Platelet turnover in stable coronary artery disease - influence of thrombopoietin and low-grade inflammation

Haematological Indices in Acute Coronary Syndrome Patients in Ethiopia: A Comparative Cross-Sectional Study

Background

Numerous biomarkers are used as diagnostic, prognostic, and predictive indicators of myocardial ischemia. The most commonly used biomarkers are cardiac troponin I (Tn-I) and creatinine kinase (CK-MB). However, in developing nations, their availability in primary care settings is extremely limited. In such situations, easily available assays such as complete blood count (CBC) should be investigated as prognostic indicators in individuals with acute coronary syndrome (ACS).

Objective

This study aimed to compare the pattern of haematological indices and blood cell ratios of ACS patients compared with apparently healthy controls.

Methods

Patients diagnosed with ACS were recruited consecutively between 01 May 2022 and 31 October 2023 at Jimma Medical Center (JMC). Biochemical analyses and complete blood counts were performed. Analysis of variance was performed to compare the continuous variables. Spearman correlation coefficient tests were performed to correlate hematologic parameters with high sensitive troponin-I (hs-Tn-I) levels.

Results

This study enrolled 220 participants (110 patients with ACS and age, sex, and place of residence matched 110 non-ACS controls). From ACS group 99 (90%) were diagnosed with ST-elevated myocardial infarction. The ACS group had a significantly greater mean platelet volume (MPV), white blood cell count, red cell distribution width (RDW), neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio. The RDW (r = 0.248, p = 0.009) and MPV (r = 0.245, p = 0.009) were significantly positively correlated with hs-Tn-I levels in the ACS group. MPV, RDW, and monocyte count were significantly higher in non-survivor ACS patients (p <0.05).

Conclusion

The significant differences observed in haematological parameters between individuals with ACS and healthy controls suggest the potential utility of these easily accessible and cost-effective diagnostics in predicting future morbidity and ACS risk. Incorporating these routine evaluations into clinical practice could enhance risk assessment and improve patient outcomes.

Platelets and the Atherosclerotic Process: An Overview of New Markers of Platelet Activation and Reactivity, and Their Implications in Primary and Secondary Prevention

The key role played by platelets in the atherosclerosis physiopathology, especially in the acute setting, is ascertained: they are the main actors during thrombus formation and, thus, one of the major investigated elements related to atherothrombotic process involving coronary arteries. Platelets have been studied from different points of view, according with the technology advances and the improvement in the hemostasis knowledge achieved in the last years. Morphology and reactivity constitute the first aspects investigated related to platelets with a significant body of evidence published linking a number of their values and markers to coronary artery disease and cardiovascular events. Recently, the impact of genetics on platelet activation has been explored with promising findings as additional instrument for patient risk stratification; however, this deserves further confirmations. Moreover, the interplay between immune system and platelets has been partially elucidated in the last years, providing intriguing elements that will be basic components for future research to better understand platelet regulation and improve cardiovascular outcome of patients.

Sex differences in the relationship between platelet count and type 2 diabetes risk in community-dwelling adults: Longitudinal findings over 14 years

AIMS

Emerging evidence suggests that platelet count predicts the development of type 2 diabetes; however, there is conflicting evidence concerning the relationship in men and women. This study aimed to assess the longitudinal association between platelet count and the incidence risk of type 2 diabetes.

MATERIALS AND METHODS

Among 10,030 participants, 7325 participants (3439 men and 3886 women) without diabetes were selected from the Korean Genome and Epidemiology Study. Platelet count quartiles were divided as follows: Q1 ≤219, Q2, 220-254, Q3, 255-296 and Q4 ≥297 (x103 /ml) for men and ≤232, 233-266, 267-305 and ≥306 (x103 /μL) for women. The hazard ratios (HRs) with 95% confidential intervals (CIs) for incident type 2 diabetes were calculated using multiple Cox proportional hazards regression models according to sex-specific platelet count quartiles.

RESULTS

During the biennial follow-up period from 2001 to 2002 to 2013-2014, 750 male participants (21.8%, 750/3439) and 730 female participants (18.8%, 730/3886) had newly developed type 2 diabetes. For women, compared to the reference first quartile, the HRs for incident type 2 diabetes in the second, third, and fourth platelet count quartiles were 1.20 (0.96-1.50), 1.21(0.97-1.51), and 1.47 (1.18-1.82) after adjusting for age, body mass index, smoking status, alcohol intake, physical activity, mean arterial blood pressure, family history of diabetes, and HOMA-IR. However, these positive relationships were not observed in men after adjusting for the same co-variables.

CONCLUSIONS

Platelet count was independently associated with an increased risk of incident type 2 diabetes only in women.

Associations Between Mean Platelet Volume and Various Factors in Type 2 Diabetes Patients: A Single-Center Study from Poland

BACKGROUND Thromboembolic episodes, which are largely mediated by blood platelets, are prevalent chronic complications of diabetes. The mean platelet volume (MPV) serves as a marker for in vivo platelet activation. This study aimed to assess the factors influencing MPV in 106 patients with type 2 diabetes, compared with 59 non-diabetic individuals at a single center in Poland. MATERIAL AND METHODS We performed linear regression analysis, with MPV as the dependent variable and factors such as age, sex, thrombopoiesis-influencing cytokines, blood pressure, body mass index, glycosylated hemoglobin percentage, platelet count, large platelet count, lipid profile parameters, creatinine concentration, estimated glomerular filtration rate, treatment modalities, and comorbidities as independent variables. MPV was measured using the ADVIA 2120 hematology analyzer, with a reference range of 7-12 fL. RESULTS The analysis revealed that in patients with type 2 diabetes, an increase in platelet count by 10×10³/μL resulted in a decrease in MPV by 0.05 (P<0.001), while an increase in large platelet count by 1×10³/μL led to an increase in MPV by 0.18 (P<0.001). Additionally, patients taking ß-blockers or insulin had lower MPVs by 0.77 (P=0.008) and 5.63 (P<0.001), respectively, compared with those not on these medications. CONCLUSIONS This study delineates the relationship between MPV, platelet parameters, and treatment modalities in type 2 diabetes, paving the way for further research to elucidate underlying mechanisms and potential clinical applications.

Adaptive changes in redox response and decreased platelet aggregation in lead-exposed workers

Chronic lead exposure can generate pro-oxidative and pro-inflammatory conditions in the blood, related to high platelet activation and aggregation, altering cell functions. We studied ADP-stimulated aggregation and the oxidant/antioxidant system of platelets from chronically lead-exposed workers and non-exposed workers. Platelet aggregation was low in lead-exposed workers (62 vs. 97%), who had normal platelet counts and showed no clinical manifestations of hemostatic failure. ADP-activated platelets from lead-exposed workers failed to increase superoxide release (3.3 vs. 6.6 µmol/g protein), had low NADPH concentration (60 vs. 92 nmol/mg protein), high concentration of hydrogen peroxide (224 vs. 129 nmol/mg protein) and high plasma PGE₂ concentration (287 vs. 79 pg/mL). Altogether, those conditions, on the one hand, could account for the low platelet aggregation and, on the other, indicate an adaptive mechanism for the oxidative status of platelets and anti-aggregating molecules to prevent thrombotic problems in the pro-oxidant and pro-inflammatory environment of chronic lead exposure.

