Clinical Phase 2 Trial of AP31969 Versus Placebo for Rhythm Control of Atrial Fibrillation

• Willing and able to provide written informed consent.
• Age 18 or older.
• ECG documented diagnosis of paroxysmal or persistent AF.
• AF history at screening indicating an expected AF burden of 1-90%, i.e., at least 1 self-terminating AF episode within 4 months prior to the screening visit.
• AF burden of ≥ 1% and ≤ 90% assessed with an ECG patch device during the screening period prior to the randomisation visit.

• Investigator and participant agreement to avoid non-trial related rhythm control intervention for the duration of the trial, including:

  • Antiarrhythmic drug class I and/or III (including amiodarone)
  • Electrical or pharmacological cardioversion
  • AF ablation procedure
• Willing to have a loop recorder implanted.

Exclusion Criteria:

• Prior AF ablation procedure other than pulmonary vein isolation (PVI) only.
• Any of the following events within 4 weeks prior to the screening visit: Myocardial infarction, Unstable angina pectoris, Stroke or transient, ischaemic attack, Percutaneous coronary intervention (PCI), Coronary artery bypass graft (CABG), Peripheral revascularisation procedure.
• Cardiac pacing device e.g. pacemaker and cardiac resynchronization therapy device with atrial or ventricular pacing for > 5% of the time or existing implantable loop recorder.
• Heart failure, New York Heart Association class III (3) or IV (4).
• Left ventricular ejection fraction \< 40% based on imaging (e.g. echocardiography) performed within 6 months prior to or during the screening visit.
• Clinically significant valvular heart disease, including severe aortic stenosis, severe mitral regurgitation and/or severe mitral stenosis, in the opinion of the investigator.
• QTc (Fridericia, QTcF) interval > 450 ms for males and > 470 ms for females at screening.
• eGFR \<60 mL/min /1.73 m² based on creatine and CKD-EPI formula
• Use of antiarrhythmic drug class I and/or III within 7 days or, for amiodarone, within 3 months prior to the screening visit.