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

Evaluation of the Impact of Glycemic Control on Mean Platelet Volume and Platelet Activation in Children with Type 1 Diabetes

OBJECTIVE

The studies evaluating cases with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) in the adult population reported hyperreactive platelets and increased activation of prothrombotic factors, resulting in an increased risk of thrombosis. The aim of this study was to evaluate the effects of poor glycemic control and the duration of diabetes on platelet parameters in pediatric population.

METHODS

The study included 366 children, out of which 144 (39.3%) were included in the T1DM group and 222 (60.6%) in the healthy control group. The platelet count, mean platelet volume (MPV), platelet distribution width and plateletcrit values were recorded. The children with T1DM were divided into three groups as per their glycated hemoglobin (HbA1c) levels, good (<7.5%), moderate (7.5-9%) and poor metabolic control (>9%).

RESULTS

No significant difference in the MPV level between the T1DM (7.41 ± 1.49 fl) and control (7.15 ± 1.23 fl) groups was observed. However, the MPV levels were significantly higher in the poor glycemic control group than in the healthy control group (p = 0.026). Furthermore, as the duration of diabetes and HbA1c levels increased, the MPV levels also increased (p < 0.001, p = 0.441).

CONCLUSION

This study suggested as the duration of diabetes and HbA1c levels increased, the MPV levels also increases. Evaluation of hematological parameters can be a cheap and useful method in the evaluation of diabetes regulation in patients with diabetes.

The effects of additive solutions on the development of storage lesions in stored canine platelet concentrates

OBJECTIVE

To determine if platelet additive solutions (PAS) decrease the occurrence and degree of platelet storage lesions, maintain platelet function, and extend storage time in vitro beyond 5 days at 22°C when compared to platelets stored in plasma only.

DESIGN

Prospective, ex vivo experimental controlled study.

SETTING

Research laboratory in a school of veterinary medicine.

ANIMALS

Twelve units of canine platelet concentrate prepared from fresh whole blood donations.

INTERVENTIONS

Platelet concentrates were aliquoted into 4 units and stored at room temperature (22°C) under constant agitation in either 100% plasma (control) or 35% plasma and 65% of 1 of 3 different PAS (Plasma-Lyte A, Isoplate, and InterSol) for 7 days. At days 0, 3, 5, and 7, samples were analyzed for presence of swirling, degree of aggregate formation, platelet count, platelet indices, glucose, lactate, lactate dehydrogenase, Pvo₂ , and Pvco₂ concentrations, aggregation via light aggregometry, and activation percentage based on flow cytometric measurement of surface P-selectin. Bacterial cultures were performed on days 0, 5, and 7.

MEASUREMENTS AND MAIN RESULTS

Isoplate had a higher incidence of aggregate formation on day 0 (n = 2), and Plasma-Lyte A had a higher incidence of loss of swirl on day 7 (n = 5). Plasma-stored samples had significantly higher platelet counts (P < 0.001), pH (P < 0.05), Pvco₂ (P < 0.001), and lactate (P < 0.001), and significantly lower lactate dehydrogenase (P < 0.05) as compared to all PAS. The mean pH remained above 7.2 in PAS and plasma. There was no difference in platelet activation between plasma and PAS. Changes in platelet indices, glucose consumption, and maximum aggregation varied by storage solution. There was no bacterial growth seen in any samples.

CONCLUSIONS

The 3 PAS performed similarly and could all be considered as potential replacements for plasma during the room temperature storage of canine platelet concentrate for up to 7 days.

Use of complete blood count for predicting preterm birth in asymptomatic pregnant women: A propensity score-matched analysis

Background

Accurate prediction of preterm birth (PTB) is still difficult, mostly because of the multifactorial etiology of PTB. Previous studies have been mostly focused on the prediction of PTB in symptomatic women or those presenting with threatened preterm labor. We aimed to study whether complete blood count (CBC) parameters at 20‐30 weeks of pregnancy can predict asymptomatic PTB.

Methods

In this retrospective case‐control study, the preterm and term delivery groups were matched by propensity score‐matched (PSM) analysis. Baseline data and the CBC parameters examined at 20‐30 weeks of gestation were recorded.

Results

The combined marker of neutrophil‐to‐lymphocyte ratio (NLR), hemoglobin (HGB), and platelet distribution width (PDW) accurately predicts PTB at a cutoff value of 0.25, with sensitivity and specificity of 88.6% and 40.5% and negative and positive predictive value of 97.9% and 10.2%, respectively.