Immature platelet fraction in cardiovascular diagnostics and antiplatelet therapy monitoring

Immature platelet fraction (IPF), circulating platelets still containing RNA, can be easily calculated by automated flow cytometry, this makes them an accessible biomarker. Higher IPF concentrations were reported in patients with thrombocytopenia, patients who were smokers, and also those who were diabetics. Several studies have reported their diagnostic and prognostic importance in patients presenting with acute coronary syndromes, especially ST-segment elevation myocardial infarction, where increased IPF level is an independent predictor of cardiovascular death. In addition, higher IPF were reported in patients with inadequate response to either clopidogrel or prasugrel, suggesting their potential role in antiplatelet therapy monitoring. Their prognostic significance was also observed in both coronary artery disease and postcardiac surgery status, where their higher levels correlated with the risk of major adverse cardiac events. The current review aims to present the current evidence on diagnostic, prognostic and potentially therapeutic roles of IPF in cardiovascular medicine.

Systemic immune-inflammation index as a prognostic marker for advanced chronic heart failure with renal dysfunction

AIMS

We aim to investigate the correlation between high levels of the systemic immune-inflammation index (SII) and long-term mortality and major cardiovascular adverse events in advanced chronic heart failure patients with renal dysfunction.

METHODS AND RESULTS

Seven hundred seventeen advanced chronic heart failure patients with renal dysfunction, who visited the First affiliated hospital of Zhengzhou University from September 2019 to December 2020, were included. All-cause mortalities (ACM) were selected as primary endpoints and major cardiovascular adverse events (MACEs) as the secondary endpoints. Based on the receiver operating characteristic (ROC) curve and the Youden index, the optimal cut-off values of SII for ACM and MACEs were 1228 and 1406. In the group where ACM were the primary endpoint, patients were categorized into the low-SII group (n = 479) and the high-SII group (n = 238). Patients in the group using MACEs as the secondary endpoint were also categorized into the low-SII groups (n = 514) and the high-SII groups (n = 203). Univariate and multivariate COX regression were used to screen the independent predictors for ACM and MACEs, revealing the relationship between SII levels and endpoints. According to the univariate COX analysis, SII was the risk factor (hazard ratio [HR] = 2.144, 95% confidence interval [CI]: 1.565-2.938, P < 0.001) for the ACM subgroup. It was also the risk factor (HR = 1.625, CI: 1.261-2.905, P < 0.001) for the MACEs subgroup. Multivariate COX regression analysis indicated that the occurrence of ACM and MACEs in high-level SII and low-level SII patients had statistical differences. The incidence of ACM increased by 70.3% (HR = 1.703; 95% CI: 1.200-2.337; P = 0.002) in patients of the high SII level group, the incidence of MACEs increased by 58.3% (HR = 1.583, 95% CI: 1.213-2.065, P = 0.001). Kaplan-Meier (K-M) survival analysis further suggested that patients with a high SII level had an increased risk of having ACM (log-rank P < 0.001) and MACEs (log-rank P < 0.001) within 30 months. SII could be considered as a novel predictor of the occurrence of ACM and MACEs for patients with advanced chronic heart failure and renal dysfunction.

CONCLUSIONS

This study suggested that SII is a novel independent predictor of mortality in advanced chronic heart failure patients with renal dysfunction, and it should be considered in current clinical management.

A mean platelet volume in inflammatory bowel disease: A systematic review and meta-analysis

Background

Inflammatory bowel disease (IBD) is a chronic gastrointestinal tract inflammatory state, which is affecting millions of individuals in the world. It can affect alimentary canals such as colon, rectum, ileum and other parts. In IBD, platelet parameters underwent several changes. Therefore, the aim of this review was determining the estimated pooled mean platelet volume and mean difference in inflammatory bowel disease to elucidate its potential diagnostic value.

Methods

Articles were extensively searched in bibliographic databases using Medical Subject Heading and entry phrases or terms. In addition, articles were directly searched in Google Scholar to account for the studies omission in searching bibliographic databases. Observational (cohort, cross-sectional and case-control) studies, published in English language and conducted on IBD were included. For studies meeting the eligibility criteria, the first author’s name, publication year, population, study design, study area, sample size, mean platelet volume and standard deviation were extracted and entered in to Microsoft-excel. The analysis was done by Stata version 11. In order to estimate the pooled mean platelet volume and mean difference, random effect model was done. The heterogeneity was quantified using Higgin’s I² statistics. Publication bias was determined using Egger’s test statistics and funnel plot. Sub-group analysis based on population carried to reduce heterogeneity.

Results

A total of 17 relevant articles with 2957 participants (1823 IBD cases and 1134 healthy controls) were included to this study. The pooled estimated MPV was 9.29fl; 95% CI: 9.01–9.57 and 9.50fl; 95% CI: 8.81–10.20 in IBD and control groups, respectively. The standardized pooled estimate of mean difference in mean platelet volume was -0.83fl; 95% CI: -1.15, -0.51; I²: 93.1%; P-value < 0.001. In subgroup analysis based on population, the highest estimated mean difference in MPV was observed among patients of CD; -2.30; 95% CI: -3.46, -1.14; I²: 97.8%; P-value < 0.001.

Conclusion

According to the current systematic review and meta-analysis, mean platelet volume was lower in IBD compared to control. The decreased mean platelet volume could be attributed to platelet consumption or sequestration associated with the progression of IBD. As a result, in IBD, mean platelet volume can provide diagnostic and prognostic information.

Comparison of the value of immature retyculocyte and immature platelet in the diagnosıs of sepsis

BACKGROUND

Sepsis is one of the causes of pre-treatment morbidity and mortality in the pediatric age group. In the present study, we investigated the place of the immature granulocyte percentage, (IG) immature reticulocyte fraction (IRF), and immature platelet fraction (IPF) in the diagnosis of sepsis.

METHODS

Complete blood count, C-reactive protein, (CRP) procalcitonin (PCT) and blood cultures were measured in 125 critical patients who were followed-up in the intensive care unit with the suspicion of sepsis and 65 healthy children between 2017 and 2019. In addition to the complete blood counts and routine parameters, IG, IRF, and IPF were examined in the patients.

RESULTS

When the critical patient group and the healthy control group were compared, it was found that the total number of leukocytes (white blood cells), neutrophil count, platelet count, CRP, PCT, IG, IRF, and IPF values were higher at statistically significant levels. When septic and non-septic patients were compared, it was found that the CRP, PCT,IGP, and IPF were higher at statistically significant levels in the septic patients.

CONCLUSIONS

It was concluded that CRP, PCT, IG, and IPF were significant in determining sepsis and that PCT was the most sensitive and specific biomarker in these parameters. We believe that these parameters may be suitable for practical use in determining sepsis because they give faster results and suggest the diagnosis of sepsis.

Aspirin for the prevention of pre-eclampsia in women with pre-existing diabetes: Systematic review

BACKGROUND

There is a lack of evidence for pre-eclampsia prophylaxis with aspirin in women with pre-existing diabetes mellitus (DM).

AIMS

To examine the evidence for aspirin in pre-eclampsia prophylaxis in women with pre-existing DM.

