The CHA2DS2-VASc score for predicting atrial fibrillation in patients presenting with ST elevation myocardial infarction: prospective observational study

ABSTRACT BACKGROUND: Atrial fibrillation (AF) is the most common form of supraventricular arrhythmia following ST-elevation myocardial infarction (STEMI). The CHA2DS2-VASc and CHADS2 scores are used to estimate thromboembolic risk in cases of AF. Their usefulness in predicting the development of AF in patients presenting STEMI is unknown. OBJECTIVE: To evaluate the predictive value of the CHADS2 and CHA2DS2-VASc scores in patients with AF following STEMI. DESIGN AND SETTING: This prospective cohort study on 696 patients with STEMI was conducted at a tertiary-level cardiology clinic in a public university hospital. METHODS: Models including clinical and laboratory parameters were constructed to test the predictive value of CHADS2 and CHA2DS2-VASc scores. Patients were divided into two groups: with and without AF. Predictors of AF were determined using multivariate regression analysis. RESULTS: In the patients with AF, CHADS2 and CHA2DS2-VASc scores were significantly higher than in those without AF (for both P < 0.001). Factors associated with AF in multivariate analyses included CHA2DS2-VASc score (odds ratio, OR: 1.48; 95% confidence interval, CI: 1.25-1.75; P < 0.001), peak creatine kinase-myocardial binding (OR: 1.002; 95% CI: 1.00-1.003; P = 0.0024), duration of the coronary intensive care unit stay (OR: 1.69; 95% CI: 1.24-12.30; P = 0.001) and no use of renin-angiotensin system blockers (OR: 2.16; 95% CI: 1.14-4.10; P = 0.0017). Receiver operating characteristic curve analyses showed that CHA2DS2-VASc scores were significant predictors for new-onset AF (C-statistic: 0.698; 95% CI: 0.631-0.765; P < 0.001). CONCLUSION: CHADS2 and CHA2DS2-VASc scores predicted new AF in patients presenting STEMI.

Effect of plasma level of vitamin d on postoperative atrial fibrillation in patients undergoing isolated coronary artery bypass grafting

Abstract Objective: Postoperative atrial fibrillation (PoAF) is a common complication after coronary artery bypass grafting (CABG). The aim of the present study was to evaluate the association between development of PoAF and vitamin D levels in patients undergoing isolated CABG. Methods: This prospective randomized clinical trial was conducted on the patients with isolated CABG. The study was terminated when 50 patients in both PoAF(+) group and PoAF(-) group were reached. Development of AF until discharge period was assessed. Vitamin D level was measured immediately after AF; it was measured on the discharge day for the patients without PoAF. Predictive values of the independent variables were measured for the development of PoAF. Results: The groups were separated as PoAF(-) group (66% male, mean age 58.18±10.98 years) and PoAF(+) group (74% male, mean age 61.94±10.88 years). 25(OH) vitamin D level (OR=0.855, 95% CI: 0.780-0.938, P=0.001) and > 65 years (OR=3.525, 95% CI: 1.310-9.483, P=0.013) were identified as an independent predictor of postoperative AF after CABG surgery in multivariate analysis. The cut-off level for 25(OH) vitamin D level in receiver-operating characteristic curve analysis was determined as 7.65 with sensitivity of 60% and specificity of 64% for predicting PoAF (area under the curve: 0.679, P=0.002). Conclusion: Vitamin D level is considered an independent predictor for development of PoAF. Lower vitamin D levels may be one of the reasons for PoAF.

Strain auricular izquierdo y biomarcadores cardíacos como predictores de accidente cerebrovascular en pacientes con fibrilación auricular de reciente comienzo / Left atrial strain and biomarkers for stroke in patients with recent onset atrial fibrillation

