Catheter Ablation in Atrial Fibrillation Patients With HFpEF (STABLE-SR IV Trial)

To investigate whether RFCA is superior to AADs in AF patients with HFpEF on the basis of optimized anti-heart-failure drug therapy regarding their longterm clinical outcomes.

Background: Atrial Fibrillation (AF) is a common cardiac rhythm disorder and radiofrequency catheter ablation (RFCA) has become the first-line therapy in the symptomatic AF patients. Heart failure is often the sister disease with AF. Recently, RFCA was found to be superior to antiarrhythmic drugs (AADs) in heart failure patients with AF and reduced ejection fraction (HFrEF), regarding all-cause mortality and hospitalization for worsening heart failure (HF). However, in heart failure patients with AF and preserved ejection fraction (HFpEF), it remains unknown whether RFCA is superior to AADs in an even larger population, despite several nonrandomized retrospective studies. Thus, this prospective, multi-center, randomized controlled trial aims to investigate whether RFCA could better improve the clinical outcome of AF patients with HFpEF than longterm AADs use.

Aim of this study: To investigate whether RFCA is superior to AADs in AF patients with HFpEF on the basis of optimized anti-heart-failure drug therapy regarding their longterm clinical outcomes.

Design: The STABLE-SR-IV trial is an international, prospective, multi-center, randomized controlled trial. In this trial, physical examination, echocardiogram, NT-proBNP and other blood test would be assessed before enrollment. Those who conform to all the inclusion criteria and absent from any exclusion criteria would enter into a run-in period of 5 weeks (±7 days). Anticoagulation and anti-heart-failure therapy for HFpEF must be optimized according to the current guideline. After the run-in period, inclusion and exclusion criteria would be reassessed. Thereafter, all the subjects enrolled would be randomized into RFCA arm and Medical Therapy arm with a 1:1 manner, namely 218 subjects in each arm. Each arm will follow the protocol of RFCA and medical therapy, respectively. Follow-up duration of this study is up to 2\~3 years (12 month enrollment).

Eligibility Criteria:
Inclusion Criteria:

* Symptomatic paroxysmal or persistent atrial fibrillation
* CHADS2-VASc score≥ 2
* Conform to the diagnosis of HFpEF

  1. NYHA II-IV level;
  2. Left ventricular ejection fraction (LVEF)≥ 50%;
  3. NT-proBNP≥ 300 pg/mL under sinus rhythm or NT-proBNP≥ 600 pg/mL under atrial fibrillation or flutter;
  4. Evidence of left ventricular diastolic dysfunction/raised left ventricular filling pressure on echocardiogram.
* Sign informed consent

Exclusion Criteria:

* A life expectancy below 2 years due to any non-cardiovascular condition
* Reversible atrial fibrillation, such as hyperthyroidism or hypokalemia-related atrial fibrillation
* Prior atrial fibrillation ablation
* Left atrial size≥ 55 mm
* Heart failure due to any of the following: known genetic hypertrophic cardiomyopathy, infiltrative cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, constrictive pericarditis, active myocarditis, cardiac tamponade, or uncorrected primary valvular disease
* Previous cardiac transplantation, complex congenital heart disease, rheumatic heart disease
* Any contraindication for radiofrequency catheter ablation, antiarrhythmic drugs or anticoagulation
* Acute coronary syndrome, cardiac surgery, angioplasty or cerebrovascular accident within 12 weeks before enrollment
* Severe hepatic and renal dysfunction
* Body mass index\> 50 kg/m2
* Female in period of pregnancy or breast-feeding
* Any conditions that, in the opinion of the investigator, may render the patient unable to complete the study
* Involved in other studies

The inclusion and exclusion criteria would be reassessed after run-in period and the cut-off of NT-proBNP would be set as \>125 pg/ml under sinus rhythm or \>365 pg/ml under AF/atrial flutter (AFL).