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Resumen: Se presenta el caso de un hombre de 79 anos con miocardiopatia dilatada severa, disfuncion ventricular izquierda, fibrilacion auricular permanente y portador de un resincronizador ventricular. Al efectuar un recambio del resincronizador se implanto un electrodo adicional para estimulacion multisitio del ventriculo izquierdo. Ello condujo a significativa mejoria clinica y de la fraccion de eyeccion del ventriculo izquierdo.

ObjectivesThis study was designed to assess whether the reinforcement of the antioxidant system, through n-3 fatty acids plus antioxidant vitamin supplementation, could reduce the incidence of post-operative atrial fibrillation.BackgroundTherapy to prevent post-operative atrial fibrillation remains suboptimal. Although oxidative stress plays a key role in the pathogenesis of this arrhythmia, antioxidant reinforcement has produced controversial results.MethodsA total of 203 patients scheduled for on-pump cardiac surgery were randomized to placebo or supplementation with n-3 polyunsaturated fatty acids (2 g/day) (eicosapentaenoic acid:docosahexaenoic acid ratio 1:2), vitamin C (1 g/day), and vitamin E (400 IU/day). The primary outcome was the occurrence of post-operative atrial fibrillation. Secondary outcomes were the biomarkers related to oxidative stress and inflammation.ResultsPost-operative atrial fibrillation occurred in 10 of 103 patients (9.7%) in the supplemented group versus 32 of 100 patients (32%) in the placebo group (p < 0.001). Early after surgery, placebo patients presented with increased levels of biomarkers of inflammation and oxidative stress, which were markedly attenuated by antioxidant supplementation. The activity of catalase, superoxide dismutase, and glutathione peroxidase in atrial tissue of the supplemented patients was 24.0%, 17.1%, and 19.7% higher than the respective placebo values (p < 0.05). The atrial tissue of patients who developed atrial fibrillation showed NADPH oxidase p47-phox subunit protein and mRNA expression 38.4% and 35.7% higher, respectively, than patients in sinus rhythm (p < 0.05).ConclusionsThis safe, well-tolerated, and low-cost regimen, consisting of n-3 polyunsaturated fatty acids plus vitamins C and E supplementation, favorably affected post-operative atrial fibrillation, increased antioxidant potential, and attenuated oxidative stress and inflammation. (Prevention of Post-Operative Atrial Fibrillation: Pathophysiological Characterization of a Pharmacological Intervention Based on a Novel Model of Nonhypoxic Pre-Conditioning; ISRCTN45347268)

0 0 1 881 881 Particular 881 880 882 14.0 96 800x600 Normal 0 false false false ES-TRAD JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 CLINICAL CHARACTERISTICS, COMPLICATIONS AND MORTALITY IN 506 PATIENTS WITH INFECTIVE ENDOCARDITIS AND DETERMINANTS OF SURVIVAL RATE AT 10 YEARS Background : Rates of morbidity and mortality in Infective Endocarditis (IE) remain high and prognosis in this disease is still difficult and uncertain. Aim : To study IE in Chile in its active phase during inpatient hospital stay and long term survival rates. Material and methods: Observational prospective national cohort study of 506 consecutive patients included between June 1, 1998 and July 31, 2008, from 37 Chilean hospitals (secondary and tertiary centers) nationwide. Results : The main findings were the presence of Rheumatic valve disease in 22.1% of patients, a history of intravenous drug abuse (IVDA) only in 0.7%, the presence of Staphylococcus aureus in 29.2% of blood cultures, negative blood cultures in 33.2%, heart failure in 51.7% and native valve involvement in 86% of patients. Echocardiographic diagnosis was achieved in 94% of patients. Hospital mortality was 26.1% and its prognostics factors were persisting infection (Odds ratio (OR) 6.43, Confidence Interval (CI) 1.45 – 28.33%), failure of medical treatment and no surgical intervention (OR 48.8; CI 6.67 – 349.9). Five and 10 years survival rates were 75.6 and 48.6%, respectively. The significant prognostic factors for long term mortality, determined by multivariate analysis were the presence of diabetes, Staphylococcus aureus infection, sepsis, heart failure, renal failure and lack of surgical treatment during the IE episode. Conclusions : The microbiologic diagnosis of IE must be urgently improved in Chile. Mortality rates are still high (26.1%) partly because of a high incidence of negative blood cultures and the need for more surgical valve interventions during in-hospital period. Long term prognostic factors for mortality should be identified early to improve outcome. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