Introducción: La miopatía y fibrosis auricular representan el sustrato protrombótico y proarrítmico en pacientes con fibrilación auricular (FA). Estudios recientes muestran relación entre el strain auricular izquierdo (SAI), eventos cardiovasculares y recurrencia en pacientes con FA. La asociación entre SAI y bio-marcadores cardíacos como predictores de accidente cerebrovascular silente (ACVs) en pacientes con FA de reciente comienzo (FArc) no ha sido estudiada. Objetivo: Determinar si la asociación entre SAI y biomarcadores cardíacos contribuye a la predicción de ACV en pacientes con FArc. Métodos: Se realizó un estudio prospectivo que permitió reclutar 57 pacientes con FArc (primer episodio de < de 8 semanas de evolución). Obtenido consentimiento informado (CI) se realizó recolección de datos clínicos y muestras de sangre para determinación de Pro-BNP, Dimero-D y GDF-15. Se realizó resonancia nuclear magnética cerebral (RNMc) y ecocardiograma transtorácico (ETT) durante los primeros 3 días de inclusión y en ritmo sinusal. Para la evaluación de SAI se consideró la curva de deflexión positiva durante la sístole ventricular (SAIs), derivada de speckle tracking, considerando el promedio de 5 ciclos. Se utilizó Mann Whitney U test y Spearman Rho para análisis estadístico. Resultados: La edad promedio fue 70±8,2 años y el 70% fueron hombres. El CHA2DS2-VASc score promedio fue 3,1±1 y el promedio de pro-BNP, Di-mero-D y GDF-15 fue 96,1±12,4 pg/ml, 990±140 ng/ ml y 12 ng/ml respectivamente. 15% de los pacientes (n=9) presentaban ACVs en la RNMc al momento del diagnóstico. Se observó, además, que los pacientes con ACV presentaban un SAIs más bajo que los pacientes sin eventos (5,5±1,1% y 14,6±7,3% respectivamente p=0.04). Adicionalmente, se encontró una correlación significativa entre SAIs y pro-BNP, Dimero-D y GDF-15. Conclusiones: En este trabajo se evidenció que el 15% de los pacientes con FArc presenta ACVs al momento del diagnóstico. El SAIs bajo se correlaciona de forma inversa con los biomarcadores de sobrecarga, trombogénesis, fibrosis auricular y presencia de ACV silente. Estos resultados pueden ser utilizados para una mejor estratificación del riesgo de ACV en pacientes con FA.

Introduction: Atrial myopathy and fibrosis constitute a pro-arrhythmic and pro-thromboembolic substrate in patients with atrial fibrillation (AF). Recent studies using left atrial strain (LAS) have shown that LAS contributes to predict AF recurrence in patients with paroxysmal AF. The association between LAS and cardiac biomarkers in predicting silent stroke (SS) in patients with new AF has not been studied. Aim: The association of LAS and cardiac biomarkers contribute to predict SS in patients with new AF. Methods: We have prospectively evaluated 57 consecutive patients with new AF (first episode with less than 8 weeks of evolution). Baseline clinical characteristics and blood samples for determinations of Pro-BNP, D-Dimer and GDF-15 were obtained. Brain magnetic resonance (BMRI) and 2D Echo were performed within 3 days. In sinus rhythm, the positive deflection during ventricular systole of the LAS curve derived from speckle tracking was considered (mean of 5 cycles) (LASS). Mann Whitney U test and Spearman Rho were used for statistical analysis. Results: Mean age was 70±8,2 years, 70% were men. The mean CHA2DS2-VASc score was 3,1±1. Mean pro-BNP, D-Dimer and GDF-15 were 96,1±12,4 pg/ml, 990±140 ng/ml and 12 ng/ml, respectively. Fifteen percent of patients (n=9) had evidence of previous SS in BMRI. Patients with SS had significantly less LASS than patients without events (5,5±1,1% and 14,6±7,3% respectively p=0,04). In addition, a significant correlation between LASs and pro-BNP, D-Dimer and GDF-15 was found. Conclusion: Evidence of SS was found in 15% of patients with new AF. This was associated with LASs impairment, which was inversely correlated with cardiac biomarkers of LV overload, thrombogenesis and LA fibrosis. These findings could be utilized for a better risk stratification of stroke in patients with new AF.

Evaluación de la anticoagulación con rivaroxaban, en pacientes con fibrilación auricular no valvular de reciente diagnóstico / Evaluation of oral anticoagulation with rivaroxaban, in patients with new onset non valvular atrial fibrillation

Background: Atrial fibrillation (AF) generates a hypercoagulable state with an increased thrombin generation and raised levels of thrombin-antithrombin complexes, which results in a high risk of stroke and thromboembolism. Aim: To evaluate the anticoagulant effect of rivaroxaban by anti-Xa factor activity and its correlation with thrombin-antithrombin complexes, thrombin generation and prothrombin time in patients newly diagnosed with non-valvular AF. Patients and Methods: Prospective study in patients with indication of anticoagulation. Demographic variables, cardiovascular risk factors, CHA2DS2-VASc and HAS-BLED scores were recorded. Blood samples were taken at baseline, at 3 and 24 hours after the administration of the drug and at 30 days. Rivaroxaban levels, anti-Xa activity, prothrombin time, thrombin generation and plasma levels of thrombin-antithrombin complexes were determined. Results: We studied 20 patients aged 76.3 ± 8.0 years (60% female) with a CHA2DS2-VASc score > 2 points. The anti-Xa factor activity correlated with rivaroxaban plasma levels at 3 hours (r = 0.61, p < 0.01), at 24 hours (r = 0.85, p < 0.01) and at 30 days (r = 0.99, p < 0.01), with prothrombin time at 3 hours (r = -0.86, p = 0.019) and at 30 days (r = -0.63, p = 0.02) and with a sustained decrease in thrombin generation at 30 days of follow-up (r = -0.74, p < 0.01). There was no correlation with thrombin-antithrombin complexes (r = -0.02, p = 0.83). Conclusions: Rivaroxaban consistently inhibited the mild pro-coagulant state found in newly diagnosed non-valvular AF patients through the first 24 hours and this effect was maintained at 30 days. Plasma levels of the drug correlated with anti-Xa factor activity, thrombin generation and prothrombin time

