Atrial Fibrillation Ablation for Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is characterized by the heart's inability to effectively relax and fill with blood during the resting phase of the cardiac cycle (diastole). In HFpEF, the heart's ejection fraction, which measures the percentage of blood pumped out of the heart with each contraction, is typically within the normal range (50% or higher).

However, the heart muscle becomes stiff and less compliant, impairing diastolic function and reducing the filling of the heart's chambers. This results in decreased cardiac output and an inadequate supply of oxygen-rich blood to the body's organs and tissues, leading to heart failure symptoms. HFpEF is commonly associated with conditions such as hypertension, diabetes, obesity, and aging.

Atrial Fibrillation

Patients with HFpEF develop atrial fibrillation (AF), where the heart's upper chambers (atria) beat irregularly and too fast. Instead of contracting coordinately, they quiver or flutter, affecting blood flow to the lower chambers (ventricles). AF can lead to various symptoms like palpitations, shortness of breath, and fatigue. Treatment aims to restore a regular heart rhythm, control heart rate, and prevent complications through medications, lifestyle changes, and sometimes procedures like cardioversion or ablation.

Clinical Trial

A clinical trial compared the effects of AF ablation (a procedure to treat AF) versus usual medical therapy on markers of HFpEF severity. Thirty-one patients with AF and HFpEF were enrolled and randomly assigned to either AF ablation or medical therapy groups. Exercise right heart catheterization and cardiopulmonary exercise testing were performed to confirm HFpEF. The primary outcome was the peak exercise pulmonary capillary wedge pressure (PCWP) change after six months.

Results

AF ablation reduced peak PCWP significantly compared to baseline levels, indicating improved heart diastolic function. Exercise capacity, measured by peak relative VO2, also increased significantly after ablation. N-terminal pro-B-type natriuretic peptide levels, a marker of heart failure severity, decreased in the ablation group. Quality of life, assessed by the Minnesota Living with Heart Failure (MLHF) score, improved significantly after AF ablation.

In contrast, the medical therapy group did not show significant changes in the measured parameters. After AF ablation, 50% of the patients no longer met the criteria for HFpEF based on exercise right heart catheterization, compared to only 7% in the medical therapy group.

Conclusion

AF ablation benefits HFpEF severity, exercise capacity, and quality of life in patients with both AF and HFpEF. The procedure improved the heart's diastolic function, resulting in better exercise performance and reduced heart failure symptoms. AF ablation could be a promising treatment option for concomitant AF and HFpEF patients. However, further research and extensive studies are needed to confirm these results and explore the procedure's long-term effects on HFpEF outcomes.
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