Objectives This study investigated the left atrial appendage (LAA) by computed tomography (CT) and magnetic resonance imaging (MRI) to categorize different LAA morphologies and to correlate the morphology with the history of stroke/transient ischemic attack (TIA). Background LAA represents one of the major sources of cardiac thrombus formation responsible for TIA/stroke in patients with atrial fibrillation (AF). Methods We studied 932 patients with drug-refractory AF who were planning to undergo catheter ablation. All patients underwent cardiac CT or MRI of the LAA and were screened for history of TIA/stroke. Four different morphologies were used to categorize LAA: Cactus, Chicken Wing, Windsock, and Cauliflower. Results CT scans of 499 patients and MRI scans of 433 patients were analyzed (age 59 ± 10 years, 79% were male, and 14% had CHADS2 [Congestive heart failure, Hypertension, Age >75, Diabetes mellitus, and prior Stroke or transient ischemic attack] score ≥2). The distribution of different LAA morphologies was Cactus (278 [30%]), Chicken Wing (451 [48%]), Windsock (179 [19%]), and Cauliflower (24 [3%]). Of the 932 patients, 78 (8%) had a history of ischemic stroke or TIA. The prevalence of pre-procedure stroke/TIA in Cactus, Chicken Wing, Windsock, and Cauliflower morphologies was 12%, 4%, 10%, and 18%, respectively (p = 0.003). After controlling for CHADS2 score, gender, and AF types in a multivariable logistic model, Chicken Wing morphology was found to be 79% less likely to have a stroke/TIA history (odd ratio: 0.21, 95% confidence interval: 0.05 to 0.91, p = 0.036). In a separate multivariate model, we entered Chicken Wing as the reference group and assessed the likelihood of stroke in other groups in relation to reference. Compared with Chicken Wing, Cactus was 4.08 times (p = 0.046), Windsock was 4.5 times (p = 0.038), and Cauliflower was 8.0 times (p = 0.056) more likely to have had a stroke/TIA. Conclusions Patients with Chicken Wing LAA morphology are less likely to have an embolic event even after controlling for comorbidities and CHADS2 score. If confirmed, these results could have a relevant impact on the anticoagulation management of patients with a low-intermediate risk for stroke/TIA.

Incomplete LAA Occlusion by WATCHMAN Device. Introduction: Transcatheter left atrial appendage (LAA) closure with the WATCHMAN device has become one of the therapeutic options in atrial fibrillation (AF) patients who are at high risk for ischemic stroke. However, the incidence and evolution of incomplete occlusion of the LAA during and after placement of the WATCHMAN device has not been reported. Methods and Results: Fifty-eight consecutive patients who had undergone WATCHMAN device implant were included in the study. Intraprocedural, 45-day and 12-month transesophageal echocardiogram images were reviewed and analyzed. Peridevice gap was noted in 16 (27.6%), 17 (29.3%), and 20 (34.5%) patients across the 3 time points. Intraprocedural gaps are more likely to be persistent until 12 months and become larger in size over time. New gap also occurs during follow-up even if the LAA was completely sealed at implantation. One patient had an ischemic stroke 4.7 months after implant; another patient developed a left atrial thrombus over the device 21.6 months after implant. Both patients had intraprocedural gap and discontinued warfarin therapy after the 45-day evaluation. Conclusion: Incomplete LAA occlusion with a gap between the WATCHMAN device surface and the LAA wall is relatively common. Intraprocedural gaps are more likely to become bigger over time and persist, while new gaps also occur during follow-up. Further studies are warranted to verify whether the presence and persistence of a peridevice gap is associated with increased risk of thromboembolic event in AF patients implanted with a WATCHMAN device. (J Cardiovasc Electrophysiol, Vol. 23, pp. 455-461, May 2012)

