Mean platelet volume is related with ischemic stroke in patients with sinus rhythm

Do Mean Platelet Volume and Platelet Distribution Width Have An Association with White Matter Hyperintensities in Migraine Patients?

Objective

Increased prevalence of white matter hyperintensities (WMH) is reported in migraine patients; however, the pathophysiology and the progression of these lesions are not definitely clear. Mean platelet volume (MPV) and platelet distribution width (PDW) are easily obtained markers for platelet activity. The aim of this study is to evaluate the relationship between the presence of WMH and MPV and PDW in patients with migraine in order to determine the role of platelet activity in the pathophysiology of WMH.

Methods

Patients who were admitted to the neurology outpatient clinics of Baskent University Hospital from January 2011 to December 2015 with migraine and between 18 and 55 years of age were evaluated retrospectively. The blood samples were taken and total blood count parameters including MPV and PDW were analyzed. Brain magnetic resonance images were evaluated.

Results

Totally, 218 patients were evaluated in this study. Forty-eight (22.0%) patients had WMH in the brain magnetic resonance imaging. In patients with WMH, the median of age was higher than the patients without WMH and the difference was statistically significant (P < 0.05). There was no statistically significant difference between MPV, PDW values, and the presence of WMH.

Conclusions

There are multiple theories suggested for the mechanism of WMH, but the major cause and pathophysiology are still undetermined. Our data suggested that increased platelet activity is insufficient by itself to explain the pathophysiology of WMH in migraine patients and to improve the knowledge on this issue further large longitudinal studies should be performed.

The relationship between mean platelet volume and reverse dipping blood pressure pattern in patients with essential hypertension

OBJECTIVE

An association between increased mean platelet volume (MPV) and cardiovascular events is well established. Recent studies suggest that a nondipper blood pressure pattern is closely related to increased MPV. Because little information has been revealed about the relationship between reverse dipper hypertension (RDHT) and MPV, we aimed to investigate this relation.

METHODS

A total of 317 patients were retrospectively evaluated by analyzing the records of ambulatory blood pressure monitoring (ABPM). Patients were categorized into three groups according to their ABPM values as RDHT (n = 63), non-dipper hypertension (NDHT) (n = 95), and dipper hypertension (DHT) groups (n = 159). MPV and biochemical analyses were recorded from the hospital database.

RESULTS

The largest MPV was found in patients with RDHT, followed by patients with NDHT and DHT group (9.1 ± 0.4 fl, 8.8 ± 0.6 fl, and 8.6 ± 0.5 fl, respectively, for all p < .05). MPV was positively correlated with mean 24-hour systolic blood pressure (SBP), mean 24-hour diastolic blood pressure (DBP), mean daytime SBP, mean nighttime SBP and mean nighttime DBP. In multivariate logistic regression analysis, MPV (OR 1.761, 95% CI 1.329 to 2.334, p = .001) and age (OR 1.065, 95% CI 1.019 to 1.113, p = .001) were found to be associated with RDHT. ROC curve analysis of MPV for prediction of RDHT showed that at the cutoff value of >9,1 fl with a sensitivity of 60% and specificity of 69%, respectively (AUC = 0.696 ± 0.035, 95% CI: 0.627-0.764). Our data show that the RDHT pattern is associated with increased MPV values in patients with essential hypertension.

Mean Platelet Volume is a Prognostic Marker in Acute Ischemic Stroke Patients Treated with Intravenous Thrombolysis

BACKGROUND AND OBJECTIVES

There is conflicting data regarding the association between platelet parameters and prognosis of stroke patients treated with intravenous thrombolysis. We aimed to analyze this association in a cohort of patients treated with rtPA.

MATERIAL AND METHODS

Retrospective, observational study in adult ischemic stroke patients treated with rtPA between January 2015 and February 2017. Demographic and clinical characteristics, stroke severity (NIHSS), etiology (TOAST), mean platelet volume (MPV), platelet count (PC), platelet distribution width (PDW) and functional outcome (mRS) at discharge and 90 days were recorded. The association between platelet parameters and unfavorable prognosis (mRS 3-6) was tested using non-parametric tests and logistic regression analysis.

RESULTS

267 patients were included, 134 (50.2%) females, with a median (IQR) age of 74 years (64-82). The median admission NIHSS was 14 (8-19) and the most frequent etiology was cardioembolism (n = 115, 43.1%). At discharge, 170 (63.7%) patients had mRS 3-6. MPV values were higher in patients with mRS 3-6 (median 8.2fL versus 7.8fL, p = 0.013). This association remained significant (OR = 1.36, 95% CI 1.003-1.832, p = 0.048) after adjustment for variables associated with prognosis. There were no significant associations between other platelet parameters and prognosis. There was a trend to unfavorable prognosis at 90 days in patients with higher MPV. Regarding the association between platelet parameters and hemorrhagic transformation, higher PDW was associated with more severe hemorrhagic transformation (PH1/PH2).

