HFpEF-related atrial fibrillation -Significance of sinus rhythm

Epidemiologic studies have shown that approximately 50% of patients with heart failure have a preserved ejection fraction, and this proportion has increased over time. Despite significant progress in heart failure therapies, there has been no proven effective medical treatment for HFpEF probably because of the lack of a precise mechanism of this disease. Atrial fibrillation is commonly complicated with HF, with a reported prevalence of 21–65% in HFpEF, which is higher than what has been reported in HFrEF (< 10–50%). Previous studies reported that AF is independently associated with a reduced functional capacity and an increased risk of mortality. The left atrium modulates the left ventricular filling by acting as an elastic reservoir, passive conduit, and active booster. Concomitant AF, which impairs the left atrium function, can impose greater hemodynamic stress on the pulmonary vasculature, promoting remodeling, and worsening pulmonary hypertension. Specifically targeting AF as a result of atrial remodeling in HF has been proposed with the aim of reversing the electrical remodeling induced by AF and preserved/restored contribution of the left atrium to ventricular filling. The CASTLE-AF showed that AF ablation significantly decreased the composite of all-cause mortality and unscheduled heart failure hospitalization in HFrEF. However, in HFpEF, it is not clear whether restoring sinus rhythm improves the exercise capacity as well as mortality. In this session, we will discuss whether restoration of sinus rhythm contributes to the atrial properties and hemodynamic parameters of the left ventricle in patients with HFpEF and AF.