogrelate) in patients with elevated blood viscosity (BV), after 12 and 24 weeks of twice (BID) or thrice (TID) daily administrations of sarpogrelate (100 mg). The participants received oral sarpogrelate administration for 24 weeks and visited the hospital every 12 ± 2 week for blood viscosity measurements at shear rates of 5 and 300 s-1. The BV measured at shear rate of 5 s-1 in male patients decreased significantly from 18.91 cP at the baseline to 16.3 cP after 24 weeks of sarpogrelate administration (13.6 % drop, p < 0.001). The BV measured at 5 s-1 in female decreased more significantly from 17.5 cP at the baseline to 13.4 cP after 24 weeks of sarpogrelate administration (23.0 % drop, p < 0.001). In summary, sarpogrelate may be considered as a possible therapeutic option for improving BV in patients with elevated blood viscosity. In particular, the reduction of the low-shear BV with the help of a viscosity-reducing drug such as sarpogrelate may be considered as a potentially new pharmacological tool for microvascular disease.

Whole blood viscosity is associated with baseline cerebral perfusion in acute ischemic stroke.

Whole blood viscosity (WBV) is the intrinsic resistance to flow developed due to the frictional force between adjacent layers of flowing blood. Elevated WBV is an independent risk factor for stroke. Poor microcirculation due to elevated WBV can prevent adequate perfusion of the brain and might act as an important secondary factor for hypoperfusion in acute ischaemic stroke. In the present study, we examined the association of WBV with basal cerebral perfusion assessed by CT perfusion in acute ischaemic stroke. Confirmed acute ischemic stroke patients (n = 82) presenting in hours were recruited from the single centre. Patients underwent baseline multimodal CT (non-contrast CT, CT angiography and CT perfusion). Where clinically warranted, patients also underwent follow-up DWI. WBV was measured in duplicate within 2 h after sampling from 5-mL EDTA blood sample. WBV was significantly correlated with CT perfusion parameters such as perfusion lesion volume, ischemic core volume and mismatch ratio; DWI volume and baseline NIHSS. In a multivariate linear regression model, WBV significantly predicted acute perfusion lesion volume, core volume and mismatch ratio after adjusting for the effect of occlusion site and collateral status. Association of WBV with hypoperfusion (increased perfusion lesion volume, ischaemic core volume and mismatch ratio) suggest the role of erythrocyte rheology in cerebral haemodynamic of acute ischemic stroke. The present findings open new possibilities for therapeutic strategies targeting erythrocyte rheology to improve cerebral microcirculation in stroke.

Another possible determinant for ischemic stroke with nonvalvular atrial fibrillation other than conventional oral anticoagulant treatment: The relationship between whole blood viscosity and stroke☆.

OBJECTIVES: Patients with nonvalvular atrial fibrillation (NVAF) still experience ischemic stroke despite recommended medications and this could be the consequence of increased whole blood viscosity (WBV). We evaluated the predictive value of WBV for stroke in patients with NVFA despite receiving oral anticoagulant (OAC) therapy. METHODS: One thousand and forty-three NVAF patients on OAC medication were followed up for median 36.13 ± 18.31 months. WBV was calculated according to the validated de Simone's formula. RESULTS: WBV was significantly higher in stroke group when compared to non-stroke group at both low shear rate (LSR) and high shear rate (HSR). Multiple regression analysis demonstrated an independent association between WBV and stroke when adjusted for other risk factors. CONCLUSIONS: WBV appears to be a profitable predictor of ischemic stroke in patients with NVAF receiving OAC.

Effect of warfarin versus aspirin on blood viscosity in cardioembolic stroke with atrial fibrillation: a prospective clinical trial.

