A Mechanistic Exploratory Study of AF-induced Cardiac Dysfunction and Symptoms

Inclusion criteria

• Referred for first AFCA procedure by their responsible physician.
• Persistent AF captured on ECG but not in continuous AF for more than 3 years. (Persistent AF will be defined as any continuous episode lasting longer than 7 days or requiring intervention to restore sinus rhythm after this time.)
• Participants must have either:

• Left Ventricular Ejection Fraction (LVEF) < 50% by echocardiogram during routine screening or within 12 months prior to enrolment day. The echo must have been performed >3 weeks after optimisation of HF and rate control therapies, otherwise repeat imaging will be performed after this has been achieved

With:

o NYHA functional status II-III at the enrolment visit.

Or:

o Left Ventricular Ejection Fraction (LVEF) >50% by echocardiogram during routine screening or within 12 months prior to enrolment day.

With:

o modified European Heart Rhythm Association 2a-4.

Exclusion criteria

• Previous left atrial ablation procedure or surgery.
• Contraindication to chronic anticoagulation therapy or heparin
• Unable or unwilling to consent to investigation and follow-up requirements or inability to comply with planned study procedures.
• LA anteroposterior diameter ≥ 5.5 cm or indexed LA volume ≥ 50mL/m2 on echo.
• Recent (last 6 months) event that may impact LV function- myocardial infarction, coronary revascularization, pacemaker or cardiac resynchronization therapy.
• AF suspected to be due to a reversible cause (e.g. hyperthyroidism, recent surgery)
• Acute coronary syndrome within 4 weeks as defined by ECG ST segment depression or prominent T-wave inversion and/or positive biomarkers of necrosis (e.g. troponin) in the absence of ST-segment elevation and in an appropriate clinical setting (chest discomfort or angina equivalent).
• Cardiac surgery, angioplasty, or cerebrovascular accident within 4 weeks prior to enrolment.
• Life expectancy less than 1 year.
• Chronic kidney disease stage 4 or 5.
• Any of the below cardiac diagnoses:

• Hypertrophic obstructive cardiomyopathy
• Severe valvular disease
• Restrictive or constrictive cardiomyopathy, including known amyloidosis, sarcoidosis,
• haemochromatosis
• Complex congenital heart disease
• Constrictive pericarditis
• Severe pulmonary hypertension (RVSP > 60 mmHg),
• Non-cardiac pulmonary oedema
• Active myocarditis