Impact of Atrial Fibrillation Presentation on Heart Failure and Sudden Death in Hfpef

Aims: We studied the impact of atrial fibrillation (AF) presentation on total & cause-specific cardiovascular (CV) mortality & hospitalizations (H) in mild & advanced heart failure (HF) strata as well as HF worsening in the TOPCAT AMERICAS study.Methods: We analyzed 1765 subjects with HF & preserved ejection fraction (pEF) and AF with two AF different presentations at entry: a) Any AF event (remote or ongoing, n=760), to those without any such AF events (n=1005) and b) Ongoing AF on ECG at enrollment (n=446), to those in sinus rhythm (SR, n=1319). Results; During a mean follow-up of 2.9 years, CV mortality was higher in subjects with AF on ECG (30% vs. 18% at year 5, hazard ratio (HR) of 1.44, 95% CI 1.08-1.92, p=0.014) with an disproportionate increase in pump failure deaths {PFD} (HR 2.04, 95% CI 1.22-3.42, p=0.007) but not sudden death {SCD} (HR 1.17, 95% CI 0.69-1.96, p=0.563). HF worsening was more frequent with Any AF (HR 1.31, 95% CI 1.09-1.58, p=0.005). Increased risk of PFD was seen with Any AF ( p= 0.001) & AF on ECG (p=0.002) in the advanced HF class stratum without enhancing SCD risk (p>0.7 for both). Conclusions: Both AF presentations increased risk of PFDs, but not SCD. Ongoing AF worsened CV mortality in HFpEF by disproportionately increasing PFDs and Any AF promoted HF worsening. Adverse CV outcomes with AF in HFpEF are caused by excess PFDs and/ or by HF worsening varying by AF presentation & HF stratum.