Platelets as Predictors of Vascular Risk: Is There a Practical Index of Platelet Activity?

Association of mean platelet volume and red blood cell distribution width with coronary collateral development in stable coronary artery disease

INTRODUCTION

The prognostic value of hematological indices in cardiovascular diseases and the association between these parameters and cardiovascular conditions have been established in the literature.

AIM

In this study, we aimed to investigate the relation of mean platelet volume (MPV), MPV to platelet ratio (MPR) and red cell distribution width (RDW) with degree of coronary collateral development (CCD) in stable coronary artery disease (CAD) subjects with established critical coronary artery stenosis.

MATERIAL AND METHODS

A total of 306 patients with stable angina pectoris undergoing coronary arteriography were enrolled and divided on the basis of the development of CCD into two groups: a group with adequate CCD (n = 214) and a group with impaired CCD (n = 92). Routine complete blood count and biochemical parameters were measured before coronary arteriography.

RESULTS

The MPV and MPR levels were significantly higher in the inadequate CCD group (10.5 ±1.8 fl vs. 8.7 ±1.9 fl, p < 0.001 and 0.06 ±0.08 vs. 0.05 ±0.07, p = 0.036). Patients with inadequate CCD had significantly higher RDW levels compared to patients with adequate CCD (15.5 ±1.7% vs. 15.0 ±1.9%, p = 0.01). MPV and RDW were significantly associated with Rentrop collateral grading (r = -0.523, p < 0.001 and r = -0.239, p < 0.001, respectively), whereas the association with MPR was not significant. An MPV value greater than 9.95 fl, determined with ROC curve analysis, had 71% sensitivity and 70% specificity in predicting inadequate CCD. An RDW greater than 14.3% has 71% sensitivity and 53% specificity in selecting patients with adequate CCD.

CONCLUSIONS

The present study suggests that MPV and MPR may be associated with the degree of collateral development in chronic stable CAD. However, the negative association of RDW with inadequate CCD, in combination with previous contradictory reports, raises a doubt about the possible value of RDW in stable CAD. Although these parameters may be affected by various conditions, a high MPV may lead clinicians to suspect possible inadequate collateral development in stable CAD patients.

Obstructive Sleep Apnea: From Intermittent Hypoxia to Cardiovascular Complications via Blood Platelets

Obstructive sleep apnea is a chronic condition characterized by recurrent episodes of apneas or hypopneas during sleep leading to intermittent hypoxemia and arousals. The prevalence of the sleep disordered breathing is estimated that almost 50% of men and 24% of women suffer from moderate to severe form of the disorder. Snoring, collapse of upper airways and intermittent hypoxia are main causes of smoldering systemic inflammation in patients suffering from obstructive sleep apnea. The systematic inflammation is considered one of the key mechanisms leading to significant cardiovascular complications. Blood platelets, formerly not even recognized as cells, are currently gaining attention as crucial players in the immune continuum. Platelet surface is endowed with receptors characteristic for cells classically belonging to the immune system, which enables them to recognize pathogens, immune complexes, and interact in a homo- and heterotypic aggregates. Platelets participate in the process of transcellular production of bioactive lipids by delivering both specific enzymes and substrate molecules. Despite their lack of nucleus, platelets synthetize proteins in a stimuli-dependent manner. Atherosclerosis and consequent cardiovascular complications result from disruption in homeostasis of both of the platelet roles: blood coagulation and inflammatory processes modulation. Platelet parameters, routinely evaluated as a part of complete blood count test, were proposed as markers of cardiovascular comorbidity in patients with obstructive sleep apnea. Platelets were found to be excessively activated in this group of patients, especially in obese subjects. Persistent activation results in enhanced spontaneous aggregability and change in cytokine production. Platelet-lymphocyte ratio was suggested as an independent marker for cardiovascular disease in obstructive sleep apnea syndrome and continuous positive air pressure therapy was found to have an impact on platelet parameters and phenotype. In this literature review we summarize the current knowledge on the subject of platelets involvement in obstructive sleep apnea syndrome and consider the possible pathways in which they contribute to cardiovascular comorbidity.

Genetic Variant in Human PAR (Protease-Activated Receptor) 4 Enhances Thrombus Formation Resulting in Resistance to Antiplatelet Therapeutics

OBJECTIVE

Platelet activation after stimulation of PAR (protease-activated receptor) 4 is heightened in platelets from blacks compared with those from whites. The difference in PAR4 signaling by race is partially explained by a single-nucleotide variant in PAR4 encoding for either an alanine or threonine at amino acid 120 in the second transmembrane domain. The current study sought to determine whether the difference in PAR4 signaling by this PAR4 variant is because of biased G_q signaling and whether the difference in PAR4 activity results in resistance to traditional antiplatelet intervention.

APPROACH AND RESULTS

Membranes expressing human PAR4-120 variants were reconstituted with either G_q or G₁₃ to determine the kinetics of G protein activation. The kinetics of G_q and G₁₃ activation were both increased in membranes expressing PAR4-Thr120 compared with those expressing PAR4-Ala120. Further, inhibiting PAR4-mediated platelet activation by targeting COX (cyclooxygenase) and P2Y₁₂ receptor was less effective in platelets from subjects expressing PAR4-Thr120 compared with PAR4-Ala120. Additionally, ex vivo thrombus formation in whole blood was evaluated at high shear to determine the relationship between PAR4 variant expression and response to antiplatelet drugs. Ex vivo thrombus formation was enhanced in blood from subjects expressing PAR4-Thr120 in the presence or absence of antiplatelet therapy.

CONCLUSIONS

Together, these data support that the signaling difference by the PAR4-120 variant results in the enhancement of both G_q and G₁₃ activation and an increase in thrombus formation resulting in a potential resistance to traditional antiplatelet therapies targeting COX-1 and the P2Y₁₂ receptor.

Usefulness of Platelet-to-Lymphocyte Ratio to Predict Long-Term All-Cause Mortality in Patients at High Risk of Coronary Artery Disease Who Underwent Coronary Angiography

Platelet-to-lymphocyte ratio (PLR) has recently been studied as a biomarker in patients with established coronary artery disease (CAD). The association between PLR and long-term all-cause mortality is unclear in patients at high risk of CAD who undergo coronary angiography for various indications. Follow-up was completed for 514 patients who underwent coronary angiography in a prospective study cohort. The primary end point was all-cause mortality. Patients were classified into tertiles based on preangiography PLR and also dichotomized based on the optimal cutoff at a PLR of 137, determined from the receiver operating characteristic curve analysis. The mean follow-up period was 5.0 ± 1.3 years, with 50 all-cause deaths. On the Kaplan-Meier analysis, patients in Tertile 3 (PLR > 145) had worse prognosis than patients in Tertiles 1 (PLR ≤ 106) and 2 (PLR 106.1 to 145) (p = 0.0075), and patients with PLR ≥ 137 had a significantly higher rate of all-cause mortality than those with PLR < 137 (p = 0.0006). On multivariate Cox regression adjusting for known cardiovascular risk factors, PLR was a strong, independent predictor of long-term all-cause mortality on the tertile analysis (Tertile 3 vs Tertile 1: hazard ratio 2.52, 95% confidence interval 1.18 to 5.39, p = 0.017) and based on the cutoff at a PLR of 137 (PLR ≥ 137 vs <137: hazard ratio 2.25, 95% confidence interval 1.21 to 4.20, p = 0.011). In conclusion, elevated PLR is associated with long-term all-cause mortality in patients at high risk of CAD who undergo coronary angiography, and PLR may be a useful prognostic biomarker in this population.