Ischaemia reperfusion injury is a pathophysiological event that occurs after cardiac surgery with extracorporeal circulation. This clinical event has been associated with the induction of oxidative and inflammatory damage in atrial tissue. Here, we tested whether combined omega 3 polyunsaturated fatty acids (n-3 PUFA)-antioxidant vitamin protocol therapy reduces oxidative and inflammatory cardiac tissue damage. This trial assigned 95 either-sex patients to supplementation with n-3 PUFA (2 g/day), or matching placebo groups, 7 days before on-pump surgery. Antioxidant vitamins C (1 g/day) and E (400 IU/day) or placebo were added from 2 days before surgery until discharge. Blood and atrial tissue samples were obtained during the intervention. Reduced/oxidized glutathione (GSH/GSSG) ratio, malondialdehyde (MDA) and protein carbonylation were determined in atrial tissue. Leucocyte count and high-sensitivity C-reactive protein (hs-CRP) in blood plus nuclear factor (NF)-κappaB activation in atrial tissue served for inflammation assessment. Lipid peroxidation and protein carbonylation were 27.5 and 24% lower in supplemented patients (p < 0.01). GSH/GSSG ratio was 38.1% higher in supplemented patients compared with placebo (p < 0.01). Leucocyte count and serum hs-CRP levels were markedly lower throughout the protocol in supplemented patients (p < 0.01). Atrial tissue NF-κB DNA activation in supplemented patients was 22.5% lower than that in placebo patients (p < 0.05). The combined n-3 PUFA-antioxidant vitamin protocol therapy here proposed reduced the oxidative stress and inflammation biomarkers, in patients undergoing on-pump cardiac surgery.

Rates of morbidity and mortality in Infective Endocarditis (IE) remain high and prognosis in this disease is still difficult and uncertain.To study IE in Chile in its active phase during inpatient hospital stay and long term survival rates.Observational prospective national cohort study of 506 consecutive patients included between June 1,1998 and July 31, 2008, from 37 Chilean hospitals (secondary and tertiary centers) nationwide.The main findings were the presence of Rheumatic valve disease in 22.1 % of patients, a history of intravenous drug abuse (IVDA) only in 0.7%, the presence of Staphylococcus aureus in 29.2% of blood cultures, negative blood cultures in 33.2%, heart failure in 51.7% and native valve involvement in 86% of patients. Echocardiographic diagnosis was achieved in 94% of patients. Hospital mortality was 26.1% and its prognostics factors were persisting infection (Odds ratio (OR) 6.43, Confidence Interval (CI) 1.45-28.33%), failure of medical treatment and no surgical intervention (OR 48.8; CI 6.67-349.9). Five and 10 years survival rates were 75.6 and 48.6%, respectively. The significant prognostic factors for long term mortality, determined by multivariate analysis were the presence of diabetes, Staphylococcus aureus infection, sepsis, heart failure, renal failure and lack of surgical treatment during the IE episode.The microbiologic diagnosis of IE must be urgently improved in Chile. Mortality rates are still high (26.1%) partly because of a high incidence of negative blood cultures and the need for more surgical valve interventions during in-hospital period. Long term prognostic factors for mortality should be identified early to improve outcome.

Antecedentes: Publicaciones internacionales señalan que las hospitalizaciones por fibrilación auricular (FA) están aumentando, lo que tiene importantes implicaciones para la salud pública y el cardiólogo. En Chile no se dispone de mayor información sobre el problema. Objetivo: Estudiar las hospitalizaciones asociadas al diagnóstico de FA en Chile. Métodos: Los egresos hospitalarios con el diagnóstico de FA fueron obtenidos del Ministerio de Salud (código 1^48 FA) de la Clasificación Internacional de Enfermedades. Hubo datos disponibles solo para los años 2002 al 2007; se analizó género, grupos etarios y regiones del país. Las tasas (T) de egresos hospitalarios con este diagnóstico por 10.000 habitantes (H) fueron calculadas en base a la población proyectada del último censo nacional para los años señalados. Para el análisis estadístico se utilizó el test de proporsiones de Z. Resultados: La T total de egreso hospitalario asociada al diagnóstico de FA el año 2002 fue de 2,2/10.000 H la que aumentó gradualmente hasta una T de 2,8/10.000 H el año 2007 (P80 años las T fueron de 32,4 y 43,7/10.000 H respectivamente (P 65 años, y en las regiones del sur del país. Se requiere profundizar en las causas de este aumento.

