Organic or Inorganic Zinc for Laying Hens? A Systematic Review and Meta-analysis of the Effects of Zinc Sources on Laying Performance, Egg Quality, and Zinc Excretion.

The higher availability of zinc (Zn) from organic than inorganic sources is already established, but more assertive and cost-friendly protocols on the total replacement of inorganic with organic Zn sources for laying hens still need to be developed. Because some discrepancy in the effects of this replacement in laying hen diets is noticeable in the literature, the objective of this meta-analysis was to properly quantify the effect size of total replacing inorganic Zn with organic Zn in the diet of laying hens on their laying performance, egg quality, and Zn excretion. A total of 2340 results were retrieved from Pubmed, Scielo, Scopus, WOS, and Science Direct databases. Of these, 18 primary studies met all the eligibility criteria and were included in this meta-analysis. Overall, the replacement of inorganic Zn with organic Zn, regardless of other factors, improved (p < 0.01) egg production by 1.46%, eggshell thickness by 0.01 mm, and eggshell resistance by 0.11 kgf/cm2. Positive results of the same nutritional strategy on egg weight and Zn excretion were only observed at specific conditions, especially when organic Zn was supplemented alone in the feed, not combined with other organic minerals. Therefore, there is evidence in the literature that the total replacement of inorganic Zn with organic Zn improves egg production, eggshell thickness, and eggshell resistance. Factors such as hen age and genetics, organic Zn source, concentration of Zn in the feed, and the strategy of its supplementation have to be more carefully considered in protocols designed to address egg weight and Zn excretion by the hen.

Abordagem fisioterapêutica no pós-operatório de cirurgia bariátrica: revisão sistemática / Physiotherapeutic approach in the postoperative period of bariatric surgery: systematic review

Objetivo: O presente estudo tem por objetivo verificar os principais benefícios e efeitos fisiológicos de um programa de exercícios, como intervenção fisioterapêutica, no pós-operatório de cirurgia bariátrica. Métodos: Trata-se de uma revisão sistemática de literatura na qual foi realizado um levantamento bibliográfico nos bancos de dados Bireme e Pubmed e nas bases de dados Scielo e Lilacs. Foram utilizados artigos na língua inglesa e portuguesa publicados no período de 2011 a 2018. Os critérios de inclusão foram estudos que envolvessem procedimentos experimentais realizados em adultos com obesidade mórbida, que apresentassem um programa de exercícios físicos como intervenção pós-cirurgia bariátrica e que contivessem um grupo controle. Também de forma independente, foi avaliada a qualidade metodológica dos estudos selecionados com a Escala de Qualidade de JADAD. Resultados: Os treinamentos compostos por exercícios combinados aeróbicos e resistidos apresentaram uma resposta mais eficaz e quando realizados de maneira personalizada foram capazes de proporcionar maior aderência e resultados mais significativos. Conclusão: Um programa composto por exercícios aeróbicos e resistidos, quando realizado de maneira personalizada no pós-operatório de cirurgia bariátrica é capaz de promover perda de peso significativa, diminuição do percentual de gordura, ganho de força muscular, melhora da sensibilidade à insulina, aumento da capacidade física e aeróbica, melhora da variabilidade da frequência cardíaca e do bem-estar psicológico do paciente.

Contributions of the heart rate turbulence method to risk stratification in patients after myocardial infarction: a review.

Coronary artery disease remains an important cause of morbidity and mortality worldwide. The impact of ventricular arrhythmias and impaired cardiac vagal activity on coronary events is one of the most relevant prognostic factors, despite little research being conducted in clinical practice. A simple and cost-effective way to analyze cardiac autonomic regulation is through the heart rate turbulence (HRT) method. Studies have shown that altered HRT, which indicates reduction in the vagal cardiac activity, can identify patients who are at a higher risk of sudden death. Thus, aspects related to the definition, pathophysiological mechanism, conditions that alter the HRT behavior, and the main studies that analyzed the prognostic importance of HRT in patients with ischemic disease were discussed in this review. HRT analysis was proven to be a simple and cost-effective way to assess cardiac autonomic dysfunction by providing complementary information to classic parameters, such as the assessment of ventricular function.

New ATP7B Gene Mutation in a Brazilian Patient with Wilson Disease.