High red cell distribution width at the time of ST segment elevation myocardial infarction is better at predicting diastolic than systolic left ventricular dysfunction: A single-center prospective cohort study

Multiple studies have demonstrated the association of red cell distribution width (RDW) with the ultrasound parameters of both systolic and diastolic heart dysfunction. We aimed to further investigate the clinical associations of RDW in the setting of ST-elevation myocardial infarction (STEMI) and to comparatively evaluate its predictive properties regarding systolic and diastolic dysfunction.A total of 89 patients with STEMI were prospectively analyzed. RDW was obtained at the time of STEMI and compared to the parameters of systolic and diastolic dysfunction obtained by transthoracic heart ultrasound on the 5th through 7th day post-STEMI.The median RDW was 13.9%, and among other factors, RDW was significantly associated with older age (P < .001), arterial hypertension (P = .017), hyperlipoproteinemia 2, nonsmoking (P = .027), increased thrombolysis in myocardial infarction score (P = .004), and multivessel disease (P = .007). A higher RDW was observed in patients with parameters that indicated systolic and diastolic dysfunction (ejection fraction of the left ventricle < 50% [P = .009], early/late diastolic filling wave ratio [E/A] < 1 [P = .001], ratio of peak early transmitral velocity and early diastolic annular velocity [E/E'] >10 [P < .001], and combined E/A < 1 and E/E' > 10 [P < .001]). The best discriminatory properties were observed for combined E/A < 1 and E/E' > 10. RDW remained significantly associated with the aforementioned parameters in a series of multivariate regression models.Elevated RDW is significantly associated with the parameters of systolic and diastolic dysfunction even after adjusting for several confounding factors in the setting of STEMI and subsequent percutaneous coronary intervention. RDW seems to be better at discriminating patients with diastolic rather than systolic dysfunction.

The association between mean platelet volume and inflammation in geriatric patients with emergency hypertension

Objectives

We aimed to investigate the role of inflammation parameters and platelet activation in geriatric patients with hypertension. Therefore, we compared the levels of those parameters in patients with hypertensive urgency and emergency. We also investigated the potential relationship between those parameters.

Methods

Ninety-six hypertensive (HT) patients (aged > 60) were included in the study in two groups: HT emergency (N = 48, group 1) and HT urgency (N = 48, group 2). Mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (NLR) and high-sensitive C reactive protein (hs-CRP) were compared between those groups. Optimum cut-off levels of each parameter were determined by the use of Receiver operating characteristic (ROC) curve analysis. Pearson correlation test was used to examine the relationship between variables.

Results

The mean MPV and hs-CRP levels were significantly higher in patients with HT emergencies (both P < 0.001). Mean NLR was also significantly different between the two groups (P = 0.011). Pearson correlation analysis revealed a positive but weak correlation between the MPV and NLR (r = 0.245, P = 0.016), the hs-CRP level (r = 0.394, P < 0.001), and the WBC count (r = 0.362, P < 0.001).

Conclusion

Increased platelet activity and inflammation are associated with the end organ failure. Levels of MPV and other inflammatory parameters may be useful in the management of geriatric patients with HT.

Utility of Hematological Parameters in Predicting No-Reflow Phenomenon After Primary Percutaneous Coronary Intervention in Patients With ST-Segment Elevation Myocardial Infarction

Objective:

Because the no-reflow phenomenon in patients with ST- segment elevation myocardial infarction can lead to poor outcomes and early identification of patients at high risk may alter the clinical outcome, we aimed to study possible differences in the predictive utility among hematological parameters for early identification of patients at high risk of the no-reflow phenomenon during the primary percutaneous coronary intervention.

Methods:

A total of 612 patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention were enrolled. The patients were divided into 2 groups: no-reflow and normal reflow. Hematological parameters were measured on admission. Sensitivity, specificity, positive and negative predictive values, and receiver–operating characteristic areas under the curve were determined to evaluate the predictive values of these parameters.

Results:

The patients in the no-reflow group had a significantly higher neutrophil count, neutrophil–lymphocyte ratio, platelet–lymphocyte ratio, and mean platelet volume-to-lymphocyte ratio when compared to the normal reflow patients. We identified mean platelet volume-to-lymphocyte ratio to have a moderate predictive value and high specificity (66.8%) for the no-reflow phenomenon. Neutrophil–lymphocyte ratio provided the largest area under the curve for predicting no reflow. Regarding the predictive utility for no reflow, the comparison showed no statically significant differences among evaluated hematological parameters.

Conclusion:

For the prediction of no reflow, mean platelet volume-to-lymphocyte ratio yielded moderate performance. No hematological parameter on admission had persuasive superior capacities to predict no-reflow in patients receiving the primary percutaneous coronary intervention.

Relationship between monocytes to lymphocytes ratio and axial spondyloarthritis

BACKGROUND

Axial spondyloarthritis (axSpA) is a progressive, chronic, inflammatory skeletal disorder affecting the spine and sacroiliac joints. Many studies have shown that neutrophils, lymphocytes, monocytes, platelets, and red blood cells (RBCs) play important roles in the inflammatory process of axSpA. Neutrophils to lymphocytes ratio (NLR) and red blood cell distribution width (RDW) have been reported to be simple and inexpensive markers to indicate the disease activity of axSpA. However, the role of monocytes to lymphocytes ratio (MLR) and platelets to lymphocytes ratio (PLR) in axSpA was rarely mentioned.

OBJECTIVE

The study's aim was to determine the role of MLR and PLR in axSpA patients and to investigate their relationships with disease severity.

METHODS

AxSpA patients who fulfilled the Assessment in Ankylosing Spondylitis International Society classification criteria published in 2009 were enrolled in this study and divided into nonradiographic axial spondyloarthritis (nr-axSpA) group and ankylosing spondylitis (AS) group. Healthy age and gender-matched subjects were also enrolled as control group. MLR, PLR, NLR, RDW, C-reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR) level were assessed. The correlation between the variables with finger-to-floor distance, Modified Schober test, and occiput-to-wall distance were tested with Pearson correlation. Furthermore, area under curve (AUC) value, sensitivity, specificity, and the optimal cutoff values were determined using receiver operating characteristic (ROC) curves.

RESULTS

A total of 148 axSpA patients (67 nr-axSpA patients and 81 AS patients) and 58 healthy subjects were included in the study. The MLR, NLR, PLR, and RDW in axSpA group were higher than those in the control group (P < 0.05). Among them, MLR and RDW were highly increased in AS group compared with the nr-axSpA group (P < 0.05). MLR, NLR, PLR, and RDW were all positively correlated with ESR level and CRP level (P < 0.05). MLR and RDW were positively correlated with finger-to-floor distance and negatively correlated with Modified Schober test (P < 0.05). RDW was positively correlated with occiput-to-wall distance (P < 0.05). ROC curve results showed MLR yielded a higher AUC than NLR, PLR, and RDW (P < 0.05). In addition, the optimal cutoff value of MLR for axSpA was 0.22, with a specificity of 70.9% and sensitivity of 68.4%.

CONCLUSIONS

MLR was elevated in AS patients compared to nr-axSpA patients and had a close relationship with CRP level, ESR level, and spine movements. MLR may be a reliable, cost-effective, and novel potential parameter to evaluate disease severity in axSpA.

The Relationship Between Mean Platelet Volume and Fasting Plasma Glucose and HbA1c Levels in a Large Cohort of Unselected Health Check-Up Participants

Background

Larger platelets are more active and mean platelet volume (MPV) is an indicator of platelet activation and an independent risk factor of cardiovascular diseases. While MPV is reported to be higher in diabetic patients, the relationship between MPV and glycemic parameters in general population remains inconclusive.

Methods

In this cross-sectional study, we studied relationship between MPV and fasting plasma glucose (FPG) and HbA1c levels in 38,204 unselected participants of general health check-up aged 20 years or older in the year of 2014 who were considered to be representative of the general population. Individuals with known diabetes, coronary artery disease and/or cerebrovascular disease who were on drug therapy and those with platelet counts below 100 × 10⁹/L or above 400 × 10⁹/L were excluded.