Tako-Tsubo syndrome resembles an acute myocardial infarction in symptoms, laboratory parameters and electrocardiographic changes. However, angiography does not show evidence of coronary occlusion, and typically an apical ballooning of the ventricle in systole is observed. We report a 78-year-old woman with no coronary risks factors, admitted to the emergency room due to acute chestpain and an electrocardiogram compatible with an acute coronary syndrome with ST elevation. Serum troponin and creatin-kinase (MB fraction) were elevated. An emergency coronary angiography did not show a coronary occlusion. Due to the apical ballooning observed in the left ventriculography, a probable diagnosis of Tako-Tsubo was proposed. The patient had a favorable evolution. A treadmill test, echocardiogram and myocardial perfusión SPECT, performed one month later, disclosed no abnormalities.

Tako-Tsubo syndrome resembles an acute myocardial infarction in symptoms, laboratory parameters and electrocardiographic changes. However, angiography does not show evidence of coronary occlusion, and typically an apical ballooning of the ventricle in systole is observed. We report a 78-year-old woman with no coronary risks factors, admitted to the emergency room due to acute chestpain and an electrocardiogram compatible with an acute coronary syndrome with ST elevation. Serum troponin and creatin-kinase (MB fraction) were elevated. An emergency coronary angiography did not show a coronary occlusion. Due to the apical ballooning observed in the left ventriculography, a probable diagnosis of Tako-Tsubo was proposed. The patient had a favorable evolution. A treadmill test, echocardiogram and myocardial perfusion SPECT, performed one month later, disclosed no abnormalities.

Ischaemia reperfusion injury is a pathophysiological event that occurs after cardiac surgery with extracorporeal circulation. This clinical event has been associated with the induction of oxidative and inflammatory damage in atrial tissue. Here, we tested whether combined omega 3 polyunsaturated fatty acids (n-3 PUFA)-antioxidant vitamin protocol therapy reduces oxidative and inflammatory cardiac tissue damage. This trial assigned 95 either-sex patients to supplementation with n-3 PUFA (2 g/day), or matching placebo groups, 7 days before on-pump surgery. Antioxidant vitamins C (1 g/day) and E (400 IU/day) or placebo were added from 2 days before surgery until discharge. Blood and atrial tissue samples were obtained during the intervention. Reduced/oxidized glutathione (GSH/GSSG) ratio, malondialdehyde (MDA) and protein carbonylation were determined in atrial tissue. Leucocyte count and high-sensitivity C-reactive protein (hs-CRP) in blood plus nuclear factor (NF)-κappaB activation in atrial tissue served for inflammation assessment. Lipid peroxidation and protein carbonylation were 27.5 and 24% lower in supplemented patients (p0.01). GSH/GSSG ratio was 38.1% higher in supplemented patients compared with placebo (p0.01). Leucocyte count and serum hs-CRP levels were markedly lower throughout the protocol in supplemented patients (p0.01). Atrial tissue NF-κB DNA activation in supplemented patients was 22.5% lower than that in placebo patients (p0.05). The combined n-3 PUFA-antioxidant vitamin protocol therapy here proposed reduced the oxidative stress and inflammation biomarkers, in patients undergoing on-pump cardiac surgery.

Oxidative stress has been strongly involved in the underlying mechanism of atrial fibrillation, particularly in the arrhythmia occurring in patients undergoing cardiac surgery with extracorporeal circulation (postoperative atrial fibrillation). The ischemia/reperfusion injury thus occurring in the myocardial tissue contributes to the development of tissue remodeling, thought to be responsible for the functional heart impairment. Consequently, structural changes due to the cardiac tissue biomolecules attack by reactive oxygen and/or nitrogen species could account for functional changes in ion channels, transporters, membrane conductance, cytosolic transduction signals, and other events, all associated with the occurrence of arrhythmic consequences. The lack of success and significant side effects of anti-arrhythmic drugs have given rise to attempts aimed to develop alternative novel pharmacologic treatments. On this line, the biological properties of the antioxidant vitamins C and E suggest that they could decrease the vulnerability of the heart to the oxidative damage. Nevertheless, very few studies to assess their anti-arrhythmic effects have been reported in humans. The clinical and experimental evidence supporting the view that the pharmacological use of antioxidant vitamins could contribute to prevent postoperative atrial fibrillation is presented.

