Association between atrial fibrillation and patient-important outcomes in heart failure patients with implantable cardioverter-defibrillators. A systematic review and meta-analysis.

Aims: To assess the association between atrial fibrillation (AF) and all-cause mortality and implantable cardioverter defibrillators (ICD) therapies in heart failure (HF) patients with reduced ejection fraction and an ICD implanted.

Methods and Results: A systematic MEDLINE search performed from inception through November 2016, supplemented by hand searching of reference lists, identified 62 eligible studies (227,998 patients) reporting on the association between AF and outcomes in HF patients; 36 studies included data on all-cause mortality, 30 on appropriate and 17 on inappropriate ICD interventions. Hazard Ratio, Risk Ratio, or Odds Ratio estimates were used based on data availability. Effect estimates were synthesized under a random-effects model. ICD-implanted HF patients with a history of AF had a 42% [combined effect estimate (cEE) 1.42 (95% CI: 1.28-1.57)] higher risk of all-cause mortality compared to patients with no AF history. Furthermore, AF patients had a higher risk of appropriate [cEE 1.44 (95% CI: 1.27-1.64)] and inappropriate ICD interventions [cEE 2.05 (95% CI 1.75-2.44)].

Conclusions: AF 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 to patients with no AF history. Whether AF may have an independent deleterious effect on HF prognosis or may simply be a marker of HF severity should be further investigated.