Results

The mean age of the individuals was 52.3 ± 12.1 years and 46.1% were male. There were positive associations between MPV and both FPG (r = 0.066; P < 0.001) and HbA1c (r = 0.025; P < 0.001) levels when all individuals were analyzed as a whole. While the association was only marginal in individuals with HbA1c levels below 6.5% (r = 0.009; P = 0.068), it was significant in those with HbA1c ≥ 6.5% (r = 0.138; P < 0.001). When the individuals were categorized into four groups according to the HbA1c values: HbA1c < 5.5%, 5.5% ≤ HbA1c < 6.0%, 6.0% ≤ HbA1c < 6.5%, and HbA1c ≥ 6.5%, the mean MPV was virtually same among groups with HbA1c level < 6.5% and that of the individuals with HbA1c ≥ 6.5 was significantly higher than groups with lower HbA1c levels. Multivariate analyses adjusted with age and sex showed the same results.

Conclusion

FPG and HbA1c appeared to be associated with MPV in unselected health check-up participants; however, the association between glycemic state and MPV was apparent only in individuals with impaired glycemic control and only marginal in those with normal glycemic control. The clinical significance of the associations warrants further study.

Platelet-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio, and platelet indices in patients with acute deep vein thrombosis

BACKGROUND

Inflammation is associated with an increased risk of thrombotic events and complete blood count (CBC) is an easily measured test. The purpose of this study was to evaluate the value of CBC relative parameters including mean platelet volume (MPV), platelet-to-lymphocyte ratio (PLR), mean platelet volume-to-lymphocyte ratio (MPVLR), and neutrophil-to-lymphocyte ratio (NLR) for patients with acute deep vein thrombosis (DVT).

PATIENTS AND METHODS

A total of 115 patients with unprovoked DVT of the lower extremities and 105 controls were recruited in this study. Blood samples were drawn from all participants to obtain the concentrations of CBCs and D-dimers.

RESULTS

MPVs (P = 0.044), PLRs (P = 0.005), MPVLRs (P = 0.001), and NLRs (P < 0.0001) were significantly higher in acute DVT patients compared to controls. The MPV was inversely correlated with platelet count (P < 0.0001) and the NLR was positively associated with D-dimers (P = 0.002) and the PLR (P < 0.0001). Notably, on multivariate logistic regression analysis, NLRs and D-dimers were independent risk factors of acute DVT (OR: 1.889, P = 0.024; OR: 1.009, P < 0.0001, respectively).

CONCLUSIONS

MPV, PLR, MPVLR, and NLR have potential diagnostic values for patients with unprovoked DVT. NLR is an independent risk factor related to DVT.

Could Platelet Indices and Neutrophil to Lymphocyte Ratio Be New Biomarkers for Differentiation of Arteritic Anterior Ischemic Neuropathy from Non-Arteritic Type?

The aim of this study was to assess the possible relationship between AAION (arteritic anterior ischemic optic neuropathy) and NAION (non-arteritic anterior ischemic optic neuropathy) with blood platelet parameters and NLR (neutrophil-to-lymphocyte ratio). The medical records of 12 patients with AAION, 33 patients with NAION, and 35 healthy subjects were examined. MPV, PDW, and PCT values showed marked elevation in AAION and NAION groups compared with control group. The mean NLR was statistically significantly higher only in AAION group compared to the NAION and control groups, suggesting that platelet function plays an important role in AIONs and NLR might be used to differentiate AAION from NAION.

Association between platelet distribution width and poor outcome of acute ischemic stroke after intravenous thrombolysis

PURPOSE

The platelet distribution width (PDW) reflects the status of platelet activity and may be useful for early predictions of the clinical outcome of stroke patients. The purpose of the study was to determine the associations between PDW and clinical outcomes after intravenous thrombolysis in stroke patients.

PATIENTS AND METHODS

Acute ischemic stroke patients who received intravenous treatment with recombinant tissue-type plasminogen activator were selected for inclusion in the retrospective cohort of this study. The relations between PDW at admission and clinical outcomes were analyzed, including a poor outcome as assessed using the modified Rankin Scale at 3 months, early neurological improvement, and any hemorrhage. The effect of PDW at admission on a poor outcome at 3 months was analyzed using a multivariable logistic regression model with adjustment for potential confounders. The optimal PDW cutoff for predicting poor outcome at 3 months was determined by analyzing the receiver operating characteristics curve.

RESULTS

PDW was significantly higher for a good outcome than a poor outcome (p=0.005), with median (interquartile range) values of 16.2 (13.2-17.2) and 13.6 (12.5-15.9), respectively. PDW was also higher in patients with early neurological improvement than in patients without improvement (p=0.020) and did not differ between hemorrhage and nonhemorrhage patients. The association between PDW <16.05% and poor outcome remained in a multivariable logistic regression analysis, with an OR of 6.68 and a 95% CI of 1.69-26.49 (p=0.007).

CONCLUSION

Results suggest a novel hypothesis that a lower PDW may be related with a poor outcome at 3 months after intravenous thrombolysis in acute ischemic stroke patients.

Can mean platelet volume and neutrophil-to-lymphocyte ratio be biomarkers of acute exacerbation of bronchiectasis in children?

Introduction

Bronchiectasis (BE) is a parenchymal lung disease evolving as a result of recurrent lung infections and chronic inflammation. Although it has been shown in adult studies that mean platelet volume (MPV) and neutrophil-to-lymphocyte ratio (NLR) can be used as biomarkers of airway inflammation, knowledge is limited in the paediatric age group. The aim of our study is to investigate the potential of MPV and NLR as biomarkers that may indicate acute exacerbations of non-cystic fibrosis BE in children.

Material and methods

Children with non-cystic fibrosis BE (n = 50), who were followed in the division of Paediatric Pulmonology of our hospital between June 2010 and July 2015, were involved in the present retrospective cross-sectional study. Haemogram values during acute exacerbations and non-exacerbation periods, and a control group were compared.

Results

In children with bronchiectasis, the average leukocyte count (p < 0.001), platelet count (p = 0.018), absolute neutrophil count (p < 0.001), and NLR (p < 0.001) were higher, as expected, when compared with the control group. NLR values, in the period of acute exacerbation were significantly higher than the values of both the non-exacerbation periods (p = 0.02) and the control group (p < 0.001). In contrast, MPV values in the period of acute exacerbation did not exhibit a significant difference from those of non-exacerbation periods (p = 0.530) and the control group (p = 0.103).

Conclusions

It was concluded that leukocyte count, platelet count, absolute neutrophil count, and NLR can be used to show chronic inflammation in BE, but only NLR and absolute neutrophil count can be used as biomarkers to show acute exacerbations.

Evaluation of the coronary flow by the coronary clearance time in patients with cardiac syndrome X

Objective

The vessels involved in the microcirculation are too small to be visualized by conventional angiography and no tools are currently available that can directly evaluate the coronary microcirculation. This study evaluated the coronary clearance frame count (CCFC) in patients with cardiac syndrome X (CSX).

Methods

The retrospective study enrolled patients with angina, who had a positive nuclear imaging test and normal coronary angiography; and a control group consisting of patients who underwent an angiogram to exclude coronary artery disease. Thrombosis in myocardial infarction frame count (TFC) and CCFC for each coronary artery (left anterior descending coronary artery [LAD], circumflex coronary artery [CFX] and right coronary artery [RCA]) were calculated offline.

Results

A total of 71 patients with CSX and 61 control patients were enrolled in the study. No significant differences were found between the two groups regarding the baseline demographic and clinical variables. The TFC of LAD, CFX and RCA were similar between the two groups. The mean CCFC-LAD, CCFC-CFX and CCFC-RCA were significantly longer in the CSX group compared with the control group.

Conclusion

CCFC is a simple, quantitative and highly reproducible method that might be used as a marker of coronary microvascular dysfunction.

A pilot study evaluating the prognostic utility of platelet indices in dogs with septic peritonitis

OBJECTIVE

To characterize platelet indices at time of diagnosis of septic peritonitis in dogs and to assess the relationship between platelet parameter data and survival to discharge in dogs treated surgically.

DESIGN

Retrospective, observational, descriptive pilot study from 2009 to 2014.