BACKGROUND: Warfarin is evidence-based therapy for the prevention of cardioembolic stroke, but has not been studied for its effects on whole blood viscosity (WBV). This study investigated the effect of warfarin versus aspirin on WBV in patients presenting with non-valvular atrial fibrillation (NVAF) and acute cardioembolic stroke. METHODS: We enrolled patients with acute cerebral infarction, aged 56-90 years who had NVAF, CHADS2 score ≥ 2, presenting with mild-to-moderate stroke (National Institute of Health Stroke Scale (NIHSS) score < 20 and modified Rankin Scale (2mRS) score < 4) in a single center. The patients were alternately assigned to warfarin or aspirin groups. Post-treatment WBV was assessed after international normalized ratio (INR) reached target range [2, 3] for patients in the warfarin group, and 5 days after baseline in the aspirin group. RESULTS: Total 67 patients were included, and 56 completed this study (33 warfarin and 23 aspirin). Compared to baseline values, warfarin reduced post-treatment BV at all shear rates. The BV reductions greater than 1 cP measured at shear rates of 300, 150, 5, and 1 s- 1 were independently and significantly associated with warfarin treatment compared to aspirin after adjusting for age, sex, CHA2DS2-VASc scores, and baseline hematocrit. CONCLUSIONS: Warfarin confers greater reductions in BV than aspirin in patients with acute cardioembolic stroke. BV could be a useful method to estimate thrombotic risk in patients receiving warfarin. TRIAL REGISTRATION: KCT0001291 , Date of Registration: 2014-12-01.

The Relationship between Blood Viscosity and Isolated Coronary Artery Ectasia.

BACKGROUND: It is unclear whether isolated coronary artery ectasia (iCAE) is associated with whole blood viscosity (WBV). In the present study, we investigated WBV in coronary artery ectasia (CAE) patients. METHODS: Seventy-eight patients with iCAE and 83 controls with normal coronary arteries were selected from 12290 patients who underwent coronary angiography between January 2014 and December 2017. WBV was calculated with a validated equation from hematocrit and total plasma protein levels for a low (LSR) and high (HSR) shear rate. RESULTS: Baseline demographic characteristics and medical history of the groups were similar. The mean level of C-reactive protein (2.1 ± 0.53 vs. 1.93 ± 0.44; p = 0.042) and total protein (7.2 ± 0.3 vs. 7.0 ± 0.6; p = 0.009) were significantly higher in the iCAE group than in the control subjects. Both HSR (4.57 ± 0.6 vs. 3.9 ± 0.7; p < 0.001) and LSR (33.5 ± 9.6 vs. 25.1 ± 9.2; p < 0.001) levels were significantly higher in the iCAE group than in the control group. In ROC analysis, a cut-off value of 4.19 WBV for HSR had an 80.8% sensitivity and 72.3% specificity [area under the curve (AUC): 0.779, 95% CI 70.6-85.1; p < 0.001] and a cut-off value of 27.5 WBV for LSR had an 80.1% sensitivity and 72.3% specificity for predicting iCAE (AUC: 0.788, 95% CI 71.4-86.2; p < 0.001). In multivariate analysis, both LSR (p < 0.001, OR 1.10, 95% CI 1.05-1.15) and HSR (p < 0.001, OR 4.60, 95% CI 2.33-9.09) were independent predictors for the presence of iCAE. CONCLUSIONS: In the present study, we determined that in WBV, both HSR and LSR were significantly higher in the iCAE group than in the control subjects, and that this may be a possible cause of iCAE.

The Contribution of Whole Blood Viscosity to the Process of Aortic Valve Sclerosis.

OBJECTIVE: We aimed to investigate whether increased whole blood viscosity (WBV) could be an important factor for the occurrence of aortic valve sclerosis (AVS). SUBJECTS AND METHODS: A total of 209 patients were enrolled in the study. WBV was calculated using the hematocrit and total plasma protein at a low shear rate (LSR) and a high shear rate (HSR). AVS was defined as irregular valve thickening and calcification (without evidence of outflow obstruction) documented by a peak transvalvular velocity < 2.5 m/s on echocardiographic examination. The patient group consisted of 109 patients with AVS (77 females, 32 males), and 100 subjects without AVS (65 females, 35 males) were assigned to the control group. RESULTS: In the AVS group, WBV values were significantly higher for HSR (17.4 ± 0.5 vs. 17.1 ± 0.7 208 s-1, p < 0.001) and LSR (65.9 ± 12.5 vs. 59.7 ± 16.7 0.5 s-1, p = 0.002). In multivariate logistic regression analysis, WBV at HSR and LSR were independent predictors of AVS (odds ratio, OR: 2.24, 95% confidence interval, CI: 1.38-3.64, p = 0.001; OR: 1.026, 95% CI: 1.006-1.046, p = 0.01, respectively). Receiver-operating characteristic (ROC) curve analysis indicated that a WBV cutoff value of 65.4 at LSR had a sensitivity of 46.8% and a specificity of 60.0% (area under the ROC curve, AUC: 0.615, 95% CI: 0.535-0.696, p = 0.004), and a WBV cutoff value of 17.1 at HSR had a sensitivity of 61.5% and specificity of 53% (AUC: 0.648, 95% CI: 0.571-0.725, p < 0.001) for the prediction of AVS. CONCLUSION: This study demonstrated that WBV was independently associated with AVS. WBV could be an indicator of inflammation and vessel remodeling without evidence of outflow obstruction.