CONCLUSIONS

Higher MPV values were associated with unfavorable prognosis at discharge in patients treated with intravenous thrombolysis. Future studies should address its added value in stroke prediction models.

Role of the Platelets and Nitric Oxide Biotransformation in Ischemic Stroke: A Translative Review from Bench to Bedside

Ischemic stroke remains the fifth cause of death, as reported worldwide annually. Endothelial dysfunction (ED) manifesting with lower nitric oxide (NO) bioavailability leads to increased vascular tone, inflammation, and platelet activation and remains among the major contributors to cardiovascular diseases (CVD). Moreover, temporal fluctuations in the NO bioavailability during ischemic stroke point to its key role in the cerebral blood flow (CBF) regulation, and some data suggest that they may be responsible for the maintenance of CBF within the ischemic penumbra in order to reduce infarct size. Several years ago, the inhibitory role of the platelet NO production on a thrombus formation has been discovered, which initiated the era of extensive studies on the platelet-derived nitric oxide (PDNO) as a platelet negative feedback regulator. Very recently, Radziwon-Balicka et al. discovered two subpopulations of human platelets, based on the expression of the endothelial nitric oxide synthase (eNOS-positive or eNOS-negative platelets, respectively). The e-NOS-negative ones fail to produce NO, which attenuates their cyclic guanosine monophosphate (cGMP) signaling pathway and-as result-promotes adhesion and aggregation while the e-NOS-positive ones limit thrombus formation. Asymmetric dimethylarginine (ADMA), a competitive NOS inhibitor, is an independent cardiovascular risk factor, and its expression alongside with the enzymes responsible for its synthesis and degradation was recently shown also in platelets. Overproduction of ADMA in this compartment may increase platelet activation and cause endothelial damage, additionally to that induced by its plasma pool. All the recent discoveries of diverse eNOS expression in platelets and its role in regulation of thrombus formation together with studies on the NOS inhibitors have opened a new chapter in translational medicine investigating the onset of acute cardiovascular events of ischemic origin. This translative review briefly summarizes the role of platelets and NO biotransformation in the pathogenesis and clinical course of ischemic stroke.

Platelet count and mean volume in acute stroke: a systematic review and meta-analysis

Changes of mean platelet volume (MPV) and platelet count (PC) could be a marker or a predictor of acute stroke (AS). We conducted a systematic review and meta-analysis of the published literature on the reporting of MPV and PC in AS. Studies were included in accordance with Patient Population or Problem, Intervention, Comparison, Outcomes, and Setting framework. The PRISMA strategy was used to report findings. Risk of bias was assessed with the Newcastle-Ottawa Scale. We included 34 eligible articles retrieved from the literature. PC was significantly lower in AS patients [standardized mean difference (SMD) = - 0.30, (95% CI: - 0.49 to - 0.11), N = 2492, P = .002] compared with controls (N = 3615). The MPV was significantly higher [SMD = 0.52 (95% CI: 0.28-0.76), N = 2739, P < .001] compared with controls (N = 3810). Subgroup analyses showed significantly lower PC in both ischemic stroke (Difference SMD = -0.18, 95% CI: -0.35-0.01) and hemorrhagic stroke (-0.94, -1.62 to -0.25), but only samples by citrate anticoagulant showed significantly lower result for patients compared to controls (-0.36, -0.68 to -0.04). Ischemic stroke patients had higher MPV (0.57, 0.31-0.83), and samples by Ethylenediaminetetraacetic acid (EDTA) anticoagulant showed significantly higher result for patients compared to controls (0.86, 0.55-1.17). PC and MPV appeared to be significantly different between patients with AS and control populations. MPV was significantly higher in ischemic stroke and PC was significantly lower in both ischemic and hemorrhagic strokes. These characteristics might be related to AS and associated with it. It is advisable to pay attention to elapsed time between phlebotomy and hematology analysis, anticoagulant and hemocytometer types in AS.

SYSTEMATIC REVIEW REGISTRATION

This meta-analysis is registered on the International Prospective Register of Systematic Reviews (PROSPERO) under registration number CRD42017067864 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=67864).

Predictive and prognostic role of mean platelet volume in patients with first-ever acute ischemic stroke

Objective:

To investigate any possible effects of mean platelet volume (MPV) on short-term stroke prognosis and functional outcome in patients with first-ever acute ischemic stroke (FEAIS).

Methods:

This retrospective cross-sectional study included 798 FEAIS patients admitted to the emergency department of a tertiary care hospital in Adiyaman, Turkey between January 2013 and June 2015. The data were evaluated according to whether alive or dead, MPV levels, modified Rankin scale (MRS) scores, National Institutes of Health Stroke Scale (NIHSS) scores. The patients were divided into 3 groups based on MPV level as 4.4-7.4 fL, 7.5-10.4 fL, higher than 10.4 fL.