SETTING

University teaching hospital.

ANIMALS

Forty-eight dogs diagnosed with septic peritonitis were included in this study. Thirty-six dogs had surgical source control. Blood samples from 46 healthy control dogs were used for reference interval (RI) generation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Dogs with septic peritonitis had significantly increased mean values for mean platelet volume (MPV), plateletcrit (PCT), and platelet distribution width (PDW) with increased proportions of dogs having values above the RI compared to healthy dogs. A significantly increased proportion of dogs with septic peritonitis had platelet counts above (12.5%) and below (8.3%) the RI, with no significant difference in mean platelet count compared to healthy dogs. No significant differences in the mean platelet count, MPV, PCT, or PDW were found between survivors and nonsurvivors in dogs with surgical source control; however, dogs with MPV values above the RI had significantly increased mortality compared to dogs within the RI (P = 0.025). Values outside the RI for other platelet parameters were not associated with significant differences in mortality.

CONCLUSIONS

Dogs with septic peritonitis have increased frequency of thrombocytosis and thrombocytopenia with increased MPV, PCT, and PDW. An increased MPV may be a useful indicator of increased risk of mortality in dogs treated surgically.

Thrombin induced platelet-fibrin clot strength in relation to platelet volume indices and inflammatory markers in patients with coronary artery disease

Platelet aggregation and inflammation are both implicated in coronary artery disease (CAD). Thrombin induced platelet-fibrin clot strength (MA_Thrombin) measured by thrombelastography (TEG) has been proved to be a novel marker of platelet aggregation. The aim of this study was to investigate the correlation of MA_Thrombin to platelet volume indices (PVIs) or to inflammatory markers in different types of CAD. 206 patients with different types of CAD were enrolled. MA_Thrombin, PVIs, including mean platelet volume (MPV), platelet distribution width (PDW), and platelet-large cell ratio (P-LCR) as well as inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP) and fibrinogen (Fbg) were measured. Multiple linear regression models were used to analyze the association between MA_Thrombin, PVIs, and inflammatory markers. MA_Thrombin and inflammatory markers both varied with CAD types (P<0.001). MA_Thrombin was correlated to PVIs in NSTEMI individuals (MPV, r=0.393, P=0.007; PDW, r=0.334, P=0.023; P-LCR, r=0.382, P=0.008), but had inner-link with inflammatory markers in STEMI cases (hs-CRP, r=0.499, P<0.001; Fbg, r=0.500, P<0.001). These findings may suggest different mechanisms of platelet aggregation in different types of CAD. Moreover, MA_Thrombin may be used as a potential parameter to evaluate platelet aggregation and inflammation together.

The potential role of endothelial dysfunction and platelet activation in the development of thrombotic risk in COPD patients

INTRODUCTION

Despite lack of knowledge in the field, several studies have underlined the role of endothelium dysfunction and platelet activation as significant players in the development and progression of chronic obstructive pulmonary disease (COPD). Indeed, endothelium plays a crucial role in vascular homeostasis and impairment, due to the inflammation process enhanced by smoking. Chronic inflammation and endothelial dysfunction have been proved to drive platelet activity. Consequently, thrombotic risk is enhanced in COPD, and might explain the higher percentage of cardiovascular death in such patients. Areas covered: This review aims to clarify the role of endothelium function and platelet hyper-activity as the pathophysiological mechanisms of the increased thrombotic risk in COPD. Expert commentary: In COPD patients, chronic inflammation does not impact only on lung parenchyma, but potentially involves all systems, including the endothelium of blood vessels. Impaired endothelium has several consequences, such as reduced vasodilatation capacity, enhanced blood coagulation, and increased platelet activation resulting in higher risk of thrombosis in COPD patients. Endothelium dysfunction and platelet activation are potential targets of therapy in patients with COPD aiming to reduce their risk of cardiovascular events.

Focusing on a complete blood cell parameter: mean platelet volume levels may be a predictor of coronary slow flow

Background

The relationship between increased mean platelet volume (MPV) and atherosclerosis is well known. In the present study, MPV in patients with coronary slow flow (CSF) and in cases with normal coronary anatomy (NCA) was investigated and compared with the aim of identifying the relationship between CSF and MPV.

Patients and methods

We studied 40 patients previously determined via coronary angiography as having NCA and 40 patients with CSF in the coronary blood stream, as identified by thrombolysis in myocardial infarction square. Thus, a total of 80 patients from the Elaziğ Education and Research Hospital (Elaziğ, Turkey) were included in the present study retrospectively and laboratory and anamnesis information was scanned into their files. The relationship between MPV and CSF was studied.

Results

MPV levels were observed to be significantly higher in the CSF group compared to the NCA group (10.05±1.3 and 8.6±0.6, p<0.001). In receiver operating characteristics analyses, it was determined that an MPV >9.05 measured in CSF patients at application had a predictive specificity of 77.5% and sensitivity of 77.5% for CSF (area under the curve: 0.825, 95% confidence interval [CI]: 0.726–0.924, p<0.0001). It was found that MPV level was an independent predictor of CSF (β=−600, p<0.001, 95% CI: −0.383 to −0.176).

Conclusion

MPV is increased in patients with CSF when compared to patients with NCA. This finding supports the fact that MPV could be a predictor of CSF.

Platelet reactivity and mean platelet volume as risk markers of thrombogenesis in atrial fibrillation

Atrial fibrillation (AF) is associated with increased risk of thromboembolic complications. One of the markers of the increased risk of hypercoagulable state is platelet hyperreactivity. The aim of the study was to assess impact of arrhythmia on platelet reactivity.

METHODS

The study included 36 (mean age 48,3; range 21-60) male patients with lone atrial fibrillation, with exclusion of concomitant diseases known to trigger hypercoagulable state. The AF patients underwent cardioversion to restore sinus rhythm and were subsequently under observation for 1month. Echocardiography, ECG and blood collection was performed before cardioversion (T0) and 4weeks after successful cardioversion (T1). During the study period patients have been contacted and examined every week and 24h ECG monitoring was performed. Platelet reactivity was assessed based on changes of CD62 and CD42b expression on platelet surface after stimulation with thrombin. Also changes in MPV were assessed.

RESULTS

In all patients sinus rhythm was maintained at the end of the study period, however in 14 patients recurrences of AF were observed, confirmed by 24h ECG monitoring (atrial fibrillation recurrence group - AFR) and 22 patients maintained sinus rhythm throughout the whole study period (SR group). Mean fluorescence intensity (MFI) of CD62 on thrombin stimulated platelets decreased significantly 4weeks after electrical cardioversion as compared to T0 (48.04±22.42 vs 41.47±16.03; p<0.01). Also MFI of CD42b on thrombin stimulated platelets decreased significantly 4weeks after electrical cardioversion as compared to T0 (22.16±10.82 vs 12.06±5.99; p<0.0001). Platelets reactivity estimated by CD 62 expression in SR group decreased significantly after 4weeks observation (58.01±15.26 vs 46.57±13.44; p<0.001) opposite to AFR group 35.66±21.87 vs 34.54±16.4; p-ns). Moreover there were significant differences between basal reactivity during AF between SR and AFR groups (58.01±15.26 vs 35.66±21.87; p-0.01). MFI of CD42b on thrombin stimulated platelets decreased significantly both in AFR and SR groups (22.05±11.36 vs 13.8±6.03; p<0.001 and 21.87±14.18 vs 10.04±5.09; p<0005). MPV decreased significantly 4weeks after electrical cardioversion as compared to T0 (8.81±0.19 vs 8.42±0.14; p<0.0001).

CONCLUSION

The changes of platelet reactivity to thrombin observed after restoration of sinus rhythm in patients prove that arrhythmia intrinsically leads to increased reactivity of platelets.

