Atrioventricular Node Ablation and Conduction System Pacing in Patients With Well Controlled Permanent Atrial Fibrillation (AF), Heart Failure and Preserved Ejection Fraction: Heart Rate Regularization Versus Medical Rate Control

Heart failure with preserved ejection fraction is a major public health issue affecting 4.9% of general population aged ≥ 60 years. It accounts for more than half of all heart failure hospital admissions. Atrial fibrillation is very common in this diseased population as pathophysiologies are highly interrelated. Atrial fibrillation occurs in two thirds of Heart failure with preserved ejection patients at some point in the natural history and confers a poor prognosis. Therapeutic alternatives are currently limited as patients with permanent Atrial fibrillation and Heart failure with preserved ejection are often treated with drug therapies for lenient rate control.

Recently, the APAF-CRT mortality trial demonstrated a reduction in mortality and hospitalization in Heart Failure and Atrial fibrillation patients treated with Atrioventricular node ablation plus Cardiac Resynchronization Therapy versus pharmacological rate control, irrespective of their baseline Ejection Fraction. The optimal rate regularization achieved with atrioventricular node ablation emerges as the main determinant of reduction in mortality and hospitalization. This conclusion is supported by old robust physiology studies showing that beat-to-beat heart rate irregularity has significant hemodynamic effects and notably decreases cardiac output. However, no specific trials have been conducted in patients with Heart failure with preserved ejection, a population for whom treatment strategies that effectively improve outcomes are sparse. We aim at analyzing the benefit of heart rate regularization and physiological pacing in patients with Heart failure with preserved ejection (Left Ventricular Ejection Fraction ≥ 50%) and permanent Atrial Fibrilation.

We hypothesize that heart rate regularization added to physiological pacing - preventing the deleterious effect of right ventricular apical pacing - would reduce mortality and Heart Failure hospitalizations.