MATERIAL AND METHODS

An electronic search using Ovid MEDLINE, Embase, CinicalTrials.gov and the Cochrane CENTRAL register of controlled trials through to February 2021 was performed. Reference lists of identified studies, previous review articles, clinical practice guidelines and government reports were manually searched. Randomised controlled trials (RCTs) of aspirin vs placebo for pre-eclampsia prophylaxis were included. Articles were manually reviewed to determine if cohorts included women with DM. The systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Data from included trials were extracted independently by two authors who also independently assessed risk of bias as per the Cochrane Handbook criteria version 5.1.0. Data were analysed using Rev-Man 5.4.

RESULTS

Forty RCTs were identified, of which 11 included a confirmed subset of women with DM; however, data were insufficient for meta-analysis. Meta-analysis of 930 women with DM, from individual patient data included in a systematic review and unpublished data from one of the 11 RCTs, showed a non-significant difference in the outcome of pre-eclampsia in participants treated with aspirin compared to placebo (odds ratio 0.58; 95% CI 0.20-1.71; P = 0.33).

CONCLUSIONS

Pre-eclampsia risk reduction with aspirin prophylaxis in women with pre-existing DM may be similar to women without pre-existing DM. However, randomised data within this meta-analysis were insufficient, warranting the need for further studies within this high-risk group of women.

Can immature platelet fraction be an early predictor for congenital pneumonia?

Aim:

Timely diagnosis and treatment of congenital pneumonia are crucial. A new hematologic parameter, immature platelet fraction, has been used to gather clinical information on the prognosis of thrombocytopenia, as well as to measure inflammatory activity in adult patients. This study aimed to compare immature platelet fraction and sepsis biomarkers in late-preterm infants diagnosed as having congenital pneumonia and to evaluate its predictive value for congenital pneumonia.

Material and Methods:

Late-preterms were categorized based on infectious vs. non-infectious etiology of respiratory distress. Two sets of blood samples for markers were taken at 12–24 (sample-1) and 48–72 hours (sample-2) after birth. Immature platelet fraction was measured using a Sysmex XN-3000 analyzer.

Results:

From a total of 30 non-thrombocytopenic late-preterms, 16 were included in the congenital pneumonia group and 14 comprised the transient tachypnea group. The groups were comparable in terms of gestational age, birth weight, and cesarean section rate. The proportion of prolonged membrane rupture was significantly higher in the congenital pneumonia group. Values of immature platelet fraction-1, immature platelet fraction-2, and procalcitonin-2 were significantly higher in the congenital pneumonia group than in the transient tachypnea group. No significant differences were found between the groups in other biomarkers. It was determined that an immature platelet fraction-1 cut-off value of 2.9% could predict congenital pneumonia with a sensitivity of 65%, a specificity of 71.4%, a positive predictive value of 70.5%, and negative predictive value of 63.7% (area under the curve=0.724; p=0.028).

Conclusion:

Immature platelet fraction may have an early predictive role in the diagnosis of congenital pneumonia.

Association between platelet distribution width and prognosis in patients with heart failure

Background

The prognostic impact of platelet distribution width (PDW), which is a specific marker of platelet activation, has been unclear in patients with heart failure (HF).

Methods and results

We conducted a prospective observational study enrolling 1,746 hospitalized patients with HF. Patients were divided into tertiles based on levels of PDW: 1^st (PDW < 15.9 fL, n = 586), 2^nd (PDW 15.9–16.8 fL, n = 617), and 3^rd (PDW ≥ 16.9, n = 543) tertiles. We compared baseline patients’ characteristics and post-discharge prognosis: all-cause death; cardiac death; and cardiac events. The 3^rd tertile showed the highest age and levels of B-type natriuretic peptide compared to other tertiles (1^st, 2^nd, and 3^rd tertiles; age, 69.0, 68.0, and 70.0 years old, P = 0.038; B-type natriuretic peptide, 235.2, 171.9, and 241.0 pg/mL, P < 0.001). Left ventricular ejection fraction was equivalent among the tertiles. In the Kaplan-Meier analysis, rates of all endpoints were the highest in the 3^rd tertile (log-rank P < 0.001, respectively). The Cox proportional hazard analysis revealed that the 3^rd tertile was associated with adverse prognosis (all-cause death, hazard ratio [HR] 1.716, P < 0.001; cardiac death, HR 1.919, P < 0.001; cardiac event, HR 1.401, P = 0.002).

Conclusions

High PDW is a novel predictor of adverse prognosis in patients with HF.

Immature Platelet Dynamics in Immune-Mediated Thrombocytopenic States

A major challenge encountered by clinicians is differentiating presentations characterized by significant thrombocytopenia due to overlapping clinical symptoms and signs in the setting of ambiguous laboratory results. Immature platelets represent the youngest platelets that can be measured in peripheral blood by current hematology analyzers. These young platelets are larger, with higher RNA content recently released from the bone marrow. Thrombocytopenic presentations caused directly or indirectly by immune responses can lead to compensatory bone marrow responses seeking to normalize the platelet count; thus obtaining absolute immature platelet counts may be informative while triaging patients. Over the last decade, their use has expanded beyond being an early biomarker of bone marrow reconstitution post-hematopoietic stem cell transplantation to being used to establish bone marrow responses to infection and thrombocytopenias due to immune etiologies. Its accessibility as part of more detailed platelet indices obtained with routine laboratories makes it a promising option to understand the bone marrow's real-time response to disease states characterized by thrombocytopenia. This review will look at the immature platelet count as a biomarker, while presenting current attempts trying to understand how it could be used in thrombocytopenias occurring secondary to a given immune etiology.

Vascular injury biomarkers and stroke risk

Objective

Because little is known about associations between biomarkers of vascular injury and stroke risk, we evaluated associations between plasma concentrations of 6 novel biomarkers of vascular injury and stroke risk in a population-based study.

Methods

A case–cohort subset of EPIC-Heidelberg (European Prospective Investigation for Cancer and Nutrition–Heidelberg) including incident stroke cases (n = 335) and a random subcohort (n = 2,418) was selected. Concentrations of intercellular adhesion molecule 3 (ICAM3), soluble E-selectin and P-selectin, soluble thrombomodulin (sTM), thrombopoietin, and glycoprotein IIb/IIIa were measured in baseline plasma samples. Weighted Cox regression analyses were used to assess associations between biomarker levels and stroke risk.

Results

Median follow-up in the subcohort and among cases was 9.8 (range, 0.1–12.5) years and 6.2 (range, 0.01–12.1) years, respectively. ICAM3 levels were associated with increased risk of incident stroke after multivariable adjustment (hazard ratio, highest vs lowest quartile: 1.64 [95% confidence interval, 1.15–2.32]; plinear trend < 0.001). This association was more apparent for ischemic (1.65 [1.12–2.45]; plinear trend < 0.01) than for hemorrhagic stroke (1.29 [0.60–2.78]; plinear trend = 0.3). We further observed a borderline significant trend for a positive association between sTM and overall stroke risk (1.47 [0.99–2.19]; plinear trend = 0.05).

Conclusions

In this population-based study, circulating levels of ICAM3, an adhesion molecule shed by leukocytes, were associated with increased risk of incident stroke. Further mechanistic studies are needed to elucidate the pathophysiology underlying this association.

