Whole Blood Viscosity Values Research Articles

May high blood viscosity predict cardiac involvement in COVID-19 patients?

Aims: Assessing the effects of whole blood viscosity (WBV) on prognosis and deterioration in cardiac parameters in COVID-19 patients after recovery using cardiac magnetic resonance imaging (CMRI) and echocardiography is the purpose of this study. Methods: The study involved 70 patients. Patients who had COVID-19 pneumonia were admitted to the hospital. All patients met the eligibility criteria if they remained symptom-free of respiratory and cardiac symptoms and had negative swab test results at the end of the isolation period, for at least two weeks following the positive swab test result. Transthoracic echocardiography was performed within 24 hours prior to CMRI. WBV was measured in centipoises (cP) at 208 seconds-1 shear rate. The median value of WBV was calculated for the entire study population, which was subsequently utilized to divide the population into two subgroups. These were designated as high WBV and low WBV subgroups. Results: Elevated levels of hemoglobin, hematocrit, total protein, C-reactive protein, D-dimer, and fibrinogen were observed in individuals with high WBV. Conversely, TAPSE, S, and FAC were notably reduced in those with high WBV. Notably, CMRI revealed significant increases in native T1, native T2 mapping signal, and extracellular volume among patients with high WBV. Furthermore, in individuals with high WBV, there was a significant decrease in right ventricle stroke volume and right ventricle ejection fraction, accompanied by a notable increase in right ventricle end-systolic volume. Conclusion: WBV values measured during hospital admission may have early and late prognostic importance for COVID-19 infection.

Prediction of long-term ischemic stroke with estimated whole blood viscosity in heart failure patients

Aims: Heart failure (HF) and stroke often coexist and share common risk factors, including atrial fibrillation. Whole blood viscosity (WBV), one of the most significant indicators of endothelial stress, is a fundamental determinant of blood flow and is involved in the aetiology of atherosclerosis and thrombosis. The purpose of this study was to assess the association between estimated WBV and long-term ischemic stroke (IS) risk in patients hospitalized for acute HF.
 Methods: A total of 409 patients with reduced ejection fraction HF hospitalized with acute HF were included. The primary outcome was IS post-discharge follow-up. 
 Results: IS occurred in 26 (6%) patients during a follow-up. In the IS group, older age, diabetes mellitus frequency and WBV were higher, left ventricular end-diastolic and left atrial anteroposterior diameter were increased and left ventricular ejection fraction was lower. In multivariate regression analysis, WBV was found to be a predictor of long-term IS (OR, 2.68; 95% CI, 1.96-3.12, p=0.008). In the receiver operating characteristic curve, the optimal cut-off value of WBV for one-year IS was 6.28 with 61.5% sensitivity and 70.2% specificity (area under the curve: 0.748).
 Conclusion: WBV is a novel, easily measurable, cost-effective, non-invasive risk marker for the prediction of long-term IS in patients with HF, independent of traditional risk factors.

Relationship between blood viscosity and thrombus burden in ST-segment elevation myocardial infarction.

İncreased whole blood viscosity (WBV) is associated with increased infarct area, impaired microvascular circulation and mortality in patients with ST-elevation myocardial infarction (STEMI). We aimed to analyze the association between the WBV and thrombus burden (TB) in STEMI patients. This cross-sectional study included 167 STEMI patients who received primary percutaneous coronary intervention. WBV values were assessed using hematocrit and total protein values, and low shear rate(LSR) and high shear rate(HSR) were calculated. Angiographic TB was assessed according to the definition of the Thrombolysis in Myocardial Infarction (TIMI) study group. The cases were dichotomized into low TB (grade 1-3) (n = 87) and high TB (grade 4-5) (n = 80) groups. The mean HSR and LSR values of the high TB group were significantly increased compared to the low TB group (p < 0.001, for each). In ROC analysis,for prediction of TB, a cut-off value of 3.83 WBV for HSR had a 71% sensitivity and a 60.7% specificity, and a cut-off value of 21 WBV for LSR had a 70% sensitivity and 59.9% specificity (p < 0.001,for each). Multivariate regression analysis showed that both HSR (OR = 2.408;p=0.020) and LSR (OR = 1.055;p=0.021) were independent predictors for high TB. İncreased WBV was an independent predictor for the presence of high TB in patients with STEMI.

