Usefulness of mean platelet volume for predicting stroke risk in atrial fibrillation patients

The Association of Hematological Markers with Occurrence of Thrombotic and Bleeding Events following Left Atrial Appendage Occlusion

INTRODUCTION

Patients undergoing left atrial appendage occlusion (LAAO) are at increased risk for bleeding or thromboembolic events. Concurrently, biomarkers are of growing importance in risk stratification for atrial fibrillation patients. We aimed to evaluate the association of hematological markers and clinical characteristics with the occurrence of thromboembolic and bleeding events following LAAO.

METHODS

Seven implanting centers retrospectively gathered data on hematological markers (i.e., platelet count [PC], mean platelet volume [MPV], and fibrinogen) prior to LAAO. Prespecified thromboembolic and major bleeding outcomes were collected and the association with pre-procedural hematological markers and clinical characteristics was evaluated using Cox regression analysis.

RESULTS

In total, 1,315 patients were included (74 ± 9 years, 36% female, CHA2DS2-VASc 4.3 ± 1.5, HAS-BLED 3.3 ± 1.1). Over a total follow-up duration of 2,682 patient years, 77 thromboembolic events and 107 major bleeding events occurred after LAAO. Baseline PC was the only biomarker showing a signal for a relation to thromboembolic events (HR 1.18, 95% CI: 1.00-1.39) per 50*109 increment, p = 0.056). Thrombotic event rates, including device-related thrombus, increased within higher PC quartiles. Thromboembolism was associated with age (HR 1.05, 95% CI: 1.00-1.10, per year increase) and prior thromboembolism (HR 2.08, 95% CI: 1.07-4.03), but with none of the biomarkers in multivariate analysis. No association of any of the hematological markers with major bleeding was observed. Major bleeding following LAAO was associated with prior major bleeding (HR 5.27, 95% CI: 2.71-10.22), renal disease (HR 1.93, 95% CI: 1.17-3.18), and discharge on dual antiplatelet therapy (DAPT) (HR 1.71, 95% CI: 1.05-2.77).

CONCLUSION

Most thrombotic events occurred in the highest PC quartile, but no association of any of the hematological markers with thromboembolism or major bleeding was observed in our analysis. In multivariate analysis, older age and prior thromboembolism were associated with thromboembolism. Prior major bleeding, renal disease and discharge on DAPT were multivariate predictors of major bleeding after LAAO.

Atrial fibrillation and stroke

INTRODUCTION

Stroke is one of the leading causes of mortality and morbidity globally. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. It is set to reach epidemic proportions. AF is associated with a five-fold increase in risk of stroke. Strokes caused by AF more often are fatal or result in severe disability. Even though the incidence of stroke has been significantly reduced by oral anticoagulation, AF is thought to account for a significant proportion of cryptogenic strokes where no etiology is identified.

AREAS COVERED

This article reviews the literature related to AF and stroke, pathophysiological insights, diagnosis of AF in stroke patients, and its management (Graphical Abstract).

EXPERT OPINION

The pathophysiology of thrombogenesis that links AF and stroke is not well understood and is an area of active research to identify new therapeutic targets to prevent AF and stroke. As the nature of AF and stroke is multifaceted, an integrated care approach to managing AF and stroke is increasingly essential.

Mean Platelet Volume to Platelet Count Ratio Predicts Left Atrial Stasis in Patients with Non-Valvular Atrial Fibrillation

Background

The mean platelet volume to platelet count ratio (MPV/PC) has been investigated in the diagnosis, prognosis and risk stratification in several diseases. However, the predictive role of MPV/PC in left atrial stasis (LAS) of non-valvular atrial fibrillation (NVAF) patients remains unknown.

Methods

A total of 217 consecutive NVAF patients undergoing transesophageal echocardiogram (TEE) evaluation were retrospectively enrolled. The demographic, clinical, admission laboratory and TEE data were extracted and analyzed. Patients were categorized into those with or without LAS. The associations between the MPV/PC ratio and LAS were assessed by multivariate logistic regression analysis.

