Platelet activation and cardiovascular outcomes in acute coronary syndromes

Mean Platelet Volume/Platelet Count Ratio as a Predictor of Both Incidence and Prognosis of Acute Ischemic Stroke in Hemodialysis Patients

Purpose

This study aimed to explore whether the mean platelet volume/platelet count ratio (MPR) has predictive value for the occurrence and prognosis of acute ischemic stroke (AIS) in hemodialysis patients.

Patients and Methods

A total of 402 patients undergoing maintenance hemodialysis were screened and 259 were enrolled in this study. The receiver operating characteristic curve and area under the curve (AUC) were used to evaluate the predictive power of the models. The patients enrolled in this study were divided into three groups based on the tertiles of the MPR value (Q1, Q2, and Q3). Kaplan-Meier curves were used to investigate the association between the MPR and AIS-free survival in hemodialysis patients. Chi-square analysis was performed to explore the association between the MPR and AIS outcomes in hemodialysis patients. And the AIS outcome was assessed using the modified Rankin Scale (mRS).

Results

MPR had a predictive value for the occurrence of AIS (AUC=0.814) in hemodialysis patients with a high sensitivity and specificity. AIS-free survival rates in the MPR Q1, MPR Q2, and MPR Q3 groups were 0.930, 0.701, and 0.360, respectively. The proportion of patients with good outcomes (mRS 0-2) was significantly greater among patients in the MPR Q1-Q2 group than in the MPR Q3 group (0.844 vs 0.745, p <0.001).

Conclusion

The MPR can be used as a good predictor of AIS in patients undergoing hemodialysis. Patients on hemodialysis with increased MPR levels had a higher incidence of AIS and poorer functional outcomes than those with low MPR levels.

Does periodontitis affect mean platelet volume(MPV) and plateletcrit (PCT) levels in healthy adults?

OBJECTIVE

Periodontitis may stimulate infectious and immune response and cause the development of atherogenesis, coronary heart disease, and myocardial infarction. The aim of this study was to compare the plateletcrit (PCT) and mean platelet volume (MPV) levels derived from complete blood count (CBC) tests in patients suffering from stage 3 periodontitis with those of healthy individuals without periodontal disease.

METHODS

The study included 57 patients (28 females and 29 males) with Stage 3 Periodontitis and 57 volunteering individuals (31 females and 26 males) who were periodontally healthy. The age of study participants ranged from 18 to 50 years. Their periodontal condition was investigated with probing depth (PD), clinical attachment level, bleeding on probing, and plaque index. Leukocyte (WBC) and erythrocyte count (RBC), hemoglobin (Hb) and hematocrit (HCT) levels, mean corpuscular volume (MCV) and red cell distribution width (RDW), thrombocyte count, mean platelet volume (MPV), plateletcrit (PCT ), and neutrophil and lymphocyte counts were evaluated based on the CBC test results of the study participants.

RESULTS

PCT, WBC, Neutrophil, and MPV values were found to be significantly higher in the periodontitis group (p<0.05). There were no significant differences in RBC counts, Hb, HCT, MCV, RDW, and platelet and lymphocyte counts between the two study groups (p>0.05).

CONCLUSIONS

PCT and MPV levels may be a more useful marker to determine an increased thrombotic state and inflammatory response in periodontal diseases.

The mean platelet volume and plateletcrit as predictors of short-term outcome of acute ischemic stroke

Background

Activation of the platelet plays an important role in the process of atherosclerosis. Mean platelet volume (MPV) is significantly associated with the poor outcome of acute ischemic stroke while the results of studies about the relationship between plateletcrit (PCT) and stroke outcome were inconsistent. The aim of this work is to determine whether an association exists between MPV and plateletcrit (PCT) and outcome of acute ischemic stroke.

Methods

We examined 157 patients with ischemic stroke, admitted to the Sohag University Hospital. The diagnosis of stroke was performed clinically according to The World Health Organization and confirmed by brain CT and MRI when needed. Platelet indices including MPV and PCT were assessed immediately (within 2 h) after admission. After 3 months, the functional outcome was assessed using the modified Rankin Scale (mRS) with assessment of the relationship between platelet indices and stroke outcome.

Results

About 50% of the participants have favorable outcome. MPV was significantly higher in the unfavorable group (10.4 ± 2.3 fL) than in the favorable one (8.7 ± 1.3 fL) (P < 0. 001). MPV was an independent predictor of poor short-term outcome of acute stroke after controlling for confounders like diabetes mellitus. The mean PCT was significantly higher in the unfavorable group (0.28 ± 0.1%) than in the favorable one (0.25 ± 0.1%) (P = 0. 04) but not considered as an independent predictor of poor short-term outcome of acute stroke.

Conclusions

MPV and PCT were significantly correlated with poor functional outcome, only MPV was an independent predictor of poor short-term outcome of acute stroke after controlling for confounders like DM, and these platelet indices can be used as a prognostic tool.

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.

