Supported by the recent results of the Catheter Ablation vs Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) and Early Treatment of Atrial Fibrillation for Stroke Prevention (EAST-AFNET4) trials, catheter ablation is a preferable contemporary linchpin in the treatment of symptomatic atrial fibrillation (AF). 1 Packer D.L. Mark D.B. Robb R.A. et al. Effect of Catheter Ablation vs Antiarrhythmic Drug Therapy on Mortality, Stroke, Bleeding, and Cardiac Arrest Among Patients With Atrial Fibrillation: The CABANA Randomized Clinical Trial.

JAMA. 2019; 321: 1261-1274

,2 Kirchhof P. Camm A.J. Goette A. et al. Early Rhythm-Control Therapy in Patients with Atrial Fibrillation.

N Engl J Med. 2020; 383: 1305-1316

Traditionally, the efficacy with ablation has been broadly defined by either objective arrhythmic recurrence such as atrial arrhythmias of over 30 seconds in duration or subjective recurrence of symptomatic arrhythmias. Moreover, clinical trials focused on pulmonary vein isolation ablation technique tend to adopt a three-month “blanking period” under the guidance of the Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation. 3 Calkins H. Hindricks G. Cappato R. et al. HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: Executive summary.

Heart Rhythm. 2017; 14 (2017): e445-e494

This window is designed to “blindfold” investigators of catheter ablation to potentially clinically irrelevant arrhythmias related to myocardial inflammation, autonomic disturbances, or left atrial hemodynamic strain, all of which should theoretically resolve in the weeks-to-months after the index procedure. Similarly, the clinician commonly chalks up early recurrences of atrial tachyarrhythmias (ERAT, defined by atrial fibrillation/AF, atrial flutter/AFL, or atrial tachycardia/AT) in the three-month post ablation window as secondary to these reversible etiologies rather than suggestive of procedural failure. Unfortunately, this blindfold may be too opaque and in place for too long. Post-hoc analysis data from several clinical studies have demonstrated that post-blanking freedom from atrial arrhythmias drops significantly for those who experience ERAT later within the 3-month blanking window. In fact, a recent meta-analysis published identified across multiple studies that those participants whom did not experience AF during the blanking period had a much lower prevalence of AF after the blanking period (pooled negative predictive value of 89.7%). 4 Calkins H. Gache L. Frame D. et al. Predictive value of atrial fibrillation during the postradiofrequency ablation blanking period.

Heart Rhythm. 2021; 18: 366-373

The included studies were limited by lack of randomization and/or intermittent remote monitoring during study follow up.