RESULTS.
Patients. The two groups of patients(with PAF and PersAF) were homogeneous in terms of age, sex, diabetes, coronary artery disease and body mass index (Tab. 1). Hypertension and LA dilation were more frequent in PsAF than in PAF patients (p=0.04 and p<0.001 respectively), while left ventricular ejection fraction >50% and normal LA were more frequent in PAF than in PsAF (p=0.01and p<0.001 respectively - Tab. 1).
Procedural data. Complete PVI with bidirectional conduction block was achieved in all 70 patients by means of pacing maneuvers and HD mapping. The procedural time, including HD mapping, was 126 ± 13 minutes in patients who underwent PVI and mapping by CMC LassoNav or MC (p>0.5), and 119 ± 15 minutes in patients in whom CMC AFocus or OC (p>0.5) was used for mapping. The numbers of voltage points acquired were:1,583±431 with CMC AFocus versus 1,501±317 with LassoNav (p>0.5), and 18,626±4,617 with OC versus 2,037±343 with MC (p<0.0001). In our intra-patient comparison of “along” and “across” bipolar maps, we observed both an increase in LV on passing from the 0.05-0.5 mV range to the 0.5-1 mV range and a shift from the set of different colors to gray (transformation of areas characterized by potential patchy fibrosis into scar) in all 11 patients re-evaluated (100%). Comparison of the 22 omnipolar maps (HD-wave maps) also showed an increase in LV in 100% of patients re-evaluated when the 0.5-1.0 mV range was used, but with a shift from purple to the set of different colors (transformation of areas characterized by normal tissue into potential patchy fibrosis). An example of these comparisons is shown in Fig. 3. HD-wave maps in the 0.5-1.0 mV range were therefore used to analyze the voltage value of 1 point of purple color and 1 point of gray or red color close to and inside the set of different colors. The lower voltage cut-off was a mean value of 0.3±0.05 mV, while the higher voltage cut-off was 0.6±0.03 mV (Fig.4). Onthe basis of these results, we defined the optimal voltage range, which was between 0.3and 0.6 mV, and used this value in our further evaluations. After ablation, mild pericardial effusion occurred in 3 of the 70 patients (4.3%); this only required observation for two additional days of hospitalization and echocardiographic evaluation.
Comparison of patients with and without non-PV LV. Table 2 shows our comparison of patients with and without non-PV LV. LVs were found in 38 of 70 patients (54.3%). From the comparison between HD maps, no statistically significant differences emerged, in terms of the number of patients with LV areas, between CMC AFocus and CMC LassoNav (p=0.725), or between OC and MC (p=0.332). No LV were found in 32 of 70 patients (45.7%), nor did any statistically significant differences emerge, in terms of patients without LV areas, between CMC AFocus and CMC LassoNav (p=0.725), or between OC and MC (p=0.332).
Comparison of marked LV areas: CMC AFocus versus LassoNav and OC versus MC. Asno LVs were found in the LA roof in any patient, this anatomical area was excluded from the analysis. Fig. 5 reports the mean values of LV percentage in each LA anatomical area analyzed (MLV). No significant differences were found between the MLV areas identified by the 2 CMC, while a lower percentage of LV was identified by OC than by MC in all the anatomical areas analyzed, except for the LW (Fig. 5).
Clinical outcomes. After the blanking period, 18/70 (25.7%) of all patients had recurrences, without significant differences between patients with HD maps acquired by means of the two CMC (AFocus versus LassoNav, p=0.9) nor between OC and MC (p=0.8). Fig. 6 shows the Kaplan-Meier curves of time to the first AF recurrence; no significant differences were observed in terms of freedom from AF episodes during follow-up in all patients (AFocus versus LassoNav, p=0.6 and OC versus MC, p=0.8).