Hotspots in the Field of Cardiac Electrophysiology

Identification of Circumferential Pulmonary Vein Isolation Responders Among Patients with Persistent Atrial Fibrillation

Patient segmentation: "early" persistent AF:
Several multicenter clinical trials recently reported that CPVI alone was a reasonably effective strategy for patients with short-lasting persistent AF. In the PRECEPT trial, which enrolled patients with continuous AF that lasted beyond 7 days but less than 1 year, investigators reported a primary effectiveness success rate of 62% and a clinical success rate of 80% at 15 months.

"Health" of atrial substrate:
Atrial fibrosis has been shown to play a critical role in the maintenance of persistent AF. Multiple modalities, including magnetic resonance imaging and high-density mapping of atrial endocardial activation during sinus rhythm, can identify the fibrotic tissue before or during the ablation procedure. In the STABLE-SR trial, 74% of patients with persistent AF and without abnormal left atrial electrograms who underwent CPVI alone maintained freedom from AF at 18 months.

Sequential low dose ibutilide test:
In early 2020, we reported our clinical team's experience with a novel method for identifying CPVI responders, the sequential low-dose ibutilide test (EUROPACE 2020). In a prospective cohort of 180 consecutive patients with persistent AF, intravenous low-dose (0.004 mg/kg) ibutilide was administered 3 days before ablation and after the completion of CPVI. In patients in whom ibutilide did not terminate AF pre-procedurally, but successfully terminated it after CPVI, no further atrial substrate modification was performed. Using this test, approximately one-third (30.6%) of patients with persistent AF were found to be suitable candidates for CPVI alone, with a 2-year success rate of 70.9%.