Vis-NIR spectroscopy with moving-window PLS method applied to rapid analysis of whole blood viscosity.

A rapid analytical method of human whole blood viscosity with low, medium, and high shear rates [WBV(L), WBV(M), and WBV(H), respectively] was developed using visible and near-infrared (Vis-NIR) spectroscopy combined with a moving-window partial least squares (MW-PLS) method. Two groups of peripheral blood samples were collected for modeling and validation. Separate analytical models were established for male and female groups to avoid interference in different gender groups and improve the homogeneity and prediction accuracy. Modeling was performed for multiple divisions of calibration and prediction sets to avoid over-fitting and achieve parameter stability. The joint analysis models for three indicators were selected through comprehensive evaluation of MW-PLS. The selected joint analysis models were 812-1278 nm for males and 670-1146 nm for females. The root-mean-square errors (SEP) and the correlation coefficients of prediction (RP) for all validation samples were 0.54 mPa•s and 0.91 for WBV(L), 0.25 mPa•s and 0.92 for WBV(M), and 0.22 mPa•s and 0.90 for WBV(H). Results indicated high prediction accuracy, with prediction values similar to the clinically measured values. Overall, the findings confirmed the feasibility of whole blood viscosity quantification based on Vis-NIR spectroscopy with MW-PLS. The proposed rapid and simple technique is a promising tool for surveillance, control, and treatment of cardio-cerebrovascular diseases in large populations. Graphical Abstract The caption/legend of the online abstract figure: The selected wavebands and the prediction effects for the three indicators of whole blood viscosity.

Hemorheological abnormalities and their associations with coronary blood flow in patients with cardiac syndrome X: a comparison between males and females.

AIM: The role of elevated whole blood viscosity (WBV) in the pathogenesis of atherosclerosis is well known. We sought to investigate the gender differences in the association between WBV, coronary blood flow and tissue oxygen delivery index (TODI) in cardiac syndrome X (CSX). METHODS: Forty-six CSX patients and 14 healthy volunteers were enrolled. The coronary flow parameters were obtained with transthoracic Doppler echocardiography and WBV was measured (at high-shear and low-shear rates of 300s-1 and 5s-1, respectively) using a scanning capillary tube viscometer. TODI was determined from the ratio of hematocrit to WBV measured at a low-shear rate of 5s-1. RESULTS: In male patients, the mean diastolic coronary flow velocity (CFV) and diastolic velocity time integral (VTI) were significantly decreased compared to control group (all p<0.05) and the WBV showed significant negative correlation with peak systolic CFV (r = -0.559 at 300s-1, r = -0.438 at 5s-1), mean systolic CFV (r = -0.577 at 300s-1, r = -0.488 at 5s-1), systolic VTI (r = -0.576 at 300s-1, r = -0.530 at 5s-1) and diastolic VTI (r = -0.553 at 300s-1, r = -0.551 at 5s-1) (all p<0.01). Meanwhile, although female patients showed no significant relationships between WBV and coronary flow parameters, TODI were significantly decreased compared to the control group (3.64 ± 0.34 vs. 4.07 ± 0.38%/centipoises (cP), respectively, p=0.008). CONCLUSION: Our study suggests that there are gender-related differences in the pathogenesis of microvascular angina and gender-specific approaches for CSX patients might be needed.

Hemorheological Alteration in Patients Clinically Diagnosed with Chronic Liver Diseases.

