Mean platelet volume in patients with nonvalvular atrial fibrillation

The Pathophysiology of Sex Differences in Stroke Risk and Prevention in Atrial Fibrillation: A Comprehensive Review

Atrial fibrillation (AF) is the most common chronic arrhythmia and is a leading cause of stroke, with well-documented differences in pathophysiology, clinical manifestations, and prognosis according to the sex of the patient. This review provides an overview of known or hypothesized sex differences in physiology and stroke risk for patients with AF. Women are reported to have more extensive fibrosis of the left atrium, different functional properties of the atria, and higher sensitivity to prothrombotic stimuli, especially after menopause. Variations in stroke risk with AF are linked to age, hypertension, diabetes, and chronic kidney disease; overall, women have worse outcomes. The widely clinically implemented CHA2DS2-VASc score no longer considers sex as a variable, and its propriety for women is still debated. However, women are usually under prescribed anticoagulation despite having a higher long-term risk of stroke compared to men, suggesting a lack of equity of treatment for certain patient groups. New AI-based risk stratification models and precision medicine approaches are potentially useful in reducing these gaps. Future work should also aim to improve sex-based predictive models, considering different gender categories, and understanding the part played by hormonal alterations, atrial structural alterations, and thromboembolic risk in the treatment of AF.

The Prognostic Value of Total Blood Count Parameter Ratios in Acute Pulmonary Embolism

Background/Objectives: Acute pulmonary embolism (PE) is a leading cause of cardiovascular mortality, characterized by nonspecific symptoms and variable clinical presentations. Accurate risk stratification is essential for effective management. While conventional tools like the simplified pulmonary embolism severity index (sPESI) and imaging modalities are widely used, they are often costly and have limitations in predictive accuracy. Inflammatory and coagulative markers, such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean-platelet-volume-to-lymphocyte ratio (MPVLR), have shown promise in thrombotic conditions. This study explores their prognostic value in PE, focusing on their associations with risk stratification and clinical outcomes. Methods: This retrospective study included 231 adult patients diagnosed with PE at a tertiary care center. Exclusion criteria included recent infection, autoimmune diseases, or immunosuppressive therapy. Laboratory data, clinical parameters, and outcomes (e.g., hospitalization duration, complications, and mortality) were analyzed. Ratios were calculated from routine blood counts, and statistical comparisons were conducted between low- and high-risk groups based on sPESI. Results: High-risk patients (n = 203) exhibited significantly higher troponin, blood urea nitrogen, aspartate aminotransferase, lactate, the NLR (median 4.9 vs. 2.7, p = 0.005), and the MPVLR (median 7.1 vs. 3.9, p = 0.001) compared to low-risk patients. The PLR showed no significant difference between risk groups (p = 0.233). An elevated NLR, PLR, and MPVLR correlated with ICU admission, intubation, and mortality (p < 0.001, p < 0.007, and p < 0.001, respectively). The NLR was the most consistently associated with hospitalization duration and mortality, while the MPVLR and PLR were less predictive of overall hospitalization. Conclusions: The NLR, MPVLR, and PLR are cost-effective, easily calculable markers with the potential for improving risk stratification in PE patients. Among these, the NLR showed the strongest prognostic value, correlating with multiple clinical outcomes. Multicenter studies are needed to validate these findings further and establish clinical utility.

Mean platelet volume: a prognostic marker in heart failure with preserved ejection fraction

Heart failure (HF) with preserved ejection fraction (HFpEF) is associated with high burden of comorbidities known to increase the mean platelet volume (MPV). This parameter has been associated with morbidity and mortality in HF. However, the role of platelets and the prognostic relevance of MPV in HFpEF remain largely unexplored. We aimed to evaluate the clinical usefulness of MPV as a prognostic marker in HFpEF. We prospectively enrolled 228 patients with HFpEF (79 ± 9 years; 66% females) and 38 controls of similar age and gender (78 ± 5 years; 63% females). All subjects underwent two-dimensional echocardiography and MPV measurements. Patients were followed-up for a primary end point of all-cause mortality or first HF hospitalization. The prognostic impact of MPV was determined using Cox proportional hazard models. Mean MPV was significantly higher in HFpEF patients compared with controls (MPV: 10.7 ± 1.1fL vs. 10.1 ± 1.1fL, p = .005). HFpEF patients (n = 56) with MPV >75th percentile (11.3 fL) displayed more commonly a history of ischemic cardiomyopathy. Over a median follow-up of 26 months, 136 HFpEF patients reached the composite endpoint. MPV >75th percentile was a significant predictor of the primary endpoint (HR: 1.70 [1.08; 2.67], p = .023) adjusted for NYHA class, chronic obstructive pulmonary disease, loop diuretics, renal function, and hemoglobin. We demonstrated that MPV was significantly higher in HFpEF patients compared with controls of similar age and gender. Elevated MPV was a strong and independent predictor of poor outcome in HFpEF patients and may be relevant for clinical use.

