Ablation of visual spatiotemporal dispersion added to pulmonary vein isolation in persistent atrial fibrillation

Abstract Background The best approach for persistent atrial fibrillation (AF) ablation is unknown. Purpose To test a tailored ablation strategy for persistent AF which includes pulmonary vein isolation (PVI) plus ablation of visually detected areas with spatiotemporal dispersion (STD) (i.e. all the cycle length comprised within the mapping catheter). Methods From May 2017, 100 consecutive patients with persistent AF and ongoing AF at the beginning of the procedure were included. STD was visually identified using conventional high-density mapping catheters (PentaRay NAV, IntellaMap Orion or Advisor HD Grid), without the use of dedicated software. Only areas with STD + fractionated electrograms were targeted with ablation, prioritizing areas with continuous (or quasi-continuous) fractionation on single bipoles, which were ablated first if detected (Figure 1A, dashed line showing quasi-continuous fractionation on bipoles A3-B3, A2-A3 and A3-A4, Advisor HD Grid catheter; ORB: 24-pole ORBITER Woven catheter; paper speed 200 mm/s). Ablation included radiofrequency PVI + focal or linear ablation targeting sites with STD; patients without STD received only PVI. Ablation success was defined as conversion to sinus rhythm or atrial flutter during ablation. The right atrium was only treated if left atrial ablation was no successful and the AF cycle length was shorter at the right atrial appendage than at the left atrial appendage (after left atrial ablation). Follow-up included visits with 24h Holter ECG at 3-6-12 months. The primary endpoint was one-year survival free from atrial arrhythmias lasting >30 seconds. We compared the results of this tailored approach with all consecutive patients with persistent AF treated with a PVI-only strategy during the same period. Results 385 Patients received ablation: 100 with the tailored approach and 285 with only PVI (87% cryoablation, 13% radiofrequency). Basal characteristics were similar (Figure 2), but more patients with prior ablation procedures were included in the tailored-approach group. In this group, 96 patients (96%) presented 320 detectable sites with STD + fractionation (3 [2-4] sites per patient); 58 (18%) of these sites showed continuous fractionation. The right atrium was treated in 47 patients (47%). Ablation success was achieved in 31 patients (31%; conversion to sinus rhythm, n=11; conversion to atrial flutter, n=20). Excluding a 3-month blanking period, the tailored approach, compared to only PVI, improved one-year freedom from atrial arrhythmias (74% Vs 53%, p<0,001) (Figure 1B), at the cost of a longer median procedural time (199 [153–254] Vs 102 [80–138] min, p<0,001), with similar fluoroscopy use (25 [8–46] Vs 26 [17–37] min, p=0,356). Long-term progression to permanent AF was also reduced (13% Vs 30%, p=0,001) (Figure 1C). Conclusion Ablation of visually detected STD, added to PVI, improved one-year survival free from atrial arrhythmias.Figure 1.  Figure 2.Basal characteristics.