Atrial fibrillation is the most common complication of cardiac surgical procedures performed with cardiopulmonary bypass. It contributes to increased hospital length of stay and treatment costs. At present, preventive strategies offer only suboptimal benefits, despite improvements in anesthesia, surgical technique, and medical therapy. The pathogenesis of postoperative atrial fibrillation is considered to be multifactorial. However oxidative stress is a major contributory factor representing the unavoidable consequences of ischemia/reperfusion cycle occurring in this setting. Considerable evidence suggests the involvement of reactive oxygen species (ROS) in the pathogenic mechanism of this arrhythmia. Interestingly, the deleterious consequences of high ROS exposure, such as inflammation, cell death (apoptosis/necrosis) or fibrosis, may be abrogated by a myocardial preconditioning process caused by previous exposure to moderate ROS concentration known to trigger survival response mechanisms. The latter condition may be created by n-3 PUFA supplementation that could give rise to an adaptive response characterized by increased expression of myocardial antioxidant enzymes and/or anti-apoptotic pathways. In addition, a further reinforcement of myocardial antioxidant defenses could be obtained through vitamins C and E supplementation, an intervention also known to diminish enzymatic ROS production. Based on this paradigm, this review presents clinical and experimental evidence supporting the pathophysiological and molecular basis for a novel therapeutic approach aimed to diminish the incidence of postoperative atrial fibrillation through a non-hypoxic preconditioning plus a reinforcement of the antioxidant defense system in the myocardial tissue.

Atrial fibrillation is the most common sustained arrhythmia in clinical practice and is associated to thromboembolic complications. Anticoagulation with vitamin K antagonists is clearly useful to reduce the incidence of emboli, but associated with important limitations. Therefore, there is an active search for medications that are more effective and simpler to prescribe and manage. Synthetic pentasaccharides of heparin such as idraparinux for parenteral use, showed promising results. Direct inhibitors of thrombin were also useful for the prevention of thromboembolism. However, they were withdrawn from the market due to potentially fatal adverse reactions. Other area of investigation has been the effectiveness of the combination of antiplatelet agents such as aspirin and clopidrogel. Although this combination is attractive, results of clinical trials must be awaited to have an opinion about its real usefulness. Finally, left atrial appendage transcatheter occlusion (PLAATO) is an effective and reasonably safe method for patients with contraindications for anticoagulation or those that continue to embolize despite well prescribed anticoagulation. The long term results of this intervention must also be awaited.

Atrial fibrillation is the most common sustained arrhythmia inclinical practice and is associated to thromboembolic complications. Anticoagulation withvitamin K antagonists is clearly useful to reduce the incidence of emboli, but associated withimportant limitations. Therefore, there is an active search for medications that are moreeffective and simpler to prescribe and manage. Synthetic pentasaccharides of heparin such asidraparinux for parenteral use, showed promising results. Direct inhibitors of thrombin werealso useful for the prevention of thromboembolism. However, they were withdrawn from themarket due to potentially fatal adverse reactions. Other area of investigation has been theeffectiveness of the combination of antiplatelet agents such as aspirin and clopidrogel. Althoughthis combination is attractive, results of clinical trials must be awaited to have an opinionabout its real usefulness. Finally, left atrial appendage transcatheter occlusion (PLAATO) is aneffective and reasonably safe method for patients with contraindications for anticoagulation orthose that continue to embolize despite well prescribed anticoagulation. The long term results ofthis intervention must also be awaited (Rev Med Chile 2007; 135: 1048-55).(

Oxidative stress underlies postoperative atrial fibrillation and electrophysiological remodelling associated with rapid atrial pacing. An increasing body of evidence indicates that the formation of reactive oxygen species (ROS) released following extracorporeal circulation are involved in the structural and functional myocardial impairment derived from the ischemia-reperfusion cycle. ROS behave as intracellular messengers mediating pathological processes, such as inflammation, apoptosis and necrosis, thereby participating in the pathophysiology of atrial fibrillation. Thus, increased superoxide (O(2)(.-)) production has been found in isolated atrial cardiomyocytes from patients with atrial fibrillation. Therefore, it seems reasonable to assume that the reinforcement of the antioxidant defense system should protect the heart against functional alterations in the cardiac rhythm. On this line, antioxidant enzyme induction through in vivo exposure to moderate concentration of ROS is associated with a reduction in the susceptibility of myocytes to ROS-induced injury. This response could be due to a prevailing effect of survival over apoptotic pathway. Previously, tissue preconditioning caused by prior exposure to an ischemia/reperfusion cycle has been successfully applied in experimental models and clinical settings associated with oxidative damage by ROS. However, such hypoxic preconditioning method is harmful to be applied to many clinical conditions associated with oxidative stress. In turn, experimental studies have revealed that non-enzymatic antioxidants produce a significant functional amelioration in cardiomyocytes subjected to an oxidative challenge. Moreover, clinical studies with patients scheduled for primary coronary artery bypass graft surgery had a reduced incidence of postoperative atrial fibrillation. We present the hypothesis of non-hypoxic preconditioning based on the association of pretreatment with n-3 polyunsaturated fatty acids followed by ascorbate plus alpha-tocoferol supplementation diminishes the incidence of postoperative atrial fibrillation in patients subjected to cardiac surgery with extracorporeal circulation.