Conclusion

The combined marker of CBC parameters can supplement other markers to predict PTB about 10 weeks in advance. This combined marker had a very high negative predictive value for PTB. Therefore, in subjects with normal combined marker value, further screening tests for PTB may be eliminated unless clinical suspicion is high.

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.

Can mean platelet volume play a role in evaluating the severity of acute pancreatitis?

AIM

To investigate serum mean platelet volume (MPV) levels in acute pancreatitis (AP) patients and assess whether MPV effectively predicts the disease severity of AP.

METHODS

We included 117 consecutive patients with AP as the AP group and 34 consecutive patients with colorectal polyps (before endoscopic treatment) as the control group. Complete blood counts, liver function, platelet indices (MPV), coagulation parameters, lactate dehydrogenase (LDH) and C-reactive protein (CRP) were measured on days 1, 2, 3 and 7 after admission. Receiver operating characteristic curves were used to compare the sensitivity and specificity of MPV, white blood cell (WBC), LDH and CRP in predicting AP severity. The Modified Glasgow Prognostic Score (mGPS) and the 2012 revised Atlanta criteria were used to evaluate disease severity in AP.

RESULTS

MPV levels were significantly lower in the AP group than in the control group on day 1 (P = 0.000), day 2 (P = 0.029) and day 3 (P = 0.001) after admission. In addition, MPV values were lower on day 1 after admission than on day 2 (P = 0.012), day 3 (P = 0.000) and day 7 (P = 0.002) in all AP patients. Based on the mGPS, 78 patients (66.7%) were diagnosed with mild and 39 patients (33.3%) with severe AP. There was no significant difference in mean MPV levels between patients diagnosed with mild and severe AP based on the mGPS (P = 0.424). According to the 2012 revised Atlanta criteria, there were 98 patients (83.8%) without persistent organ failure (OF) [non-severe acute pancreatitis (non-SAP) group] and 19 patients (16.2%) with persistent OF (SAP group). MPV levels were significantly lower in the SAP group than in the non-SAP group on day 1 after admission (P = 0.002). On day 1 after admission using a cut-off value of 6.65 fL, the overall accuracy of MPV for predicting SAP according to the 2012 revised Atlanta criteria (AUC = 0.716) had a sensitivity of 91.8% and a specificity of 47.4% and was superior to the accuracy of the traditional markers WBC (AUC = 0.700) and LDH (AUC = 0.697).

CONCLUSION

MPV can be used at no additional cost as a useful, non-invasive biomarker that distinguishes AP with persistent OF from AP without persistent OF on day 1 of hospital admission.

Platelet genomics: the role of platelet size and number in health and disease

Taken together, there is ample evidence of the association of cardiovascular disease, cerebrovascular, and inflammatory disease with single nucleotide variants (SNV) due to their impact on platelet size, number, and function. With the use of electronic medical record (EMR) or other phenotypic-linked bioinformatics sources, the more important "functional" variants are emerging and provide valuable information on their specific role in promoting early onset of disease or poor response to therapeutic measures. This review will focus upon the recognized common polymorphisms or gene variants with small, but functional effects, as it is becoming clear that these contribute to hyper- or hypo-responsive platelet phenotypes. The impact of these gene variants is distinguishable among normal individuals, and they are suspected contributors to increased risk of adverse outcomes in patients with underlying disease. There are thousands of gene variants and environmental factors that may mitigate risk or amplify the potential for disease within each of us. When combined with the environment and epigenetic influences, it is clear that whole-genome sequencing and bioinformatics alone will not be enough to truly predict "risk" or probability, but awareness of their potential influence may be a starting point in selective screening and generating prevention strategies to promote a healthy lifestyle or fine-tune therapeutic choices in the future.

Mean platelet volume and cardiovascular outcomes in acute myocardial infarction

OBJECTIVE

High levels of mean platelet volume (MPV) may be associated with adverse outcomes in patients with myocardial infarction (MI). We examined the association between MPV and the risk of death and adverse cardiovascular outcomes in patients with MI.

METHODS

We studied consecutive patients with MI admitted to a tertiary-care hospital during a period of 1 year. MPV was measured at admission and at third month. Patients were followed up for 1-year primary composite outcome of cardiovascular death, stroke, fatal or non-fatal MI and cardiac failure. Patients were classified according to tertile of baseline MPV.

