Postoperative atrial fibrillation after cardiac surgery: who should receive chemoprophylaxis?

To evaluate arrhythmogenic risk factors associated with greater incidence of postoperative atrial fibrillation (POAF) in patients undergoing cardiac surgery (CABG and/or valvular surgery) in order to identify those more prone to the development of this arrhythmia for possible chemoprophylaxis. Sixty-six patients who underwent elective cardiac surgery were assessed. The following risk factors for the development of POAF were correlated: advanced age, valvular heart disease (VHD), left atrial (LA) enlargement, left ventricular dysfunction (LVD), electrolyte imbalance (EI), previous CABG, prior use and withdrawal of beta-blockers (BB) and/or digitalis 24 hours before surgery). The incidence of AF was high (47%) in our study, most frequently on the first postoperative day. Sixty-four percent of the study sample was male, and the mean age was 62 years. Among patients with two or less risk factors for AF, only 24% developed arrhythmia, while the presence of three or more risk factors was associated with increased incidence of postoperative AF (69%), (p = 0.04). Age > 65 years (58% of the patients) was the most prevalent risk factor, followed by LA enlargement in 45% (p = 0.001), and VHD in 38% (p = 0.02). The presence of three or more risk factors increases significantly the incidence of this arrhythmia in the postoperative period after cardiac surgery. Among the primary risk factors are advanced age, left atrial enlargement, and valvular heart disease.

Fibrilação atrial no pós-operatório de cirurgia cardíaca: quem deve receber quimioprofilaxia? / Fibrilación atrial en el postoperatorio de cirugía cardiaca: ¿quién debe recibir quimioprofilaxia? / Postoperative atrial fibrillation after cardiac surgery: who should receive chemoprophylaxis?

Avaliar fatores de risco arritmogênicos associados à maior incidência de fibrilação atrial (FA) no pós-operatório (PO) de cirurgia cardíaca (revascularização miocárdica e/ou cirurgia valvar), com o intuito de selecionar os mais propensos ao desenvolvimento dessa arritmia para possível quimioprofilaxia. Avaliarem-se 66 pacientes submetidos à cirurgia cardíaca eletiva. Correlacionaram-se os principais fatores de risco (idade avançada, doença valvar (DV), aumento atrial esquerdo (AE), disfunção ventricular (DVE), distúrbio eletrolítico (DHE), cirurgia cardíaca prévia (CCP), uso prévio e suspensão de betabloqueador (B-Bloq) e/ou digital 24 horas antes da cirurgia) para o desenvolvimento de FA no PO. A incidência de FA foi elevada (47 por cento) em nossa casuística e mais freqüente no primeiro dia de PO. Dos pacientes pesquisados, 64 por cento eram do sexo masculino com idade média de 62 anos. Entre os pacientes com dois ou menos fatores de risco para FA, apenas 24 por cento desenvolveram a arritmia, enquanto a presença de três ou mais desses fatores esteve associada à sua maior incidência no PO (69 por cento), (p = 0,04). Em ordem de maior freqüência, idade > 65 anos (em 58 por cento dos pacientes) foi o fator de risco mais prevalente, seguido de aumento do AE em 45 por cento (p = 0,001) e DV em 38 por cento (p = 0,02). A presença de três ou mais fatores de risco aumenta consideravelmente a incidência dessa arritmia no PO de cirurgia cardíaca. Entre os principais fatores, destacaram-se idade avançada, aumento do AE e doença valvar.