Results

There were 24.9% (n = 54) patients with LAS according to TEE. Compared with patients without LAS, the MPV/PC ratio was significantly higher in those with LAS (5.6±1.6 vs 4.8±1.0, P < 0.001). After multivariable adjustment, higher MPV/PC ratio levels (OR 1.747, 95% CI 1.193-2.559, P = 0.004) were positively associated with LAS, with the optimal cut-point for LAS prediction of 5.36 (area under the curve, AUC = 0.683, sensitivity 48%, specificity 73%, 95% CI 0.589-0.777, P < 0.001). The stratification analysis showed that a significant positive correlation between MPV/PC ratio ≥5.36 and LAS in patients of male, younger (<65 years), paroxysmal AF, without history of stroke/TIA, CHA₂DS₂-VASc score ≥2, left atrial diameter (LAD) ≥40mm and left atrial volume index (LAVI) >34mL/m² (all P < 0.05).

Conclusion

Increasing MPV/PC ratio was associated with an increased risk of LAS, which was mainly reflected in the subgroups of male, younger (<65 years), paroxysmal AF, without history of stroke/TIA, CHA₂DS₂-VASc score ≥2, LAD ≥40mm and LAVI >34mL/m² patients.

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

BACKGROUND AND OBJECTIVES

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Predictors of left atrial thrombus in acute ischemic stroke patients without atrial fibrillation: A single-center cross-sectional study

INTRODUCTION

The present study aimed to determine independent predictors of left atrial thrombus (LAT) in acute ischemic stroke (AIS) patients without atrial fibrillation (AF) using transesophageal echocardiography (TEE).

METHODS

In this single-center, retrospective study, we enrolled 149 consecutive AIS patients. All of the patients underwent a TEE examination to detect LAT within 10 days following admission. Multivariate logistic regression analysis was performed to assess independent predictors of LAT.

RESULTS

Among all cases, 14 patients (9.3%) had a diagnosis of LAT based on the TEE examination. In a multivariate analysis, elevated mean platelet volume (MPV), low left-ventricle ejection fraction (EF), creatinine, and reduced left-atrium appendix (LAA) peak emptying velocity were independent predictors of LAT. The area under the receiver operating characteristic curve analysis for MPV was 0.70 (95%CI: 0.57-0.83; p = 0.011). With the optimal cut-off value of 9.45, MPV had a sensitivity of 71.4% and a specificity of 63% to predict LAT.

CONCLUSION

AIS patients with low ventricle EF and elevated MPV should undergo further TEE examination to verify the possibility of a cardio-embolic source. In addition, this research may provide novel information with respect to the applicability of MPV to predict LAT in such patients without AF.

Effectiveness of complete blood count parameters for predicting intracranial injury in children with minor head trauma

Objective: We aimed to investigate the relationship between trauma severity and platelet indices (PI) and white blood cell (WBC) count to identify traumatic brain injury (TBI) in children with minor head trauma (MHT). Materials and methods: This prospective study included children with acute isolated MHT who underwent head computed tomography (CT) based on Pediatric Emergency Care Research Network (PECARN) criteria. Mean platelet volume (MPV), platelet distribution width (PDW), MPV to platelet ratio (MPV/PL), MPV to white blood cell ratio (MPV/WBC), and MPV to Neutrophil ratio (MPV/Neu) were evaluated. Results: 86 children with MHT and 245 controls were included the study. WBC, Neu count, MPV, MPV/WBC, MPV/Neu and MPV/PI ratios were statistically different among patients with abnormal CT, patients with normal CT and healthy controls (p < 0.05). For predicting abbreviated injury score (AIS) > 1, the AUC values of WBC, neutrophil, MPV/WBC and MPV/Neu were 0.746, 0.739, 0.726 and 0.724, respectively. Conclusion: In children with MHT who underwent CT, WBC, Neu counts, MPV/WBC and MPV/Neu ratios may be helpful for predicting the severity of trauma in pediatric emergency department.