Hypoxia and inflammation indicate significant differences in the severity of obstructive sleep apnea within similar apnea-hypopnea index groups

PURPOSE

We determined whether hypoxia parameters are associated with C-reactive protein (CRP), mean platelet volume (MPV), white matter hyperintensity (WMH), and the severity of obstructive sleep apnea (OSA), and also evaluated whether hypoxia parameters, CRP, MPV, and WMH differ in patients with similar apnea-hypopnea index (AHI) scores.

METHODS

A total of 297 patients, who were evaluated using polysomnography, were assessed retrospectively. The measured hypoxia parameters included total sleep time with oxygen saturation <90% (ST₉₀), percentage of cumulative time with oxygen saturation <90% (CT₉₀), and lowest oxygen saturation (min SaO₂). The patients were divided into subgroups according to their CT₉₀ values, and patients with different AHI severities were divided into subgroups according to their ST₉₀ and min SaO₂ levels.

RESULTS

Hypoxia parameters are associated with CRP, MPV, WMH, and the severity of OSA (P < 0.05). The hypoxia parameters differed in all subgroup analyses of similar AHI groups (P < 0.001), and CRP differed only in severe OSA (P < 0.008, P < 0.001). In subgroup analyses of similar AHI groups, MPV and WMH were not significantly different (P > 0.05). Above the hypoxia threshold (CT₉₀ ≥ 10%) of CRP, MPV increased significantly and the presence of WMH increased twofold.

CONCLUSIONS

These data suggest that increased hypoxia severity may mediate increased inflammation and activation of platelets and contribute to the pathogenesis of WMH in patients with OSA. In addition, patients with severe OSA may show significant variability in inflammation and vascular risk. Further prospective data are needed.

Development of Atherosclerotic Cardiovascular Mortality in Gouty Arthritis and Rheumatoid Arthritis Patients: Are They Associated With Mean Platelet Volume and Neutrophil-Lymphocyte Ratio? A Comparative Study

Objectives

This study aims to evaluate the mean platelet volume (MPV) and neutrophil-lymphocyte ratio (NLR) in gouty arthritis (GA) and rheumatoid arthritis (RA) patients, as well as their relationship with atherosclerotic cardiovascular mortality (ACVM).

Patients and methods

The study included 122 GA patients (96 males, 26 females; mean age 64.6±13.4 years; range 34 to 82 years), 82 RA patients (40 males, 42 females; mean age 62.1±12.1 years; range 29 to 83 years), and 61 healthy controls (34 males, 27 females; mean age 65.3±4.8 years; range 33 to 80 years). Clinical and ACVM data were obtained from medical charts. Erythrocyte sedimentation rate, C-reactive protein, MPV, and NLR were recorded at the time of diagnosis and one month after therapy.

Results

Mean platelet volume in GA (8.49±1.5) and RA (7.98±0.99) groups were significantly lower than in healthy controls (9.8±15) (p<0.001). NLR in healthy controls (1.9±0.74) was significantly lower than in GA (3.6±2.3) and RA (3.7±2.5) groups (p<0.001). After treatment, MPV did not change significantly in GA and RA groups (p values >0.05); however, NLR decreased in both groups (p<0.001). Nine GA and 12 RA patients died from ACVM during follow-up. GA patients with ACVM were older and had more frequent hypertension, higher MPV, and higher intercritical CRP level. In multivariate analysis, MPV was an independent poor prognostic factor for ACVM in GA patients.

Conclusion

Gouty arthritis and RA patients had significantly lower MPV and significantly higher NLR than controls. MPV might be used as a potential biomarker for the development of ACVM in GA.

An Increase in Mean Platelet Volume/Platelet Count Ratio Is Associated with Vascular Access Failure in Hemodialysis Patients

After stenosis of arteriovenous vascular access in hemodialysis patients, platelets play a crucial role in subsequent thrombus formation, leading to access failure. In a previous study, the mean platelet volume (MPV)/platelet count ratio, but not MPV alone, was shown to be an independent predictor of 4-year mortality after myocardial infarction. However, little is known about the potential influence of MPV/platelet count ratio on vascular access patency in hemodialysis patients. A total of 143 patients undergoing routine hemodialysis were recruited between January 2013 and February 2016. Vascular access failure (VAF) was defined as thrombosis or a decrease of greater than 50% of normal vessel diameter, requiring either surgical revision or percutaneous transluminal angioplasty. Cox proportional hazards model analysis ascertained that the change of MPV/platelet count ratio between baseline and 3 months [Δ(MPV/platelet count ratio)_3mo-baseline] had prognostic value for VAF. Additionally, the changes of MPV/platelet count ratio over time were compared in patients with and without VAF by using linear mixed model analysis. Of the 143 patients, 38 (26.6%) were diagnosed with VAF. During a median follow-up of 26.9 months (interquartile range 13.0–36.0 months), Δ(MPV/platelet count ratio)_3mo-baseline significantly increased in patients with VAF compared to that in patients without VAF [11.6 (6.3–19.0) vs. 0.8 (-1.8–4.0), P< 0.001]. In multivariate analysis, Δ(MPV/platelet ratio count)_3mo-baseline was an independent predictor of VAF, after adjusting for age, sex, diabetes, hypertension, coronary artery disease, cerebrovascular disease, vascular access type, the presence of previous VAF, and antiplatelet drug use (hazard ratio, 1.15; 95% confidence interval, 1.10–1.21; P< 0.001). Moreover, a liner mixed model revealed that there was a significant increase of MPV/platelet count ratio over time in patients with VAF compared to those without VAF (P< 0.001). An increase in MPV/platelet count ratio over time was an independent risk factor for VAF. Therefore, continuous monitoring of the MPV/platelet count ratio may be useful to screen the risk of VAF in patients undergoing routine hemodialysis.

Platelet to lymphocyte ratio in the prediction of adverse outcomes after acute coronary syndrome: a meta-analysis

Recent studies have shown platelet to lymphocyte ratio (PLR) to be a potential inflammatory marker in cardiovascular diseases. We performed a meta-analysis to systematically evaluate the prognostic role of PLR in acute coronary syndrome (ACS). A comprehensive literature search up to May 18, 2016 was conducted from PUBMED, EMBASE and Web of science to identify related studies. The risk ratio (RR) with 95% confidence interval (CI) was extracted or calculated for effect estimates. Totally ten studies involving 8932 patients diagnosed with ACS were included in our research. We demonstrated that patients with higher PLR level had significantly higher risk of in-hospital adverse outcomes (RR = 2.24, 95%CI = 1.81–2.77) and long-term adverse outcomes (RR = 2.32, 95%CI = 1.64–3.28). Sensitivity analyses confirmed the stability of our results. We didn’t detect significant publication bias by Begg’s and Egger’s test (p > 0.05). In conclusion, our meta-analysis revealed that PLR is promising biomarker in predicting worse prognosis in ACS patients. The results should be validated by future large-scale, standard investigations.

Mean platelet volume: a potential biomarker of the risk and prognosis of heart disease

Platelets are essential for progression of atherosclerotic lesions, plaque destabilization, and thrombosis. They secrete and express many substances that are crucial mediators of coagulation, inflammation, and atherosclerosis. Mean platelet volume (MPV) is a precise measure of platelet size, and is routinely reported during complete blood count analysis. Emerging evidence supports the use of MPV as a biomarker predicting the risk of ischemic stroke in patients with atrial fibrillation, and as a guide for prescription of anticoagulation and rhythm-control therapy. In addition, MPV may predict the clinical outcome of percutaneous coronary intervention (PCI) in patients with coronary artery disease and indicate whether additional adjunctive therapy is needed to improve clinical outcomes. This review focuses on the current evidence that MPV may be a biomarker of the risk and prognosis of common heart diseases, particularly atrial fibrillation and coronary artery disease treated via PCI.

Blood count parameters can predict the severity of coronary artery disease

BACKGROUND/AIMS

Because of the inflammatory nature of coronary artery disease (CAD), both platelets and white blood cells have been investigated for years. The aim of this study was to investigate the relationships between some prominently hematologic blood count parameters (mean platelet volume [MPV], neutrophil to lymphocyte ratio [NLR]) and the severity of CAD by using Gensini scores.