Intraventricular resynchronization with pacemakers is a promising therapy for patients with refractory cardiac failure and intraventricular conductions delay. However its long term effects are not well known.To report the results of this therapy in patients with cardiac failure.Fourteen patients (11 male), whose mean age was 68 years, with a severe and refractory cardiac failure, have been treated in our unit using intraventricular resynchronization with pacemakers. Eight had a coronary heart disease and six a dilated myocardiopathy. The pacemaker was implanted transvenously, with conventional stimulation in atrium and right ventricle. The left ventricle was stimulated through an epicardial vein, accessed through the coronary sinus.In one patient the high thresholds did not allow a left ventricular stimulation. In the other 13 patients, a clinical improvement was observed in 11 (85%), that has been sustained for a mean of 8.2 months. The ejection fraction improved form 23.5 to 32.4% (p0.001), the 6 min walking test improved from 347 to 437 m (p = 0.003) and the functional capacity changes from 3.3 to 2.7 (p0.001). Three patients died during follow up. One was the patient in whom the stimulation failed and two had a sudden death. No complications of the procedure were observed.In this series, intraventricular resynchronization with pacemakers was effective in 11 of 13 patients, improving functional capacity and ejection fraction. Sudden death could be avoided adding a defibrillator to the pacemaker system.

Fourteen patients (11 male), whose mean age was 68years, with a severe and refractory cardiac failure, have been treated in our unit using intraventricu-lar resynchronization with pacemakers. Eight had a coronary heart disease and six a dilated myocar-diopathy. The pacemaker was implanted transvenously, with conventional stimulation in atrium andright ventricle. The left ventricle was stimulated through an epicardial vein, accessed through the coro-nary sinus.

Background The risk of cerebrovascular embolic events with atrial fibrillation (AF) is potentially linked to an increased risk of cognitive decline and dementia. However, epidemiologic studies exploring the association between AF and incident dementia have reported conflicting results. Objective The purpose of this study was to perform a meta-analysis of observational studies specifically designed to evaluate the prospective relationship between AF and incident dementia. Methods We searched PubMed, CENTRAL, BioMedCentral, Embase, Cardiosource, clinicaltrials.gov, and ISI Web of Science (January 1980 to May 2012). No language restriction was applied. Two independent reviewers screened titles and abstracts to identify population-based studies that prospectively evaluated the association between AF and the incidence of dementia in patients not suffering an acute stroke and with normal cognitive function at baseline, providing the hazard ratio (HR) obtained in multiple Cox regression analyses, and adjusted for all confounding variables. Two independent reviewers assessed risk of bias according to the Cochrane Collaboration, and extracted patient and study characteristics and the adjusted HR of incident dementia with its 95% confidence interval (CI) of patients with AF vs those without AF. Results Eight studies with 77,668 patients were included in the analysis. All studies had a prospective observational design and included elderly patients (mean age range 61–84 years) with normal cognitive function at baseline, of whom 11,700 (15%) had AF. After a mean follow-up of 7.7 ± 9.1 years (range 1.8–30 years), 4773 of 73,321 (6.5%) patients developed dementia. Two studies did not report the rates of dementia at follow-up but reported the adjusted HR and were included in the pooled analysis. At pooled analysis adjusted for baseline confounders and covariates, AF was independently associated with increased risk of incident dementia (HR = 1.42 [95% CI 1.17–1.72], P Conclusion AF is independently associated with increased risk of dementia. Patients with AF should be periodically screened for dementia, which should be included among the outcomes assessed in AF treatment trials.