Colesterol HDL y troponina T ultrasensible como biomarcadores predictivos de fibrilación auricular postoperatoria / HDL cholesterol and high-sensitive troponin T as predictives biomarkers of atrial fibrillation after heart surgery

Introducción: La fibrilación auricular (FA), con una incidencia aproximada del 30%, es la arritmia más frecuente tras cirugía cardiaca. Se han asociado a la FA factores como la inflamación, la presencia de fibrosis cardiaca, el estrés y la apoptosis de cardiomiocitos. Objetivos: Consideramos que el remodelado auricular es un proceso preexistente en los pacientes con FA posquirúrgica. Analizamos los factores relacionados con la incidencia de FA en el postoperatorio de cirugía cardiaca. Métodos: Incluimos a pacientes consecutivos, estables hemodinámicamente y en ritmo sinusal, sometidos a cirugía cardiaca programada con circulación extracorpórea. Se valora la caída en FA posquirúrgica. Resultados: Se incluyeron un total de 100 pacientes sometidos a cirugía de revascularización coronaria (59) o sustitución valvular aórtica (41) por estenosis aórtica grave. La FA postoperatoria se produjo en 29 pacientes con predominio de la cirugía valvular respecto a la cirugía coronaria. Los factores predictivos de la aparición de FA postoperatoria en el análisis multivariable fueron el sexo masculino, la ausencia de terapia crónica con betabloqueadores, la perfusión de fibrinógeno intraoperatorio, valores bajos de colesterol HDL y valores elevados de troponina T ultrasensible en el preoperatorio. Conclusiones: El colesterol HDL y la troponina T ultrasensible pueden ser biomarcadores útiles para predecir la aparición de FA postoperatoria. La identificación precoz de estos pacientes nos permite adoptar medidas preventivas para minimizar sus efectos negativos.

Introduction: Atrial fibrillation (AF) has an incidence rate of approximately 30% and is the most frequent arrhythmia following heart surgery. Factors such as inflammation, the presence of heart fibrosis, stress and cardiomyocyte apoptosis, have all been associated with AF. Objectives: We believe that atrial remodelling is a pre-existent process in patients with post-surgical AF. We have analyzed the factors related to the incidence of atrial fibrillation in the period after heart surgery. Methods: We included consecutive, hemodynamically stable patients with a sinusal rhythm who were subjected to programmed heart surgery with extracorporeal circulation. An assessment was made of the fall in atrial fibrillation after surgery using prolonged electrocardiographic monitoring. Results: A total of 100 patients were included in the study and were subjected to either coronary revascularisation surgery (59) or aortic valve substitution due to severe aortic stenosis (41). Postoperative AF occurred in 29 patients who received predominantly more valve surgery than coronary surgery. The following factors were predictive of postoperative AF in the multivariate analysis: Male sex; beta-blocker therapy for chronic disease; the use of intraoperative; fibrinogen perfusion; low HDL cholesterol values; and high sensitive troponin T values, in the preoperative period. Conclusions: HDL cholesterol and high sensitive troponin T can be useful biomarkers to predict the occurrence of AF after surgery. The early identification of these patients who develop of FA allows us to take preventive measures to minimize the negative effects.

Bajos niveles de colesterol HDL es un predictor de mortalidad y de fibrilación auricular postoperatoria posterior a la cirugía de revascularización miocárdica / Low HDL level is a predictor of post operative atrial fibrillation and mortality after coronary artery bypass surgery

Introducción: Se ha demostrado que bajos niveles de colesterol HDL (C-HDL) se asocian a una mayor incidencia de fibrilación auricular y de mortalidad global y cardiovascular. En un estudio observacional previo en nuestro centro, encontramos que un bajo nivel de C-HDL se asoció a mayor riesgo de fibrilación auricular postoperatoria (FAPO) en pacientes sometidos a cirugía de revascularización miocárdica (CRM). Objetivo: Evaluar si el bajo nivel de C-HDL se asocia a mayor incidencia de FAPO y mortalidad en un seguimiento a un año en un estudio controlado. Método: Se realizó un estudio observacional prospectivo que incluyó a 100 pacientes consecutivos sometidos a CRM por enfermedad coronaria estable sin antecedentes de FA y que ingresaron a la UCI Cardio-quirúrgica en ritmo sinusal. Se definió FAPO como FA con duración mayor a 5 minutos o 5 episodios de FA mayores a 30 segundos de duración en los primeros 5 días post operatorios. Se consideró bajo nivel de C-HDL a un valor < 30mg/dL. Los pacientes se siguieron por un año. Se utilizó un análisis univariado y multivaria-do para identificar factores predisponentes de FAPO y mortalidad. Resultados: 31 pacientes presentaron FAPO. El análisis multivariado mostró un incremento de FAPO con C-HDL <30mg/dL (OR 5.01, IC95% 1.3-18.8, p=0,017) y con albúmina <3,5 gr/dL (OR 6.42, IC95% 1.58-26.0, p=0,009). En un seguimiento de 14.1±1.7 meses. La mortalidad global fue 6% y un C-HDL <30mg/dL resultó ser un predictor independiente (HR 11.1, IC95% 1.1-38.4, p=0,039). Conclusión: En nuestra serie un C-HDL menor a 30mg/dL es un predictor independiente de FAPO y mortalidad posterior a la CRM.