Classification of evidence

This study provides Class II evidence that plasma levels of ICAM3 are associated with increased stroke risk.

Impact of diabetes mellitus on immature platelet fraction and its association with coronary artery disease

BACKGROUND

Higher prothrombotic status and alterations in platelet function and thrombopoiesis are associated with diabetes mellitus (DM). We assessed the impact of diabetes and glucose control on the immature platelet fraction (IPF) and their relationship with prevalence and extent of coronary artery disease (CAD).

METHODS

Consecutive patients undergoing coronary angiography were included. Significant CAD was defined as at least one vessel stenosis greater than 50%. IPF levels were measured at admission by routine blood cells count (A Sysmex XE-2100).

RESULTS

We included 1781 patients, of whom 660 (37.1%) suffered from diabetes. Diabetes was associated with advanced age and a higher cardiovascular risk profile. No difference in the mean values of IPF were observed between patients with or without DM (3.6 ± 2.5 vs 3.5 ± 2.5, P = 0.39) and neither in the rate of patients with IPF above the median (2.9%) (51.6% vs 50.6%, P = 0.73). In patients with DM, the IPF levels did not relate with glucose control parameters (glycaemia: r = -0.024, P = 0.54, glycosylated haemoglobin: r = 0.11, P = 0.72). The prevalence of CAD was significantly lower in patients with DM and IPF greater than the median (80.5% vs 86.5%, P = 0.04, adjusted odds ratio [OR] [95% confidence interval {CI}] = 0.57[0.36-0.91], P = 0.02), while not left main/three-vessel CAD (36.9% vs 38.2%, P = 0.75, adjusted OR [95%CI] = 0.91[0.64-1.28], P = 0.90).

CONCLUSION

In the present study, neither DM nor glucose control are independent predictors of IPF above the median. In patients with DM, higher IPF levels were associated with a lower prevalence of CAD and with a similar extent of severe CAD and angiographic findings. Therefore, until new data become available, elevated IPF should not be systematically applied on a large scale as cardiovascular risk marker in patients with diabetes.

Impact of aging on platelet reactivity in diabetic patients receiving dual antiplatelet therapy

Advanced age and diabetes represent summative conditions in the determination of cardiovascular risk, and especially for the management of dual antiplatelet therapy (DAPT), often requiring balancing between bleeding and thrombotic complications. However, few studies have so far evaluated the impact of age on platelet reactivity and suboptimal platelet inhibition (high-on treatment platelet reactivity-HRPR) on DAPT among diabetic patients, that was, therefore the aim of the present study. In diabetic patients treated with DAPT (ASA + clopidogrel or ticagrelor) platelet reactivity was assessed at 30-90 days post-discharge for an acute coronary syndrome or elective PCI. Aggregation was assessed by multiple-electrode aggregometry. HRPR was defined for values above the lower limit of normality (in non-treated patients). Elderly patients were considered ≥ 75 years of age. We included 462 patients, among them 149 (32.2%) were ≥ 75 years. Elderly patients were more often females (p = 0.006), with lower body size (p = 0.04), acute coronary syndrome at presentation and renal failure (p < 0.001), non-smokers (p = 0.002), in therapy with insulin (p = 0.02) and diuretics (p < 0.001) and lower rate of betablockers (p = 0.02). Age directly related with C reactive protein (p = 0.01), creatinine levels and inversely with hemoglobin (p < 0.001) and triglycerides (p = 0.003). No association was found at linear regression analysis for platelet reactivity and age with different activating stimuli, but for ASPI test (r = 0.12; p = 0.03). No significant difference in HAPR was found in elderly patients (2.4 vs. 3.2%, p = 0.76, OR[95% CI] = 0.45[0.1-2.11], p = 0.31). HRPR for ADP antagonists was similarly not affected by age (30.1% vs. 35.7%, p = 0.28, adjusted OR[95% CI] = 0.78[0.47-1.29], p = 0.33). Comparable results were obtained when considering separately the DAPT strategies with clopidogrel or ticagrelor, or when adjusting our results according to propensity score values. Among diabetic patients receiving dual antiplatelet therapy for an acute coronary syndrome or elective percutaneous coronary intervention, age does not affect platelet reactivity or the rate of high-on treatment platelet reactivity. Similar results were obtained for ASA and clopidogrel or ticagrelor.

Impact of active smoking on the immature platelet fraction and its relationship with the extent of coronary artery disease

INTRODUCTION

Smoking represents a major cardiovascular risk factor, due to the induction of oxidative stress and low-grade, continuous, inflammation that contribute to promote atherothrombosis. However, the mechanisms leading to increased platelet aggregability associated with smoking are only partially defined. A potential role has been hypothesized for immature platelets, a younger and potentially more reactive fraction, previously associated with the main determinants of coronary artery disease (CAD). Therefore, the aim of our study was to define the impact of smoking on the immature platelet fraction (IPF) and its relationship with prevalence and extent of coronary artery disease.

METHODS

We enrolled a cohort of consecutive patients undergoing coronary angiography in a single centre. Significant CAD was defined as at least 1 vessel stenosis >50%, while severe CAD was defined as left main and/or three-vessel disease. IPF was measured at admission by routine blood cell count (Sysmex XE-2100).

RESULTS

We included in our study 2553 patients who were divided according to smoking status (active smokers: 512; nonactive smokers: 2041). Smokers were younger, more frequent males, with lower rate of diabetes mellitus, previous PCI and previous CABG (P < .001, respectively) and were in treatment less often with ARB, BB, nitrates, statins, ASA, clopidogrel, CCB and diuretics (P < .001, respectively) as compared to nonactive smokers. Higher percentage of smokers was observed in patients with higher IPF values, and at multivariate analysis, active smoking resulted as an independent predictor of higher IPF (adjusted OR [95% CI] = 1.59[1.03-2.45], P = .035). Among smokers, higher IPF was associated with lower ejection fraction (P = .034), percentage of acute coronary syndrome (P = .002) and platelet count (P < .001) compared to ones with lower IPF. However, the IPF (according to quartiles values) was not associated with the prevalence and extent of CAD (82.5%, 80.4%, 86.1% and 80.9%, from 1st to 4th quartile, respectively, adjusted OR[95% CI] = 0.98[0.79-1.23], P = .89) and severe CAD (31%, 31.1%, 39.1% and 35.2%, from 1st to 4th quartile, respectively, adjusted OR[95% CI] = 1.03[0.86-1.23], P = .76).

CONCLUSION

The present study shows an independent association between active smoking and the levels of immature platelet fraction in patients undergoing coronary angiography. However, among active smokers, IPF did not result as an independent predictor of CAD or severe CAD.