METHODS

A total of 194 patients, who had undergone coronary angiography, enrolled in this study. The control group consisted of 42 patients who had normal coronary arteries. Remaining CAD patients were divided into two groups according to their Gensini scores.

RESULTS

NLR and MPV were higher in the severe atherosclerosis group compared with the mild atherosclerosis group (p = 0.007, p = 0.005, respectively). The Gensini score showed significant correlations with NLR (r = 0.20, p = 0.011), MPV (r = 0.23, p = 0.004) and high density lipoprotein cholesterol (r = -0.161, p = 0.047). Using a cut-off level of 2.54, NLR predicted severe atherosclerosis with a sensitivity of 74% and specificity of 53% (area under curve [AUC], 0.627; 95% confidence interval [CI], 0.545 to 0.704; p = 0.004). MPV values above 10.4 predicted severe atherosclerosis with a sensitivity of 39% and specificity of 90% (AUC, 0.631; 95% CI, 0.549 to 0.708; p = 0.003). In the multiple logistic regression analysis, high levels of NLR (odds ratio [OR], 1.450; 95% CI, 1.080 to 1.945; p = 0.013) and MPV (OR, 1.622; 95% CI, 1.147 to 2.295; p = 0.006) were found to be independent predictors of severe atherosclerosis.

CONCLUSIONS

Our study suggests that both NLR and MPV are predictors of severe atherosclerosis and may be used for the prediction and identification of cardiac risks in CAD patients.

Mean platelet volume-to-lymphocyte ratio: a novel marker of poor short- and long-term prognosis in patients with diabetes mellitus and acute myocardial infarction

INTRODUCTION

Platelet activation and hyperreactivity plays a pivotal role in developing intravascular thrombus in ST elevation myocardial infarction (STEMI). Mean platelet volume (MPV), which is readily available in clinical settings, has been linked to poor prognosis following STEMI. Recently, platelet-to-lymphocyte ratio (PLR) has emerged as a new marker of worse outcomes linking inflammation and thrombosis. We investigated the prognostic significance of the new marker, MPVLR, in diabetic patients with STEMI undergoing percutaneous coronary intervention (PCI).

METHODS

A total of 623 patients with diabetes mellitus and STEMI undergoing primary PCI were enrolled and divided based on the median MPVLR on admission into two groups: group 1 (N=266) with an MPVLR ≤4.46 and group 2 (N=257) with an MPVLR >4,46.

RESULTS

Despite similar clinical features patients with elevated MPVLR (group 2) had worse angiographic characteristic suggestive of a higher thrombus burden. In-hospital and one-year mortality was higher in group 2. ROC analysis revealed moderate diagnostic value in predicting in-hospital mortality (adjusted HR 1.13; 95% CI 1.04-1.23; P=0.003; MPVLR cut-off >6.13) similar to that of PLR a good diagnostic value in predicting long-term mortality (adjusted HR 1.52; 95% CI 1.42-1.63; P<0.0001; MPVLR cut-off >5.88) better than that of PLR. MPVLR remained an independent risk factor of early and late mortality.

CONCLUSIONS

To the best of our knowledge, this is the first ever study that has investigated MPVLR. Despite similar clinical characteristics, patients with elevated MPVLR had worse angiographic features which may indicate a greater thrombus burden. Elevated MPVLR is an independent risk factor of early and late mortality following STEMI. In addition, it has similar value to PLR in predicting in-hospital mortality, and a better value than PLR in predicting long-term mortality.

Can mean platelet volume be used as a biomarker for asthma?

Introduction

Platelets play important roles in airway inflammation and are activated in inflammatory lung diseases, including asthma.

Aim

We evaluated the mean platelet volume (MPV), used as a marker of platelet activation, in asthmatic patients during asymptomatic periods and exacerbations compared to healthy controls to determine whether MPV can be used as an indicator of inflammation.

Material and methods

Our patient group consisted of 95 children with exacerbation of asthma who were admitted to our allergy clinic. The control group consisted of 100 healthy children matched for age, gender, and ethnicity. Mean platelet volume values of the patient group obtained during exacerbation of asthma were compared to those of the same group during the asymptomatic period and with the control group. We investigated factors that can affect the MPV values of asthma patients, including infection, atopy, immunotherapy treatment, and severity of asthma exacerbation.

Results

The patient group consisted of 50 (52.6%) boys and 45 (47.4%) girls with a mean age of 125 ±38 months old. Mean MPV values in the exacerbation period, the healthy period, and in the control group were 8.1 ±0.8 fl, 8.1 ±1.06 fl, and 8.2 ±0.9 fl, respectively; there were no significant differences between groups (p > 0.05). The severity of asthma, severity of asthma exacerbation, immunotherapy, coinfection, eosinophil count, and IgE level also had no effect on MPV (p > 0.05).

Conclusions

Although platelets play a role in the pathophysiology of asthma, MPV measurement is insufficient to detect inflammation through platelets.

Altered mean platelet volume in patients with polymyositis and its association with disease severity

Polymyositis (PM) is an autoimmune disease characterized by chronic inflammation in skeletal muscle. Mean platelet volume (MPV), a marker in the assessment of systemic inflammation, is easily measured by automatic blood count equipment. However, to our knowledge, there are no data in the literature with respect to MPV levels in PM patients. Therefore, in this study we aimed to investigate MPV levels in patients with PM. This study included 92 newly diagnosed PM patients and 100 healthy individuals. MPV levels were found to be significantly lower compared with healthy controls (10.3±1.23 vs 11.5±0.74 fL, P<0.001). Interestingly, MPV was found to be positively correlated with manual muscle test (MMT) score and negatively correlated with erythrocyte sedimentation rate (ESR) in patients with PM (r=0.239, P=0.022; r=-0.268, P=0.010, respectively). In addition, MPV was significantly lower in active PM patients compared with inactive PM patients (9.9±1.39 vs 10.6±0.92 fL, P=0.010). MPV was independently associated with PM in multivariate regression analyses, when controlling for hemoglobin and ESR (OR=0.312, P=0.031, 95%CI=0.108 to 0.899). The ROC curve analysis for MPV in estimating PM patients resulted in an area under the curve of 0.800, with sensitivity of 75.0% and specificity of 67.4%. Our results suggest that MPV is inversely correlated with disease activity in patients with PM. MPV might be a useful tool for rapid assessment of disease severity in PM patients.

Platelet-Mediated Thrombosis

The pivotal role that platelets play in thrombosis and resultant ischemic event occurrences in patients with high-risk coronary artery disease is well established. This role provides the fundamental basis for the current wide implementation of dual antiplatelet therapy with aspirin and a P2Y 12 receptor inhibitor. The development of user friendly point-of-care methods to assess platelet reactivity to adenosine diphosphate has increased the frequency of platelet function testing in clinical practice. Recent large observational studies have established an independent relation between the results of point-of-care platelet function testing and clinical event occurrence in patients undergoing coronary artery stenting. However, prospective, randomized trials have failed to demonstrate that personalized antiplatelet therapy based on point-of-care assessment of platelet function is effective in reducing ischemic event occurrences. Important limitations were associated with these trials. In addition, the concept of a therapeutic window of P2Y 12 receptor reactivity with an upper threshold associated with ischemic event occurrence and a lower threshold associated with bleeding has also been proposed. In the absence of strong prospective evidence to support personalized antiplatelet therapy, clinical decision making about antiplatelet therapy rests on the large body of observational data and the fundamental importance of platelet physiology in catastrophic event occurrence in patients with high-risk coronary artery disease.

The Role of Platelets in Chronic Urticaria

BACKGROUND

Platelets are implicated in many pathophysiological processes, including inflammation and immunity. Ever-growing evidence suggests the active involvement of platelets in the pathogenesis of various inflammatory disorders, including cutaneous inflammatory diseases. A limited number of studies have investigated the role of platelets in chronic urticaria (CU). In this review, we summarize the current knowledge regarding the role of platelets in chronic spontaneous and inducible urticarias.