RESULTS

A total of 1206 patients with MI, including 934 men (77.4%) and 272 women (22.6%) were studied. The mean age of the study population was 56 years. At 1-year follow-up, 292 (28.57%) primary outcome occurred: cardiovascular mortality 78 (7.6%), fatal or non-fatal MI 153 (15.0%), stroke 30 (2.9%) and cardiac failure 128 (12.52%). Patients with the highest tertile MPV had higher primary outcome as compared with those with MPV in the lowest tertile (adjusted OR=2.31; 95% CI 1.60 to 3.35; p<0.001). Total mortality was also more in high-MPV group (adjusted OR 2.62; 95% CI 1.47 to 4.70; p<0.001). There were no significant changes in mean MPV values at admission from those at third month interval (9.15, (SD 0.99) vs 9.19 (SD 0.94); p=0.2).

CONCLUSIONS

Elevated MPV was associated with worse outcome in patients with acute MI. Elevated MPV in these patients may be due to inherently large platelets.

TRIAL REGISTRATION NUMBER

http://ctri.nic.in/Clinicaltrials/rmaindet.php?trialid=5485&EncHid=98036.61144&modid=1&compid=19; CTRI/2012/12/003222.

Mean platelet volume levels in children with adenoid hypertrophy

Adenoid hypertrophy (AH) is a common disorder in children, resulting in chronic nasal congestion. This chronic congestion should be evaluated carefully because it can lead to chronic upper airway obstruction. Many authors have suggested that increased nasal resistance to respiration may cause disturbances in the pulmonary ventilation and carry the risk of cardiopulmonary diseases. Mean platelet volume (MPV) is a marker of platelet function and is positively associated with indicators of platelet activity. Mean platelet volume is an indicator of larger and more reactive platelets and has been shown to be increased in patients with vascular disease, including peripheral, pulmonary, and coronary artery disease. Recently, MPV levels have also been shown to be increased in patients with severe obstructive sleep apnea, and marked nasal septal deviation. Moreover, increased MPV has also been shown to have a prognostic role in cardiovascular disease. We investigated whether MPV is higher in patients with AH and whether higher MPV levels can be reduced by adenoidectomy. To the best of our knowledge, this is the first study to investigate MPV in patients with AH. Our results suggest that MPV, a determinant of platelet activation, is elevated in patients with AH and adenoidectomy is an effective therapeutic measure in such patients. Increased platelet activation may be related to an increase of cardiopulmonary risk in patients with AH.

Effect of Deviated Nasal Septum on Mean Platelet Volume: A Prospective Study

In E.N.T clinical practice, patients with nasal obstruction due to deviated nasal septum is a common presentation. Nasal airway obstruction is a common cause of upper airway obstruction further leading to obstructive and hypoxic manifestations. Mean platelet volume (MPV) levels increase in hypoxic conditions. MPV is one of the platelet activation index which reflects the platelet production rate. Present prospective study conducted in the department of Otorhinolaryngology and Head and Neck surgery, Gandhi Medical College and Hamidia Hospital, Bhopal, on 63 patients with the clinical evidence of DNS and 63 healthy age matched subjects as control group, aimed to evaluate the relationship between MPV levels and nasal obstruction due to deviated nasal septum (DNS). The diagnosis of patients with DNS was based on anterior rhinoscopy and endoscopic nasal examination. Blood samples were collected before surgical correction. In present study, the authors found that there is preponderance of DNS in the age group of 25-45 years being the most active age group, males having the higher incidence. Majority of cases of DNS being left sided and of obstructed type. MPV were significantly higher in patients with DNS than the control group. Among the cases MPV being higher in females and in the impacted type of DNS. Present study reemphasized the concept that MPV is increased in chronic nasal obstruction due to DNS and this increase is in accordance with the severity of DNS.

Can the mean platelet volume be a risk factor for vasculogenic erectile dysfunction?

Purpose

The mean platelet volume (MPV) is a marker of the platelet activity and is reported to increase in vascular diseases. We aimed to investigate the association between MPV and vasculogenic erectile dysfunction (ED).

Materials and Methods

MPV and platelet (PLT) levels were measured in 50 cases of ED and 40 healthy controls. The diagnosis of vasculogenic ED was based on a detailed sexual history, physical examination, laboratory assessment, and color Doppler ultrasonography. The results are given as mean±standard deviation of the mean.

Results

The mean ages of the patient and the control groups were 53.70±12.39 years (range 24~77 years) and 53.85±9.5 years (range 30~73 years), respectively (p=0.947). The MPV and PLT values were significantly higher in the patients with ED than those of the controls (7.49±1.4), (6.85±1.2), (262.97±68), (252.89±82) respectively, p<0.001). However, the MPV values were not statistically significantly different in the patients with severe ED according to the International Index of Erectile Function than in those with mild ED, p>0.05), and there was no correlation between MPV and either age of patients (p=0.905) or duration of ED (p=0.583).

