The objective of CABA-HFPEF is to test whether catheter ablation (CA) for atrial fibrillation (AF) can prevent adverse cardiovascular outcomes in patients with heart failure with preserved (HFpEF) or mildly reduced ejection fraction (HFmrEF).

HFpEF accounts for approximately half of HF diagnoses and HFmrEF adds another 20%. HFpEF patients are predisposed to AF with a prevalence of AF up to 65%. Conversely, the presence of AF increases the likelihood of subsequent HFpEF by up to 4-fold across diverse populations. The vulnerable hemodynamic state in HFpEF patients due to LV diastolic dysfunction can be significantly affected by AF with loss of atrial contraction and reduction in cardiac output. Thus, presence of AF in HFpEF patients leads to a significant increase in hospitalization, mortality and stroke.

Restoring and maintaining sinus rhythm in patients with HFpEF and AF could reduce cardiovascular (CV) outcomes. Catheter ablation (CA), particularly when performed as initial rhythm control, results in less recurrences of AF than anti arrhythmic drug therapy. In patients with HF with reduced ejection fraction (HFrEF) and AF, CA showed a significant reduction in all-cause mortality and worsening HF admissions compared to medical therapy.

No randomized clinical trial has tested or is currently testing the effects of CA on CV outcomes in patients with HFmrEF or HFpEF and AF. To address this, CABA-HFPEF tests whether CA can improve CV outcomes compared to usual care in these patients. The results of CABA-HFPEF will critically extend the current evidence on ablation-based rhythm control to this large population in dire need for treatments that improve clinical outcomes.

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