We report the case of a 70-year-old man diagnosed with late-onset Wilson disease (WD) with mild neurological symptoms only and a new mutation in the ATP7B gene. A compound mutation of the ATP7B gene was found with the variant c.98T>C p(Met33Thr) in exon 2, in heterozygosis, and variant c.2224G>A (Val742Ile) in exon 8, in heterozygosis. Patient age should not be a determinant for excluding WD. Genetic sequencing is an important tool for the discovery of new genetic mutations. LEARNING POINTS: Wilson disease (WD) is an autosomal recessive disorder of copper metabolismPatient age should not exclude WD, and symptoms compatible with WD should raise suspicion for WD even in older people.Genetic sequencing is an important tool in the discovery of new genetic mutations.

Granulomatosis With Polyangiitis: A Clinical Case.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is characterized by inflammation and the destruction of small- and medium-caliber blood vessels in the presence of circulating ANCAs. Anti-neutrophil cytoplasmic antibody-associated vasculitis predominantly affects the lung and kidney with a multifactorial pathogenesis. This case refers to a 55-year-old woman with constitutional symptoms, hypoacusis, cough, and bloody sputum. Physical examination revealed polypnea and decreased lung auscultation at the bases; blood work showed elevated inflammatory parameters, acute kidney injury, and hematuria; pulmonary computed tomography revealed areas of peribronchial thickening in both lungs; immunological study resulted in positive ANCA-PR3. Corticotherapy and double immunosuppression with cyclophosphamide and rituximab were initiated, which resulted in clinical and analytical improvement. This case of granulomatosis with polyangiitis (GPA), with pulmonary, renal, cutaneous, and ear involvement, allows us to demonstrate the importance of timely clinical suspicion and initiation of immunosuppression for a favorable disease prognosis.

On-pump versus off-pump coronary artery bypass surgery for multi-vessel coronary revascularization.

BACKGROUND: This study aims to compare the operative and postoperative results of on-pump (ONCAB) and off-pump (OPCAB) coronary artery bypass surgery (CABG) for multi-vessel coronary revascularization (≥4 anastomoses). METHODS: From May 2018 to August 2019, a total of 120 patients (22.5% women, mean age 61.5±8.4 years) received either ONCAB (Group 1, n=60) or OPCAB (Group 2, n=60) for multi-vessel coronary artery disease (CAD). Preoperative left ventricular (LV) ejection fraction (EF) was 53.1%±8.4%. Median EuroSCORE II was 1.59 (interquartile range, 1.01-2.54). The median number of performed coronary anastomoses was 4 (interquartile range, 4-5), with equal distribution in both groups (P=0.4). All procedures were performed by highly experienced surgeons. The primary endpoints were overall survival at 30 days and freedom from severe adverse events (SAE), which included myocardial infarction (MI), coronary artery re-operation, and re-thoracotomy, caused by bleeding and stroke. RESULTS: The overall survival in both groups was 100% with no intraoperative OPCAB-to-on-pump conversion. The median procedure time was 169 min (interquartile range, 150-179 min) for Group 1 and 183 min (interquartile range, 169-205 min) for Group 2 (P<0.001). The overall freedom from SAE numbered 93.3% (98.3% vs. 88.3%, P=0.030). Postoperative MI rate was 2.5% (n=3) with no significant difference for either group (0 vs. 5.0%, P=0.100). One MI patient underwent a re-operation, and two other patients received a conservative treatment. A total of 2.5% (n=3) of patients underwent a re-thoracotomy on account of bleeding (0 vs. 5.0%, P=0.100); no anastomosis-related bleeding was detected. Blood transfusion was applied in 31.7% of patients (38.3% vs. 25.0%, P=0.090). A total of 1.7% of patients (1.7% vs. 1.7%, P=0.800) developed a stroke. Ventilation time, intensive care unit stay, and hospital stay were similar in both groups. CONCLUSIONS: ONCAB showed superior freedom from SAE and shorter procedure times when compared to OPCAB for multi-vessel coronary artery revascularization.

Logistic Regression Model in a Machine Learning Application to Predict Elderly Kidney Transplant Recipients with Worse Renal Function One Year after Kidney Transplant: Elderly KTbot.