Impact of aging on immature platelet count and its relationship with coronary artery disease

Despite the fact that elderly patients represent a prevalent and challenging population in the current practice, few data exist on the impact of platelet parameters on cardiovascular risk in these patients. Therefore, the aim of the present study was to evaluate the impact of age on the immature platelet count (IPC) and their relationship with CAD. We included a total of 2236 consecutive patients undergoing coronary angiography in a single center. Elderly patients (age ≥ 75 years) were 756 (33.7%). IPC was measured at admission. Elderly patients were more often females (p < .001), with lower BMI and prevalence of smokers (p < .001), and a more complex cardiovascular risk profile and coronary disease (p = .02). Platelet count decreased with aging (p = .05), whereas no difference in the mean IPC was found between patients < or ≥75 years. In fact, advanced age did not emerge as an independent predictor of IPC above III tertile (≥8.6*10^6/ml), (adjusted OR[95%CI] = 0.97[0.78-1.21], p = .79). When considering elderly patients according to tertiles values of IPC (<5.1,5.1-8.59; ≥8.6*10^6/ml), we found no impact of IPC on the prevalence of CAD (81.1% vs 84.5% vs 81.5%, p = .92; adjusted OR[95%CI] = 1.08[0.67-1.72], p = .75) and its extent (37.7% vs 34.5% vs 40.2%, p = .57; adjusted OR[95%CI] = 1.22[0.85-1.73], p = .28). However, we observed a higher rate of calcified and type C lesions in elderly patients with higher IPC (p = .03 and p < .001, respectively). Therefore, advanced age is not associated with higher immature platelet count and the prevalence and severity of CAD. Moreover, IPC does not contribute to explain the higher prevalence and extent of coronary artery disease observed in elderly patients.

Determinants of aspirin resistance in patients with type 2 diabetes

BACKGROUND

Cardiovascular disease is a leading cause of mortality among patients with type 2 diabetes mellitus (T2DM). Numerous patients with T2DM show resistance to aspirin treatment, which may explain the higher rate of major adverse cardiovascular events observed compared with non-diabetes patients, and it has recently been shown that aspirin resistance is mainly related to accelerated platelet turnover with persistent high platelet reactivity (HPR) 24h after last aspirin intake. The mechanism behind HPR is unknown. The aim of this study was to investigate the precise rate and mechanisms associated with HPR in a population of T2DM patients treated with aspirin.

METHODS

Included were 116 consecutive stable T2DM patients who had attended our hospital for their yearly check-up. HPR was assessed 24h after aspirin intake using light transmission aggregometry (LTA) with arachidonic acid (AA) and serum thromboxane B2 (TXB2) measurement. Its relationship with diabetes status, insulin resistance, inflammatory markers and coronary artery disease (CAD) severity, using calcium scores, were investigated.

RESULTS

Using LTA, HPR was found in 27 (23%) patients. There was no significant difference in mean age, gender ratio or cardiovascular risk factors in patients with or without HPR. HPR was significantly related to duration of diabetes and higher fasting glucose levels (but not consistently with HbA_1c), and strongly related to all markers of insulin resistance, especially waist circumference, HOMA-IR, QUICKI and leptin. There was no association between HPR and thrombopoietin or inflammatory markers (IL-6, IL-10, indoleamine 2,3-dioxygenase activity, TNF-α, C-reactive protein), whereas HPR was associated with more severe CAD. Similar results were found with TXB2.

CONCLUSION

Our results reveal that 'aspirin resistance' is frequently found in T2DM, and is strongly related to insulin resistance and severity of CAD, but weakly related to HbA_1c and not at all to inflammatory parameters. This may help to identify those T2DM patients who might benefit from alternative antiplatelet treatments such as twice-daily aspirin and thienopyridines.

Biomarkers of vascular injury in relation to myocardial infarction risk: A population-based study

Little is known about circulating biomarkers of vascular injury in relation to cardiovascular disease risk. Thus, we evaluated associations between six novel markers (E-Selectin, P-Selectin, thrombomodulin, thrombopoietin, intercellular adhesion molecule 3 and GPIIb/IIIa) and established cardiovascular risk factors as well as the risk of myocardial infarction (MI) in a population-based study. Biomarkers were measured in pre-diagnostic plasma samples of a case-cohort subset of EPIC-Heidelberg (incident MI cases: n = 369, random sub-cohort: n = 2,418). Generalized Linear models were used to analyse cross-sectional associations between biomarkers and cardiovascular risk factors. Multivariable Cox Regression analyses were carried out to obtain Hazard Ratios (HRs) of MI across quartiles of biomarkers levels. Cross-sectional analyses showed that sex, smoking, alcohol consumption, diabetes and exogenous hormone use were associated with biomarker levels. However, while fibrinogen was associated with MI risk (HR per standard deviation: 2.97 [95% confidence interval: 1.61, 5.46]), none of the six novel biomarkers was associated with MI risk after multivariable adjustment. In a population-based cohort, biomarkers of vascular injury were associated with established cardiovascular risk factors, but not MI risk. The tested biomarkers may reflect pathophysiological alterations in cardiovascular disease development rather than constituting independent MI risk factors.

Hematological Parameters as Prognostic Biomarkers in Patients with Cardiovascular Diseases

Cardiovascular diseases are the major causes of preventable health loss from disease in the world and lead to functional disturbances including hematological parameters. The inflammatory and hypoxemic nature of cardiovascular diseases causes a stimulus in the bone marrow and, depending on the intensity of this stimulus, there is a release of immature cells or increase of other cells in the bloodstream. Therefore, their presence in the circulation is an important variable used to diagnose, stratify and predict diseases. In the last five decades, with the advent of automated counting of immature cells in the peripheral blood, the hemogram was transformed into a clinical tool of great importance in hospital surveillance for demonstrating this daily variability in the hematopoietic response according to the existing injury in the patient. Studies have shown that the presence of nucleated red blood cells and increases in mean platelet volume, immature granulocytes and neutrophil to lymphocyte ratio in the systemic circulation are independent prognostic biomarkers. This review article has as main objective to demonstrate the association of these hematological parameters to cardiovascular diseases, emphasizing their importance in clinical decision making.

Impact of statin therapy on the immature platelet count in patients with coronary artery disease: A single centre cohort study

BACKGROUND

Statins represent a pivotal therapy among patients with coronary artery disease (CAD), providing both lipid-lowering and pleiotropic, anti-thrombotic and anti-inflammatory benefits. Immature platelet count (IPC) has been proposed as the fraction of younger and potentially more reactive platelets, therefore potentially affecting the risk of major cardiovascular ischemic events. The aim of the present study was to evaluate the impact of statin therapy on IPC in patients with CAD.

METHODS

Patients undergoing coronary angiography in a single centre were included. IPC levels were measured by routine blood cells count (A Sysmex XE-2100) as the product of immature platelet fraction (IPF) and platelet count, in patients naïve or chronically treated with statins at admission.

RESULTS

We included in our study 642 patients, 61.2% treated with statins at admission. Patients on chronic statins were more often males, with a worse metabolic profile, but for lower total and LDL cholesterol, and a higher prevalence of major cardiovascular risk factors. The mean levels of IPC did not differ between statin treated and naive patients (7.9 ± 4.7 vs 7.7 ± 5, p = 0.60) and neither the distribution of IPC across tertiles (p = 0.36). In fact, at multivariate regression analysis, statin use was not independently associated with the rate of IPC above the 3rd tertile (adjusted OR[95%CI] = 1.19[0.80-1.79], p = 0.39). Moreover, among the 190 patients that introduced the therapy with statins at admission, the levels of IPC and major platelet parameters did not differ at a median follow-up of 32 days, as compared to chronically treated or non-treated patients.

CONCLUSION

The present study shows that among patients with CAD the use of statins does not affect the immature platelet count or main platelet parameters.