The pathogenesis of aging-induced left atrial appendage thrombus formation and cardioembolic stroke in mice is influenced by inflammation-derived matrix metalloproteinases

Elderly people without atrial fibrillation (AF) still have a high incidence of cardioembolic stroke, suggesting that thrombus formation within the left atrial appendage (LAA) may also occur in an AF-independent manner. In the present study, we explored the potential mechanisms for aging-induced LAA thrombus formation and stroke in mice. We monitored stroke events in 180 aging male mice (14-24 months) and assessed left atrium (LA) remodeling by echocardiography at different ages. Mice that had stroke were implanted with telemeters to confirm AF. Histological features of LA and LAA thrombi were examined, as well as collagen content, expression of matrix metalloproteinases (MMPs), and leukocyte density in the atria at different ages, in mice with or without stroke. Also, the effects of MMP inhibition on stroke incidence and atrial inflammation were tested. We detected 20 mice (11 %) with stroke, 60 % of which were within 18-19 months of age. Although we did not detect AF in mice with stroke, we detected the presence of LAA thrombi, suggesting that stroke originated from the hearts of these mice. Compared with 18-month-old mice without stroke, 18-month-old stroke mice had enlarged LA with a very thin endocardium, that was associated with less collagen and heightened MMP expression in the atria. During aging, we found that the expression of mRNAs for atrial MMP7, MMP8, and MMP9 peaked at 18 months, which closely correlated with reductions in collagen content and the time-window for cardioembolic stroke in these mice. Treatment of mice with an MMP inhibitor at 17-18 months of age reduced atrial inflammation and remodeling, and stroke incidence. Taken together, our study demonstrates that aging-induced LAA thrombus formation occurs through a mechanism involving upregulation of MMPs and breakdown of collagen, and that treatment with an MMP inhibitor may be effective as a treatment strategy for this heart condition.

Mean Platelet Volume: A Possible Predictor for Patients with Decompensated Chronic Heart Failure

Purpose

Despite all medical efforts and discoveries, heart failure (HF) remains one of the most important and common public health problems, with high mortality and hospitalization rates, due to decompensation of HF. In the present study, we aimed to identify a predictive factor through which we can evaluate the risk of readmission and mortality in the first year, given the initial admission of a patient with decompensated heart failure.

Patients and Methods

The parameter we have investigated is the mean platelet volume (MPV). Studies have shown that there is a significant correlation between the value of MPV and the risk of cardiovascular disease (CVD) and cardiovascular (CV) death. In this study, we enrolled 130 patients hospitalized for decompensated chronic HF (NYHA class IV HF or acute pulmonary edema) and analyzed whether there is a relationship between the value of the MPV at admission and 6-month rehospitalization, and 1-year mortality, respectively.

Results

The statistical analysis revealed significantly different values (p = 0.041) for MPV at admission between the group of patients without decompensated chronic HF compared to the group of patients with decompensated chronic HF (8.74 fl vs 9.08 fl). Also, the results of our study revealed that patients with decompensated chronic heart failure who were readmitted at 6 months and died at 1 year, respectively, had a higher MPV at admission (>9 fl), compared to those without the above-mentioned events, with a statistical significance.

Conclusion

A higher MPV at admission can be considered in our study as an independent predictor for rehospitalization and 1-year mortality of patients with decompensated chronic HF.

Vitamin D Level in Patients with Consecutive Acute Coronary Syndrome Is Not Correlated with the Parameters of Platelet Activity

Coronary artery disease continues to be the leading cause of death in developed countries. Elevated mean platelet volume (MPV) is associated with an increased incidence of myocardial infarction (MI) and MI-related mortality. Vitamin D concentrations affect the level and function of platelets, which are the crucial mediator of atherothrombosis and plaque rupture. The main aim of this study was to examine the relationship of serum 25-hydroxyvitamin D (25(OH)D) levels with the platelet activity in patients with a history of an acute coronary syndrome (ACS). This prospective study recruited 268 patients with a history of MI who underwent coronary angiography due to the suspicion of another ACS. Serum 25(OH)D concentration was determined by electrochemiluminescence. Platelet activity was assessed using the MPV and platelet-large cell ratio (P-LCR) parameters. There was no significant difference in MPV and P-LCR values between patients diagnosed with subsequent MI and patients with chronic coronary syndrome (CCS). A significantly lower level of 25(OH)D was demonstrated in patients who had another MI compared to those with CCS (p < 0.05). No significant correlation of 25(OH)D concentrations with platelet activity parameters values was found. The subgroup of patients with consecutive MI was characterized by significantly lower serum vitamin D levels, but this was not related to the analyzed parameters of platelet activity.