Background: Low C-HDL level has been associated to an increased incidence of atrial fibrillation (AF) and cardiovascular mortality. Previously, we have observed that low C-HDL had the same type of association with post operative AF (POAF) and mortality following surgery for coronary artery disease. Aim: to evaluate whether a low C-HDL level is a predictor of POAF and mortality following revascularization surgery in a controlled study. Method: A prospective observational study included 100 consecutive patients undergoing revascularization surgery for stable coronary artery disease (CAD) in sinus rhythm and no prior AF. POAF was defined as AF sustained for more than 5 min or the occurrence of 5 or more episodes of AF extending for more than 5 seconds during the first 5 post operative days. A value <30 mg/dl was considered low C-HDL. Patients were followed for one year. Uni and multivariate analysis were used to identify predictors of POAF and mortality. Results: 31 patients developed POAF. A significant (p=0.017) OR of 5.01 (95% CI 1.3 - 18.8) between low C-HDL and POAF was shown. A similar association linked low serum albumin level to POAF (OR 6.4, C.I. 1.6 - 26). After 14.1 ± 1.7 months of follow-up global mortality was 6%. Low C-HDL turned out to be a significant predictor of mortality (H.R. 11.1, C.I. 1.1 - 38.4, p=0.04). Conclusion: Low C-HDL is an independent predictor of POAF and mortality after coronary artery revascularization surgery.

Mitochondrial DNA 4977bp Deletion Mutation in Peripheral Blood Reflects Atrial Remodeling in Patients with Non-Valvular Atrial Fibrillation

PURPOSE: Recently, mitochondrial DNA 4977bp deletion (mtDNA4977-mut), a somatic mutation related to oxidative stress, has been shown to be associated with atrial fibrillation (AF). We hypothesized that patient age, as well as electroanatomical characteristics of fibrillating left atrial (LA), vary depending on the presence of mtDNA4977-mut in peripheral blood among patients with non-valvular AF. MATERIALS AND METHODS: Analyzing clinical and electroanatomical characteristics, we investigated the presence of the mtDNA4977-mut in peripheral blood of 212 patients (51.1+/-13.2 years old, 83.5% male) undergoing catheter ablation for non-valvular AF, as well as 212 age-matched control subjects. RESULTS: The overall frequency of peripheral blood mtDNA4977-mut in patients with AF and controls was not significantly different (24.5% vs. 19.3%, p=0.197). When the AF patient group was stratified according to age, mtDNA4977-mut was more common (47.4% vs. 20.0%, p=0.019) in AF patients older than 65 years than their age-matched controls. Among AF patients, those with mtDNA4977-mut were older (58.1+/-11.9 years old vs. 48.8+/-11.9 years old, p<0.001). AF patients positive for the mtDNA mutation had greater LA dimension (p=0.014), higher mitral inflow peak velocity (E)/diastolic mitral annular velocity (Em) ratio (p<0.001), as well as lower endocardial voltage (p=0.035), and slower conduction velocity (p=0.048) in the posterior LA than those without the mutation. In multivariate analysis, E/Em ratio was found to be significantly associated with the presence of mtDNA4977-mut in peripheral blood. CONCLUSION: mtDNA4977-mut, an age-related somatic mutation detected in the peripheral blood, is associated with advanced age and electro-anatomical remodeling of the atrium in non-valvular AF.

Hemodiálisis para remover el anticoagulante dabigatrán en situaciones de urgencia / Hemodialysis to remove anticoagulant dabigatran during emergencies

El dabigatrán es un nuevo inhibidor directo de la trombina, de administración oral, empleado para la prevención de eventos tromboembólicos en pacientes con fibrilación auricular no valvular. A diferencia de la warfarina, no se dispone de un antídoto conocido. La hemodiálisis ha sido sugerida como un método para remover el dabigatrán y reducir el efecto anticoagulante. Se presenta el caso de un paciente con antecedente de fibrilación auricular y medicado con dabigatrán, que fue admitido en el hospital para una cirugía abdominal de urgencia. A las seis horas de la última dosis recibida, los estudios de coagulación mostraban alteración. Ante la falta de antídoto para revertir los efectos, se decidió realizar hemodiálisis. Luego de tres horas de diálisis los parámetros de coagulación tendieron a normalizarse y el paciente fue operado sin presentar hemorragias anormales durante la cirugía o en el postoperatorio.