BACKGROUND: Renal replacement therapy (RRT) is a public health problem worldwide. Kidney transplantation (KT) is the best treatment for elderly patients' longevity and quality of life. OBJECTIVES: The primary endpoint was to compare elderly versus younger KT recipients by analyzing the risk covariables involved in worsening renal function, proteinuria, graft loss, and death one year after KT. The secondary endpoint was to create a robot based on logistic regression capable of predicting the likelihood that elderly recipients will develop worse renal function one year after KT. METHOD: Unicentric retrospective analysis of a cohort was performed with individuals aged ≥60 and <60 years old. We analysed medical records of KT recipients from January to December 2017, with a follow-up time of one year after KT. We used multivariable logistic regression to estimate odds ratios for elderly vs younger recipients, controlled for demographic, clinical, laboratory, data pre- and post-KT, and death. RESULTS: 18 elderly and 100 younger KT recipients were included. Pretransplant immune variables were similar between two groups. No significant differences (P > 0.05) between groups were observed after KT on laboratory data means and for the prevalences of diabetes mellitus, hypertension, acute rejection, cytomegalovirus, polyomavirus, and urinary infections. One year after KT, the creatinine clearance was higher (P = 0.006) in youngers (70.9 ± 25.2 mL/min/1.73 m2) versus elderlies (53.3 ± 21.1 mL/min/1.73 m2). There was no difference in death outcome comparison. Multivariable analysis among covariables predisposing chronic kidney disease epidemiology collaboration (CKD-EPI) equation <60 mL/min/1.73 m2 presented a statistical significance for age ≥60 years (P = 0.01) and reduction in serum haemoglobin (P = 0.03). The model presented goodness-fit in the evaluation of artificial intelligence metrics (precision: 90%; sensitivity: 71%; and F 1 score: 0.79). CONCLUSION: Renal function in elderly KT recipients was lower than in younger KT recipients. However, patients aged ≥60 years maintained enough renal function to remain off dialysis. Moreover, a learning machine application built a robot (Elderly KTbot) to predict in the elderly populations the likelihood of worse renal function one year after KT.

Calcific Aortic Valve Stenosis and Atherosclerotic Calcification.

PURPOSE OF REVIEW: This review summarizes the pathophysiology of calcific aortic valve stenosis (CAVS) and surveys relevant clinical data and basic research that explain how CAVS arises. RECENT FINDINGS: Lipoprotein(a) [Lp(a)], lipoprotein-associated phospholipase A2 (Lp-PLA2), oxidized phospholipids (OxPL), autotaxin, and genetic driving forces such as mutations in LPA gene and NOTCH gene seem to play a major role in the development of CAVS. These factors might well become targets of medical therapy in the coming years. CVAS seems to be a multifactorial disease that has much in common with coronary artery disease, mainly regarding lipidic accumulation and calcium deposition. No clinical trials conducted to date have managed to answer the key question of whether Lp(a) lowering and anti-calcific therapies confer a benefit in terms of reducing incidence or progression of CAVS, although additional outcome trials are ongoing.

Boldo-Induced Hepatotoxicity: A Case of Unexplained Jaundice.

An 87-year-old man was admitted with a 2-week history of asthenia, anorexia and jaundice. Blood tests showed increased serum liver enzymes. The aetiological study was inconclusive. The patient had a favourable clinical evolution during hospitalization with supportive care. His wife revealed that the patient had repeatedly consumed infusions of Peumus boldus (commonly known as boldo) leaves during the previous month. After common causes of hepatobiliary pathology were excluded, boldo-induced hepatotoxicity was considered probable. Cessation of its consumption led to complete clinical and laboratory recovery within a week. LEARNING POINTS: Herbal medicines are commonly used by the public.Peumus boldus leaves consumed as an infusion can be hepatotoxic and may cause otherwise unexplained jaundice or abnormal liver enzyme values, particularly in elderly patients.A detailed clinical history is crucial to establish the consumption of alternative medicines in order to identify possible adverse effects and toxicity.

Family members' satisfaction with the care flow in the Pediatric Emergency Department.