The Predictive role of Neutrophil-to-Lymphocyte Ratio (NLR) and Mean Platelet Volume-to-Lymphocyte Ratio (MPVLR) for Cardiovascular Events in Adult Patients with Acute Heart Failure

Introduction

The inflammatory response plays a potential role for the pathogenesis and adverse outcomes of heart failure (HF). We aimed to explore the predictive role of baseline neutrophil-to-lymphocyte ratio (NLR) and mean platelet volume-to-lymphocyte ratio (MPVLR) on cardiovascular events (CVEs) in patients hospitalized with acute HF.

Materials and Methods

A retrospective cohort study was conducted in 321 patients with HF between January 2017 and December 2019. The association between their NLR, MPVLR, and combined NLR and MPVLR and CVEs, rehospitalization for HF, in-hospital death, and a composite outcome was explored by survival analysis using a Cox proportional hazard model. They were separately investigated and compared with the area under the receiver operating characteristics curve (AUC).

Results

Up to the end of the 3-year follow-up, 96 (29.9%) had CVEs, 106 (33.0%) died, 62 (19.3%) were rehospitalized with HF, and 21 (6.5%) died during admission. The NLR and MPVLR were significantly associated with CVEs (adjusted HR for NLR ≥ 3.29, 3.11; 95% CI, 1.98-4.89; MPVLR ≥ 8.57, 2.86; 95% CI, 1.87-4.39), readmissions for HF (adjusted HR for NLR ≥ 3.58, 2.70; 95% CI, 1.58-4.61; MPVLR ≥ 6.43, 2.84; 95% CI,1.59-5.07), in-hospital mortality (adjusted HR for NLR ≥ 3.29, 9.54; 95% CI, 2.19-41.40; MPVLR ≥ 8.57, 7.87; 95% CI, 2.56-24.19), and composite outcome (adjusted HR for NLR ≥ 3.32, 4.76; 95% CI, 3.29-6.89; MPVLR ≥ 7.07, 3.64; 95% CI, 2.58-5.15). The AUC of NLR and MPVLR for CVEs were 0.67 (95% CI, 0.61-0.72) and 0.63 (95% CI, 0.58-0.69). Combined NLR and MPVLR increased the AUC to 0.77 (95% CI, 0.72-0.83) with statistical significance.

Conclusion

The elevated NLR and MPVLR on admission in patients with acute HF were independently associated with worse CVEs, rehospitalization for HF, in-hospital death, and composite outcomes. These economical biomarkers should be considered in the management and follow-up care of patients with acute HF.

Platelets Promote Ang II (Angiotensin II)-Induced Atrial Fibrillation by Releasing TGF-β1 (Transforming Growth Factor-β1) and Interacting With Fibroblasts

Hypertension is a risk factor of atrial fibrillation (AF), and a certain number of patients with hypertension were found with an enlarged left atrium. Platelet activation is found in patients with hypertension or pressure overload/Ang II (angiotensin II)-induced hypertensive animal models and contribute to ventricular fibrosis. Whether hypertension-induced atrial fibrosis is mediated by platelets remains unknown. Our previous experimental data showed that platelet-derived TGF-β1 (transforming growth factor-β1) was reduced in patients with hypertensive AF. The present study is to investigate whether platelet-derived TGF-β1 promotes Ang II-induced atrial fibrosis and AF. Platelet activation and atrial platelet accumulation were measured in sinus rhythm controls, normotensive AF, and patients with hypertensive AF. Ang II (1500 ng/kg per minute, 3 weeks) infused mice with pharmacological (clopidogrel) and genetic platelet inhibition (TGF-β1 deletion in platelets) were used. Platelet activation, atrial structural remodeling, atrial electrical transmission, AF inducibility, inflammation, and fibrosis were measured in mice. We found that circulating platelets were activated in patients with hypertensive AF. A large amount of platelet was accumulated in the atriums of patients with hypertensive AF. Both clopidogrel treatment and platelet-specific deletion of TGF-β1 attenuated Ang II-induced structural remodeling, atrial electrical transmission, AF inducibility, as well as atrial inflammation and fibrosis than mice without interventions. Furthermore, clopidogrel blocked atrial platelet accumulation and platelet-fibroblast conjugation. Platelets promoted atrial fibroblast differentiation in cell culture. Profibrotic actions of platelets are largely via activation of atrial fibroblasts by releasing TGF-β1 and inducing platelet-fibroblast conjugation, and platelet inhibition is sufficient to inhibit atrial fibrosis and AF inducibility.