Novel Automated Hematology Parameters in Clinical Pediatric Practice

Blood sampling in children is a challenging task, and to extract maximum possible information from these 'precious' samples, the modern-day automated hematology analyzers have been aided with much technological advancement. Various novel blood cell parameters are now available to narrow down the differential diagnoses. However, only few of these are available for routine clinical reporting. Knowledge about their interpretation and reference ranges can prove useful in challenging situations.

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.

Mean platelet volume: a potential biomarker of the risk and prognosis of heart disease

Platelets are essential for progression of atherosclerotic lesions, plaque destabilization, and thrombosis. They secrete and express many substances that are crucial mediators of coagulation, inflammation, and atherosclerosis. Mean platelet volume (MPV) is a precise measure of platelet size, and is routinely reported during complete blood count analysis. Emerging evidence supports the use of MPV as a biomarker predicting the risk of ischemic stroke in patients with atrial fibrillation, and as a guide for prescription of anticoagulation and rhythm-control therapy. In addition, MPV may predict the clinical outcome of percutaneous coronary intervention (PCI) in patients with coronary artery disease and indicate whether additional adjunctive therapy is needed to improve clinical outcomes. This review focuses on the current evidence that MPV may be a biomarker of the risk and prognosis of common heart diseases, particularly atrial fibrillation and coronary artery disease treated via PCI.

Association of epicardial adipose tissue thickness and inflammation parameters with CHA2DS2-VASASc score in patients with nonvalvular atrial fibrillation

BACKGROUND

Epicardial adipose tissue (EAT), mean platelet volume (MPV), platelet-to- lymphocyte ratio (PLR), and neutrophil-to-lymphocyte ratio (NLR) have been shown to be helpful in predicting adverse cardiovascular events. However, to date, in the literature, there have been no studies demonstrating the relationship between EAT, MPV, PLR, NLR, and thromboembolism risk in atrial fibrillation (AF). Therefore, we examined the relationship between EAT, MPV, PLR, NLR, and CHA2DS2-VASc score used for the evaluation of thromboembolism risk in patients with AF.

METHODS

The study included 96 consecutive patients with AF and 52 age- and sex-matched control subjects. We calculated CHA2DS2-VASc risk score for each patient and measured baseline EAT thickness, MPV, PLR, NLR, left atrial volume index, and left ventricular ejection fraction.

RESULTS

The group with high CHA2DS2-VASc score had higher EAT (7.2±1.5 vs 5.9±1.2 mm, P<0.001), MPV (9.1±1.1 vs 8.4±1.0 fL, P=0.004), PLR (152.3±28.4 vs 126.7±25.4, P=0.001), and NLR (4.0±1.6 vs 3.2±1.3, P<0.001) compared to group with low-intermediate CHA2DS2-VASc score. Moreover, CHA2DS2-VASc score was found to be positively correlated with EAT (r=0.623, P<0.001), MPV (r=0.350, P=0.004), PLR (r=0.398, P=0.001), and NLR (r=0.518, P<0.001).

CONCLUSION

Our study results demonstrated that EAT thickness, MPV, PLR, and NLR were associated with the thromboembolic risk exhibited by CHA2DS2-VASc score in patients with nonvalvular AF.

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.

Association of inflammatory and hemostatic markers with stroke and thromboembolic events in atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) increases the risk of stroke and thromboembolic events. Recently, biomarkers have been proposed as a practical tool to predict adverse outcomes in patients with AF. The prognostic value of inflammatory and hemostatic markers in AF has been widely studied; however, the results of previous studies have been inconclusive.

METHODS

We conducted a systematic review and meta-analysis to evaluate the association of inflammatory and hemostatic markers with stroke and thromboembolic events in patients with AF.