Dabigatran is an oral anticoagulant from the class of the direct thrombin inhibitors, indicated for prevention of thromboembolic events in patients with non valvular atrial fibrillation. Unlike warfarin, dabigatran has no known antidote. Hemodialysis has been suggested as a method for removing dabigatran and thereby reducing its anticoagulant effect. We report the case of a patient with a known history of atrial fibrillation, treated with dabigatran, who was admitted for emergency abdominal surgery. At six hours after the last dose received, coagulation studies were altered. In absence of an antidote to reverse its effects, it was decided to perform hemodialysis. After three hours of dialysis coagulation parameters were improved and the patient underwent surgery without showing abnormal bleeding during surgery or in the postoperative period.

Warfarin doses for anticoagulation therapy in elderly patients with chronic atrial fibrillation

OBJECTIVE: Anticoagulation is a challenge for the prophylaxis of thromboembolic events in elderly patients with chronic atrial fibrillation. Stable anticoagulation is defined as the time within >70% of the therapeutic range. However, the dosage required to achieve stable anticoagulation remains unknown. The aim of this study was to analyze the warfarin dose necessary for the maintenance of stable oral anticoagulation therapy in elderly patients. METHODS: We analyzed 112 consecutive outpatients with atrial fibrillation who were >65 years of age, had received anticoagulation therapy with warfarin for more than 1 year and had a stable international normalized ratio between 2.0 and 3.0 for >6 months. The international normalized ratio was measured in the central laboratory using the traditional method. RESULTS: The patients were stratified according to the following age groups: <75 or >75 years and <80 or >80 years. The mean daily doses of warfarin were similar for patients <75 or >75 years (3.34+1.71 versus 3.26 +1.27 mg/ day, p = 0.794) and <80 or >80 years (3.36+ 1.49 versus 3.15 + 1.23 mg/day, p = 0.433). In 88 (79%) patients, the daily warfarin dose was between 2 and 5 mg/day; in 13 (11%) patients, the daily warfarin dose was <2.0 mg/day; and in 11 (10%) patients, the daily warfarin dose was >5.0 mg/day. The correlation between the daily warfarin dose and the international normalized ratio was 0.22 (p = 0.012). CONCLUSION: Stable anticoagulation was achieved in 80% of patients who received doses of 2 to 5 mg/day of warfarin, and the mean daily dose was similar across the age groups analyzed.

Proteína C reactiva de alta sensibilidad como predictor de fibrilación auricular postoperatoria / High-sensitivity C-reactive protein predicts postoperative atrial fibrillation

Introducción: La fibrilación auricular postoperatoria (FAPO) es una complicación frecuente en la cardiocirugía con circulación extracorpórea (CEC). El evento de isquemia-reperfusión secundario a la CEC produce inflamación como mediador de daño miocárdico causando FAPO. Objetivo: determinar el poder predictivo del marcador de inflamación proteína C reactiva de alta sensibilidad (hsCRP) en la FAPO. Hipótesis: la hsCRP predice la ocurrencia de FAPO. Material y Método: estudio observacional, analítico, incluyó 123 pacientes sometidos a cardiocirugía con CEC en el Hospital Clínico de la Universidad de Chile entre 2007 y 2010. El muestreo fue aleatorio simple de pacientes concurrentes a cirugía cardíaca. Se realizó monitoreo electrocardiográfico continuo y medición de hsCRP plasmática antes de la cirugía, 8 horas postoperatorias y al alta. Se realizó un análisis de regresión multivariada, considerando los factores de riesgo conocidos de FAPO, así como la hsCRP. Para variable cuantitativa continua, se realizó ANOVA-Bonferroni. Para análisis de Kaplan-Meier de cuartiles de hsCRP, se realizó test de tendencia log-rank. Se realizó una receiver operator curve (ROC) para determinar el poder predictivo de la hsCRP. Significancia: p<0,05. Resultados: Se describe el perfil clínico-epidemiológico de los pacientes. La hsCRP fue máxima a las 8 horas postoperatorias (ANOVA-Bonferroni p<0,01). El análisis de regresión multivariada relacionó significativamente hsCRP y ocurrencia de FAPO (p<0,01). A mayor cuartil de hsCRP se asoció mayor ocurrencia de FAPO (p<0,01). El área bajo la curva ROC fue 0,73. Discusión: La hsCRP postoperatoria constituye una valiosa herramienta predictora de ocurrencia de FAPO en el contexto de cirugía cardíaca con CEC.