Mean platelet volume and mean platelet volume/platelet count ratio in nonvalvular atrial fibrillation stroke and large artery atherosclerosis stroke

Ischemic stroke subtypes such as patients with large artery atherosclerosis, cardioembolism, and embolic stroke of undetermined source were investigated. This study was performed aimed to determine mean platelet volume (MPV) and mean platelet volume/platelet count (MPV/Plt) ratio in nonvalvular atrial fibrillation (AF) stroke and large artery atherosclerosis (LAA) stroke.We conducted a retrospective study of consecutive patients for treatment of acute ischemic stroke at Ruian People's Hospital from March 2017 to October 2018. The patients with ischemic stroke caused by AF and LAA were recruited to this study. Ischemic stroke was confirmed by magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA), ischemic lesions on diffusion-weighted imaging were measured in terms of size, composition, and pattern. MPV and platelet count were examined and (MPV/Plt) ratio was calculated.Three hundred seventy one patients were enrolled composing of 177 (47.7%) nonvalvular AF and 194 (52.2%) with LAA. The MPV (11.3 ± 1.3 vs 10.8 ± 1.0, P < .001) and MPV/Plt ratio (0.066 ± 0.025 vs 0.055 ± 0.20, P < .001) were much higher in AF group than LAA group. Receiver-operating characteristic (ROC) analysis showed MPV (AUC: 0.624, confidence interval: 0.567-0.68, P < .001) and MPV/Plt (AUC: 0.657, confidence interval: 0.601-0.713, P < .001) predicted AF between the 2 groups. MPV/Plt ratio was negatively associated with lesion volume (r = -0.161, P = .033) in AF. The analyses of subtypes of composition of infarcts and infarct pattern showed that MPV/Plt ratio was almost higher in AF than LAA except for subcortical-only pattern. Multivariable regression analyses demonstrated National Institutes of Health Stroke Scale (NIHSS) score (r = 2.74; P < .001), LAD (r = -1.15; P = .025) and MPV/Plt ratio (r = -180.64; P = .021) were correlated with lesion volume.Our results indicated elevated MPV and MPV/Plt ratio for the identification of difference between AF and LAA in patients with ischemic stroke.

Suppression of experimental atrial fibrillation in a canine model of rapid atrial pacing by the phosphodiesterase 3 inhibitor cilostazol

OBJECTIVE

Atrial fibrillation (AF) represents the most common arrhythmia encountered in cardiology department. The purpose of this study was designed to investigate whether cilostazol, an oral phosphodiesterase 3 inhibitor (PDE3) could have protective effects on atrial remodeling in a canine model of AF and explore the potential molecular mechanisms.

METHODS

Dogs were randomly assigned to Sham, Paced, Paced + cilostazol group, 7 dogs in each group. In Sham group, pacemaker was instrumented but without pacing. Rapid atrial pacing (RAP) at 600 or 500 bpm/min was maintained in Paced group and Paced + cilo group for 2 h or 2 weeks in acute or chronic experiment, respectively. The Paced + cilo group of dogs were pretreated with cilostazol orally (10 mg·kg-1·d-1, cilo) for 1 h or 2 days prior RAP induction and served as treatment group. Atrial effective refractory periods (AERP) at different basic cycle lengths (BCLs), inducibility, and duration time of AF were measured after pacing for 2 h. The blood sample, echocardiography, histopathology, inflammation and oxidative stress makers, protein and mRNA expression levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 were detected after 2 weeks pacing in each group.

RESULTS

Significant changes in electrophysiological parameters were observed in the acute RAP canine model, the AERPs shortened with increased inducibility and duration of AF, which was attenuated by cilostazol (P < 0.05). The serum inflammation makers as interleukin-8 (IL-8) and toll like receptor 4 (TLR 4) levels and oxidative stress indicators like xanthine oxidative (XO) and reactive oxygen species (ROS) in the Paced group was significantly higher than that in Sham group (P < 0.01), and was significantly reduced by cilostazol treatment (P < 0.01). The level of mean platelet volume (MPV) which is one of the platelet indices was significantly elevated in Paced group (P < 0.01). While after cilostazol treated for 2 weeks, the level of MPV was obviously decreased than Paced group (P < 0.01). Pathology and echocardiography studies showed that cilostazol can also prevent RAP induced cardiac fibrosis and structural remodeling. The MPV level has close correlations with IL-8, TLR4, XO and ROS (all P < 0.01). MMP-2 and MMP-9 expression were significantly increased in Paced group (all P < 0.01), which can be attenuated by cilostazol.

CONCLUSIONS

Cilostazol may have protective effects on RAP-induced atrial remodeling by anti-inflammatory, anti-oxidative stress action and regulate the extracellular collagen matrix in a canine model. Moreover, MPV level is associated with inflammation and oxidative stress response of RAP, which might be an important predictors of new-onset and recurrent AF.

The Mean Platelet Volume in the Prognosis of Coronary Artery Disease Severity and Risk Stratification of Acute Coronary Syndromes

Introduction:

Platelets play a crucial role in thrombotic episodes. Mean Platelet Volume (MPV) is the primary indicator of platelet’s activation; its measurement is easy and time-effective.

Aim:

We tested the hypothesis that MPV is correlated with SYNTAX score in patients that suffered from an Acute Coronary Syndrome (ACS).