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

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. 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). In this study, WBV was found to be an independent predictor for iCAVB, and in these patients WBV was associated with poor clinical outcomes.

The relationship between nitrate induced headache and whole blood viscosity: an observational prospective study.

Nitrates are one of the most prescribed medications in the treatment of angina pectoris today. Headache is the most common side effect of nitrates, and there is limited prospective data on the determinants of this effect. Our aim in this study is to open a foresight window for clinicians in clinical practice by explaining the possible relationship between nitrate induced headache (NIH) and whole blood viscosity (WBV). After coronary revascularization treatment, 869 patients with angina who were prescribed nitrate preparations were divided into groups according to the development of headache or not, and categorized according to the four-grade scale (4GS) level. Those who had no headache during nitrate use were graded as Grade 0, those who felt mild headache were Grade 1, those who felt moderate headache were Grade 2, and those who described severe headache were graded as Grade 3. The groups were compared according to WBV values. A total of 869 participants were included in the study. Most patients (82.1%) experienced any level of headache. Headache severity was correlated with both WBV at HSR (r=0.657, p<0.001) and WBV at LSR (r=0.687, p<0.001). In multivariate analysis, WBV was determined as an independent predictor of headache experience. WBV predicted NIH with 75% sensitivity and 75% specificity at HSR and 77% sensitivity and 77% specificity at LSR. WBV seems to be one of the major determinants for NIH. WBV may be a guide for initiating alternative antianginal drugs without prescribing nitrates to the patient in order to increase patient compliance.

Can whole blood viscosity predict the development of acute mesenteric arterial thrombosis?

Acute mesenteric ischemia is a serious condition with high mortality rate, resulting internal organ damage and intestinal necrosis due to sudden occlusion in the arteries feeding the abdominal solid organs and intestines. The most common causes of acute mesenteric artery ischemia are embolic processes and thrombosis that develops on the basis of primary mesenteric artery atherosclerosis. Whole blood viscosity (WBV) was defined by De Simon and could be calculated with a formula that consists of total plasma protein and hematocrit (HCT). In our study, we aimed to investigate the predictive value of WBV for acute mesenteric ischemia caused by primary mesenteric artery occlusion. Between January 2015 and February 2021, a total of 55 patients with a retrospective diagnosis of acute mesenteric ischemia (AMI) and 50 healthy volunteers as a control group were included in the study. WBV was calculated with the De Simon for-mula using the HCT and plasma protein levels from the blood tests of healthy volunteers and patients at the time of admission with acute abdomen. No significant differences between the two groups in terms of baseline demographic characteristics except the preva-lence of age (72.1±12.4 vs. 65.7±6.4; p<0.001) and hypertension (40% vs. 23% p=0.002). AMI patients had significantly higher WBV values both at low shear rate (LSR) ([46.3±21.7 vs. 33.4±±13.1, p<0.001] and high shear rate [HSR] [16.5±11 vs. 15.8±0.7, p<0.001]). The univariate analysis identified several variables for predicting AMI including age (odds ratio [OR]: 1.066 confidence interval [CI]: 1.023-1.111, p=0.003), hypertension (OR: 3.612 CI: 1.564-8.343, p=0.003), WBV at HSR (OR: 2.074 CI: 1.193-3.278, p=0.002), and WBV at LSR (OR: 2.156 CI: 1.331-3.492, p=0.002). However, after multivariate analysis, only hypertension (OR: 3.537 CI: 1.298-9.639, p=0.014) and age (OR: 1.085 CI: 1.026-1.147, p=0.004) showed significance. In receiver operating characteristic analysis, a cut-off value of 43.5 WBV for LSR had a 72% sensitivity and a 70% specificity for prediction of mesenteric ischemia patients (area under curve [AUC]: 0.743, p<0.001) and a cut-off value of 16.29 WBV for HSR had a 78% sensitivity and 76% specificity for prediction of mesen-teric ischemia patients (AUC: 0.773, p<0.001). In our study, we determined that the WBV value obtained with the De Simon formula is a valuable parameter in predicting the development of acute mesenteric artery ischemia caused by primary mesenteric artery occlusion.