Conclusions

The platelet count and MPV was detected to be increased in patients with vasculogenic ED. This finding suggests a role for platelets in the pathogenesis of vascular complications and that the MPV would be useful in monitoring disease progression.

Predictive Value of Admission Platelet Volume Indices for In-hospital Major Adverse Cardiovascular Events in Acute ST-Segment Elevation Myocardial Infarction

Although mean platelet volume (MPV) is an independent correlate of impaired angiographic reperfusion and 6-month mortality in ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI), there is less data regarding the association between platelet distribution width (PDW) and in-hospital major adverse cardiovascular events (MACEs). A total of 306 patients with STEMI pPCI were evaluated. No reflow was defined as a post-PCI thrombolysis in myocardial infarction (TIMI) flow grade of 0, 1, or 2 (group 1). Angiographic success was defined as TIMI flow grade 3 (group 2). The values of MPV and PDW were higher among patients with no reflow. In-stent thrombosis, nonfatal myocardial infarction, in-hospital mortality, and MACEs were significantly more frequent among patients with no reflow. In multivariate analysis, PDW, MPV, high-sensitivity C-reactive protein, and glucose on admission were independent correlates of in-hospital MACEs. Admission PDW and MPV are independent correlates of no reflow and in-hospital MACEs among patients with STEMI undergoing pPCI.

Genetic variants that affect platelet function

PURPOSE OF REVIEW

This review summarizes our current knowledge of common gene variants (polymorphisms) that have small individual effects on platelet function in humans, but can cumulatively lead to hyperreactive platelets and increase risk for negative outcomes in thrombotic disorders.

RECENT FINDINGS

Candidate gene association and genome-wide association studies (GWAS) have identified loci that include single nucleotide polymorphisms, which exert a cumulative effect on platelet function by modifying basic platelet parameters, such as mean platelet volume (MPV) or platelet count, by altering the expression or activity of key platelet receptors, or by influencing downstream effector pathways utilized by these receptors.

SUMMARY

Variation in MPV between normal individuals is responsible for roughly a two-fold range in platelet protein content, including key surface receptors and reactive granule constituents, the association of ADRA2, GP1BA, GP6, ITGA2 and P2Y12 variants with platelet reactivity, initially identified by candidate gene analyses, has now been validated by genome-wide approaches in much larger individual cohorts, and GWAS have identified novel gene variants, most notably PEAR1, that participate in variation in platelet reactivity among normal individuals, all of which contribute to a genetic basis for differences in platelet reactivty among normal individuals.

Mean platelet volume may represent a predictive parameter for overall vascular mortality and ischemic heart disease

OBJECTIVE

An increased mean platelet volume (MPV), as an indicator of larger, more reactive platelets resulting from an increased platelet turnover, may represent a risk factor for overall vascular mortality, including myocardial infarction. We intended to identify patients at higher risk of dying from vascular disease in a large, hospital-based cohort.

METHODS AND RESULTS

A total of 206 554 first-ever admissions to the Allgemeines Krankenhaus Wien for determination of MPV between January 1996 and July 2003 were included. Primary end points were overall vascular mortality and death due to ischemic heart disease. Multivariate Cox regression adjusted for sex, age, and platelet count was applied for analysis. MPV values were categorized into quintiles, with the lowest quintile serving as the reference category. Compared with individuals with lower MPV (<8.7 fL), hazard ratios for overall vascular mortality gradually increased to 1.5 in the highest category (≥11.01 fL). The relationship of MPV to ischemic heart disease was even stronger and increased from 1.2 (8.71 to 9.60 fL category) to 1.8 in the highest category (≥11.01 fL).

CONCLUSIONS

Our results indicate that patients with an increased MPV (≥11.01 fL) are at higher risk of death due to ischemic heart disease, with hazard ratios comparable to those reported for obesity or smoking.