METHODS

A literature search was performed using PubMed and Google Scholar, and the references of relevant literature were reviewed.

RESULTS

Overall, in CU patients, conflicting results have been obtained from the assessment of platelet indices, such as mean platelet volume, platelet count and distribution width, as well as markers of platelet aggregation and activation. Nevertheless, a few studies showed significant changes of such parameters in CU patients compared to controls, in apparent correlation with clinical severity, autoreactivity and/or inflammatory status.

CONCLUSIONS

In the absence of definitive conclusions, the pathogenic role of platelets in CU needs to be further explored. Platelets might represent a link between inflammation, coagulation and histamine release in the pathophysiological network of CU.

Platelet-lymphocyte ratio is an independent predictor for cardiovascular disease in obstructive sleep apnea syndrome

There is a strong relationship between obstructive sleep apnea syndrome (OSAS) and cardiovascular disease (CVD). Chronic intermittent hypoxia, inflammation, oxidative stress, and endothelial dysfunction may constitute etiologic mechanisms, linking OSAS to CVD. Inflammation play an important role in the development of CVD. Platelet-lymphocyte ratio (PLR) is a new biomarker showing inflammation. No previous study has ever investigated the association between PLR, CVD and OSAS severity in patients with OSAS. This study was designed to investigate the association between PLR and CVD in patients with OSAS, and relationship between severity of OSAS, polysomnographic parameters and PLR. This was a cohort study in which patients who had undergone a full night polysomnoraphy for diagnosis of OSA were recruited. Patients were divided according to their apnea-hypopnea index (AHI) scores into OSAS negative (Group 1: AHI < 5), mild (Group 2: AHI, 5-15), moderate (Group 3:AHI,15-30), and severe OSAS (Group 4: AHI > 30) groups. The presence of heart failure, coronary artery disease or arrhythmia was defined as CVD. A total of 424 patients were included in this study. There were 57, 93, 82, and 192 patients in Groups 1, 2, 3, and 4, respectively. PLR were significantly different between groups (Group 1: 87.38; Group 2: 95.07; Group 3: 97.01, Group 4: 126.9, P < 0.05). PLR were significantly correlated with AHI, oxygen desaturation index, average and minimum O2 saturation values (P < 0.05). Values of PLR were significantly higher in patients with CVD compared with those without. Multiple regression analysis demonstrated that PLR is an independent predictor of CVD. PLR cut-off value for demonstrating the presence of CVD is higher than 108.56. In the light oh findings, PLR is strongly associated with the severity of OSAS and cardiovascular disease in OSAS patients. PLR might be used as a biomarker to predict CVD in OSAS patients.

Inhibition of platelet function with clopidogrel is associated with a reduction of inflammation in patients with peripheral artery disease

BACKGROUND

The reactivity of platelets is increased in patients with peripheral artery disease (PAD). RANTES and sCD40L are chemokines which are stored in the alpha-granules of platelets. Clopidogrel inhibits and thus reduces platelet reactivity. Whether a treatment with clopidogrel is associated with an inhibition of systemic inflammation in patients with PAD has not been thoroughly explored. This study examined the effect of clopidogrel on platelet reactivation and the release of inflammatory chemokines in patients with PAD.

METHODS

40 patients with PAD were randomized into two groups. In the first group A the patients were treated with 100mg acetylsalicylic acid (ASA) and additional placebo for 4weeks. The patients in group B received 75mg/d clopidogrel in addition to ASA 100mg for 4weeks. After obtaining blood at days 0, 7 and 28 the platelet activation was determined by measuring the surface protein expression of CD63, CD62p and thrombospondin (TSP) after stimulation with TRAP and ADP. The release of the chemokines RANTES and sCD40L from platelets was analyzed by ELISA.

RESULTS

Platelet activation markers (CD62p and CD63) and chemokine RANTES were significantly reduced in patients with PAD after 7 and 28days after treatment with clopidogrel. No alterations were found in TSP expression and sCD40L during the treatment.

CONCLUSION

The treatment with clopidogrel leads to a reduction of platelet reactivity and release of RANTES from the platelets of patients with PAD.

Red cell distribution width predicts totally occluded infarct-related artery in NSTEMI

Objective Since non-ST segment elevation myocardial infarction (NSTEMI) patients with totally occluded infarct-related artery (TO-IRA) have worse prognosis, it is important to recognize TO-IRA in NSTEMI. Red cell distribution width (RDW) and mean platelet volume (MPV) are novel markers of inflammation and oxidative stress and were associated with poor clinical outcomes in acute coronary syndrome. In the present study, association of RDW and MPV with the presence of TO-IRA in NSTEMI was investigated. Methods Data of 201 consecutive patients who underwent coronary angiography with a diagnosis of NSTEMI were analyzed. Independent predictors of TO-IRA were investigated with logistic regression analysis. Results Sixty-six (32.8%) of the patients had TO-IRA. In patients with TO-IRA, RDW and troponin-T were significantly higher and left ventricular ejection fraction (LVEF) was lower. MPV did not differ between groups. Circumflex (CX) IRA was more common in TO-IRA group. The ROC curve analysis showed that the RDW at a cut-point of 13.95% has 76% sensitivity and 66% specificity in detecting TO-IRA. RDW, troponin-T, LVEF and CX-IRA were independent predictors of TO-IRA in NSTEMI, but MPV was not. Conclusion RDW is a cheap and readily available marker that may have a role to predict TO-IRA in NSTEMI.

Association Between Platelet to Lymphocyte Ratio and Saphenous Vein Graft Disease

Atherosclerosis plays an important role in saphenous vein graft disease (SVGD). Previous trials showed that inflammatory blood cells play a role in this process. The platelet to lymphocyte ratio (PLR) has been proposed as a novel predictor for cardiovascular risk and indicator of atherosclerosis. The aim of this study was to assess the relationship between SVGD and PLR. A total of 220 patients with SVG were enrolled (n = 87 with SVGD and n = 133 with patent SVG). A ≥ 50% stenosis within the SVG was defined as clinically significant. Median PLR (P < .001) and mean platelet volume (MPV; P = .043) were significantly higher in patients with SVGD. Also, PLR showed significantly positive correlation with age of SVG (P < .05). Median age of SVGs was also higher in the SVGD group (P = .025). In multivariate logistic regression analyses, the PLR and MPV were independent predictors of SVGD. Using a cutoff level of 106.3, the PLR predicted SVGD with a sensitivity of 87.4% and a specificity of 80.3%. To the best of our knowledge, this study showed, for the first time, that PLR was independently associated with SVGD. Both PLR and MPV might predict SVGD.

The Prognostic Impact of In-Hospital Change in Mean Platelet Volume in Patients With Non-ST-Segment Elevation Myocardial Infarction

It is unclear whether changes in mean platelet volume (MPV) are associated with total mortality in acute coronary syndromes. We investigated whether the change in MPV predicts total mortality in patients with non-ST-segment elevation myocardial infarction (NSTEMI). We retrospectively analyzed 419 consecutive patients (19 patients were excluded). The remaining patients were categorized as survivors (n = 351) or nonsurvivors (n = 49). Measurements of MPV were performed at admission and after 24 hours. The difference between the 2 measurements was considered as the MPV change (ΔMPV). The end point of the study was total mortality at 1-year follow-up. During the follow-up, there were 49 deaths (12.2%). Admission MPV was comparable in the 2 groups. However, both MPV (9.6 ± 1.4 fL vs 9.2 ± 1.0 fL, P = .044) and ΔMPV (0.40 [0.10-0.70] fL vs 0.70 [0.40-1.20] fL, P < .001) at the first 24 hours were higher in nonsurvivors than survivors. In multivariate analysis, ΔMPV was an independent predictor of total mortality (odds ratio: 1.84, 95% confidence interval: 1.28-2.65, P = .001). An early increase in MPV after admission was independently associated with total mortality in patients with NSTEMI. Such patients may need more effective antiplatelet therapy.