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

ObjectivesPatients 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. MethodsOne 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. ResultsWBV 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. ConclusionsWBV appears to be a profitable predictor of ischemic stroke in patients with NVAF receiving OAC.

The association between whole blood viscosity and high thrombus burden in patients with non-ST elevation myocardial infarction.

Prior studies showed that patients with elevated whole blood viscosity (WBV) had a higher risk of arterial thrombosis, acute stent thrombosis, and left ventricular apical thrombus presence after acute coronary syndrome. This investigation aimed to determine the association between WBV and high thrombus burden (HTB) in non-ST elevation myocardial infarction (NSTEMI) patients treated with percutaneous coronary intervention (PCI). This retrospective cohort investigation included data from consecutive 290 NSTEMI patients who received PCI at a tertiary institution. Patients with grade 1-3 thrombus burden were categorized as having low thrombus burden (LTB) (n = 178), whereas those with grade 4-5 thrombus burden were classified as having HTB (n = 112). WBV at high shear rate (HSR) and low shear rate (LSR) were estimated using hematocrit (HTC) and total protein levels. Patients with HTB had higher WBV at both LSR and HSR. In HTB patients, the frequency of infarct-related artery (IRA) reference vessel diameter, distal embolization, and no-reflow was also higher. Multivariable logistic regression models indicated that WBV at LSR (odds ratio [OR], 1.028; 95% confidence interval [CI], 1.014-1.043; P < 0.001) and HSR (OR, 1.606; 95% CI, 1.334-1.953; P < 0.001) were independent predictors of HTB in NSTEMI patients. Notably, the area under the curve value of WBV at both shear rates was greater than that of its components, including total protein and HTC. This is the first study showing that WBV at both shear rates is a significant predictor of HTB in NSTEMI patients.

Blood Rheology Alterations in Patients with Cardiovascular Diseases.

Blood rheology is an important determinant of blood flow but is probably one of the most neglected areas in clinical literature and practice. Blood viscosity changes according to shear rates and depends on cellular and plasma factors. RBCs' aggregability and deformability are the main determinants of local flow characteristics in areas with lower and higher shear rates, but plasma viscosity is the main regulatory factor of flow resistance in the microcirculation. In individuals with altered blood rheology, the mechanical stress to vascular walls induces endothelial injury and vascular remodelling, and promotes atherosclerosis. Increased values of whole blood viscosity and plasma viscosity are correlated with cardiovascular risk factors and adverse cardiovascular events. The long-term effects of physical exercise can produce a hemorheological fitness that protects against cardiovascular diseases.

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.

Whole blood viscosity in patients with aortic stenosis.

Whole blood viscosity (WBV) may promote endothelial shear stress, inflammation, and can accelerate the atherosclerotic process. We aimed to evaluate the relationship between WBV and aortic stenosis. The study included 209 participants of whom 49 patients had severe aortic stenosis, 98 patients had mild-to-moderate aortic stenosis and 62 patients served as control. WBV values were significantly higher for high shear rate (HSR) (P = 0.001) and for low shear rate (LSR) (P = 0.002) in severe aortic stenosis group. HSR and LSR were correlated with mean systolic transaortic gradient (P < 0.001 and P < 0.001, respectively). WBV for both LSR and HSR were found to be independent predictors for the aortic stenosis severity (P = 0.034 and P = 0.049, respectively). We found a significant relationship between WBV and aortic stenosis.

Relationship Between Blood Viscosity and No-Reflow Phenomenon in St-Segment Elevation Myocardial Infarction Performed in Primary Percutaneous Coronary Interventions

Background: This study aimed to analyze the associations between no-reflow (NR) phenomenon development and whole-blood viscosity in patients with ST-elevated myocardial infarction. Methods: A total of 217 patients with ST-elevated myocardial infarction were included. whole-blood viscosity values were assessed using hematocrit and total protein values, and low shear rate (LSR) and high shear rate (HSR) were calculated. Results: The average LSR and HSR values of the study group were significantly higher than the control group (p<0.001). Multivariate logistic regression analysis showed that both HSR (odds ratio: 4.957; p<0.001) and LSR (odds ratio: 1.114; p<0.001) were independent predictors for NR development. Conclusion: This study found that increased blood viscosity was an independent predictor for NR development.

