Fehmi Keçe

Chapter 8 168 8.3 Results 8.3.1 Study group During the study period, 76 patients underwent box lesion isolation in addition to PVI. From this group, 6 patients were excluded (EA maps were of insufficient quality to delineate the box lesion surface area (n=4), EA maps were not retrievable (n=1), multi-slice CT-scan was not performed prior to ablation (n=1)). The remaining 70 patients (63 ± 11 years, 53 men) comprised the study population. 8.3.2 Baseline characteristics Persistent AF was diagnosed in 39 (56%) and long-standing persistent AF in 31 (44%) patients. The median duration of AF from first diagnosis to the index ablation procedure was 70 (IQR 40–114) months. The left atrium volume index was 50±22 ml/m² in the recurrence group and 41±13 ml/m² in the non-recurrence group (p=0.050). Thirty-one patients (56%) had undergone prior PVI. This was not significantly different between the recurrence and the non-recurrence group. In the entire population, the median LA surface area was 196 (IQR 172-233) cm², the box lesion surface area 20 ± (IQR 18-24) cm² and the median box surface ratio 0.10 (IQR 0.09 – 0.14). Eighty-four percent of the population was on AAD before the ablation. Fifty-one patients (73%) were using beta-receptor blocking drugs (sotalol: n=27, 38%), 11 (16%) patients were using flecainide, 19 patients (27%) were using amiodarone and 2 patients (3%) were using disopyramide. Four patients (6%) were on rate control with digoxin. Baseline characteristic are provided in table 1. 8.3.3 Procedural Characteristics and complications Table 2 provides the procedural details of the index ablation including additional ablation lesions beyond pulmonary vein and box isolation. The box lesion was successfully isolated in 67 patients (96%), while isolation could not be achieved in 3 patients despite extensive ablation. Thirty-five patients (50% of the cases in which the index procedure was a re- ablation) underwent a redo PVI. Additional ablation (focal AT ablation, CFAE ablation, SVC ablation and Mitral isthmus ablation) during the index procedure was performed in 10 (14%) patients. This was equally distributed between the groups and not significantly different. One patient (1%) had a complication related to the vascular access (femoral pseudo-aneurysm). No other complications occurred during the index procedure. During the repeated procedure a single patient experienced cardiac tamponade that required drainage. No other complications were reported during the repeated procedures.