Results:

A total of 250 patients with FEAIS were included in the study. In both those who survived and those who died, the area under the curve related to hospitalization days, time interval of venipuncture (TIV), and MPV measurements was not statistically significant (p>0.05). The 3 MPV groups showed no significant differences in terms of MRS score, median NIHSS score, hospitalization, and TIV. In subgroups based on MRS scores, there were no statistically significant differences according to median latency (p=0.087), median hospitalization (p=0.394), TIV (p=0.201), and MPV levels (p=0.847). Furthermore, there were no differences in MPV levels between the MRS based groups (p=0.527).

Conclusion:

The results showed that MPV was not a significantly associated and reliable marker for the prediction of prognosis or functional outcome of FEAIS attack.

Increased platelet count and reticulated platelets in recently symptomatic versus asymptomatic carotid artery stenosis and in cerebral microembolic signal-negative patient subgroups: results from the HaEmostasis In carotid STenosis (HEIST) study

BACKGROUND

The pathophysiological mechanisms responsible for the disparity in stroke risk between asymptomatic and symptomatic carotid stenosis patients are not fully understood. The functionally important reticulated platelet fraction and reticulocytes could play a role.

OBJECTIVES

We performed a prospective, multi-centre, observational analytical study comparing full blood count parameters and platelet production/turnover/activation markers in patients with asymptomatic versus recently symptomatic moderate (≥ 50-69%) or severe (≥ 70-99%) carotid stenosis.

PATIENTS/METHODS

Data from 34 asymptomatic patients were compared with 43 symptomatic patients in the 'early phase' (≤ 4 weeks) and 37 of these patients in the 'late phase' (≥ 3 months) after TIA/ischaemic stroke. Reticulated platelets were quantified by whole blood flow cytometry and reticulated platelets and red cell reticulocytes by 'automated assays' (Sysmex XE-2100™). Bilateral simultaneous transcranial Doppler ultrasound monitoring classified patients as micro-embolic signal (MES)+ve or MES-ve.

RESULTS

Mean platelet count was higher in early (216 × 10⁹/L; P = 0.04) and late symptomatic (219 × 10⁹/L; P = 0.044) than asymptomatic patients (194 × 10⁹/L). Mean platelet volume was higher in early symptomatic than asymptomatic patients (10.8 vs. 10.45 fl; P = 0.045). Automated assays revealed higher % reticulated platelet fractions in early (5.78%; P < 0.001) and late symptomatic (5.11%; P = 0.01) than asymptomatic patients (3.48%). Red cell reticulocyte counts were lower in early (0.92%; P = 0.035) and late symptomatic (0.93%; P = 0.036) than asymptomatic patients (1.07%). The automated % reticulated platelet fraction was also higher in early symptomatic than asymptomatic MES-ve patients (5.7 vs. 3.55%; P = 0.001).

DISCUSSION

The combination of increased platelet counts and a shift towards production of an increased population of larger, young, reticulated platelets could contribute to a higher risk of first or recurrent cerebrovascular events in recently symptomatic versus asymptomatic carotid stenosis, including those who are MES-ve.

The relationship of fibroblast growth factors 21 and 23 and α-Klotho with platelet activity measured by platelet volume indices

BACKGROUND

Subjects with high fibroblast growth factor 21(FGF21) and 23 (FGF23), endocrine hormones that regulate insulin sensitivity and phosphate metabolism, respectively, are reported to have a higher risk for adverse cardiovascular outcome. Therefore, the relationship of FGF21, FGF23, and α-Klotho (co-receptor for FGF23 signaling) with mean platelet volume (MPV) and platelet distribution width (PDW), two platelet volume indices that reflect platelet activity, was investigated.

METHODS

Data from 156 patients admitted to the cardiology department were analyzed. MPV and PDW were measured by an automatic blood counter, and serum FGF21, FGF23, and α-Klotho concentrations were measured by an enzyme-linked immunoassay.

RESULTS

Log(FGF21) was significantly correlated with serum triglycerides but did not differ according to the use of non-use of antidiabetic or lipid-lowering drugs. MPV and PDW were significantly correlated (R=0.475, p<0.001). MPV was significantly correlated with log(FGF21) (R=-0.167, p<0.05) and log(FGF23) (R=0.351, p<0.001) but not with log(α-Klotho). Linear regression analysis showed a negative and positive association of log(FGF21) and log(FGF23), respectively, with MPV that was independent of possible confounders including sex, age, renal function, and antithrombotic drug use. In addition, log(FGF23) was found to have a significant independent positive association with PDW.

CONCLUSIONS

Among cardiac patients, FGF21 had a negative association with MPV, whereas FGF23 had a positive association. Future studies of serum FGF23/FGF21 concentrations and the incidence of thromboembolic disorders are warranted.