Platelet activation patterns in platelet size sub-populations: differential responses to aspirin in vitro

Circulating platelets are heterogeneous in size and structure. Whether this translates into differences in platelet function and efficacy of antiplatelet therapy is unclear. Hence, we decided to investigate the activation patterns among different platelet populations differentiated by size, and to compare the inhibitory effects of aspirin in these populations. Circulating platelets from 9 healthy volunteers were separated by size and stratified into the largest and smallest quintiles. Platelets were stimulated with 75 μM arachidonic acid (AA), 10 μM ADP or 25 μM TRAP. Alpha-granule protein secretion and expression (P-selectin, VWF, fibrinogen), surface-protein activation (activated integrin αIIbβ3) were assessed. Platelet thromboxane B(2) (TxB(2)) synthesis following AA stimulation was measured in vitro before and after incubation with 265 μM aspirin. Reticulated (juvenile) platelets were assessed using thiazole orange staining. A greater number of large platelets in the largest quintile were reticulated compared with the smallest quintile (6.1 ± 2.8% vs. 1.2 ± 1.5% respectively, p < 0.001). Larger platelets also synthesized more TxB(2) than small platelets both before (1348 ± 276 pg/mL vs. 1023 ± 214 pg/mL, respectively, p = 0.01) and after aspirin (1029 ± 190 pg/mL vs. 851 ± 159 pg/mL, respectively, p = 0.03). After stimulation with each agonist, a greater proportion of large platelets bound fibrinogen, VWF, P-selectin and activated integrin αIIbβ3 than small platelets both in the presence and in the absence of in vitro aspirin. In an in vitro setting, large platelets appear to be more active than small platelets and continue to be more active even after in vitro aspirin. Platelets exhibit heterogeneity in size and structure. Whether this translates into platelet function and efficacy of antiplatelet therapy is unclear. We evaluated platelet functional properties and the effects of aspirin on separated platelet subpopulations in an in vitro setting. Platelets were sorted into the largest and smallest size quintiles using flow cytometry forward scatter. Alpha-granule protein release, dense granule content, surface protein activation and thromboxane synthesis were significantly greater in large platelets compared with small platelets, before and after stimulation with arachidonic acid, ADP and TRAP. Even after incubation with aspirin, large platelets continued to be more active than small platelets. In conclusion, large platelets are more active than small platelets and aspirin fails to eliminate these differential activation properties.

Usefulness of mean platelet volume as a biomarker for long-term outcomes after percutaneous coronary intervention

Larger size platelets have enhanced reactivity. The mean platelet volume (MPV) is a marker of platelet activation and is usually measured as part of blood testing. The aim of the present study was to investigate the utility of the MPV as a biomarker in prognosticating the long-term outcomes after percutaneous coronary intervention (PCI). The baseline MPV values from consecutive patients undergoing PCI were screened. Of the 1,432 patients, the composite primary end point of mortality or myocardial infarction at 1 year occurred in 80 (5.6%). The patients in the highest tertile (MPV >9.1 fL) had an increased frequency of the primary end point compared to those in the mid (8.1 to 9.1 fL) and lowest (<8.1 fL) tertiles (9.0%, 4.5%, and 3.5%, respectively; p <0.01). Logistic regression analysis demonstrated diabetes (odds ratio 2.44, 95% confidence interval 1.48 to 4.00) and highest tertile of MPV (odds ratio 2.42, 95% confidence interval 1.47 to 3.99) as the best predictors of adverse outcomes. In patients with acute coronary syndrome, the preprocedural MPV and troponin levels demonstrated a comparable predictive relation to the primary end point (receiver operator characteristics curve analysis, area under the curve 0.64, p = 0.01; and 0.63, p = 0.01, respectively). In conclusion, an elevated MPV was a strong independent predictor of long-term outcomes after PCI. The preprocedural MPV had prognostic value similar to that of troponin in patients with acute coronary syndrome. These findings could be of importance in the clinical evaluation of patients before PCI and the design of future studies assessing antiplatelet therapies.

Mean platelet volume as a predictor of cardiovascular risk: a systematic review and meta-analysis

AIM

To determine whether an association exists between mean platelet volume (MPV) and acute myocardial infarction (AMI) and other cardiovascular events. Platelet activity is a major culprit in atherothrombotic events. MPV, which is widely available in clinical practice, is a potentially useful biomarker of platelet activity in the setting of cardiovascular disease.

