A history of heart failure predicts arrhythmia treatment efficacy: Data from the Antiarrythmics versus Implantable Defibrillators (AVID) Study

Background In survivors of life-threatening ventricular tachycardia (VT), a history of CHF (HxCHF) before the VT episode may provide different prognostic information than their measured left ventricular ejection fraction (LVEF). Methods We evaluated outcomes from patients in the AVID study. Patients were included in the study if they presented with ventricular fibrillation, VT with syncope or VT with hemodynamic compromise, and LVEF <= 40%. Treatment options included implantable cardioverter defibrillator (ICD) or antiarrhythmic drugs (AAD), usually amiodarone. Results As expected, a HxCHF is associated with an increased and high risk of arrhythmic and nonarrhythmic death. However, an interaction was observed between arrhythmia treatment (ICD or AAD) and HxCHF status: the survival advantage with an ICD, as compared with AAD therapy, is largely. restricted to HxCHF patients. Conclusions The ICD is no better than AAD therapy in preventing arrhythmic death in patients with no HxCHF. In this data set, a HxCHF is somewhat more accurate in predicting prognosis and the response to therapy than a reduced LVEF.