Rationale and design of the NEO-NORMAL-AF study examination of the usefulness of implantable loop recorder for arrhythmia detection including atrial fibrillation in heart failure with non-reduced ejection fraction cases: a pilot study

INTRODUCTION: The incidence of arrhythmia in heart failure with non-reduced ejection fraction (HFnon-rEF) in patients who have a history of hospitalisation is unclear. The aim of this study is to investigate the usefulness of an implantable loop recorder (ILR) for arrhythmia detection including atrial fibrillation (AF) in HFnon-rEF patients after discharge. METHODS AND ANALYSIS: This is a multicentre single arm study to evaluate the usefulness of ILR for detecting arrhythmia. The eligible patients are HFnon-rEF patients (left ventricular ejection fraction ≥40%) aged ≥20 years with a history of hospitalisation. The ILR will be implanted for qualified patients, and ECGs will be monitored and recorded for 1 year to check for arrhythmias. The primary endpoint is new-onset 6 min or more persistent AF detected by ILR. Secondary endpoints are 30 s or more persistent supraventricular tachycardia and ventricular tachycardia, 3 s or more persistent pause, bradycardia with 40 beats per minutes or lower heart rate, AF burden, all-cause death, cardiovascular death, hospital readmission due to exacerbation of HF, acute coronary syndrome, ischaemic or haemorrhagic stroke, non-pharmacological therapy such as pacemaker implantation and ablation. CONCLUSIONS: This study is expected to provide valuable findings regarding arrhythmia in HFnon-rEF patients, and elucidate a potential new therapeutic approach for HFnon-rEF. TRIAL REGISTRATION NUMBER: This trial has been registered in the Japan Registry of Clinical Trials (jRCT) (Trial Registration: jRCTs052210060).