OBJECTIVE: To evaluate the satisfaction index of the pediatric patient's caregiver (person responsible for the child) regarding the waiting time for the care flow in an emergency service. METHOD: A prospective, cross-sectional, quantitative study with 300 family members in the Pediatric Emergency Department of a general hospital. An instrument was used to analyze the service flow, waiting time and satisfaction evaluation. Descriptive statistical analysis was performed. RESULTS: The satisfaction index of caregivers was statistically significant (p<0.05) the lower was the waiting time for patient screening, care by the doctors and for receiving the prescribed medication. Caregivers who took their children to the emergency department because of the disease (p -0.029) or because they did not find doctors in other hospitals (p-0.021) were satisfied with the waiting time for this service. CONCLUSION: The quality of care is evaluated as satisfactory by caregivers when children are treated quickly in the Pediatric Emergency Department.

Family members' satisfaction with the care flow in the Pediatric Emergency Department / La satisfacción de los familiares sobre el flujo de atención en el Departamento de Emergencia Pediátrico / A satisfação dos familiares sobre o fluxo de atendimento no Pronto-Socorro Pediátrico

ABSTRACT Objective: To evaluate the satisfaction index of the pediatric patient's caregiver (person responsible for the child) regarding the waiting time for the care flow in an emergency service. Method: A prospective, cross-sectional, quantitative study with 300 family members in the Pediatric Emergency Department of a general hospital. An instrument was used to analyze the service flow, waiting time and satisfaction evaluation. Descriptive statistical analysis was performed. Results: The satisfaction index of caregivers was statistically significant (p<0.05) the lower was the waiting time for patient screening, care by the doctors and for receiving the prescribed medication. Caregivers who took their children to the emergency department because of the disease (p -0.029) or because they did not find doctors in other hospitals (p-0.021) were satisfied with the waiting time for this service. Conclusion: The quality of care is evaluated as satisfactory by caregivers when children are treated quickly in the Pediatric Emergency Department.

RESUMEN Objetivo: Evaluar el índice de satisfacción del cuidador del paciente pediátrico con relación a los tiempos de espera del flujo de atención en un servicio de emergencia. Método: Estudio transversal, prospectivo, cuantitativo, realizado con 300 familiares en el Departamento de Emergencia Pediátrico de un hospital general. Se utilizó un instrumento para analizar el flujo del servicio, el tiempo de espera y la evaluación de la satisfacción. Se realizó un análisis estadístico descriptivo. Resultados: El índice de satisfacción de los cuidadores fue estadísticamente significativo (p<0,05) cuanto menor el tiempo de espera para la clasificación de los pacientes en el triaje, atención por los médicos y recepción de la medicación prescrita. Los acompañantes que llevaron a sus niños al Departamento de Emergencia debido a la patología (p-0,029) o por no encontrar médicos en otros hospitales (p-0,021), quedaron satisfechos con el tiempo de espera para la atención en este servicio. Conclusión: La calidad de atención es percibida como satisfactoria por los acompañantes cuando los niños son atendidos con rapidez en el Departamento de Emergencia Pediátrico.

RESUMO Objetivo: Avaliar o índice de satisfação do responsável pelo paciente pediátrico referente aos tempos de espera do fluxo de atendimento em um serviço de emergência. Método: Estudo transversal, prospectivo, quantitativo, realizado com 300 familiares no Pronto-Socorro Pediátrico de um hospital geral. Um instrumento foi utilizado para análise do fluxo do serviço, tempo de espera e avaliação da satisfação. Realizada análise estatística descritiva. Resultados: O índice de satisfação dos responsáveis foi estatisticamente significante (p<0,05) quanto menor o tempo de espera para classificação dos pacientes na triagem, atendimento pelos médicos e recebimento da medicação prescrita. Os acompanhantes que levaram suas crianças ao Pronto-Socorro devido à patologia (p-0,029) ou por não encontrarem médicos em outros hospitais (p-0,021), ficaram satisfeitos com o tempo de espera para o atendimento neste serviço. Conclusão: A qualidade de atendimento manifestada pelos acompanhantes é satisfatória quando as crianças são atendidas com rapidez no Pronto-Socorro Pediátrico.

Reflection and Updates: Cardiopulmonary Resuscitation -Guidelines 2015 - Contribution to Nursing / Reflexión y actualizaciones: Resucitación cardiopulmonar -Pautas 2015 - Contribución a la enfermería

ABSTRACT The occurrence of cardiac arrest is a stressful and critical event. Despite technological advances in the training of cardiopulmonary resuscitation (CPR) techniques, mortality remains high, and patients survive up to discharge with high levels of neurological complications. The European Resuscitation Council guidelines and the American Heart Association as of 2015 hold the best recommendations in performing CPR.

