Foulkes, Stephen J; Exercise and Research Trials (HEART) Lab, St Vincent’s Institute of Medical Research, Fitzroy, Australia.
Moura-Ferreira, Sara;Milani, Mauricio;Bekhuis, Youri;+13 more
Journal of cardiac failure,2025 Dec 30
- Objective: Atrial fibrillation (AF) is a common comorbidity in patients with heart failure with preserved ejection fraction (HFpEF) that contributes to increased morbidity and mortality. We sought to evaluate the impact of AF on key HFpEF features, including exercise tolerance (peak oxygen uptake, VO 2 peak) hemodynamic responses, and peripheral oxygen extraction (a-vO 2 diff).
- Methods: Patients referred to a multi-disciplinary unexplained dyspnea clinic and diagnosed with HFpEF following comprehensive clinical and hemodynamic evaluation were stratified on whether they were in persistent/permanent AF (AF Persist ; n=86), paroxysmal AF (AF Parox ; n=328) or sinus rhythm (SR; n=274). Cardiopulmonary exercise testing with simultaneous echocardiography (CPETecho) was applied to assess the VO 2 peak, a-vO 2 diff and exercise hemodynamics. Groups were compared using ANCOVA with adjustment for age, sex, body mass index, and the presence of hypertension and diabetes.
- Results: Compared to patients in SR or with AF Parox , HFpEF patients with AF Persist had a lower VO 2 peak (1.3-2.4mL/kg/min lower, P<0.001). This coincided with lower peak exercise cardiac output (CO, 0.6-1.2L/min lower), secondary to a lesser stroke volume (14-17mL lower, P<0.001) and a smaller left-ventricular end-diastolic volume (15-18mL lower, P<0.001) that tended to decrease during exercise. In contrast, there was no impact of AF status on peak exercise a-vO 2 diff, mean pulmonary artery pressure (mPAP) or the mPAP/CO slope.
- Conclusion: Patients with HFpEF and AF Persist have a lower VO 2 peak secondary to decreased CO, SV and reduced end-diastolic volume reserve. Rhythm control strategies may therefore be pivotal in optimizing exercise performance and clinical outcomes in patients with HFpEF and AF.