Identification of Subclinical Heart Failure With Preserved Ejection Fraction in Patients With Symptomatic Atrial Fibrillation

Abstract

Background: Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) commonly coexist. We hypothesize that patients with symptomatic AF but without overt clinical HF commonly exhibit subclinical HFpEF according to established hemodynamic criteria.

Objectives: The authors sought to use invasive hemodynamics to investigate the prevalence and implications of subclinical HFpEF in AF ablation patients.

Methods: Consecutive symptomatic AF ablation patients were prospectively recruited. Diagnosis of subclinical HFpEF was undertaken by invasive assessment of left atrial pressure (LAP). Participants had HFpEF if the baseline mean LAP was >15 mm Hg and early HFpEF if the mean LAP was >15 mm Hg after a 500-mL fluid challenge. LA compliance was assessed invasively by monitoring the LAP and LA diameter during direct LA infusion of 15 mL/kg normal saline. LA compliance was calculated as Δ LA diameter/ΔLAP. LA cardiomyopathy was further studied with exercise echocardiography and electrophysiology study. Functional impact was evaluated using cardiopulmonary exercise testing and the AF Symptom Severity questionnaire.

Results: Of 120 participants, 57 (47.5%) had HFpEF, 31 (25.8%) had early HFpEF, and 32 (26.7%) had no HFpEF. Both HFpEF and early HFpEF were associated with lower LA compliance compared with those without HFpEF (P < 0.001). Participants with HFpEF and early HFpEF also displayed decreased LA emptying fraction (P = 0.004), decreased LA voltage (P = 0.001), decreased VO_2peak (P < 0.001), and increased AF symptom burden (P = 0.002) compared with those without HFpEF.

Conclusions: Subclinical HFpEF is common in AF ablation patients and is characterized by a LA cardiomyopathy, decreased cardiopulmonary reserve and increased symptom burden. The diagnosis of HFpEF may identify patients with AF with the potential to benefit from novel HFpEF therapies. (Characterising Left Atrial Function and Compliance in Atrial Fibrillation; ACTRN12620000639921).

Keywords: atrial fibrillation; cardiopulmonary reserve; heart failure with preserved ejection fraction; invasive hemodynamics; left atrial compliance.