RESUMEN La ocurrencia de un paro cardíaco es un evento estresante y crítico. A pesar de los avances tecnológicos en la práctica de técnicas de resucitación cardiopulmonar (RCP), la mortalidad sigue siendo alta, y los pacientes sobreviven al alta hospitalaria con altos niveles de complicaciones neurológicas. Las guías del Consejo Europeo de Resucitación y la Asociación Americana del Corazón a partir de 2015, poseen las mejores recomendaciones para realizar RCP.

Satisfação da qualidade de atendimento em um Pronto-Socorro Infantil / Satisfaction of quality of care in a Pediatric Emergency Room

Resumo Objetivo: Avaliar o índice de satisfação do acompanhante do paciente pediátrico com relação à qualidade do atendimento prestado em um serviço de emergência. Métodos: Pesquisa transversal e descritiva desenvolvida em um Pronto-Socorro Infantil de um hospital universitário, com a participação de 300 acompanhantes dos pacientes pediátricos. Utilizou-se um instrumento validado oferecido aos familiares para avaliar a qualidade do serviço de emergência. Resultados: Os acompanhantes dos pacientes pediátricos demonstraram satisfação com a qualidade de atendimento prestado pelo Pronto-Socorro Infantil. Registrou-se diferença estatística significativa (p<0,05) quanto ao índice de satisfação manifestado pelos familiares das crianças diagnosticadas com doenças dermatológicas, que receberam medicações administradas pela via retal e que procuraram o serviço por considerarem-no como referência ou por não possuírem plano de saúde. Conclusão: Os familiares pesquisados encontram-se satisfeitos no que se refere à qualidade de atendimento prestado às suas crianças no serviço de pronto-socorro.

Abstract Objective: To evaluate the satisfaction index of pediatric patients' companions in relation to the quality of care provided in an emergency service. Methods: Cross-sectional and descriptive study conducted in a Pediatric Emergency Room of a teaching hospital with participation of 300 companions of pediatric patients. A validated instrument was offered to family members for their evaluation of the emergency service quality. Results: Pediatric patients' companions demonstrated satisfaction with the quality of care provided at the Pediatric Emergency Room. There was a significant statistical difference (p<0.05) in the satisfaction index of family members of children diagnosed with dermatological diseases and who received medications administered via rectal route, and those who sought the service because they considered it a reference or because they did not have health insurance. Conclusion: The family members surveyed are satisfied with the quality of care provided to their children in the emergency room service.

Off-pump versus on-pump coronary artery bypass grafting in frail patients: study protocol for the fragile multicenter randomized controlled trial

Abstract Introduction: Advances in modern medicine have led to people living longer and healthier lives. Frailty is an emerging concept in medicine yet to be explored as a risk factor in cardiac surgery. When it comes to CABG surgery, randomized controlled clinical trials have primarily focused on low-risk (ROOBY, CORONARY), elevated-risk (GOPCABE) or high-risk patients (BBS), but not on frail patients. Therefore, we believe that off-pump CABG could be an important technique in patients with limited functional capacity to respond to surgical stress. In this study, the authors introduce the new national, multicenter, randomized, controlled trial "FRAGILE", to be developed in the main cardiac surgery centers of Brazil, to clarify the potential benefit of off-pump CABG in frail patients. Methods: FRAGILE is a two-arm, parallel-group, multicentre, individually randomized (1:1) controlled trial which will enroll 630 patients with blinded outcome assessment (at 30 days, 6 months, 1 year, 2 years and 3 years), which aims to compare adverse cardiac and cerebrovascular events after off-pump versus on-pump CABG in pre-frail and frail patients. Primary outcomes will be all-cause mortality, acute myocardial infarction, cardiac arrest with successful resuscitation, low cardiac output syndrome/cardiogenic shock, stroke, and coronary reintervention. Secondary outcomes will be major adverse cardiac and cerebrovascular events, operative time, mechanical ventilation time, hyperdynamic shock, new onset of atrial fibrillation, renal replacement therapy, reoperation for bleeding, pneumonia, length of stay in intensive care unit, length of stay in hospital, number of units of blood transfused, graft patency, rate of complete revascularization, neurobehavioral outcomes after cardiac surgery, quality of life after cardiac surgery and costs. Discussion: FRAGILE trial will determine whether off-pump CABG is superior to conventional on-pump CABG in the surgical treatment of pre-frail and frail patients. Trial registration: ClinicalTrials.gov, ID: NCT02338947. Registered on August 29th 2014; last updated on March 21st 2016.

