Early recurrence of atrial tachyarrhythmia during the 90-day blanking period after cryoballoon ablation in patients with atrial fibrillation: The characteristics and predictive value of early recurrence on long-term outcomes

Abstract

Objective: To investigate the characteristics of early recurrence (ER) of atrial tachyarrhythmia (ATA) defined as atrial fibrillation (AF), atrial tachycardia (AT), or atrial flutter (AFL) during a 90-day blanking period after pulmonary vein isolation by cryoablation (PVI-C) in patients with symptomatic drug refractory AF. Specifically, to determine if ER of ATA during the blanking period can predict late recurrence (LR) during a 12-month follow-up period.

Method: A total of 51 patients with symptomatic AF (who received PVI-C) were monitored by trans-telephonic wireless electrocardiogram (TWECG) event recording during the landmark 90-day blanking period following an index ablation. Recurrent ATA was defined as any AF, AT, or AFL lasting longer than 30 s (as recorded by 12‑lead ECG, 24-hour Holter monitor, or TWECG). For data analysis, patients were grouped into ER and non-ER cohorts during the 90-day blanking period and then cohorted into LR or non-LR groups during the 12-month follow-up.

Results: During the 90-day blanking period, 23 patients had an ER event of ATA while 28 patients had a non-ER experience. Also, during the 12-month follow-up period, 15 patients had a LR event while 36 patients were free from ATA (and placed in the non-LR cohort). Overall, the average success rate of cryoablation for AF was 70.6% at the 12-month follow-up period. Compared to the non-LR group, patients with LR showed a higher average percentage of diabetes mellitic (33.3% vs. 5.56%; P = 0.008) and had a larger mean left atrium diameter (41.2 ± 4.3 mm vs. 36.5 ± 4.2 mm; P = 0.0006). During evaluation of the 90-day blanking period, the LR group had more frequent attacks of ATA than compared to the non-LR group (27.7% vs. 2.4%; P < 0.001). Only two patients (7.1%) without ER in the blanking period (non-ER cohort) had relapsed into a LR of ATA during the one-year period. After multi-logistic regression analysis, ER could individually predict the risk of LR (RR = 58.8; P = 0.001).

Conclusion: In our study, ER of ATA was a common phenomenon during the 90-day blanking period after PVI-C for AF, and it mostly occurred in the first month following the index ablation across all patients. ER is not equal to the LR of ATA; however, patients with an ER event had a higher risk of a LR during the 12-month follow-up period.

Keywords: Atrial fibrillation; Blanking period; Cryoablation; Cryoballoon; Early recurrence.