The goal of this clinical trial is to determine the effect of accelerated pacing (pacemaker lower rate programmed to 80bpm) compared to pacing at the standard programmed lower rate of 60bpm in symptomatic atrial fibrillation patients undergoing pace-and-ablate strategy with LBBAP.

The main question it aims to answer is:

- To determine the effect of accelerated pacing on health-related quality of life compared to the current standard of care.

Secondary questions it aims to answer are:

• To study the acute hemodynamic effect of different (accelerated) pacing rates on pulmonary capillary wedge pressure, cardiac output and arterial blood pressure among atrial fibrillation patients undergoing pace-and-ablate strategy.
• To study the long-term effects (at 6 months) of accelerated pacing compared to the current standard of care among atrial fibrillation patients undergoing pace-and-ablate strategy on:
• NT pro BNP levels
• device detected atrial fibrillation burden and daily activity
• echocardiographic measurements (LVEF, left ventricular ejection fraction; LVEDD, left ventricular end- diastolic diameter; LVESD, left ventricular end-systolic diameter; LAVI left atrial volume index; diastolic parameters; strain

Rationale:

Permanent pacemaker implantation combined with atrioventricular node ablation (AVNA) reduces symptoms and improves health-related quality of life (HRQoL) in patients with symptomatic atrial fibrillation (AF). A high percentage of conventional right ventricular pacing increases the risk for pacing-induced cardiomyopathy, a risk which is presumably minimised by a form of conduction system pacing, termed left bundle branch area pacing (LBBAP). LBBAP attempts to recreate the normal physiologic activation of the heart through stimulation of the heart's own natural conduction system, thereby maintaining ventricular synchrony. This strategy may be particularly important in patients with heart failure with preserved ejection fraction (HFpEF), a diagnosis that frequently coexists with AF. The long-term programming of a patient undergoing a "pace-and-ablate strategy" (pacemaker implantation and AVNA), is such that the lower rate of the pacemaker is routinely set to 60 bpm. Previous studies have shown that accelerated pacing (ie. programming the pacemaker to a lower rate of 80bpm) may improve HRQoL in a subset of patients with HFpEF. It is therefore hypothesized that accelerated pacing will improve HRQoL in patients with symptomatic AF undergoing a pace and ablate strategy, when compared to pacing at 60 bpm, which is standard of care.

Objective:

Primary objective: To determine the effect of accelerated pacing (lower programmed rate of 80 bpm) compared to pacing at the standard programmed rate of 60 bpm on HRQoL in symptomatic AF patients undergoing pace-and-ablate strategy with LBBAP.

Secondary objectives:

• To study, in a subset of participants who give informed consent, the acute hemodynamic effect of accelerated pacing rates on pulmonary capillary wedge pressure (PCWP), cardiac output and arterial blood pressure, among AF patients undergoing a pace-and-ablate strategy with LBBAP.
• To study the long-term (6 months) effects of accelerated pacing among AF patients undergoing a pace-and-ablate strategy with LBBAP by measuring NT-proBNP levels, device detected AF-burden and daily activity, by evaluating HRQoL questionnaires (SF-36), and by assessing echocardiographic measurements (LVEF, left ventricular ejection fraction; LVEDD, left ventricular end-diastolic diameter; LVESD, left ventricular end-systolic diameter; LAVI left atrial volume index; diastolic parameters; strain) compared to pacing at the standard of care lower rate of 60bpm.
• To investigate whether participants experience symptoms of accelerated pacing (such as palpitations), based on the Atrial Fibrillation Effect on Quality-of-life (AFEQT) questionnaire, compared to standard of care.

Study design:

Randomized, single center, prospective, single blinded, parallel group, pilot-trial.

Study population:

Patients ≥ 18 years with symptomatic AF undergoing pace-and-ablate strategy.

Intervention:

- 1:1 randomization to a lower rate of DDDR 80 bpm (intervention) or a lower rate of DDDR 60 bpm (control). Duration of the study is 6 months.

In a subset of participants:

- Right heart catheterisation and invasive blood pressure measurements will be conducted to evaluate acute hemodynamic effects of different (accelerated) ventricular pacing rates during the standard of care AV node ablation.

Main study parameters/endpoints:

Primary endpoint:

Difference in HRQoL between a lower rate of 80 bpm and a lower rate of 60 bpm, based on the Minnesota Living with Heart Failure Questionnaire (MLHFQ), determined at 6 months follow-up.

Secondary endpoints:

• The acute hemodynamic effects of (accelerated) pacing at time of AVNA:

  • Pulmonary Capillary Wedge Pressure (PCWP)
  • Cardiac Output (CO)
  • Systemic arterial blood pressure

• The long-term effect of accelerated pacing on:

  • HRQoL, based on the MLHFQ and SF-36 questionnaires.
  • NT-proBNP levels
  • Device detected AF burden
  • Device detected daily activity comparing accelerated- vs control rate
  • Echocardiographic measurements (LVEF, LVEDD, LVESD, LAVI, LA strain)

• Symptoms experienced as a result of (accelerated) pacing based on the AFEQT questionnaire

Inclusion Criteria:

• Adults > 18 years of age
• Referred for pace-and-ablate strategy with LBBAP for symptomatic AF
• Left ventricular ejection fraction ≥ 40%.
• Willingness to participate, to understand the instructions and fill out the questionnaires, and ability to sign informed consent.

Exclusion Criteria:

• Infiltrative or constrictive cardiomyopathy (cardiac amyloidosis/sarcoidosis/ constrictive pericarditis)
• Severe Valvular heart disease (more than moderate valvular stenosis or regurgitation, aortic or mitral valve replacement)
• Patient participating in another interventional clinical trial
• Recent (< 3 months) Myocardial infarction (MI), Transient Ischemic Attack or Cerebro- Vascular Accident