Since liver function is changed by chronic liver diseases, chronic liver disease can lead to different hemorheological alterations during the course of the progression. This study aims to compare alterations in whole blood viscosity in patients with chronic liver disease, focusing on the gender effect. Chronic liver diseases were classified into three categories by patient's history, serologic markers, and radiologic findings: nonalcoholic fatty liver disease (NAFLD) (n = 63), chronic viral hepatitis B and C (n = 50), and liver cirrhosis (LC) (n = 35). Whole blood viscosity was measured by automated scanning capillary tube viscometer, while liver stiffness was measured by transient elastography using FibroScan®. Both systolic and diastolic whole blood viscosities were significantly lower in patients with LC than NAFLD and chronic viral hepatitis (P < 0.001) in male patients, but not in female patients. In correlation analysis, there were inverse relationships between both systolic and diastolic whole blood viscosity and liver stiffness (systolic: r = -0.25, diastolic: r = -0.22). Whole blood viscosity was significantly lower in male patients with LC than NAFLD or chronic viral hepatitis. Our data suggest that whole blood viscosity test can become a useful tool for classifying chronic liver disease and determining the prognosis for different types of chronic liver diseases.

Hemorheology, ankle brachial pressure index (ABPI) and toe brachial pressure index (TBPI) in metabolic syndrome.

INTRODUCTION: Microvascular dysfunction is associated with metabolic syndrome (MetS) and its components. The objective of our study was to assess macro and microvascular abnormalities in MetS and compare the strength of association of the ankle brachial pressure index (ABPI), toe brachial pressure index (TBPI) and hemorheological parameters with MetS. MATERIALS AND METHODS: 100 participants were recruited from a rural Australian town. Anthropometric measurements were taken along with blood pressures (BP) at the arm, the ankle and the big toe for calculating ABPI and TBPI. Whole blood viscosity (WBV), erythrocyte aggregation, erythrocyte deformability, lipid profile and blood sugar level were analyzed. Recruited participants were classified into MetS and non-MetS following National Cholesterol Education Program Adult Treatment Panel III definition. Data were analyzed by IBM SPSS 20 software. RESULTS: WBV and erythrocyte aggregation were higher whereas erythrocyte deformability was lower in participants with MetS when compared to participants without MetS. Age, sex and diabetes mellitus adjusted odds ratio for predicting MetS was not significant for ABPI and TBPI whereas it was significant for hemorheological parameters. Receiver Operating Characteristics curve showed that TBPI better classified MetS than ABPI but association of hemorheological parameters was superior to that of ABPI and TBPI with MetS. CONCLUSIONS: Both microcirculation defects and macrovascular circulation defects were present in MetS. The concurrences of the components of MetS could have an additive effect in enhancing alterations in hemorheological parameters which may give rise to severe microvasculopathy. The association of hemorheological parameters was stronger than the association of TBPI and ABPI with MetS.

Increased whole blood viscosity associated with arterial stiffness in patients with non-alcoholic fatty liver disease.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) is an independent risk factor for increased cardiovascular disease. The brachial-ankle pulse wave velocity (baPWV) is a marker for early atherosclerotic changes. Recently, the effect of changed blood rheology on atherosclerosis has received attention. A study confirmed that whole blood viscosity (WBV) is a predictor of cardiovascular events. Therefore, this study aimed to investigate the association of WBV with baPWV in patients with NAFLD. METHODS: In this cross-sectional study, the relationship between WBV and baPWV was investigated in 2032 participants (1035 men and 997 women) with NAFLD in a general health examination. RESULTS: Different metabolic parameters were compared across WBV (3/s) quartiles. The mean values of baPWV gradually increased with WBV (3/s) quartiles. Stepwise multiple linear regression analysis revealed that WBV (3/s) is a significant determinant for increased baPWV both in men and in women (for male, ß = 0.229; P < 0.001; for female, ß = 0.672; P < 0.001). CONCLUSIONS: The findings showed that baPWV elevated as WBV (3/s) increased in NAFLD. Moreover, WBV (3/s) is independently associated with baPWV even after adjusting other cardiovascular risk factors. Early detection of abnormal WBV levels at low shear rate should warrant for early search of undetected arterial stiffness in patients with NAFLD.