Introduction: Postoperative atrial fibrillation (POAF) is a common complication of cardiac surgery with extracorporeal circulation. Is associated with increased morbidity and health costs. The ischemia-reperfusion event secondary to extracorporeal circulation leads to inflammation, causing myocardial damage. Objective: The aim of this study is to determine the predictive power of high sensitivity C-reactive protein (hsCRP) in POAF.Hypothesis: hsCPR predicts POAF occurrence. Material and Method: An observational, analytical study, included 123 patients undergoing cardiac surgery with extracorporeal circulation at Universidad de Chile’s Hospital, between 2007 and 2010. Continuous electrocardiographic monitoring was performed and plasma hsCPR measurement before surgery, 8 hours postoperatively and at discharge. We performed a multivariate regressionanalysis considering the known risk factors for POAF and the hsCRP. For continuous quantitative variable ANOVA-Bonferroni was used. Kaplan-Meier analysis of quartiles of hsPCR was usedand Mantel-Cox log-rank test for trend test. Receiver operator curve (ROC) was performed to determine the predictive power of the hsPCR. Significance: p<0.05. Results: We describe the clinical and epidemiological characteristics of patients undergoingcardiac surgery. The hsCPR was highest at 8 postoperative hours (ANOVA-Bonferroni p<0.01). The multivariate regression analysis significantly correlated with the occurrence of hsPCRand POAF (p<0.01). The higher quartile of hsCPR was associated with increased occurrence of POAF (p<0.01). The area under the ROC curve was 0.73. Discussion: The postoperative hsPCR isa valuable predictor of the occurrence of POAF in the context of cardiac surgery with extracorporeal circulation.

Segurança da ablação de fibrilação atrial com RNI terapêutico: comparação com a transição com heparina de baixo peso / Safety of ablation for atrial fibrillation with therapeutic INR: comparison with transition to low-molecular-weight heparin

FUNDAMENTO: O manejo ideal da anticoagulação oral (ACO) no período pré- e pós-ablação de fibrilação atrial (FA) ainda é motivo de controvérsia. OBJETIVO: Comparar duas estratégias de anticoagulação: suspensão da warfarina com a utilização de heparina de baixo peso molecular (HBPM) e a realização da ablação sem a suspensão da warfarina, mantendo o RNI terapêutico (entre 2,0 e 3,0). MÉTODOS: 140 pacientes (pt) portadores de FA persistente/ permanente submetidos à ablação por cateter de FA foram divididos em dois grupos: no grupo I (70 pt), a warfarina foi suspensa cinco dias antes do procedimento e utilizada terapia de transição com HBPM (enoxaparina 1 mg/kg 2x/dia pré-ablação e 0,5 mg/kg 2x/dia após o procedimento); no grupo II (70 pt), a warfarina não foi suspensa e o procedimento foi realizado com RNI terapêutico. Ambos os grupos receberam heparina intravenosa (TCA > 350 seg) durante o procedimento. RESULTADOS: No Grupo I, observou-se complicação hemorrágica maior (1,4 por cento) e 4 pt (5,7 por cento) com complicações hemorrágicas menores. No Grupo II, 2 pt (2,8 por cento) apresentaram complicações hemorrágicas menores e 1 pt apresentou sangramento maior; porém, este ocorreu após uso de HBPM por RNI < 2,0. Não houve complicação tromboembólica ou morte cardiovascular nos dois grupos após 16 ± 8 meses. CONCLUSÃO: A realização de ablação por cateter de FA sem a suspensão de ACO e RNI terapêutico é uma estratégia semelhante em segurança e eficácia quando comparada à tradicional transição com HBPM, evitando um período inicial pós-ablação de anticoagulação potencialmente inadequada.

BACKGROUND: The ideal management of oral anticoagulation (OAC) before and after catheter ablation for atrial fibrillation (AF) is still controversial. OBJECTIVE: To compare two anticoagulation strategies for catheter ablation for AF: warfarin withholding and use of low-molecular-weight heparin (LMWH); and maintenance of warfarin and therapeutic INR (between 2.0 and 3.0). METHODS: 140 patients (pt) with persistent/permanent AF undergoing catheter ablation for AF were divided into two groups: Group I (70 pt), in which warfarin was withheld five days prior to the procedure and transition to LMWH was used (enoxaparin: 1 mg/kg 2x/day before ablation, and 0.5 mg/kg 2x/day after ablation); Group II (70 pt), in which warfarin was not withheld and the procedure was performed with therapeutic INR. Both groups received intravenous heparin (ACT > 350 seconds) during ablation. RESULTS: In Group I, one pt (1.4 percent) had a major hemorrhagic complication and four pts (5.7 percent) had minor hemorrhagic complications. In Group II, two pts (2.8 percent) had minor hemorrhagic complications and one pt had a major bleeding, which occurred after using LMWH due to INR < 2.0. None of the groups had thromboembolic complications or cardiovascular death over a period of 16 ± 8 months. CONCLUSION: Catheter ablation for AF without withholding OAC and with therapeutic INR is a strategy that has similar safety and efficacy when compared with the traditional transition to LMWH, avoiding the potentially inadequate anticoagulation of the initial post-ablation period.

