Flecainide Safety in Patients With Coronary Artery Disease and Atrial Fibrillation

Inclusion criteria

• Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures
• At least 18 years of age at the time of signing the Informed Consent Form
• Non-permanent atrial fibrillation or ectopic atrial tachycardia with rhythm control strategy, documented on any modality in the 1 year preceding the consent date
• Stable coronary artery disease without argument, defined as:
• Prior percutaneous coronary intervention; OR
• Prior revascularised ACS or coronary artery bypass surgery \> 3 months at enrolment; OR
• Invasive coronary angiography demonstrating coronary atherosclerosis, defined as ≥50% diameter stenosis in at least one major epicardial coronary artery; OR
• Coronary CT scan showing coronary stenosis CAD-RADS stage ≥ 3 on, including CAD-RADS stages 4 and 5 in the absence of ischemia on exercise testing, myocardial perfusion imaging (MIBI), stress cardiac MRI, or fractional flow reserve.
• LVEF ≥ 45% documented on any imaging modality\*

Exclusion criteria

• LVEF \< 45%
• NYHA class III or IV congestive heart failure
• Active treatment with amiodarone
• History of intolerance of flecainide or both sotalol and amiodarone
• Clinically significant uncorrected hypokalemia or hypomagnesemia before initiation of trial treatment.
• Evidence or history of thyroid dysfunction contraindicating amiodarone use, where amiodarone would be prescribed as standard of care treatment.
• Hypersensitivity to the active substances or any excipients.
• Unstable angina or inducible ischemia on exercise stress testing, myocardial perfusion imaging, stress cardiac MRI, or fractional flow reserve performed for clinical indications
• Baseline QRS duration ≥ 120 ms, unless a functioning pacemaker is present
• Baseline corrected QT interval (Fridericia) ≥ 500 ms 11 Pre-existing advanced AV block (second-, or third-degree)
• \. Pre-existing sick sinus syndrome or sinus bradycardia \<50 bpm 13. Known channelopathy 14. Contra-indication to AV-slowing agents, including beta-blockers, diltiazem or verapamil 15. Atrial fibrillation due to reversible cause 16. Active intracardiac thrombus 17. Acute coronary syndrome during the 3-month period preceding the consent date 18. Cardiac surgery, including coronary artery bypass surgery, during the 3-month period preceding the consent date or planned at a future date at the time of consent 19. Moderate or severe congenital heart disease as per 2020 ESC guidelines 20. Hypertrophic cardiomyopathy (septal or posterior wall thickness \>1.5 cm) 21. Significant chronic kidney disease (eGFR \<40 mL/min) 22. Life expectancy less than 1 year 23. Female who is pregnant, breast-feeding or intends to become pregnant or is of child-bearing potential and not using an adequate, highly effective contraceptive 24. Inability to provide written informed consent, including decision-making incapacity due to cognitive impairment or other medical or psychiatric conditions that preclude adequate understanding of the study and its procedures.
• \. Participation in an interventional Trial with an investigational medicinal product (IMP) or device