The platelet-to-lymphocyte ratio reflects the severity of obstructive sleep apnea syndrome and concurrent hypertension

Background

Chronic intermittent hypoxia, platelet activation and inflammation all play roles in the pathogenesis of obstructive sleep apnea syndrome (OSAS), which may increase the risk of cardiovascular disease (CVD). The aim of this study was to evaluate the relationship of the platelet-to-lymphocyte ratio (PLR) as a new biomarker showing systemic inflammation and platelet distribution width (PDW) as an indicator of platelet activation to the severity of OSAS.

Methods

A total of 290 patients suspected with OSAS who underwent a full night of polysomnography were included. The patients were placed into 4 separate groups according to their apnea-hypopnea index (AHI) scores; the control group (AHI <5), mild OSAS group (AHI 5–15), moderate OSAS group (AHI 16–30), and severe OSAS group (AHI >30). CVD risk was defined by the presence of hypertension, diabetes mellitus, current smoking, and dyslipidemia.

Results

Higher AHI groups were significantly correlated with increasing age, body mass index, systolic blood pressure and male sex. PLR and PDW were also significantly associated with AHI (r = 0.417 for PLR and r = 0.227 for PDW, all p-values < 0.001) and the Epworth sleepiness scale (r = 0.160 for PLR and r = 0.189 for PDW, all p-values <0.05). Multivariate regression analysis revealed that AHI ≥9.2 (adjusted odds ratios [OR] 5.03, 95 % confidential interval (CI) = 1.67-15.2, p = 0.004) and PLR ≥159 (adjusted OR 2.81, 95 % CI = 1.34-5.91, p = 0.006) were independently associated with the presence of hypertension.

Conclusion

PLR and PDW are associated with OSAS severity. PLR may also be useful as a systemic biomarker for the concurrent hypertension in OSAS patients.

The relation of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and mean platelet volume with the presence and severity of Behçet's syndrome

Behçet's syndrome (BS) is associated with chronic inflammation and endothelial dysfunction. Although there have been extensive investigations on neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV) in many diseases, their roles in BS is unclear. The purpose of the present study was to evaluate NLR, PLR, and MPV levels in BS patients and explore their clinical significance. The study included 254 patients with BS and 173 healthy individuals. Age, sex, age of onset, duration of disease, smoking, Behçet activity score, total white blood counts, neutrophil, platelet, and T lymphocyte counts of the patients were recorded. White blood cell (WBC), neutrophil, platelet, NLR, and PLR were significantly higher in patients with BS when compared with healthy controls (all p < 0.001). Lymphocyte counts and MPVs of the BS group were not statistically different from healthy controls (all p > 0.05). In the BS group, PLR and MPV were significantly different among the three severity groups (p = 0.037 and p = 0.016, respectively). We showed that any laboratory markers were not associated with joint, eye, central nervous system, large vessel, or gastrointestinal involvement in BS. NLR was shown to be an independent factor for BS by multivariate analysis. We suggest that NLR can be considered to be a diagnostic criterion of BS given the support of the findings from larger prospective studies.

Value of serial platelet indices measurements for the prediction of pulmonary embolism in patients with deep venous thrombosis

BACKGROUND

To date, no validated biomarkers with high sensitivity and specificity have been established for diagnosis of pulmonary embolism (PE) in patients with deep venous thrombosis (DVT). There is a need to develop simple and reliable noninvasive tests that can accurately identify patients with PE, even in small hospitals or clinics. The aim of this study was to investigate the value of mean platelet volume (MPV) and platelet distribution width (PDW) for predicting occurrence of PE in patients with DVT.

METHODS

Records of acute DVT patients were reviewed retrospectively. Group 1 consisted of 50 patients with acute DVT and group 2 consisted of 50 patients with acute DVT who developed PE during follow-up. The control group consisted of patients with uncomplicated primary varicose veins of the lower limbs. Venous peripheral blood samples for measurement of MPV, PDW, and platelet count were drawn on admission, before the treatment, and at the time of PE diagnosis.

RESULTS

MPV and PDW levels at the time of PE diagnosis were higher in group 2 than group 1 (P<0.001 and P=0.026, respectively). Receiver operating characteristics analysis revealed that a 5.2% increase in admission PDW during follow-up provided 70% sensitivity and 82% specificity (area under the curve, 0.80), and a 6.6% increase in admission MPV during follow-up provided 74% sensitivity and 83% specificity (area under the curve, 0.84) for prediction of PE occurrence in patients with DVT. PDW and MPV levels at the time of PE diagnosis were found to be independent risk factors for the occurrence of PE in patients with DVT.

CONCLUSION

Serial measurements of MPV and PDW, and percent change in MPV and PDW appears to be a useful marker for predicting occurrence of acute PE in patients with a first episode of acute proximal DVT.

Combined Usefulness of the Platelet-to-Lymphocyte Ratio and the Neutrophil-to-Lymphocyte Ratio in Predicting the Long-Term Adverse Events in Patients Who Have Undergone Percutaneous Coronary Intervention with a Drug-Eluting Stent

OBJECTIVES

The aim of this study was to investigate the combined usefulness of platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) in predicting the long-term adverse events in patients who have undergone percutaneous coronary intervention (PCI) with a drug-eluting stent (DES).

METHODS

798 patients with stable angina, unstable angina and non-ST elevated myocardial infarction (NSTEMI) who underwent elective successful PCI with DES were consecutively enrolled. The value of PLR and NLR in predicting adverse coronary artery disease (CAD) events and the correlations between these markers and adverse events (all-cause mortality, cardiac death, and nonfatal myocardial infarction) were analyzed.

RESULTS

The follow-up period was 62.8 ± 28.8 months. When patients were classified into four groups according to the optimal cut-off values for the PLR and NLR on receiver operating characteristic analysis, patients with a high PLR (>128) and high NLR (>2.6) had the highest occurrence of adverse events among the groups. On Cox multivariate analysis, the NLR >2.6 [hazard ratio (HR) 2.352, 95% confidence interval (CI) 1.286 to 4.339, p = 0.006] and the PLR >128 (HR 2.372, 95% CI 1.305 to 3.191, p = 0.005) were independent predictors of long-term adverse events after adjusting for cardiovascular risk factors. Moreover, both a PLR >128 and a NLR >2.6 were the strongest predictors of adverse events (HR 2.686, 95% CI 1.452 to 4.970, p = 0.002).

CONCLUSION

High pre-intervention PLR and NLR, especially when combined, are independent predictors of long-term adverse clinical outcomes such as all-cause mortality, cardiac death, and myocardial infarction in patients with unstable angina and NSTEMI who have undergone successful PCI with DES.

Hematological Parameters as Predictors of Cardiovascular Disease in Obstructive Sleep Apnea Syndrome Patients

We investigated the role of the red cell distribution width (RDW) and other parameters including platelet (PLT) count, mean platelet volume (MPV), and platelet distribution width (PDW) in patients with obstructive sleep apnea syndrome (OSAS) having cardiovascular diseases (CVDs). Patients (n = 142) having sleep disorders and who applied for a night polysomnography were included in this study. For statistical analysis, chi-square test, bivarite correlation, and logistic and stepwise regression tests were used. A positive correlation between RDW MPV, RDW, and body mass index as well as PLT and apnea-hypopnea index were observed. A negative correlation between AHI and PDW (P= .041) and a positive correlation between AHI and PLT (P= .010) were found in the patients ≥40 years old with CVD. The RDW was higher in patients ≥40 years old who had CVD (P= .016), and 19% of them had RDW >14%. The PDW (odds ratio = 6.02 [95% confidence interval = 1.3-28.2],P= .023) appeared to be associated with increased risk of hyperlipidemia in patients with severe OSAS. If these results are confirmed, RDW could be used with other markers, especially PLT and PDW, in prediction of CVD in patients with severe OSAS.