Platelet pathophysiology, pharmacology, and function in coronary artery disease

Platelets play a key role in the pathophysiology of coronary artery disease and acute coronary syndromes. Our understanding of platelet function in thrombus formation has increased considerably, resulting in the development of clinically effective treatment strategies and identification of new targets. An underappreciated platelet function is their contribution toward acute and chronic inflammatory processes including atherogenesis. In this review, we discuss the role of platelets in atherosclerosis and thrombosis, platelet function testing, and the pharmacology of currently available antiplatelet drugs.

Prognostic value of hematological parameters in patients with acute myocardial infarction: Intrahospital outcomes

Background

The intensity of the inflammatory response and hemodynamic repercussion in acute myocardial infarction causing the presence in the peripheral circulation of nucleated red blood cells (NRBCs), increases in mean platelet volume (MPV) and neutrophil to lymphocyte ratio (NLR) are associated with a poorer prognosis. The aim of this study was to assess the role of these hematological biomarkers as predictors of all causes of mortality during the hospitalization of patients with acute myocardial infarction.

Methods

Nucleated red blood cells, mean platelet volume and neutrophil to lymphocyte ratio were measured daily during the hospitalization of the patients with acute myocardial infarction. We excluded patients younger than 18 years, on glucocorticoid therapy, with cancer or hematological diseases and those that were readmitted after hospital discharge. We performed a multiple logistic analysis to identify independent predictors of mortality.

Results

We included 466 patients (mean age 64.2 ± 12.8 years, 61.6% male). The prevalence of NRBCs in the sample was 9.1% (42 patients), with levels > 200/μL in 27 patients (5.8%). The mean MPV value was 10.9 ±0,9 and the mean NLR value was 3.71 (2,38; 5,72). In a multivariate analysis of serum NRBCs (HR 2.42, 95% CI: 1.35–4.36, p = 0.003), MPV (HR 2.97, 95% CI: 1.15–7.67, p = 0.024) and NLR (HR 5.02, 95% CI: 1.68–15.0, p = 0.004). The presence in the peripheral blood of NRBCs, increased in mean platelet volume and neutrophil to lymphocyte ratio were associated with higher mortality.

Conclusions

Nucleated red blood cells, mean platelet volume and neutrophil to lymphocyte ratio are independent predictors of intrahospital mortality. Therefore, an important tool in intrahospital clinical surveillance.

The influence of low-grade inflammation on platelets in patients with stable coronary artery disease

Inflammation is likely to be involved in all stages of atherosclerosis. Numerous inflammatory biomarkers are currently being studied, and even subtle increases in inflammatory biomarkers have been associated with increased risk of cardiovascular events in patients with coronary artery disease (CAD). Low-grade inflammation may influence both platelet production and platelet activation potentially leading to enhanced platelet aggregation. Thrombopoietin is considered the primary regulator of platelet production, but it likely acts in conjunction with numerous cytokines, of which many have altered levels in CAD. Previous studies have shown that high-sensitive C-reactive protein (CRP) independently predicts increased platelet aggregation in stable CAD patients. Increased levels of CRP, fibrinogen, interleukin-6, stromal cell-derived factor-1, CXC motif ligand 16, macrophage migration inhibitory factor, RANTES, calprotectin, and copeptin have been associated with increased risk of cardiovascular events in CAD patients. Additionally, some of these inflammatory markers have been associated with enhanced platelet activation and aggregation. However, CRP and other inflammatory markers provide only limited additional predictive value to classical risk factors such as smoking, blood pressure, and cholesterol levels. Existing data do not clarify whether inflammation simply accompanies CAD and increased production and aggregation of platelets, or whether a causal relationship exists. In this review, we provide a comprehensive overview of inflammatory markers in stable CAD with particular emphasis on platelet production, activation, and aggregation in CAD patients.

[Regression analysis of red cell distribution width and mean platelet volume in patients with acute myocardial infarction]

OBJECTIVE

To investigate clinical implications of changes in red cell distribution width (RDW) and mean platelet volume (MPV) in patients with acute myocardial infarction.

METHODS

A total of 127 patients (90 men and 37 women) were enrolled in this analysis, including 66 with acute myocardial infarction (AMI) and 61 with unstable angina (UA). The patients' baseline demographic and clinical data were compared between the two groups including age, hypertension, diabetes, smoking, BMI, blood biochemical profiles, cardiac functions and platelet and red blood cell parameters. The patients were further divided into subgroups according to the RDW 50% cumulative frequency, and the MPV, P-LCR, hsCRP, NT-proBNP, RBC, Dimer and MCV were compared. The correlations between platelet and erythrocyte test results were evaluated in both the AMI and UA patients. Regression analysis was performed to identify the factors affecting the RDW in the AMI group and a regression model was established.

RESULTS

The platelet and red blood cell test results, P-LCR, MPV, and RDW differed significantly between AMI and UA groups (P<0.01 or 0.05). Correlation analysis showed a significant positive correlation between RDW and MPV in AMI group (r=0.34, P<0.01). Between the subgroups with different RDW 50% cumulative frequencies, MPV, P-LCR, hsCRP, D-Dimer, and NT-proBNP all differed significantly (P<0.05 or 0.01). In AMI group, with RDW as the dependent variable, we established a multivariate regression model of RDW=0.19MPV+10.83.

CONCLUSION

RDW and MPV are closely correlated in patients with AMI. In multiple regression analysis, MPV can explain the changes in RDW in patients with AMI.

Thrombopoietin and platelet aggregation in patients with stable coronary artery disease

Thrombopoietin (TPO) may facilitate platelet activation and aggregation. However, data on the impact of TPO on platelet aggregation in patients with stable coronary artery disease (CAD) are scarce. We aimed to investigate associations between TPO and platelet aggregation and activation in patients with stable coronary artery disease (CAD). We studied 900 stable CAD patients. Serum TPO was assessed by ELISA. Platelet aggregation was evaluated using the Multiplate Analyzer (agonists: arachidonic acid [AA] and collagen) and the VerifyNow Aspirin Assay. Platelet activation was evaluated by soluble (s)P-selectin. Cyclooxygenase-1 inhibition was evaluated by serum thromboxane B₂ (TXB₂). We found that TPO correlated weakly with platelet aggregation evaluated by Multiplate using AA (r = -0.09, p = 0.01) and collagen as agonists (r = -0.03, p = 0.43) and by VerifyNow (r = 0.07, p = 0.03). We found no correlation between TPO and sP-selectin (r = -0.01, p = 0.70). Independent predictors of AA-induced platelet aggregation by Multiplate included high levels of sP-selectin and serum TXB₂, high platelet count, increasing age and body mass index, female sex, and active smoking. Independent predictors of TPO included low AA-induced platelet aggregation by Multiplate, high levels of hs-CRP, active smoking, and high platelet aggregation evaluated by VerifyNow. In conclusion, TPO levels did not correlate with platelet activation and only weak associations were found between TPO and platelet aggregation, suggesting that TPO did not substantially facilitate platelet aggregation in stable CAD patients.

