Atrial Fibrillation in Heart Failure With Preserved Ejection Fraction: The PARAGON-HF Trial

Objectives: In this study, the authors sought to assess the relationship between AFF and outcomes, the treatment response to sacubitril/valsartan and first-detected AFF in patients with HFpEF enrolled in the PARAGON-HF trial. Background: Atrial fibrillation and flutter (AFF) are common in heart failure with preserved ejection fraction (HFpEF) and increase the risk of adverse outcomes. Methods: A total of 4,776 patients formed 3 groups: those with AFF according to electrocardiography (ECG) at enrollment (n = 1,552; 33%), those with history of AFF but without AFF on ECG at enrollment (n = 1,005; 21%), and those without history of AFF or AFF on ECG at enrollment (n = 2,219, 46%). We assessed outcomes, treatment response to sacubitril/valsartan in each group, and the risk associated with first-detected AFF in patients without any known AFF. The primary outcome was a composite of total heart failure hospitalizations and cardiovascular death. Results: History of AFF and AFF at enrollment were associated with higher risk of the primary outcome (risk ratio [RR]: 1.36 [95% CI: 1.12-1.65] and RR: 1.31 [1.11-1.54], respectively), than no AFF. Neither history of AFF nor AFF at enrollment modified the treatment effect of sacubitril/valsartan. Post randomization AFF occurred in 12% of patients without previous AFF and was associated with 2.8-fold higher risk of the primary outcome, but it was not influenced by sacubitril/valsartan. Conclusions: History of AFF and AFF on ECG at enrollment were associated with a higher risk of the primary outcome. First-detected AFF was not influenced by sacubitril/valsartan, yet it was associated with increased risk of all subsequent outcomes and may represent a potential target for future HFpEF trials.