Material and Methods:

One hundred and four (104) patients (79 male–25 female, mean age 64.2±11.1 years), who were hospitalized for an ACS and underwent coronary angiography, were included in the study. Syntax score, as an indicator of the severity of coronary artery disease (CAD), was calculated. We tried to investigate the correlation between the first measured MPV, CRP, Creatinine and high sensitivity Troponin with the Syntax score of the patient and the association of MPV and a possible Major Advanced Cardiac Event (MACE) during hospitalization.

Results:

The patients were divided into four groups according to the SYNTAX score: Group A (SYNTAX score: 0, n=12), group B: Mild CAD (SYNTAX score: 1–22, n=68), group C: Moderate CAD (SYNTAX score: 23–32, n=12), and group D: Severe CAD (SYNTAX score: ≥ 33, n=12). Four patients (3.8%) developed a MACE during their hospitalization. MPV was significantly correlated to Syntax score (r=0.658, p<0.001) and was found to be an independent predictor factor of MACE with HR=6.8 (95% Confidence Interval 1.46-33.36). The cut-off value of MPV was 7.5 with a sensitivity of 98% and a specificity of 30.8%.

Conclusion:

We determined a positive correlation between MPV and Syntax score, transforming this simple test in a possible factor of risk stratification in ACS.

Effect of new oral anticoagulants on platelet indices in non-valvular atrial fibrillation patients

New-generation oral anticoagulants (NOACs) are now preferred as a first-line treatment in the management of atrial fibrillation for prevention of thromboembolic complications. Mean platelet volume (MPV), one of the indicators of increased platelet activity, is also associated with an increased stroke risk in atrial fibrillation patients. The aim of this study was to evaluate changes in MPV, platelet distribution width (PDW) and plateletcrit following use of NOACs. The study included 116 patients with non-valvular atrial fibrillation without previous NOAC use. Complete blood counts, biochemical analyses and echocardiography were performed for all patients. No significant differences were observed in MPV or other platelet indices at 6 months compared to baseline. Our results indicate that MPV and other platelet indices are not affected by NOAC use in non-valvular atrial fibrillation patients.

Mean platelet volume and major adverse cardiovascular events in congenital heart disease patients

BACKGROUND

Platelet activation is linked with thrombosis, inflammation or heart failure.

OBJECTIVE

To establish clinical and analytical factors that may favor high mean platelet volume (MPV) and to determine if MPV levels favor major adverse cardiovascular events (MACE).

METHODS

Stable CHD patients and a control population matched for age, sex and cardiovascular factors.

RESULTS

658 CHD patients and 2092 controls were studied. Median age in CHD patients was 33 (25-41) year old with 56% of them being male. No significant differences were seen between MPV values and cardiac complexity (p = 0.308) nor between MPV values in the CHD and control groups (p = 0.911). CHD patients had significant lower platelet count and MPV levels than patients in the control group. In the binary logistic regression analysis NT-pro-BNP levels above 125 pg/ml, thrombocytopenia and having atrial fibrillation/flutter reached statistical significance as predictors of MPV levels above 11 fL. The Kaplan-Meier survival analysis showed no significance between MPV levels higher than 11 fL and MACE, cardiovascular mortality and thrombotic events in a median time follow-up of 6.7(1.5-10.6) years.

CONCLUSIONS

Atrial fibrillation/flutter, heart failure and thrombocytopenia are predictors of high MPV levels. A MPV above 11 fL is not associated with MACE at a median follow-up time.

Leukocyte TRP channel gene expressions in patients with non-valvular atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is a major cause of morbidity and mortality. The upregulation of TRP channels is believed to mediate the progression of electrical remodelling and the arrhythmogenesis of the diseased heart. However, there is limited data about the contribution of the TRP channels to development of AF. The aim of this study was to investigate leukocyte TRP channels gene expressions in non-valvular atrial fibrillation (NVAF) patients. The study included 47 NVAF patients and 47 sex and age matched controls. mRNA was extracted from blood samples, and real-time polymerase chain reaction was performed for gene expressions by using a dynamic array system. Low levels of TRP channel expressions in the controls were markedly potentiated in NVAF group. We observed marked increases in MCOLN1 (TRPML1), MCOLN2 (TRPML2), MCOLN3 (TRPML3), TRPA1, TRPM1, TRPM2, TRPM3, TRPM4, TRPM5, TRPM6, TRPM7, TRPM8, TRPC1, TRPC2, TRPC3, TRPC4, TRPC5, TRPC6, TRPC7, TRPV1, TRPV2, TRPV3, TRPV4, TRPV5, TRPV6, and PKD2 (TRPP2) gene expressions in NVAF patients (P < 0.05). However, there was no change in PKD1 (TRPP1) gene expression. This is the first study to provide evidence that elevated gene expressions of TRP channels are associated with the pathogenesis of NVAF.

