Fehmi Keçe

Optimizing Ablation Duration using Dormant Conduction 133 6 Table 3. Incidence of reconnection/ DC per patient and per vein. 90s (n=25/100) 120s (n=25/99) 150s (n=25/100) P value Reconnection 8 (32) 3 (12) 0 0.005 Reconnection (per vein) 9 (9) 3 (3) 0 (0) 0.003 DC 9 (36) 3 (12) 4 (16) 0.085 DC (per vein) 15 (15) 3 (3) 4 (4) 0.002 Reconnection/DC 16 (64) 6 (24) 4 (16) 0.001 Reconnection/DC (per vein) 22 (22) 6 (6) 4 (4) 0.001 Values are reported as the mean±standard deviation or n (%). DC indicates dormant conduction. Table 4: Univariate and multivariate regression analyses of the predictors of reconnection/DC in the pulmonary veins. Variables Univariate Multivariate Hazard ratio (95% confidence interval) P value Hazard ratio (95% confidence interval) P value Cryoapplication time (s) 0.991 [0.982-0.999] 0.035 0.975 [0.962-0.988] <0.001 Time-to-isolation (s) 1.012 [0.999-0.1025] 0.079 1.027 [1.009-1.046] 0.004 Warming time (s) 0.947 [0.955-0.994] 0.011 0.500 Nadir balloon temperature (˚C) 1.139 [1.070-1.212] <0 .001 1.163 [1.068-1.266 ] 0.001 Number of unsuccessful ablations 1.393 [0.998-1.944] 0.052 1.722 [1.113-2.664] 0.015 6.3.5 Outcome During a follow up of 1-year, the single-procedure success rate off AAD was 60% in the total group (68% on/off AAD). Median time to recurrence was 7 [5-13] months. The single-procedure success rates off AAD in the 90, 120 and 150s groups were respectively 52, 56 and 72% (p=0.27) after 1 year. Total AF-free single-procedure success on/off AAD was respectively 56, 72 and 77% (p=0.384). During follow-up a repeated procedure was performed in 15 patients (20%). During the repeated procedure, PV reconnections were observed in 14 patients (19%) and additional ablations were performed in 9 (12%) patients (4 superior vena cava, 3 mitral isthmus line, 1 posterior left atrial box lesion, 1 posterior line and 1 left atrium anterior wall ablation). During these repeated procedures 53% of the left superior veins were reconnected, 53% of the left inferior veins, 40% of the right superior veins and 20% of the right inferior veins (p=0.217). The rate of repeated procedures significantly decreased with increasing additional ablation time: 36% in the 90s group, 20% in the 120s group and 4% in the 150s group (p=0.041).