METHODS AND RESULTS

We performed a systematic review and meta-analysis investigating the association between MPV and AMI, all-cause mortality following myocardial infarction, and restenosis following coronary angioplasty. Results were pooled using random-effects modeling. Pooled results from 16 cross-sectional studies involving 2809 patients investigating the association of MPV and AMI indicated that MPV was significantly higher in those with AMI than those without AMI [mean difference 0.92 fL, 95% confidence interval (CI) 0.67-1.16, P < 0.001). In subgroup analyses, significant differences in MPV existed between subjects with AMI, subjects with stable coronary disease (P < 0.001), and stable controls (P < 0.001), but not vs. those with unstable angina (P = 0.24). Pooled results from three cohort studies involving 3184 patients evaluating the risk of death following AMI demonstrated that an elevated MPV increased the odds of death as compared with a normal MPV (11.5% vs. 7.1%, odds ratio 1.65, 95% CI 1.12-2.52, P = 0.012). Pooled results from five cohort studies involving 430 patients who underwent coronary angioplasty revealed that MPV was significantly higher in patients who developed restenosis than in those who did not develop restenosis (mean difference 0.98 fL, 95% CI 0.74-1.21, P < 0.001).

CONCLUSIONS

Elevated MPV is associated with AMI, mortality following myocardial infarction, and restenosis following coronary angioplasty. These data suggest that MPV is a potentially useful prognostic biomarker in patients with cardiovascular disease. Whether the relationship is causal, and whether MPV should influence practice or guide therapy, remains unknown.

Increased mean platelet volume in patients with acute coronary syndromes

CONTEXT

Despite remarkable progress, the diagnosis of acute coronary syndromes (ACS) is still challenging.

OBJECTIVE

The mean platelet volume (MPV), a simple and reliable indicator of platelet size that correlates with platelet activation, might be an emerging cardiovascular risk marker and potentially helpful in stratifying cardiovascular risk.

DESIGN

We analyzed MPV values in 2304 adult patients who were consecutively admitted during a 1-year period to the emergency department of the University Hospital of Verona for chest pain suggestive of ACS. In all patients, a baseline blood sample was collected for routine hematologic testing, whereas cardiac troponin T measurements were collected both at baseline and after 4, 6, and 12 hours.

RESULTS

A total of 456 patients (19.8% of total) had ACS. These patients, all having cardiac troponin T levels of 0.03 ng/mL or greater in addition to ischemic electrocardiographic changes, had higher MPV values than non-ACS patients with normal cardiac troponin T levels (median, 8.0 fL [5th to 95th percentiles, 6.7-10.0 fL] versus median, 7.4 fL [5th to 95th percentiles, 6.5-9.5 fL]; P < .001). The diagnostic accuracy of MPV, calculated as the area under the curve by the receiver operating characteristic analysis, was 0.661 (P < .001). At the 9.0-fL cutoff, the negative and positive predictive values of MPV were 83% and 43%, respectively.

CONCLUSIONS

Because MPV is a simple and inexpensive laboratory measurement, it might be considered a useful rule-out test along with other conventional cardiac biomarkers for the risk stratification of ACS patients admitted to the emergency departments.

Mean platelet volume as a predictor of cardiovascular risk: a systematic review and meta-analysis

AIM

To determine whether an association exists between mean platelet volume (MPV) and acute myocardial infarction (AMI) and other cardiovascular events. Platelet activity is a major culprit in atherothrombotic events. MPV, which is widely available in clinical practice, is a potentially useful biomarker of platelet activity in the setting of cardiovascular disease.

METHODS AND RESULTS

We performed a systematic review and meta-analysis investigating the association between MPV and AMI, all-cause mortality following myocardial infarction, and restenosis following coronary angioplasty. Results were pooled using random-effects modeling. Pooled results from 16 cross-sectional studies involving 2809 patients investigating the association of MPV and AMI indicated that MPV was significantly higher in those with AMI than those without AMI [mean difference 0.92 fL, 95% confidence interval (CI) 0.67-1.16, P < 0.001). In subgroup analyses, significant differences in MPV existed between subjects with AMI, subjects with stable coronary disease (P < 0.001), and stable controls (P < 0.001), but not vs. those with unstable angina (P = 0.24). Pooled results from three cohort studies involving 3184 patients evaluating the risk of death following AMI demonstrated that an elevated MPV increased the odds of death as compared with a normal MPV (11.5% vs. 7.1%, odds ratio 1.65, 95% CI 1.12-2.52, P = 0.012). Pooled results from five cohort studies involving 430 patients who underwent coronary angioplasty revealed that MPV was significantly higher in patients who developed restenosis than in those who did not develop restenosis (mean difference 0.98 fL, 95% CI 0.74-1.21, P < 0.001).

CONCLUSIONS

Elevated MPV is associated with AMI, mortality following myocardial infarction, and restenosis following coronary angioplasty. These data suggest that MPV is a potentially useful prognostic biomarker in patients with cardiovascular disease. Whether the relationship is causal, and whether MPV should influence practice or guide therapy, remains unknown.