Descenso de los niveles de propéptido natriurético de tipo B-N terminal luego de la reversión de pacientes con fibrilación auricular y función ventricular conservada / NT-Pro-BNP levels performance before and after reversion to sinus rhythm in patients with preserved ventricular function

El objetivo fue comparar los niveles de Pro Péptido Natriurético tipo B-N terminal (Pro-BNP-NT) basales y post reversión en pacientes con fibrilación auricular solitaria (FAS) de comienzo reciente y con función ventricular izquierda conservada. Se determinaron niveles del Pro BNP NT antes y después de su reversión en treinta pacientes con FAS de comienzo reciente y fracción de eyección de ventrículo izquierdo ≥ 50%. Basalmente, los niveles de Pro BNP NT fueron significativamente más elevados respecto a un grupo control sano: 529 pg/ml (157-1763) versus 31.5 pg/ml (24-76), p < 0.0001. Las concentraciones de Pro BNP NT descendieron significativamente luego de la cardioversión de 529 (157-1763) a 318 (98-870) pg/ml, p < 0.001. Los descensos se objetivaron tanto luego de la cardioversión eléctrica como de la obtenida por vía farmacológica, 345 (153-1151) pg/ml a 169 (86-407) pg/ml, p: 0.02 y de 1624 (541-4010) pg/ml a 856 (532-1160) pg/ml, p < 0.001, respectivamente. Este fenómeno se observó fundamentalmente en aquellos con una FAS con duración mayor a 8 horas: 1289 (338-2103) a 410 (169-905) pg/ml, p < 0.001. No se observó correlación entre los cambios de la frecuencia cardíaca y del Pro BNP NT pre y post cardioversión a ritmo sinusal. Se observaron descensos significativos de Pro BNP NT basalmente y post reversión (tanto farmacológica como eléctrica) en pacientes con FA de reciente aparición y función ventricular conservada. Estos descensos fueron más ostensibles a partir de las 8 horas de duración de la arritmia.

Our objective was to evaluate changes of N-terminal pro-BNP (NT-Pro-BNP) levels at baseline and after restoration to sinus rhythm in hemodynamic stable patients with lone atrial fibrillation (LAF) with preserved left ventricular function. NT-Pro-BNP levels were obtained before and after cardioversion in thirty hemodynamic stable patients with LAF and preserved left ventricular function. At baseline levels of NT-Pro BNP levels were significatively higher than a normal control group. NTPro-BNP levels decreased significantly following cardioversion from 529 (157-1763) to 318 (98-870) pg/ml, p < 0.0001. Decreasing of N-terminal pro-BNP concentrations was observed after any mode of cardioversion: electrical or pharmacologic, 345 (153-1151) pg/ml to 169 (86-407) pg/ml, p: 0.02 and from 1624 (541-4010) pg/ml to 856 (532-1160) pg/ml, p < 0.001, respectively. N-terminal pro-BNP decreasing was observed mainly in patients with length of LAF longer than 8 hours: 1289 (338-2103) to 410 (169-905) pg/ml, p < 0.001 but no difference was detected when such length was less than 8 hours: 274 (137-2300) to 286 (82-1440), p = NS. Our study showed that baseline levels of NT-pro-BNP decreased shortly after reversion of patients with LAF to sinus rhythm. This performance occurs predominantly in patients with LAF length of at least eight hours.

Peptídeo natriurético tipo-B e doenças cardiovasculares / B-type natriuretic peptide and cardiovascular disease

A descoberta de uma ligação endocrinológica entre o coração e os rins baseia-se em achados de microscopia eletrônica em que células de músculo estriado dos átrios de mamíferos se diferenciam tanto em células contráteis como em células endócrinas. O fator natriurético atrial (FNA), um peptídeo circulante com propriedades natriuréticas, diuréticas e vasodilatadoras, foi descoberto em 1980 por A. J. de Bold, e considerado, na ocasião, como a ligação hormonal entre o coração e os rins. Desde então, um imenso número de investigações multidisciplinares tem sido conduzido para esclarecer o real papel deste peptídeo na patogênese das doenças cardiovasculares, na regulação da pressão arterial e na excreção de sal e água. Essas investigações acabaram se tornando um excelente exemplo de pesquisa evoluída da bancada do laboratório à beira do leito do paciente. Hoje, o peptídeo natriurético tipo-B (PNB) vem gradual e lentamente se estabelecendo na área clínica. O objetivo deste artigo é prover o clínico de uma revisão atualizada dos progressos ocorridos até o momento, a fim de incluir o peptídeo natriurético tipo-B na prática clínica diária.

