CAtheter-Based Ablation of Atrial Fibrillation Compared to Conventional Treatment in Patients With Heart Failure With Preserved Ejection Fraction

INCLUSION CRITERIA: 1. Age ≥18 years 2. Signed written informed consent 3. Clinical evidence of symptomatic heart failure (NYHA Class II-III) 4. Paroxysmal or persistent atrial fibrillation (less than 24 months after first diagnosis, documented at least on one 12-lead ECG) 5. Left ventricular ejection fraction (LVEF) 40-49% OR LVEF ≥ 50% with at least one of the following HFpEF echocardiography findings (any local measurement made during the screening epoch): A. LA enlargement defined by at least 1 of the following: LA width (diameter) ≥3.8 cm or LA length ≥5.0 cm or LA area ≥20 cm2 or LA volume ≥55 ml or LA volume index ≥29 ml/m2 B. Left ventricular hypertrophy (septal thickness or posterior wall thickness ≥1.1 cm or relative wall thickness \>0.42) 6. Patients with at least 1 of the following: A. HF hospitalization (defined as HF listed as the major reason for hospitalization) within 6 months prior to screening visit and NT-proBNP \>200 pg/ml for patients in sinus rhythm (SR) or \>600 pg/ml for patients in AF at the time of blood sampling B. NT-proBNP \>300 pg/ml for patients in SR or \>900 pg/ml for patients in AF on screening ECG EXCLUSION CRITERIA: 1. Patient is unable or unwilling to provide infomed consent 2. Patient is not suitable for rhythm control of AF 3. Previous left atrial CA or surgical therapy of AF 4. Acutely decompensated HF, NYHA IV (patients can be enrolled after stabilization) 5. Valvular heart disease needing interventional or surgical treatment within 3 months 6. Heart surgery planned within 3 months 7. Prior heart transplant or listed for heart transplant or cardiac assist device implantation 8. Untreated hypothyroidism or hyperthyroidism (after successful treatment of thyroid dysfunction, patients may be enrolled) 9. Patient has absolute contra-indication to oral anticoagulation 10. Any disease that limits life expectancy to less than 1 year 11. Active systemic infection (after successful treatment of infection, patients may be enrolled) 12. Women currently pregnant or breastfeeding or women of childbearing potential without highly effective contraception (PEARL-Index \< 1%) 13. Patient is included in another clinical trial 14. Inability to comply with the study procedures