The use of platelet indices, plateletcrit, mean platelet volume and platelet distribution width in emergency non-traumatic abdominal surgery: a systematic review

Platelet indices (PI) -- plateletcrit, mean platelet volume (MPV) and platelet distribution width (PDW) -- are a group of derived platelet parameters obtained as a part of the automatic complete blood count. Emerging evidence suggests that PIs may have diagnostic and prognostic value in certain diseases. This study aimed to summarize the current scientific knowledge on the potential role of PIs as a diagnostic and prognostic marker in patients having emergency, non-traumatic abdominal surgery. In December 2015, we searched Medline/PubMed, Scopus and Google Scholar to identify all articles on PIs. Overall, considerable evidence suggests that PIs are altered with acute appendicitis. Although the role of PI in the differential diagnosis of acute abdomen remains uncertain, low MPV might be useful in acute appendicitis and acute mesenteric ischemia, with high MPV predicting poor prognosis in acute mesenteric ischemia. The current lack of consistency and technical standards in studies involving PIs should be regarded as a serious limitation to comparing these studies. Further large, multicentre prospective studies concurrently collecting data from different ethnicities and genders are needed before they can be used in routine clinical practice.

Platelet aggregation and serum adenosine deaminase (ADA) activity in pregnancy associated with diabetes, hypertension and HIV

Platelet aggregation and adenosine deaminase (ADA) activity were evaluated in pregnant women living with some disease conditions including hypertension, diabetes mellitus and human immunodeficiency virus infection. The subject population is consisted of 15 non-pregnant healthy women [control group (CG)], 15 women with normal pregnancy (NP), 7 women with hypertensive pregnancy (HP), 10 women with gestational diabetes mellitus (GDM) and 12 women with human immunodeficiency virus-infected pregnancy (HIP) groups. The aggregation of platelets was checked using an optical aggregometer, and serum ADA activity was determined using the colorimetric method. After the addition of 5 µM of agonist adenosine diphosphate, the percentage of platelet aggregation was significantly (p < 0·05) increased in NP, HP, GDM and HIP groups when compared with the CG, while the addition of 10 µM of the same agonist caused significant (p < 0·05) elevations in HP, GDM and HIP groups when compared with CG. Furthermore, ADA activity was significantly (p < 0·05) enhanced in NP, HP, GDM and HIP groups when compared with CG. In this study, the increased platelet aggregation and ADA activity in pregnancy and pregnancy-associated diseases suggest that platelet aggregation and ADA activity could serve as peripheral markers for the development of effective therapy in the maintenance of homeostasis and some inflammatory process in these pathophysiological conditions. Copyright © 2016 John Wiley & Sons, Ltd.

Platelet function and ageing

There are clear age-related changes in platelet count and function, driven by changes in hematopoietic tissue, the composition of the blood and vascular health. Platelet count remains relatively stable during middle age (25–60 years old) but falls in older people. The effect of age on platelet function is slightly less clear. The longstanding view is that platelet reactivity increases with age in an almost linear fashion. There are, however, serious limitations to the data supporting this dogma. We can conclude that platelet function increases during middle age, but little evidence exists on the changes in platelet responsiveness in old age (>75 years old). This change in platelet function is driven by differential mRNA and microRNA expression, an increase in oxidative stress and changes in platelet receptors. These age-related changes in platelets are particularly pertinent given that thrombotic disease and use of anti-platelet drugs is much more prevalent in the elderly population, yet the majority of platelet research is carried out in young to middle-aged (20–50 years old) human volunteers and young mice (2–6 months old). We know relatively little about exactly how platelets from people over 75 years old differ from those of middle-aged subjects, and we know even less about the mechanisms that drive these changes. Addressing these gaps in our knowledge will provide substantial understanding in how cell signalling changes during ageing and will enable the development of more precise anti-platelet therapies.

Drug delivery and therapeutic impact of extended-release acetylsalicylic acid

Current treatment guidelines recommend once-daily, low-dose acetylsalicylic acid (ASA; aspirin) for secondary prevention of cardiovascular events. However, the anti-thrombotic benefits of traditional ASA formulations may not extend over a 24-h period, especially in patients at high risk for a recurrent cardiovascular event. A next-generation, extended-release ASA formulation (ER-ASA) has been developed to provide 24-h anti-thrombotic coverage with once-daily dosing. The pharmacokinetics of ER-ASA indicates slower absorption and prolonged ASA release versus immediate-release ASA, with a favorable safety profile. ER-ASA minimizes systemic ASA absorption and provides sustained antiplatelet effects over a 24-h period.

The Influence of Haemoglobin A1c Levels on Platelet Aggregation and Platelet Turnover in Patients with Coronary Artery Disease Treated with Aspirin

Background

Hyperglycaemia may attenuate the antiplatelet effect of aspirin and thereby increase the risk of cardiovascular events. We investigated the influence of increased haemoglobin A1c (HbA1c) levels on platelet aggregation and turnover in a large cohort of patients with coronary artery disease (CAD) with type 2 diabetes, prediabetes or no diabetes.

Methods

In this observational study, we included 865 stable CAD patients on 75 mg aspirin as mono-therapy of whom 242 patients had type 2 diabetes and were receiving antidiabetic drugs. Among 623 patients without diabetes, we classified 303 patients with prediabetes (HbA1c ≥5.7–6.4% [39–47 mmol/mol]) naive to antidiabetic drugs. Platelet aggregation was evaluated by the Multiplate Analyzer using arachidonic acid and collagen and by the VerifyNow Aspirin. Platelet turnover was evaluated by immature platelets using flow cytometry and platelet activation by soluble P-selectin.

Results

CAD patients with type 2 diabetes had higher platelet aggregation (all p-values <0.01), platelet turnover (immature platelet count, p<0.01) and platelet activation (p<0.001) than patients without diabetes. CAD patients with prediabetes had increased platelet aggregation (p = 0.02) and platelet count (p = 0.02) compared with patients without diabetes. Increased levels of HbA1c correlated positively with increased platelet aggregation using arachidonic acid (r = 0.19, p<0.0001), collagen (r = 0.10, p<0.01) and VerifyNow (r = 0.15, p<0.0001), and with platelet count (r = 0.08, p = 0.01), immature platelet count (r = 0.11, p<0.001) and soluble P-selectin (r = 0.15, p<0.0001). These associations were mainly evident in non-diabetic and prediabetic CAD patients.

Conclusions

CAD patients with prediabetes and diabetes may have attenuated antiplatelet effect of aspirin compared with CAD patients without diabetes. This may be related to increased platelet count in patients with prediabetes. Increased levels of HbA1c correlated positively, though weakly, with increased platelet aggregation, platelet turnover and platelet activation.

Mean platelet volume is a predictor of ST resolution following thrombolysis in acute ST elevation myocardial infarction

BACKGROUND

Larger mean platelets volumes (MPV) are thrombogenic and frequently seen after ST-segment elevation myocardial infarction (STEMI). This study aimed to examine the association of MPV and resolution of ST-segment after thrombolysis in STEMI patients as and its impact on clinical outcome.

METHODS

Patients presenting to the emergency department with the diagnosis of first STEMI and were referred to thrombolysis were screened. Patients with ≥50% ST-segment resolution (STR) 90minutes after thrombolysis were assigned as "Responder" and those with <50% STR were assigned as "Non-Responders". Demographic, clinical comorbidities and risk factor were recorded along with and angiographic data. In-hospital occurrence of major adverse cardiac events (MACE), including acute heart failure (AHF), reinfarction and death were investigated. Additionally, the patients were followed for 6 additional months after their discharge from the hospital.