Stroke or left atrial thrombus prediction using antithrombin III and mean platelet volume in patients with nonvalvular atrial fibrillation

BACKGROUND

CHADS₂ (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke) and CHA₂ DS₂ -VASc (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke, vascular disease, age 65 to 74 years, sex category) scores showed just moderate discrimination ability in predicting thromboembolic complications in patients with nonvalvular atrial fibrillation (AF).

HYPOTHESIS

To determine the association of antithrombin III (AT-III) deficiency and mean platelet volume (MPV) with the development of stroke or left atrial (LA) thrombus in patients with AF.

METHODS

AT-III and MPV were analyzed in 352 patients with AF. The primary endpoint was a composite of ischemic stroke event and incidental LA thrombus.

RESULTS

There were 50 events (14.2%) during a mean 35.4 months of follow-up. A significantly higher stroke or LA thrombus rate was observed in the low-AT-III group (<70%) than that in the high-AT-III group (≥70%). A significantly higher stroke or LA thrombus rate was observed in the high-MPV group (≥7.0 fL) than that in the low-MPV group (<7.0 fL). AF patients with an MPV ≥7.0 fL and AT-III deficiency had higher stroke or LA thrombus risk than those without an MPV ≥7.0 fL and AT-III deficiency. In the Cox proportional hazard analysis, high MPV was found to be an independent predictor of stroke or LA thrombus risk (hazard ratio: 6.408; 95% confidence interval: 2.874-14.286). Although AT-III deficiency was not an independent predictor of stroke or LA thrombus risk, a trend was observed.

CONCLUSIONS

High MPV and AT-III deficiency were predictive markers for stroke or LA thrombus. Their predictive power for stroke was independent of antiplatelet treatment, anticoagulation therapy, and a high CHA₂ DS₂ -VASc score in patients with AF.

Prediction of New-Onset and Recurrent Atrial Fibrillation by Complete Blood Count Tests: A Comprehensive Systematic Review with Meta-Analysis

BACKGROUND Atrial fibrillation (AF) is one of the most critical and frequent arrhythmias precipitating morbidities and mortalities. The complete blood count (CBC) test is an important blood test in clinical practice and is routinely used in the workup of cardiovascular diseases. This systematic review with meta-analysis aimed to determine the strength of evidence for evaluating the association of hematological parameters in the CBC test with new-onset and recurrent AF. MATERIAL AND METHODS We conducted a meta-analysis of observational studies evaluating hematologic parameters in patients with new-onset AF and recurrent AF. A comprehensive subgroup analysis was performed to explore potential sources of heterogeneity. RESULTS The literature search of all major databases retrieved 2150 studies. After screening, 70 studies were analyzed in the meta-analysis on new-onset AF and 23 studies on recurrent AF. Pooled analysis on new-onset AF showed platelet count (PC) (weighted mean difference (WMD)=WMD of -26.39×10^9/L and p<0.001), mean platelet volume (MPV) (WMD=0.42 FL and p<0.001), white blood cell (WBC) (WMD=-0.005×10^9/L and p=0.83), neutrophil to lymphocyte ratio (NLR) (WMD=0.89 and p<0.001), and red blood cell distribution width (RDW) (WMD=0.61% and p<0.001) as associated factors. Pooled analysis on recurrent AF revealed PC (WMD=-2.71×109/L and p=0.59), WBC (WMD=0.20×10^9/L (95% CI: 0.08 to 0.32; p=0.002), NLR (WMD=0.37 and p<0.001), and RDW (WMD=0.28% and p<0.001). CONCLUSIONS Hematological parameters have significant ability to predict occurrence and recurrence of AF. Therefore, emphasizing the potential predictive role of hematological parameters for new-onset and recurrent AF, we recommend adding the CBC test to the diagnostic modalities of AF in clinical practice.

Platelets Cellular and Functional Characteristics in Patients with Atrial Fibrillation: A Comprehensive Meta-Analysis and Systematic Review

BACKGROUND This systematic review with meta-analysis aimed to determine the strength of evidence for evaluating the association of platelet cellular and functional characteristics including platelet count (PC), MPV, platelet distribution width (PDW), platelet factor 4, beta thromboglobulin (BTG), and p-selectin with the occurrence of atrial fibrillation (AF) and consequent stroke. MATERIAL AND METHODS We conducted a meta-analysis of observational studies evaluating platelet characteristics in patients with paroxysmal, persistent and permanent atrial fibrillations. A comprehensive subgroup analysis was performed to explore potential sources of heterogeneity. RESULTS Literature search of all major databases retrieved 1,676 studies. After screening, a total of 73 studies were identified. Pooled analysis showed significant differences in PC (weighted mean difference (WMD)=-26.93 and p<0.001), MPV (WMD=0.61 and p<0.001), PDW (WMD=-0.22 and p=0.002), BTG (WMD=24.69 and p<0.001), PF4 (WMD=4.59 and p<0.001), and p-selectin (WMD=4.90 and p<0.001). CONCLUSIONS Platelets play a critical and precipitating role in the occurrence of AF. Whereas distribution width of platelets as well as factors of platelet activity was significantly greater in AF patients compared to SR patients, platelet count was significantly lower in AF patients.