Cardiovascular benefits of phlebotomy: relationship to changes in hemorheological variables.

Renewed interest in the age-old concept of "bloodletting", a therapeutic approach practiced until as recently as the 19th century, has been stimulated by the knowledge that blood loss, such as following regular donation, is associated with significant reductions in key hemorheological variables, including whole blood viscosity (WBV), plasma viscosity, hematocrit and fibrinogen. An elevated WBV appears to be both a strong predictor of cardiovascular disease and an important factor in the development of atherosclerosis. Elevated WBV through wall shear stress is the most direct physiological parameter that influences the rupture and erosion of vulnerable plaques. In addition to WBV reduction, phlebotomy may reduce an individual's cardiovascular risk through reductions in excessive iron, oxidative stress and inflammation. Reflecting these findings, blood donation in males has shown significant drops in the incidence of cardiovascular events, as well as in procedures such as percutaneous transluminal coronary angioplasty and coronary artery bypass grafting. Collectively, the available data on the benefits of therapeutic phlebotomy point to the importance of monitoring WBV as part of a cardiovascular risk factor, along with other risk-modifying measures, whenever an increased cardiovascular risk is detected. The development of a scanning capillary tube viscometer allows the measurement of WBV in a clinical setting, which can prove to be valuable in providing an early warning sign of an increased risk of cardiovascular disease.

Investigation of Zinc on hemorheological parameters in a rat model of diabetes.

Diabetes mellitus (DM) is a complex, chronic metabolic disorder characterized by impaired regulation of blood glucose levels. Zinc (Zn) is an essential trace elements that plays a role in various physiological processes within the body, including those related to diabetes. The current study was investigated the effect of Zn supplementation on hemorheological parameters in a rat model of DM. After induction of DM, 32 male Wistar albino rats were divided into four groups: control, Zn, DM, and Zn+DM. Whole blood viscosity (WBV) was determined by using digital cone and plate viscometer and plasma viscosity (PV) was determined by a Coulter Harkness capillary viscometer. The rats in the DM Group showed a decrease in both Zn levels and body weight, as well as an increase in glucose levels when compared to the control group. Diabetic rats supplemented with Zn displayed lower blood glucose levels and higher concentrations of Zn compared to the DM Group. The higher PV and lower hematocrit level were measured in DM Group than control group and lower PV, higher hematocrit level were measured in Zn+DM group than DM Group. The WBV was measured at four different shear rates (57.6-115.2 - 172.8-230.4 s -1). A statistically significant increase was observed in the DM group compared to the control group. Additionally, a statistically significant decrease was observed in the Zn+DM Group compared to the DM Group at a shear rate of 230.4 s-1. Erythrocyte rigidity index (Tk) and oxygen delivery index (ODI) were computed under conditions of high shear rate. The rats in the DM group exhibited a reduction in ODI and an elevation in Tk in comparison to the control group. Conversely, the diabetic rats supplemented with Zn exhibited decreased Tk and increased ODI compared to the DM Group. Zn supplementation seems to have a potential beneficial effect for protecting adverse affect of diabetes on hemorheogical parameters and for maintaining vascular health.

Investigating the blood rheology in the first trimester pregnancies with high risk for preeclampsia.

BACKGROUND: Pregnancy is a dynamic process associated with changes in vascular and rheological resistance. Maternal maladaptation to these changes is the leading cause of pregnancy complications such as preeclampsia. OBJECTIVE: This study aimed to assess the hemorheological alterations in pregnancies with a high risk for preeclampsia in the first trimester. METHODS: Ninety-two pregnant women were allocated into the high preeclampsia risk group (37 cases) and control groups (55 cases). Plasma and whole blood viscosity and red blood cell morphodynamic properties, including deformability and aggregation were assessed by Brookfield viscometer and laser-assisted optical rotational cell analyzer (LORRCA) at 11-14 gestational weeks. RESULTS: Whole blood viscosity was significantly higher in the high-risk group at all shear rates. Plasma viscosity and hematologic factors showed no differences between the groups. Hematocrit levels positively correlated with high blood viscosity only in the high-risk group. There were no significant changes in the other deformability and aggregation parameters. CONCLUSIONS: Changes in the whole blood viscosity of pregnant women with high preeclampsia risk refer to impaired microcirculation beginning from the early weeks of gestation. We suggest that the whole blood viscosity is consistent with the preeclampsia risk assessment in the first trimester, and its measurement might be promising for identifying high-preeclampsia-risk pregnancies.