Akut İskemik İnme İçin Mekanik Trombektomi Sonrası Klinik Sonuçlarla Tam Kan Viskozitesinin İlişkisi

Background: Blood viscosity (BV) is relationship cerebrovascular events. However, the association with between BV and clinical outcomes after acute ischemic stroke (AIS) has not been studied. This study evaluated the relationship between whole blood viscosity (WBV) and clinical outcomes after AIS.Materials and Methods: The study enrolled 240 consecutive patients with AIS who underwent mechanical thrombectomy (MT) between 2017 and 2019 years. The all patients were divided according to the modified Rankin Scale (mRS) score, as good (mRS 0–2) and poor (mRS 3–6) clinical outcomes group. WBV was calculated by the formula derived from total protein and haematocrit levels.Results: Poor clinical outcomes group presented significantly higher WBV values both at LSR and HSR (p &amp;lt; 0.001). Multivariate analysis, both high WBV at LSR (Odd ratio: 2.679, p &amp;lt; 0.001) and high WBV at HSR (Odd ratio: 1.278, p &amp;lt; 0.001) were independent predictors for poor clinical outcomes. In receiver operating characteristic analysis, value of 16.1 WBV at HSR had 76.7% sensitivity and 76% specificity for predicting poor clinical outcomes and a value of 38.5 WBV at LSR had 75.3% sensitivity and 78% specificity for predicting poor clinical outcomes. There was a significant positive correlation between WBV at LSR and mRS score (0-6) (r = 0.457, p &amp;lt;0.001) and WBV at HSR and mRS score (0-6) (r = 0.452, p &amp;lt;0.001).Conclusions: Increased WBC may be independent risk factor and correlated with poor clinical outcomes in AIS patients treated with MT.

Tam Kan Akışkanlığı ile Alt Ekstremite Periferik Arter Hastalığı Şiddeti Arasındaki İlişki

Aim: Increased blood viscosity (BV) has good correlaton with lower extremity peripheral artery disease (LEAD). However, the relationship between BV and peripheral arterial disease (PAD) severity has not been studied adequately so far. The aim of the present study was to assess the relationship between whole blood viscosity (WBV) and LEAD severity. Methods: The study included 240 consecutive patients with suspected PAD who had lower extremity peripheral angiography between March 2016 and March 2020. A Transatlantic İntersociety Consensus II (TASC II) A-B lesion was defined as simple LEAD, and a TASC II C-D lesion was defined as prevalent and complex LEAD. Symptom severity of all patients were categorized from 0 to 6 according to Rutherford classification. WBV was assessed using a validated calculation formula derived from hematocrit and total plasma protein levels, both at low (LSR) and high (HSR) shear rate. Results: TASC II C-D group presented significantly higher WBV values both at LSR (40.2 ± 9.5 vs. 46.5 ± 13.2; p &amp;lt; 0.001) and HSR (15.9 ± 0.5 vs. 16.5 ± 0,7; p &amp;lt; 0.001). In ROC analysis, a cut-off value of 16.1 WBV at HSR had 73.4% sensitivity and 68.0% specificity for predicting TASC II C-D (AUC: 76.2%, p &amp;lt; 0.001) and a cut-off value of 42.9 WBV at LSR had 73.4% sensitivity and 66.6% specificity for predicting TASC II C-D (AUC: 74.2%, p &amp;lt; 0.001). In multivariate analysis, both high WBV at LSR (OR: 2.121, 95% CI: 1.079 – 3.164, p &amp;lt; 0.001) and high WBV at HSR (OR: 2.737, 95% CI: 1.671 – 4.483, p &amp;lt; 0.001) were independent predictors for TASC II C-D. There was a significant positive correlation between WBV at LSR and Rutherford symptom category (0-6) (r = 0.412, p &amp;lt;0.001) and WBV at HSR and Rutherford symptom category (0-6) (r = 0.402, p &amp;lt;0.001). Conclusion: Our data suggests that; increased WBV values may be associated with TASC II C-D lesions, which indicated more prevalent and complex LEAD. Also WBV values positively correlated with Rutherford symptom severity.

Relationship between Whole Blood Viscosity and Lesion Severity in Coronary Artery Disease.