Medium platelet volume as a noninvasive predictor of chronic total occlusion in non-infarct artery in patients with non-ST-segment elevation myocardial infarction and multivessel coronary artery disease

BACKGROUND

Chronic total occlusion (CTO) in a noninfarct-related artery (non-IRA) is an independent predictor of mortality in non-ST elevation myocardial infarction (NSTEMI). Mean platelet volume (MPV) is associated with cardiovascular events in NSTEMI. Little is known about the predictors of non-IRA-CTO in patients with NSTEMI. The purpose of this study was to evaluate the relationship between the presence of non-IRA-CTO with MPV level in patients with NSTEMI and multivessel coronary artery disease (MVCAD).

METHODS

Data of consecutive patients with NSTEMI and MVCAD treated in high-volume PCI center between 2006 and 2012 and included in the prospective registry were divided according to the presence of CTO and analyzed.

RESULTS

In the group of 685 patients fulfilling the inclusion criteria, 308 (45%) patients had CTO (CTO+), and in 377 (55%) patients CTO was not observed (CTO-). The MPV level on admission was significantly higher in the CTO+ group than in the CTO- group (P<0.0001). In the multivariate analysis of the entire study population, independent predictors of occurrence of CTO were medium platelet volume (MPV; per 1fL more; odds ratio [OR] 1.34; 95% confidence interval [CI] 1.15-1.57; P=0.0002) together with left ventricular ejection fraction and prior MI.

CONCLUSIONS

MPV at admission is independently associated with more frequent occurrence of non-IRA CTO in patients with NSTEMI and MVCAD.

Prognostic implications of mean platelet volume on short- and long-term outcomes among patients with non-ST-segment elevation myocardial infarction treated with percutaneous coronary intervention: A single-center large observational study

BACKGROUND

Mean platelet volume (MPV) is a simple and reliable indicator of platelet size that correlates with platelet activation and their ability to aggregate. We studied the predictive value of MPV in patients with non-ST-segment elevation myocardial infarction (NSTEMI) treated with percutaneous coronary intervention (PCI).

METHODS

We analyzed the consecutive records of 1001 patients who were hospitalized due to NSTEMI at our center. The primary end point was a composite end point that included the rates of all-cause death, non-fatal myocardial infarction, and acute coronary syndrome (ACS) driven revascularization at 12 months. The enrolled patients were stratified according to the quartile of the MPV level at admission.

RESULTS

Along with the increasing quartile of MPV, the 12-month composite end point increased significantly (p = 0.010), and this association remained significant after the risk-adjusted analyses (per 1 fL higher MPV; adjusted hazard ratio [HR] 1.13; 95% confidence interval [CI] 1.02-1.27; p = 0.026). In the multivariate analysis, the MPV was also an independent factor of all-cause mortality (per 1 fL increase; adjusted HR 1.34; 95% CI 1.12-1.61; p = 0.0014) and death or non-fatal myocardial infarction (per 1 fL increase; adjusted HR 1.16; 95% CI 1.03-1.31; p = 0.017).

CONCLUSION

In patients with NSTEMI treated with PCI, a high MPV value was associated with a significantly increased incidence of long-term adverse events, particularly for all-cause mortality.

microRNA expression changes after atrial fibrillation catheter ablation

Atrial fibrillation (AF) is most common arrhythmia in general population, with increasing trend in mortality and morbidity. Electrophysiological and structural abnormalities, promoting abnormal impulse formation and propagation, lead to this disease. AF catheter ablation is related to a not small percentage of nonresponder patients. microRNAs (miRs) have been used as AF fibrotic and electrical alterations biomarkers. miRs may differentiate responders patients to ablative approach. Selective miR target therapy, as upregulation by adenovirus transfection and/or miR downregulation by antagomiR, may be used to treat AF patients. Catheter ablation of triggering electrical pulmonary veins activity or fibrotic areas defragmentation may be upgraded by miR therapy to prevent cardiac electrical and fibrotic remodeling after AF ablation.