Local carotid stiffness, hemodynamic forces and blood viscosity in patients with cerebral lacunar infarctions.

OBJECTIVE: The carotid stiffness is an important factor in the pathogenesis of cerebrovascular small vessel disease. Our study aimed to evaluate the relation of the local arterial stiffness of the common carotid artery (CCA) to the hemodynamic forces and blood viscosity in patients with cerebral lacunar infarctions (LI). METHODS: Twenty-two patients with chronic LI and 15 age-matched controls were examined. An ultrasound examination of the CCA intima-media thickness (IMT), the parameters of local CCA stiffness: distensibility (DC) and compliance coefficients (CC), α and ß stiffness indices and pulse wave velocity (PWV) was performed. The local hemodynamic forces were calculated: circumferential wall tension (CWT) and wall shear stress (WSS). Whole blood viscosity (WBV) and shear stresses at shear rates of 0.277 s - 1 to 94.5 s - 1 were measured in patients and controls. RESULTS: Higher values of IMT, a significant decrease of DC and CC and an increase of α and ß stiffness indices and PWV in the LI patients compared to the controls were obtained. A parallel significant increase in CWT and a decrease in WSS was found. An increase in WBV and a significant increase in shear stresses were detected. In the LI patients, the increased stiffness indices were associated with an increase in age, cholesterol and WBV at higher shear rates in the left CCA. In the controls, the IMT and stiffness indices correlated significantly with the hemodynamic factors and WBV in both CCAs, while the stiffness indices correlated with the hemodynamic forces in the left CCA. CONCLUSION: The results of the present study demonstrate different associations of the local carotid stiffness indices with the hemodynamic forces and WBV in patients with LI and controls.

Blood Viscosity Changes in Diabetes Mellitus: A 20-Year Bibliometric Review and Future Directions.

Changes in hematological parameters due to diabetes are reflected in changes in whole blood viscosity (WBV). Understanding the impact of diabetes and its cardiovascular disease (CVD) complications can provide substantiation of how laboratory tests for WBV are useful to monitor the progression and treatment. The review examines research work done in the past 20 years to provide a framework for the present agenda. This was a narrative review that followed the standard Scale for the Assessment of Narrative Review Articles (SANRA) approach. It includes both conceptual and empirical reviews. WBV was appraised in the context of bibliographic research on diabetes and other related factors such as metabolic syndrome (MetS) and oxidative stress. The association of abnormal erythrocytes as well as the relationship between WBV and MetS is established. Changes in diabetes that contribute to the development of diabetic cardiovascular complications occur through the pathway of WBV physiology. However, longitudinal analysis is very limited. There is a dearth of longitudinal study data on WBV in diabetes management. This lack of data justifies a need for further studies, especially prospective and retrospective analysis, to investigate the prevalence of diabetes mellitus about the prevalence of cardiovascular complications indices, especially estimated WBV (eWBV) between periods and within cohorts.

Whole Blood Viscosity Reference Intervals and Its Correlation with Hematology and Serum Chemistry in Cats Using Scanning Capillary Method.

Whole blood viscosity, a hemorheological factor, is currently used for diagnosis, as it is correlated with various vascular diseases that are difficult to diagnose early with a general blood test. It was determined that it was necessary to set reference intervals for further studies and utilization of whole blood viscosity in cats, a representative companion animal, and this study was conducted. Fifty healthy cats were recruited for the study, and whole blood viscosity, complete blood count, and serum chemistry tests were performed. The reference intervals of whole blood viscosity were 15.169 to 43.684 cP at a shear rate of 1 s-1 reflecting diastole, and 3.524 to 5.544 cP at a shear rate of 300 s-1 reflecting systole. Red blood cells, hematocrit, hemoglobin, white blood cells, and neutrophils in the complete blood count, and total protein, albumin, globulin, and cholesterol in the serum chemistry were significantly correlated with whole blood viscosity. The results of this study set the reference intervals of whole blood viscosity for healthy cats in a wide shear rate range that has not yet been fully established, and its correlation with other blood indicators investigated.