Objective This article investigates the relationship of fractional flow reserve (FFR) with whole blood viscosity (WBV) in patients who were diagnosed with chronic coronary syndrome and significant stenosis in the major coronary arteries and underwent the measurement of FFR. Material and Method In the FFR measurements performed to evaluate the severity of coronary artery stenosis, 160 patients were included in the study and divided into two groups as follows: 80 with significant stenosis and 80 with nonsignificant stenosis. WBVs at low shear rate (LSR) and high shear rate (HSR) were compared between the patients in the significant and nonsignificant coronary artery stenosis groups. Results In the group with FFR < 0.80 and significant coronary artery stenosis, WBV was significantly higher compared with the group with nonsignificant coronary artery stenosis in terms of both HSR (19.33 ± 0.84) and LSR (81.19 ± 14.20) ( p < 0.001). In the multivariate logistic regression analysis, HSR and LSR were independent predictors of significant coronary artery stenosis (HSR: odds ratio: 1.67, 95% confidence interval: 1.17-2.64; LSR: odds ratio: 2.46, 95% confidence interval: 2.19-2.78). In the receiver operating characteristic (ROC) curve analysis, when the cutoff value of WBV at LSR was taken as 79.23, it had 58.42% sensitivity and 62.13% specificity for the prediction of significant coronary artery stenosis (area under the ROC curve: 0.628, p < 0.001). Conclusion WBV, an inexpensive biomarker that can be easily calculated prior to coronary angiography, was higher in patients with functionally severe coronary artery stenosis, and thus could be a useful marker in predicting the hemodynamic severity of coronary artery stenosis in patients with chronic coronary syndrome.

Performance evaluation of the ZL 6000i cone-plate rotational viscometer

Elevated whole blood viscosity (WBV) is associated with increasing blood flow resistance in the microcirculation and is used to predict the occurrence and outcome of cardiovascular diseases. We evaluated the analytical performance of the ZL 6000i (Zonci Technology, Beijing, China), new fully automated cone-plate rotational type viscometer. We collected blood samples from 287 adults to establish a reference range. We evaluated total precision for 20 days using quality control (QC) samples and within-run precision was evaluated by performing 50 consecutive measurements of blood samples. Aliquots of blood samples were stored at room temperature and 5°C to assess the effect of storage time and temperature on viscosity measurement. The reference ranges and median values of WBV were significantly higher in males than in females due to difference in hematocrit level. The coefficients of variation (CVs) for precision using QC and human blood samples were < 7.5% at all shear rates. WBV of the samples stored at room temperature for up to 6 h, and at 5°C for samples stored up to 2 days was not different from the control. In this study, the ZL 6000i viscometer yields reproducible WBV data and is clinically useful for monitoring viscosity.

The Relationship between Blood Viscosity and Acute Arterial Occlusion

Abstract Background: Blood viscosity is a strong predictor of cardiovascular events. However, the relationship between blood viscosity and acute arterial occlusion (AAO) has not been studied adequately so far. Objectives: The aim of the present study was to assess the relationship between whole blood viscosity (WBV) and AAO. Material and methods: The study included 93 patients who were diagnosed with AAO between January 2017 and September 2019, and 90 age- and sex-matched healthy controls. WBV was assessed using a validated calculation formula derived from hematocrit and total plasma protein levels, both as a low (LSR) and a high (HSR) shear rate. Results: There were no significant differences between the two groups in regards to the baseline characteristics, with the exception of smoking and LDL cholesterol levels. Subjects with AAO presented significantly higher WBV values both at LSR (32.2 ± 5.0 vs. 26.6 ± 5.0, p &lt;0.001) and HSR (6.2 ± 0.3 vs. 5.7 ± 0.3, p &lt;0.001). The ROC analysis revealed a cut-off value of 27.4 for WBV at LSR (sensitivity 66%, specificity 64%, AUC = 0.770, p &lt;0.001) and a cut-off value of 5.29 in case of HSR (sensitivity 69%, specificity 74%, AUC = 0.801, p &lt;0.001) for predicting AAO. Multivariate analysis, both LSR (OR 3.33, 95% CI: 1.20–9.43, p = 0.006) and HSR (p = 0.020, OR: 1.70, 95% CI: 1.020–1.123) were independent predictors of AAO. Conclusions: This study demonstrated that WBV levels at both HSR and LSR are significantly higher in the AAO group than in the control subjects, indicating that an increased WBV may be associated with the development of AAO.