The association between mean platelet volume and chronic atrial fibrillation and the presence of thrombotic events

Mean platelet volume (MPV), a marker of platelet activation, is a surrogate marker of platelet function and a potential mediator of the association between inflammation and thrombosis. The present retrospective study sought to investigate the association between MPV and the presence of thrombotic events (TEs) in patients with chronic atrial fibrillation (AF). A total of 114 consecutive patients with chronic AF were enrolled from a Chinese hospital. Individuals were divided into three groups: The AF+TE group (n=57, 33.1%), which comprised patients in AF with concomitant TEs; the AF group (n=57, 33.1%), which comprised patients in AF with no identifiable TEs, as confirmed by brain computed tomography, transesophageal echocardiography, or a combination of the two; and a control group (n=58, 33.7%), which consisted of patients who were in sinus rhythm. MPV, high-sensitivity C-reactive protein (hsCRP), D-dimer and the left atrial diameter (LAD) were analyzed in the 172 participants. The MPV level of patients in the AF+TE group was significantly higher than that of patients in the AF and control groups (P<0.05). In the correlation analysis, MPV levels were found to be positively correlated with LAD, D-dimer concentrations and hsCRP levels in patients with AF (r=0.960, P<0.05; r=0.896, P<0.05; and r=0.924, P<0.01, respectively). In the receiver operating characteristic curve analysis, the value for MPV levels required to detect TEs with a sensitivity of 77.5% and specificity of 78% was 10.5 femtoliter (fl). A high MPV level (>10.5 fl) was significantly associated with the occurrence of TEs (odds ratio, 3:1; 95% confidence interval, 1.6-5.1; P=0.000). The results of the present study suggest that an additional biomarker, MPV, has a predictive value for the presence of TEs in patients with AF. MPV may be a potential mediator between inflammation and thrombosis.

Relation of reduced expression of MiR-150 in platelets to atrial fibrillation in patients with chronic systolic heart failure

Atrial fibrillation (AF) is associated with poor prognosis in patients with heart failure (HF). Although platelets play an important role in rendering a prothrombotic state in AF, the exact mechanism by which the effect is mediated is still debated. MicroRNAs (miRNAs), which have been shown to be involved in a variety of cardiovascular conditions, are abundant in platelets and in a cell-free form in the circulation. In the present study, we performed a genome-wide screen for miRNA expression in platelets of patients with systolic HF and in controls without cardiac disease, in pursuit of specific miRNAs that are associated with the presence of AF. MiRNA expression was measured in platelets from 50 patients with systolic HF and 50 controls, of which, samples from 41 patients with HF and 35 controls were used in the final analysis because of a quality control process. MiR-150 expression was 3.2-fold lower (p = 0.0003) in platelets of patients with HF with AF relative to those without AF. A similar effect was seen in serum samples from the same patients, in which miR-150 levels were 1.5-fold lower (p = 0.004) in patients with HF with AF. Furthermore, the serum levels of miR-150 were correlated to platelet levels in patients with AF (r = 0.65, p = 0.0087). In conclusion, miR-150 expression levels in platelets of patients with systolic HF with AF are significantly reduced and correlated to the cell-free circulating levels of this miRNA.

Atrial fibrillation: inflammation in disguise?

Atrial fibrillation is highly prevalent, and affected patients are at an increased risk of a number of complications, including heart failure and thrombo-embolism. Over the past years, there has been increasing interest in the role of inflammatory processes in atrial fibrillation, from the first occurrence of the arrhythmia to dreaded complications such as strokes or peripheral emboli. As the standard drug combination which aims at rate control and anticoagulation only offers partial protection against complications, newer agents are needed to optimize treatment. In this paper, we review recent knowledge regarding the impact of inflammation on the occurrence, recurrence, perpetuation and complications of the arrhythmia, as well as the role of anti-inflammatory therapies in the treatment for the disease.

Relationship between platelet indices and international normalized ratio in patients with non-valvular atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia and associated with adverse outcomes and increased risk for thromboembolic events. Warfarin is still the most extensively prescribed oral anticoagulant in AF to prevent ischemic complications. We aimed to determine the differences at platelet indices with warfarin usage layered by International Normalized Ratio (INR). A total of 250 patients with permanent non-valvular AF (mean age 70.2 ± 9.1; 153 female) were divided into two groups. Group 1 included 125 patients whose INR is between 2.0 and 3.0 (called as "effective") and Group 2 included 125 patients whose INR is <2.0 (called as "ineffective"). Also 123 age- and sex-matched individuals in sinus rhythm enrolled as control group (Group 3). After physical and echocardiographic examination, complete blood counts and INR were studied. There was no statistically significant difference in age, sex, co-morbidities and medications, also hemoglobin, white blood cell and platelet counts among the groups. The CHA2DS2-VASc scores were similar between Groups 1 and 2. The mean platelet volume (MPV), platelet distribution width (PDW) and plateletcrit (PCT) were significantly higher in Group 2 than Groups 1 and 3 and similar between Groups 1 and 3. MPV was positively correlated with PDW and PCT and also inversely correlated with INR value and platelet count. On multivariate logistic regression analysis, MPV, PDW and PCT were independent predictors of ineffectiveness of INR. The results of this study showed that MPV, PDW and PCT are increased in patients with non-valvular AF without effective warfarin treatment. Warfarin usage adjusted by INR is associated with lower values of these platelet indices, even lower as the values of subjects in sinus rhythm. MPV, PDW and PCT are independent predictors of INR ineffectiveness and seem to be useful parameters for monitoring the effectiveness of warfarin treatment.