To evaluate arrhythmogenic risk factors associated with greater incidence of postoperative atrial fibrillation (POAF) in patients undergoing cardiac surgery (CABG and/or valvular surgery) in order to identify those more prone to the development of this arrhythmia for possible chemoprophylaxis. Sixty-six patients who underwent elective cardiac surgery were assessed. The following risk factors for the development of POAF were correlated: advanced age, valvular heart disease (VHD), left atrial (LA) enlargement, left ventricular dysfunction (LVD), electrolyte imbalance (EI), previous CABG, prior use and withdrawal of beta-blockers (BB) and/or digitalis 24 hours before surgery). The incidence of AF was high (47 percent) in our study, most frequently on the first postoperative day. Sixty-four percent of the study sample was male, and the mean age was 62 years. Among patients with two or less risk factors for AF, only 24 percent developed arrhythmia, while the presence of three or more risk factors was associated with increased incidence of postoperative AF (69 percent), (p = 0.04). Age > 65 years (58 percent of the patients) was the most prevalent risk factor, followed by LA enlargement in 45 percent (p = 0.001), and VHD in 38 percent (p = 0.02). The presence of three or more risk factors increases significantly the incidence of this arrhythmia in the postoperative period after cardiac surgery. Among the primary risk factors are advanced age, left atrial enlargement, and valvular heart disease.

Evaluar factores de riesgo arritmogénicos asociados a la mayor incidencia de fibrilación atrial (FA) en el postoperatorio (PO) de cirugía cardiaca (revascularización miocárdica y/o cirugía valvular), con el intuito de seleccionar los más propensos al desarrollo de esa arritmia para posible quimioprofilaxia. Se evaluaron a 66 pacientes sometidos a la cirugía cardiaca electiva. Se correlacionaron los principales factores de riesgo (edad avanzada, enfermedad valvar (DV), aumento atrial izquierdo (AE), disfunción ventricular (DVE), disturbio electrolítico (DHE), cirugía cardiaca previa (CCP), uso previo y suspensión de betabloqueante (B-Bloq) y/o digital 24 horas antes de la cirugía) para el desarrollo de FA en el PO. La incidencia de FA se mostró elevada (47 por ciento) en nuestra casuística y más frecuente al primer día de PO. De todos los pacientes investigados, el 64 por ciento pertenecían al sexo masculino con edad promedio de 62 años. Entre los pacientes con dos o menos factores de riesgo para FA, sólo el 24 por ciento desarrollaron la arritmia, mientras que la presencia de tres o más de esos factores estuvo asociada a su mayor incidencia en el PO (69 por ciento), (p = 0,04). Por orden de mayor frecuencia, edad > 65 años (en el 58 por ciento de los pacientes) resultó el factor de riesgo más prevalente, seguido de aumento del AE en el 45 por ciento (p = 0,001) y DV en el 38 por ciento (p = 0,02). La presencia de tres o más factores de riesgo aumenta considerablemente la incidencia de esa arritmia en el PO de cirugía cardiaca. Entre los principales factores, se destacaron: edad avanzada, aumento de AE y enfermedad valvular.

Prevention of atrial fibrillation with moderate doses of amiodarone in the postoperative period of cardiac surgery is safe and effective in patients with high risk for developing this arrhythmia.

OBJECTIVE: To assess if prophylaxis with moderate doses of amiodarone in the postoperative period of cardiac surgery (coronary artery bypass grafting and/or valve surgery), reduces the incidence of atrial fibrillation in patients with high risk for developing this arrhythmia. METHODS: A randomized and prospective clinical study involving 68 patients who underwent elective cardiac surgery. Mean age was 64 years and 59% of participants were males. Patients with three or more risk factors for atrial fibrillation, according to the literature, were randomized into two groups to receive or not prophylaxis with amiodarone in the first postoperative day. The dose administered ranged from 600 mg/day to 900 mg/day, intravenously, on the first postoperative day, followed by 400 mg/day orally until hospital discharge or until completing seven days. The other patients, who presented two or fewer risk factors, were followed up until hospital discharge. All patients were evaluated by means of cardiac and/or electrocardiographic monitoring. RESULTS: In the group treated with amiodarone, 7% of patients presented atrial fibrillation, whereas in the control group 70% of patients developed arrhythmia. Among the non-randomized individuals (with two or fewer risk factors), only 24% presented atrial fibrillation. CONCLUSION: The prophylactic use of amiodarone was effective in the prevention of atrial fibrillation in patients with three or more risk factors for this arrhythmia. This treatment can be useful to reduce stay at the Intensive Care Unit and, consequently, the complications originating from longer hospitalization.