RESULTS

STR≥50% was seen in 60.2% of patients after thrombolysis. Responders had significantly lower MPV (P=0.001) and the critical MPV values were 8.0 femtoliter (fL) and 8.2fL in predicting STR and MACE. Patients with MPV ≥8.2fL had lower probability of STR and higher rates of AHF (P<0.001), and MACE (P=0.001) compared to the patients with lower platelet volume. In multivariate regression, MPV was an independent predictor of STR (P<0.001) as well as MACE (HR=4.8, 95% CI of 1.8-12.4; P=0.001). Triple vessel disease was another independent factor that predicted MACE.

CONCLUSION

Higher MPV's at admission were associated with lower STR and higher occurrence of major adverse cardiac events in patients receiving thrombolytic therapy for first time STEMI.

Association between circulating thrombopoietin levels and cardiovascular risk prediction scores in renal transplant recipients

BACKGROUND/AIMS

The 7-year Major Adverse Cardiovascular Events Calculator (CRCRTR-MACE) predicts cardiovascular events (CVE) in renal transplant recipients (RTR), and thrombopoietin (TPO) is a humoral inflammatory factor implicated in cardiovascular disease (CVD). The aim of the study was to determine if circulating TPO levels in stable RTR are positively associated with variable(s) in the CRCRTR-MACE score.

METHODS

CRCRTR-MACE scores were calculated in 95 stable RTR. TPO levels were measured by multiplexed fluorescent bead-based immunoassay in all patients and 48 controls. Multivariate analysis (MVA) was performed between TPO and CV risk variables and patient demographics. Stepwise regression with backward elimination of insignificant variables estimated the impact of risk variables on TPO levels. Significance was defined at p < 0.05. Normalized data were presented as mean ± SD and non-normalized data as median (maximum to minimum).

RESULTS

The risk of a CVE within 7 years as predicted by the median was 9.97% (range 1.93-84.2). The percentage of patients who were above 20% risk for a CVE was 28.4%. Control TPO level of 170.41 (4.4-995.9) pg/ml was significantly lower than that of 237.90 (32.77-1,386.79) pg/ml in RTR (p = 0.010). TPO level correlated significantly with the total CRCRTR-MACE score (R = 0.310, p = 0.004), smoking (p = 0.009) and eGFR (R = -0.275, p = 0.012) but not with age, diabetes, LDL level or history of CVE. Only the total CRCRTR-MACE score (p = 0.013) and smoking (p = 0.009) remained significant in the MVA. Stepwise regression estimated that smoking increased TPO levels by 206.28 pg/ml and each 10% increase in CRCRTR-MACE score increased TPO levels by an additional 44.4 pg/ml.

CONCLUSION

TPO levels are increased in RTR with high CRCRTR-MACE, particularly in smokers with diminished eGFR. Circulating TPO may serve as a biomarker and treatment target for CVD in RTR.

Serial changes of mean platelet volume in relation to Killip Class in patients with acute myocardial infarction and primary percutaneous coronary intervention

INTRODUCTION

Mean platelet volume (MPV) is related to the reactivity of platelets. Among survivors of acute myocardial infarction (MI), greater MPV is known to be associated with impaired reperfusion and higher mortality. The aims of the study is to investigate the dynamic changes of MPV and the relation between MPV and cardiac function in patients with acute MI and received primary percutaneous coronary intervention (PCI).

MATERIALS AND METHODS

This retrospective cohort study included patients presented during January 2008 to March 2011 to Peking University Third Hospital with ST-segment elevation MI. All patients received successful PCI. MPV was measured serially, using a Sysmex XE2100 haematology analyser, from admission to day-7 after MI.

RESULTS

In 375 patients, MPV was at its highest value (10.2±1.0 fL) and correlated well with platelet distribution width (PDW, r=0.833, p<0.0001) at the admission, and then reduced by 16% within the 24 hours, together with marked weakening of its correlation with PDW. Patients with poorer ventricular function, estimated by high Killip Class (≥2, n=96), had higher MPV values at all-time points. By logistic regression model and after adjusting for related confounders, high MPV remained as an independent predictor of Killip Class ≥2 (OR 1.873, CI 95% 1.373-2.673, p=0.001). Clopidogrel pre-usage resulted in significant MPV reduction on admission.

CONCLUSIONS

MPV undergoes rapid and dynamic changes during the acute phase of MI, and was higher in patients with high Killip Class, suggesting a predictive value of MPV in ventricular dysfunction and clinical outcome of acute phase of MI.

Association of the immature platelet fraction with sepsis diagnosis and severity

Management of Sepsis would greatly benefit from the incorporation of simple and informative new biomarkers in clinical practice. Ideally, a sepsis biomarker should segregate infected from non-infected patients, provide information about prognosis and organ-specific damage, and be accessible to most healthcare services. The immature platelet fraction (IPF) and immature reticulocyte fraction (IRF) are new analytical parameters of the complete blood count, that have been studied as biomarkers of several inflammatory conditions. Recently, a study performed in critically-ill patients suggested that IPF could be a more accurate sepsis biomarker than C-reactive protein (CRP) and procalcitonin. In this retrospective study we evaluated the performance of IPF and IRF as biomarkers of sepsis diagnosis and severity. 41 patients admitted to two intensive care units were evaluated, 12 of which with severe sepsis or septic shock, and 11 with non-complicated sepsis. Significantly higher IPF levels were observed in patients with severe sepsis/septic shock. IPF correlated with sepsis severity scores and presented the highest diagnostic accuracy for the presence of sepsis of all studied clinical and laboratory parameters. No significant differences were observed in IRF levels. Our results suggest that IPF levels could be used as a biomarker of sepsis diagnosis and severity.

Deficiency in thrombopoietin induction after liver surgery is associated with postoperative liver dysfunction

Background and Aims

Thrombopoietin (TPO) has been implicated in the process of liver regeneration and was found to correlate with hepatic function in patients with liver disease. With this investigation we aimed to determine if perioperative TPO levels were associated with postoperative outcome in patients undergoing liver resection.

Methods

Perioperative TPO was analyzed prior to liver resection as well as on the first and fifth postoperative day in 46 colorectal cancer patients with liver metastasis (mCRC) as well as 23 hepatocellular carcinoma patients (HCC). Serum markers of liver function within the first postoperative week were used to define liver dysfunction.

Results

While circulating TPO levels significantly increased one day after liver resection in patients without liver cirrhosis (mCRC) (P < 0.001), patients with underlying liver disease (HCC) failed to significantly induce TPO postoperatively. Accordingly, HCC patients had significantly lower TPO levels on POD1 and 5. Similarly, patients with major resections failed to increase circulating TPO levels. Perioperative dynamics of TPO were found to specifically predict liver dysfunction (AUC: 0.893, P < 0.001) after hepatectomy and remained an independent predictor upon multivariate analysis.

Conclusions

We here demonstrate that perioperative TPO dynamics are associated with postoperative LD. Postoperative TPO levels were found to be lowest in high-risk patients (HCC patients undergoing major resection) but showed an independent predictive value. Thus, a dampened TPO increase after liver resection reflects a poor capacity for hepatic recovery and may help to identify patients who require close monitoring or intervention for potential complications.