High-intensity interval training has beneficial effects on cardiac remodeling through local renin-angiotensin system modulation in mice fed high-fat or high-fructose diets.

AIMS: HIIT (high-intensity interval training) has the potential to reduce cardiometabolic risk factors, but the effects on cardiac remodeling and local RAS (renin-angiotensin system) in mice fed high-fat or high-fructose diets still need to be fully addressed. MAIN METHODS: Sixty male C57BL/6 mice (12weeks old) were randomly divided into three groups, control (C), High-fat (HF), or High-fructose diet (HRU) and were monitored for eight weeks before being submitted to the HIIT. Each group was randomly assigned to 2 subgroups, one subgroup was started on a 12-week HIIT protocol (T=trained group), while the other subgroup remained non-exercised (NT=not-trained group). KEY FINDINGS: HIIT reduced BM and systolic blood pressure in high-fat groups, while enhanced insulin sensitivity after high-fat or high-fructose intake. Moreover, HIIT reduced left ventricular hypertrophy in HF-T and HFRU-T. Notably, HIIT modulated key factors in the local left ventricular renin-angiotensin-system (RAS): reduced protein expression of renin, ACE (Angiotensin-converting enzyme), and (Angiotensin type 2 receptor) AT2R in HF-T and HFRU-T groups but reduced (Angiotensin type 1 receptor) AT1R protein expression only in the high-fat trained group. HIIT modulated ACE2/Ang (1-7)/Mas receptor axis. ACE2 mRNA gene expression was enhanced in HF-T and HFRU-T groups, complying with elevated Mas (Mas proto-oncogene, G protein-coupled receptor) receptor mRNA gene expression after HIIT. SIGNIFICANCE: This study shows the effectiveness of HIIT sessions in producing improvements in insulin sensitivity and mitigating LV hypertrophy, though hypertension was controlled only in the high-fat-fed submitted to HIIT protocol. Local RAS system in the heart mediates these findings and receptor MAS seems to play a pivotal role when it comes to the amelioration of cardiac structural and functional remodeling due to HIIT.

Predictive Role of Coagulation, Fibrinolytic, and Endothelial Markers in Patients with Atrial Fibrillation, Stroke, and Thromboembolism: A Meta-Analysis, Meta-Regression, and Systematic Review.

BACKGROUND The pathophysiological mechanism associated with the higher prothrombotic tendency in atrial fibrillation (AF) is complex and multifactorial. However, the role of prothrombotic markers in AF remains inconclusive. MATERIAL AND METHODS We conducted a meta-analysis of observational studies evaluating the association of coagulation activation, fibrinolytic, and endothelial function with occurrence of AF and clinical adverse events. A comprehensive subgroup analysis and meta-regression was performed to explore potential sources of heterogeneity. RESULTS A literature search of major databases retrieved 1703 studies. After screening, a total of 71 studies were identified. Pooled analysis showed the association of coagulation markers (D-dimer (weighted mean difference (WMD) =197.67 and p<0.001), fibrinogen (WMD=0.43 and p<0.001), prothrombin fragment 1-2 (WMD=0.53 and p<0.001), antithrombin III (WMD=23.90 and p=0.004), thrombin-antithrombin (WMD=5.47 and p=0.004));  fibrinolytic markers (tissue-type plasminogen activator (t-PA) (WMD=2.13 and p<0.001), plasminogen activator inhibitor (WMD=11.44 and p<0.001), fibrinopeptide-A (WMD=4.13 and p=0.01)); and  endothelial markers (von Willebrand factor (WMD=27.01 and p<0.001) and soluble thrombomodulin (WMD=3.92 and p<0.001)) with AF. CONCLUSIONS The levels of coagulation, fibrinolytic, and endothelial markers have been reported to be significantly higher in AF patients than in SR patients.

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.