Fehmi Keçe

Abstract Background Predicting early reconnection/dormant conduction (ERC) immediately after pulmonary vein isolation (PVI) can avoid a waiting-period with adenosine testing. Objective To identify procedural and biophysical parameters predicting ERC. Methods Consecutive AF patients undergoing a first cryoballoon ablation (Arctic Front Advance) between 2014 and 2017were included. ERCwas defined as manifest or dormant pulmonary vein (PV) reconnection with adenosine 30 min after PVI. Time-to-isolation (TTI), balloon temperatures (BT) and thawing times were evaluated as potential predictors for ERC. Based on a multivariable model, cut-off-values were defined and a formula was constructed to be used in clinical practice. Results A total of 136 patients (60±9 years, 108 males, 95% paroxysmal AF) were included. ERC was found in 40 (29%) patients (ERC group) and in 53/575 (9%) veins. Procedural and total ablation time and the number of unsuccessful freezes were significantly longer/higher in the ERC group compared to the non-ERC group (150±40 vs. 125±34min; 24±5 vs. 17±4min and 38% vs. 24% respectively (p=0.028). Multivariable analysis showed that a higher nadir balloon temperature (HR 1.17[1.09–1.23, p<0.001), a higher number of unsuccessful freezes (HR 1.69[1.15-2.49], p=0.008) and a longer TTI (HR 1.02[1.01–1.03], p<0.001) were independently associated with ERC leading to the following formula: 0.02*TTI + 0.5*number of unsuccessful freezes + 0.2*nadir BT with a cut-off value of ≤-6.7 to refrain from a waiting-period with adenosine testing. Conclusion Three easily available parameters were associated with ERC. Using these parameters during ablation can help to avoid a 30-min waiting period and adenosine testing.