Increased whole blood viscosity is associated with primary idiopathic complete atrioventricular block and poor clinical outcomes in these patients.

BACKGROUND: Complete atrioventricular block is most commonly caused by age-related degeneration and fibrosis in the cardiac conduction system and is called primary idiopathic complete atrioventricular (iCAVB). Although many factors affect this situation, which increases with age in the cardiac conduction system, the relationship between whole blood viscosity (WBV) and iCAVB has not been clarified until now. In this study, we aim to reveal the relationship between iCAVB and WBV. METHODS AND RESULTS: 141 patients with dual-chamber permanent pacemaker implanted for iCAVB and 140 age- and sex-matched subjects were included in this study. The WBV values of the study groups were compared in both high shear rate (HSR) and low shear rate (LSR). Both WBV at HSR and WBV at LSR were significantly higher in the iCAVB group compared to the control group (16.11 [15.14-16.89] vs 14.40 [13.62-15.58]; 39.82 [17.43-55.23] vs 1.38 [-13.14-26.73]; p < 0.001, respectively). The patient population was followed up for an median of 38 months for all-cause mortality. Higher mortality rates were found in higher WBV at HSR and WBV at LSR (p < 0.001,for both). CONCLUSIONS: In this study, WBV was found to be an independent predictor for iCAVB, and in these patients WBV was associated with poor clinical outcomes.

Whole blood viscosity is an independent early predictor for metabolic syndrome and its components in men: A prospective cohort study in Northern Chinese population.

The association between whole blood viscosity (WBV) and metabolic syndrome (MetS) is still scarcely investigated in the population-based prospective cohort. We aim to explore the longitudinal effect of WBV on MetS, and to verify whether WBV measures can be used as early predictors for MetS. The longitudinal cohort consisted of 3,508 adults (2,350 males and 1,158 females) who visited the health check-up system twice. WBV were measured at four shear rate (200, 50, 10 and 1 s-1), and their values were classified into quartiles. Multivariate Cox models were used to estimate the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) in men and women, respectively. A total of 444 (12.66%) incident MetS were observed at follow-up period. The incidences of MetS significantly increased with increasing quartiles of WBVs at all of the shear rate in men. After adjusting for baseline age, smoking, obesity, hypertension, hyperglycemia, and hyperlipidemia status, all of the WBV measures were significantly associated with incident MetS in men, and the HRs showed clear increasing trend across the quartiles of baseline WBVs. There were no significant association between WBVs and incident MetS in women. These findings suggest that MetS has a hemodynamic basis, and WBVs could be used as independent early predictor for MetS in men.

Association of whole blood viscosity with thrombus presence in patients undergoing transoesophageal echocardiography.

Whole blood viscosity (WBV) is considered as a reasonable proxy measure of blood flow, and it has been investigated in different cohort settings, including in patients with deep venous thrombosis, arterial thrombosis, acute stent thrombosis, and left ventricular apical thrombus formation following acute coronary syndrome. To determine the association between WBV and the presence of thrombus in the left atrium (LA) or left atrial appendage (LAA) in individuals who had transoesophageal echocardiography (TEE). The clinical data from 262 consecutive patients who had TEE at our facility were included in this retrospective cohort study. WBV was determined at both a high shear rate (HSR) and low shear rate (LSR) using hematocrit and total protein levels. In 22 cases (8.3%), the thrombus was detected. According to multivariable analyses, WBV at HSR and LSR were independently linked with thrombus detection in TEE. In a receiver operating characteristic (ROC) analysis, the area under curve (AUC) values of WBV at HSR and LSR were 0.77 and 0.76, respectively. To predict the presence of thrombus in TEE; the ideal value of WBV at HSR was > 16.6 with 81% sensitivity and 69% specificity and the ideal value of WBV at LSR was > 51.4 with 81% sensitivity and 70% specificity. This was the first study to indicate that significantly higher levels of WBV at both the HSR and LSR were linked to the presence of thrombus in the LA and LAA in cases who underwent TEE.