RESULTS

A total of 27 studies including 22,176 participants met our inclusion criteria for the systematic review. Our meta-analysis determined that elevated circulating plasminogen activator inhibitor-1 (PAI-1) and thrombin-antithrombin (TAT) were significantly associated with increased risk of stroke in patients with AF (standardized mean difference [SMD], 0.89; 95% confidence interval [CI], 0.20-1.59 and 1.43; 95% CI, 0.40-2.47, respectively). Higher levels of D-dimer were associated with increased subsequent thromboembolic event risk with a pooled hazard ratio of 2.90 (95% CI, 1.22-6.90) for cohort studies and an SMD of 0.93 (95% CI, 0.36-1.50) for case-control studies. There was also very limited evidence indicating that other biomarkers-such as interleukin-6, von Willebrand factor, P-selectin, and mean platelet volume-could predict adverse outcomes in AF.

CONCLUSIONS

In conclusion, increased circulating PAI-1 and TAT levels were significantly associated with subsequent stroke in patients with AF, and high levels of D-dimer were associated with thromboembolic events in AF. Further epidemiologic studies are needed to accumulate more evidence on the prognostic role of inflammatory and hemostatic markers in AF.

Atrial Fibrillation Is Associated With Increased Mean Platelet Volume and Apnea Hypopnea Index in Patients With Obstructive Sleep Apnea

This study investigated whether there is a relationship between atrial fibrillation (AF), mean platelet volume (MPV), and apnea hypopnea index (AHI) in patients who have obstructive sleep apnea syndrome (OSAS). We enrolled patients who had OSAS with either AF or normal sinus rhythm (NSR). We divided 90 patients (aged 50-80 years) into 2 groups: group 1 consisted of 40 patients with OSAS having AF and group 2 of 50 patients with OSAS having NSR. Mean platelet volume was higher in patients with AF than in those with NSR (9.8 ± 0.6 vs 8.4 ± 0.6 fL; P < .001). The MPV and AHI were substantial variables associated with AF (odds ratio [OR] = 2.41; 95% confidence interval [CI], 1.36-5.26; P < .004 and OR = 1.91; 95% CI, 1.26-3.32; P = .02). Elevated MPV value of ≥9.4 fL is associated with AF (70% sensitivity and 63% specificity). More research is needed to establish the clinical relevance of this association.

Mean platelet volume is associated with the presence of left atrial stasis in patients with non-valvular atrial fibrillation

Background

Mean platelet volume has been associated with stroke in patients with atrial fibrillation. However, its role as a predictor of left atrial stasis, assessed by transesophageal echocardiography, in patients with non-valvular atrial fibrillation has not yet been clarified.

Methods

Single center cross-sectional study comprising 427 patients admitted to the emergency department due to symptomatic atrial fibrillation and undergoing transesophageal echocardiogram evaluation for exclusion of left atrial appendage thrombus before cardioversion. All patients had a complete blood count performed in the 12 hours prior to transesophageal echocardiogram. Markers of left atrial stasis were sought: left atrial appendage thrombus, dense spontaneous echocardiographic contrast and low flow velocities in the left atrial appendage. The presence of at least one of the former markers of left atrial stasis was designated left atrial abnormality. Binary logistic multivariate analysis was used for obtaining models for the prediction of transesophageal echocardiogram endpoints.

Results

Left atrial appendage thrombus was found in 12.2%, dense spontaneous echocardiographic contrast in 29.7%, low flow velocities in 15.3% and left atrial abnormality in 34.2%. Mean platelet volume (exp β = 3.41 p = 0.048) alongside with previous stroke or transient ischemic attack (exp β = 5.35 p = 0.005) and troponin I (exp β = 5.07 p = 0.041) were independent predictors of left atrial appendage thrombus. Mean platelet volume was also incorporated in the predictive models of dense spontaneous echocardiographic contrast, low flow velocities and left atrial abnormality, adding predictive value to clinical, echocardiographic and laboratory variables.

Conclusions

These findings suggest that mean platelet volume may be associated with the presence of markers of left atrial stasis, reinforcing a likely cardioembolic mechanism for its association with stroke in patients with non-valvular atrial fibrillation.