Abstract 11970: Left Atrial Hemodynamics and Invasive Functional Testing to Characterize Heart Failure With Preserved Ejection Fraction in Patients With Atrial Fibrillation

Abstract

Introduction: Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) commonly coexist. The contribution of abnormal left atrial (LA) hemodynamics to the development of HFpEF in symptomatic AF patients is unknown. Hypothesis: Hemodynamic testing of patients with symptomatic AF will reveal coexistent HFpEF associated with increased LA pressures and stiffness. Methods: Consecutive patients with AF and preserved ejection fraction (awaiting AF ablation) were prospectively recruited. Participants underwent exercise echocardiography and cardiopulmonary exercise testing (CPET), and were grouped according to low, intermediate or high probability of HFpEF based on the ‘HFA-PEFF’ score. At ablation, participants underwent invasive monitoring of LA and right atrial pressures during infusion of 15mL/kg of normal saline directly into the LA over 8 minutes. LA size was monitored during infusion with transesophageal echocardiography. LA stiffness was calculated as Δ LA pressure/Δ LA diameter. Statistical comparison across groups was performed using analysis of variance. Results: Amongst 64 participants, probability of HFpEF was low in nine (14%), intermediate in 39 (61%) and high in 16 (25%) participants. High probability HFpEF was associated with higher baseline mean LA pressure (Fig. 1A) and greater increases in peak (p=0.06) and nadir LA (p<0.01) pressures with saline loading, without significant increases in RA pressure. LA stiffness was increased in patients with high probability of HFpEF (Fig. 1B). Non-invasive testing revealed reduced peak VO 2 (p=0.01), reduced LA emptying fraction at rest and with exercise (p<0.01) and reduced LA reservoir strain (p<0.01) in participants with higher probability for HFpEF. Conclusions: In AF patients undergoing ablation, 25% meet the criteria for HFpEF. Higher probability of HFpEF is characterized by increased LA pressures and LA stiffness, exercise intolerance and reduced LA function.