Recanalization of Embolized Endovascular Intracranial Aneurysms and Changes in the Blood Viscosity: A Pilot Study.

BackgroundThe purpose of our research was to evaluate the relationships between blood viscosity and recanalization of coiled intracranial aneurysms.Material/MethodsThe study included consecutives patients treated endovascularly by a team of experienced neurosurgeons and neuroradiologists due to brain aneurysm. A total of 50 patients (the average age was 57.48 years, SD=13.71) were assigned to 2 groups: group A with recanalization (4 male and 8 female patients) and group B without recanalization (10 male and 28 female patients) were examined. All patients underwent a 6-month follow-up of the whole-blood viscosity test with a Brookfield DV III+pro cone-plate viscometer using the Rheocalc program. Differences between groups were assessed using the Statistica 12 computer program (StatSoft Inc., Tulsa, OK, USA).ResultsStudies have shown no significant difference in the age range between group A and B (P=0.31). In group A, higher viscosity values were found for whole blood [median: 4.14 dyn×sec/cm2 (mPa×sec) quartile range 0.42], compared to group B [median: 3.92 dyn×sec/cm2 (mPa×sec); quartile range 0.40; (P=0.04)]. This difference was significant (P=0.04). Additionally, the level of hematocrit was positively related with recanalization, the higher the hematocrit, the more frequent recanalization. A very strong and statistically significant relationship occurred between the frequency of recanalization and smoking (P<0.001).ConclusionsThe occurrence of higher values of whole blood viscosity which increase turbulent flow through the vessels may be a risk for recanalization of the coiled intracranial aneurysm.

Relationship between apical thrombus formation and blood viscosity in acute anterior myocardial infarction patients.

Aim: This study sought to investigate the predictive value of whole blood viscosity (WBV) to identify high-risk patients who will develop an apical thrombus during the acute phase of anterior transmural infarction. Materials & methods: Consecutive 1726 patients with first acute anterior myocardial infarction were evaluated. WBV was calculated according to the Simone's formula. Results: Patients with an apical thrombus had prolonged pain to balloon time, higher rate of post-PCI thrombolysis in myocardial infarction flow ≤1 and significantly higher mean WBV values at both shear rates than those without an apical thrombus. Conclusion: WBV values at both shear rates were found to be significant and independent predictors for early LV apical thrombus formation complicating a first-ever anterior wall myocardial infarction.

Alteration of hemostatic and hemorheological parameters in Nigerian patients with type 2 diabetes mellitus: Does age play a role?

Background: Diabetes mellitus has been associated with coagulation abnormalities characterized by decreased levels of antithrombin, protein C, increased concentrations of fibrinogen and von Willebrand factor, and alteration of hemorheological indices, which have been linked to the increased hyperviscosity state. The aim of this study was to determine the effect of age on hemostatic and hemorheological parameters in patients with type 2 diabetes mellitus. Materials and Methods: Eighty-four patients of 168 participants, aged 30–69 years, were recruited from the Metabolic Clinic of the University of Maiduguri Teaching Hospital, Borno State between January and December 2018, whereas the remaining 84, age- and sex-matched nondiabetic subjects resident in Maiduguri served as controls. Samples for platelet indices, fibrinogen concentration, hematocrit, relative plasma viscosity (RPV), whole blood viscosity (WBV), protein C, antithrombin, and d-dimer were analyzed using standard techniques. Results: The values of platelet indices, prothrombin time (PT), activated partial thromboplastin time (aPTT), protein C, antithrombin, d-dimer, fibrinogen, hematocrit, and RPV in diabetic patients with respect to different age groups showed no significance (P > 0.05). However, significantly lower levels of protein C, antithrombin and hematocrit, and significantly higher values of d-dimer, fibrinogen, and WBV were observed in patients with diabetes irrespective of the age compared to that of nondiabetic subjects (P < 0.05). Conclusion: Age had no influence on the values of platelet count, platelet indices, PT, aPTT, protein C, antithrombin III, d-dimer, fibrinogen, hematocrit, RPV, and WBV in patients with diabetes. However, patients with type 2 diabetes mellitus could be prone to thrombosis and increased fibrinolytic activity irrespective of their age.