Replication and characterisation of genetic variants in the fibrinogen gene cluster with plasma fibrinogen levels and haematological traits in the Third National Health and Nutrition Examination Survey

Previous genetic association studies of the fibrinogen gene cluster have identified associations with plasma fibrinogen levels. These studies are typically limited to plasma fibrinogen measured among European-descent populations. We sought to replicate previous well-known associations with fibrinogen variants and plasma fibrinogen. We then sought to identify and characterise novel associations with fibrinogen variants with plasma fibrinogen and several haematological traits in three racial/ethnic populations. We genotyped 25 single nucleotide polymorphisms (SNPs) in the fibrinogen gene cluster in 2,631 non-Hispanic whites, 2,108 non-Hispanic blacks, and 2,073 Mexican-Americans from the Third National Health and Nutrition Examination Survey (NHANES). We performed single SNP tests of association for plasma fibrinogen, mean platelet volume, platelet distribution width, platelet count, white blood cell count, and serum triglycerides. Five previously identified associations with plasma fibrinogen replicated in our study in non-Hispanic whites and blacks. We identified two novel associations between genetic variants and decreased plasma fibrinogen: rs2227395 (p=0.0007; non-Hispanic whites) and rs2070022 (p=0.001; Mexican-Americans). Several fibrinogen SNPs were also associated with haematological traits: rs6050 with decreased platelet distribution width in non-Hispanic whites; rs6050 and rs2066879 with decreased and increased platelet distribution width, respectively, in non-Hispanic whites;rs2227409 with increased mean platelet volume, rs2070017 with decreased platelet count, and rs6063 with increased platelet distribution width in non-Hispanic blacks; and rs4220 and rs2227395 with decreased white blood cell count, rs2227409 with increased platelet distribution width, rs2066860 and rs1800792 with increased and decreased triclyceride levels, respectively, and rs1800792 with decreased platelet counts in Mexican-Americans. We successfully replicated and identified novel associations with fibrinogen variants and plasma fibrinogen. These data confirm the importance of the fibrinogen gene cluster for plasma fibrinogen levels as well as suggest this gene cluster may have pleiotropic effects on haematological traits.

Diagnostic value of platelet indices in children with leukemia

The purpose of this study was to investigate whether platelet indices [mean platelet volume (MPV) and platelet distribution width (PDW)] could serve as diagnostic tools for screening or as surrogate marker for follow-up in children with leukemia. Blood samples were obtained from 47 patients with leukemia at diagnosis before chemotherapy (mean age: 67 mo; 30 males and 17 females) and from 47 healthy controls (mean age: 59 mo; 27 males and 20 females). We measured the blood platelet indices using an automated counter. MPV was higher in the leukemia group, but it was not statistically significant. However, PDW was significantly lower (P<0.001) in leukemia group. There was no significant difference in the MPV or PDW in patients with acute lymphoblastic leukemia versus acute myeloblastic leukemia. In conclusion, we found no significant difference in the MPV between the 2 groups. PDW proposed as indicators of certain pathologic conditions and it seems possible to use PDW as screening. However, platelet indices (MPV and PDW) cannot be used as indicator to discriminate between the subtypes of leukemia in children. The potential role of platelet indices in leukemia remains to be investigated by a multi-institutional level to verify the possible clinical significance of this finding.

The effects of coronary artery disease severity on time-dependent changes in platelet activation indices in stored whole blood

BACKGROUND

Platelets play a pivotal role in the pathogenesis of the thrombotic complications in cardiovascular disease (CVD). Abnormal platelet activation indices are evolving as potentially useful markers in CVD risk stratification. Whilst there has been some investigation into the effects of storage time on several of these indices, the effects of underlying disease severity on these temporal changes have not been previously studied.

METHODS

Using the ADVIA 120 haematology analyser, we assessed the effects of time-dependent storage of whole blood in EDTA, on a number of platelet activation indices: mean platelet volume (MPV), mean platelet component (MPC, measure of platelet density) and platelet component distribution width (PCDW, a marker of platelet shape change. We studied three age- and sex-matched patient groups: (i) healthy controls (n = 10), (ii) stable patients with coronary artery disease (CAD, n = 9); and (iii) patients with acute myocardial infarction (n = 8). Whole blood samples were processed at exactly 5 min following venesection and at 15, 30, 60 and 120 min later in storage in EDTA tubes at room temperature.

RESULTS

There was a significant and stepwise increase in MPV (P = 0.01) and decrease in PCDW (P = 0.03), with a non-significant trend to increasing MPM and decreasing MPC with increasing underlying disease (that is healthy, 'stable' and 'acute' artery disease). There was a significant time-dependent increase in MPV and decrease in MPC and PCDW (all P < 0.05), which were all significant on 'post-hoc' analyses by 30 min. There were no significant changes in platelet count or MPM with time. There was no interaction of underlying disease with whole-blood storage time for any of the platelet indices reported (P = NS).

CONCLUSION

There is a temporal increase in MPV and decrease in MPC and PCDW in venous blood stored over 2 h in EDTA. These changes are not influenced by the underlying CVD disease severity.