Author + information
- T. Rambhatla,
- E. Levine,
- K. Bhasin,
- N. Skipitaris,
- N. Bernstein and
- S. Mountantonakis
The term blanking period refers the initial 3 months post radiofrequency ablation (RFA) when early recurrence (ER) of atrial tachyarrhythmias can be ascribed to the temporary inflammatory and proarrhythmic changes that occur in the atrium post procedure and do not necessarily predict late recurrence (LR) of atrial arrhythmias. The 2007 expert consensus statement endorses implementing a blanking period for the first 3 months after RFA for atrial fibrillation (AF). A few studies have shown that ER post cryoablation may be predictive of LR but it is not generally accepted. We hypothesized that the use of cryoenergy is far less proarrhythmic than radiofrequency energy such that the initial temporary blanking period of 3 months post procedure does not apply to cryoablation and ER during this period may be a strong predictor of LR.
We retrospectively analyzed outcomes of 115 patients that underwent cryoablation at our institution since 2014 (paroxysmal n=68; persistent n = 47). All patients had circumferential ablation of all four pulmonary veins with isolation demonstrated by entrance and exit block. Patient were followed post procedure with a 12 lead ECG at 1-,3-,6-,12- month intervals, regular phone call assessment for symptom recurrence, and a 24 hour Holter monitor, 3 week event monitor, or internal loop recorder obtained on an individual need basis. ER was defined as any atrial tachyarrhythmia observed lasting > 30 seconds during the initial 3 months post procedure.
After a median follow up period of 16 months: 31/115 patients were found to have ER; of those patients, 19 (63%) developed LR; and 12 patients (38%) developed LR without ER. Individual characteristics (history of CHF, EF < 50%, dilated left atrium, CHADs-VASc score > 2, persistent AF) did not meet statistical significance for predicting LR by Chi-square and regression analysis. The only predictor of LR was the presence of ER as determined by both regression analysis and univariate analysis (p=.030; p = 0.00). Of the 19 patients that had both ER and LR, 5 had repeat procedures, and 4 out of the 5 cases (80%) had reconnection of one or more of the pulmonary veins.
In our study, ER after cryoablation for atrial fibrillation was show to be an independent strong predictor of LR. These data suggest that the presence of ER after cryoablation is not a temporary phenomenon due to the proarrhythmic state post procedure but may in fact be due to a more permanent factor and possibly, reconnection of a pulmonary vein.