Proteína C reactiva y fibrilación auricular: evidencia de un proceso inflamatorio en la iniciación y perpetuación de la arritmia / C-reactive protein and atrial fibrillation: evidence for an inflammatory process in the initiation and perpetuation of the arrhythmia

Propósitos del estudio: Determinar la existencia de un proceso inflamatorio en los pacientes (ptes) con fibrilación auricular (FA) y su eventual relación con la trombogénesis. Métodos: Se incluyeron 109 pts con valvular, tanto crónica (n =40) como paroxística (n =69) sin tratamiento anticoagulante. Se determinaron niveles de proteína C –reactiva (PCR), niveles de complejo trombina-antitrombina (TAT) y parámetros clínicos y ecocardiográficos predictores de embolia y, exámenes generales de laboratorio. Resultados: La edad promedio del grupo fue 67 ± 14 años. Los niveles de PCR fueron de 1,0 ± 1,4 mg/dl en los FA paroxística y 1,1 ± 2,4 mg/dl en los con FA crónica versus 20 controles). Los niveles de TAT confirmaron la existencia de un estado protrombótico, pero se demostró asociación entre PCR y TAT. En el análisis multivariado, la PCR se relacionó a otros marcadores de inflamación sistémica (VHS y recuento de glóbulos blancos) y la presencia de disfución VI (p =0,02). A 30 días y 1 año, se constató una caída significativa de los niveles de PCR en el grupo FA paroxística. Finalmente, los niveles de PCR resultaron ser predictores de la mantención de ritmo sinusal a 1 año (PCR =1,2 ± 1,8 mg/dl en ptes con FA versus 0,5 ± en los con ritmo sinusal a 1 año, p = 0,048). Conclusiones: Existe evidencia de un estado inflamatorio en los ptes con FA no valvular. Su persistencia se asocia a la matención de la arritmia en la evolución alejada a 1 año.

Anticoagulación en la fibrilación atrial aislada. Revisión bibliográfica / Anticoagulation in isolated atrial fibrillation. Bibliographic review

La fibrilación atrial (FA) es una de las arritmias más frecuentes en la población general y constituye además un factor de aumento del riesgo de entre cinco y siete veces para accidente vascular encefálico (AVE) y embolismo sistémico, aun si se presenta en corazón aparentemente sano. La anticoagulación permite disminuir el riesgo de accidente vascular pero aumenta el riesgo de sangrado. El objetivo de este trabajo es, por tanto, determinar exactamente el estado del conocimento actual sobre este tema como forma de orientar la mejor terapéutica. Para ello se realizó una revisión exhaustiva de la literatura, seleccionando los trabajos más relevantes y luego se les analizó para determinar cuál es la información que aportó cada uno de ellos e ir, de esta manera, conformando un conjunto seleccionado y ordenado de evidencias que determinen cómo debe el médico práctico conducirse frente a la FA sin evidencia de cardiopatía estructural. Se concluye que el beneficio de la anticoagulación en la FA excede al riesgo de no hacerlo, siempre que no exista un riesgo previo aumentado de sangrado, tanto en prevención primaria como secundaria. El beneficio es mayor en los pacientes con riesgo embolígeno aumentado. Los pacientes jóvenes sin factores de riesgo embolígeno podrían no anticoagularse. Se describen los principales marcadores de riesgo embolígeno hallados en la literatura. El nivel de anticoagulación con mejor ecuación riesgo-beneficio es de 2-3 de relación normalizada internacional (INR) ya que reduce el riesgo embolígeno en 70 por ciento aproximadamente, con un riesgo de sangrado de 1 por ciento por año

Clinical significance of serum TSH in euthyroid patients with paroxysmal atrial fibrillation

Atrial fibrillation may occur in patients with a variety of cardiovascular or chronic disease as well as in normal subjects. Many authors reported that atrial fibrillation occurs in patients with thyrotoxicosis. It is reported that a low serum thyrotrophin concentration in an asymptomatic person with normal serum thyroid hormone concentrations can be a independent risk factor for developing atrial fibrillation. But we focused on the significance of serum thyroid stimulating hormone (TSH) in the euthyroid patient with atrial fibrillation whose serum level of T3, T4, fT4, and even TSH were absolutely within normal range. On our results, there was no significant differences in age, sexual distribution, and left ventricular ejection fraction between the patients group of paroxysmal and chronic persistent atrial fibrillation (p> 0.05), but there was larger left atrial dimension (LAD) and more cases of rheumatic heart disease in the chronic persistent atrial fibrillation group and there was more cases of lone atrial fibrillation in the paroxysmal atrial fibrillation group (p< 0.05). There was no significant differences in serum levels of T3, T4, fT4 between paroxysmal and chronic persistent atrial fibrillation, but significantly lower serum TSH was found in patients with paroxysmal atrial fibrillation (p< 0.001), and these findings were more significant after the control of hemodynamic change (p< 0.001 vs p< 0.05). The discriminant value in serum TSH between the paroxysmal and chronic atrial fibrillation group was 1.568U/mL with about 76% of predictive power. There was significantly lower serum TSH in paroxysmal atrial fibrillation in all age groups (p< 0.05). There was a significantly higher prevalence of cerebral thromboembolic events in chronic persistent (27.7%) and disease-associated (15.0% atrial fibrillation than in the paroxysmal (3.3%) and lone (4.5%) atrial fibrillation group (p< 0.001). Therefore, we suggest that serum TSH below the serum concentration of 1.5U/mL can be a risk factor for developing atrial fibrillation when the serum level of T3, T4, fT4, and even TSH were within absolutely normal range.