Atrial fibrillation history is statistically significantly associated with adverse major clinical outcomes in ICD-implanted HF patients .
Patients with AF have a higher risk of all-cause mortality , appropriate , and inappropriate ICD interventions compared with patients with no AF history .
AIMS To assess the association between atrial fibrillation ( AF ) and all-cause mortality and implantable cardioverter-defibrillators ( ICDs ) therapies  in heart failure ( HF ) patients with reduced ejection fraction and an ICD implanted .
Prognostic importance of defibrillator shocks in patients with heart failure.
BACKGROUND Patients with heart failure who receive an implantable cardioverter-defibrillator ( ICD ) for primary prevention ( i.e. , prevention of a first life-threatening arrhythmic event ) may later receive therapeutic shocks from the ICD . Information about long-term prognosis after ICD therapy in such patients is limited . METHODS Of 829 patients with heart failure who were r and omly assigned to ICD therapy , we implanted the ICD in  811 . ICD shocks that followed the onset of ventricular tachycardia or ventricular fibrillation were considered to be appropriate . All other ICD shocks were considered to be inappropriate . RESULTS Over a median follow-up period of 45.5 months , 269 patients ( 33.2 % ) received at least one ICD shock , with 128 patients receiving only appropriate shocks , 87 receiving only inappropriate shocks , and 54 receiving both types of shock . In a Cox proportional-hazards model adjusted for baseline prognostic factors , an appropriate ICD shock , as compared with no appropriate shock , was associated with a significant increase in the subsequent risk of death from all causes ( hazard ratio , 5.68 ; 95 % confidence interval [ CI ] , 3.97 to 8.12 ; P<0.001 ) . An inappropriate ICD shock , as compared with no inappropriate shock , was also associated with a significant increase in the risk of death ( hazard ratio , 1.98 ; 95 % CI , 1.29 to 3.05 ; P=0.002 ) . For patients who survived longer than 24 hours after an appropriate ICD shock , the risk of death remained elevated ( hazard ratio , 2.99 ; 95 % CI , 2.04 to 4.37 ; P<0.001 ) . The most common cause of death among patients who received any ICD shock was progressive heart failure . CONCLUSIONS Among patients with heart failure in whom an ICD is implanted for primary prevention , those who receive shocks for any arrhythmia have a substantially higher risk of death than similar patients who do not receive such shocks
Atrial fibrillation history is statistically significantly associated with adverse major clinical outcomes in ICD-implanted HF patients .
Patients with AF have a higher risk of all-cause mortality , appropriate , and inappropriate ICD interventions compared with patients with no AF history .
AIMS To assess the association between atrial fibrillation ( AF ) and all-cause mortality and implantable cardioverter-defibrillators ( ICDs ) therapies  in heart failure ( HF ) patients with reduced ejection fraction and an ICD implanted .