Prevenção de fibrilação atrial com amiodarona em moderada dosagem no pós-operatório de cirurgia cardíaca é segura e eficaz em pacientes de alto risco para desenvolver essa arritmia / Prevention of atrial fibrillation with moderate doses of amiodarone in the postoperative period of cardiac surgery is safe and effective in patients with high risk for developing this arrhythmia

OBJETIVO: Avaliar se a profilaxia com amiodarona em moderada dosagem, no pós-operatório de cirurgia cardíaca (revascularização miocárdica e/ou cirurgia valvar), reduz a incidência de fibrilação atrial em pacientes de alto risco para desenvolver essa arritmia. MÉTODOS: Estudo clínico, randomizado e prospectivo, realizado em 68 pacientes submetidos a cirurgia cardíaca eletiva. A média de idade foi de 64 anos e 59 por cento dos participantes eram do sexo masculino. Os pacientes com três ou mais fatores de risco para fibrilação atrial, de acordo com a literatura, foram randomizados em dois grupos, para receber ou não profilaxia com amiodarona no primeiro dia de pós-operatório. A dose administrada foi de 600 mg/dia a 900 mg/dia, por via intravenosa, no primeiro dia de pós-operatório, seguida de 400 mg/dia por via oral até a alta hospitalar ou até completar sete dias. Os demais pacientes, com dois ou menos fatores de risco, foram seguidos até a alta hospitalar. Todos os pacientes foram observados por monitorização cardíaca e/ou eletrocardiografia. RESULTADOS: No grupo que recebeu amiodarona, 7 por cento dos pacientes apresentaram fibrilação atrial, enquanto no grupo controle 70 por cento desenvolveram a arritmia. Nos indivíduos não-randomizados (com dois ou menos fatores de risco), apenas 24 por cento apresentaram fibrilação atrial. CONCLUSÃO: O uso profilático de amiodarona foi eficaz na prevenção de fibrilação atrial nos pacientes com três ou mais fatores de risco para essa arritmia. Esse tratamento pode ser benéfico na redução da permanência na Unidade de Terapia Intensiva e, conseqüentemente, nas complicações advindas do maior tempo de internação hospitalar.

OBJECTIVE: To assess if prophylaxis with moderate doses of amiodarone in the postoperative period of cardiac surgery (coronary artery bypass grafting and/or valve surgery), reduces the incidence of atrial fibrillation in patients with high risk for developing this arrhythmia. METHODS: A randomized and prospective clinical study involving 68 patients who underwent elective cardiac surgery. Mean age was 64 years and 59 percent of participants were males. Patients with three or more risk factors for atrial fibrillation, according to the literature, were randomized into two groups to receive or not prophylaxis with amiodarone in the first postoperative day. The dose administered ranged from 600 mg/day to 900 mg/day, intravenously, on the first postoperative day, followed by 400 mg/day orally until hospital discharge or until completing seven days. The other patients, who presented two or fewer risk factors, were followed up until hospital discharge. All patients were evaluated by means of cardiac and/or electrocardiographic monitoring. RESULTS: In the group treated with amiodarone, 7 percent of patients presented atrial fibrillation, whereas in the control group 70 percent of patients developed arrhythmia. Among the non-randomized individuals (with two or fewer risk factors), only 24 percent presented atrial fibrillation. CONCLUSION: The prophylactic use of amiodarone was effective in the prevention of atrial fibrillation in patients with three or more risk factors for this arrhythmia. This treatment can be useful to reduce stay at the Intensive Care Unit and, consequently, the complications originating from longer hospitalization.