Catheter ablation of atrial fibrillation: time to look beyond iterative pulmonary vein isolation only and “one-size-fits-all” strategies

Pulmonary vein isolation (PVI) is considered the ‘cornerstone’ of catheter ablation of atrial fibrillation (AF). Despite this, it is now acknowledged that there is a ceiling to the efficacy of PVI only strategies due to non-PV substrate and/or triggers. However, identifying patients who may benefit from PVI alone remains a major challenge. Selected clinical characteristics are helpful but poorly specific. Individualized assessment of non-PV substrate, including voltage mapping and functional endpoints such as AF non-inducibility, have shown better accuracy. Adjunctive ablation strategies that seek to eliminate non-PV AF mechanisms, either in an individualized fashion or targeting general mechanisms with anatomical approaches, have historically been limited by technical limitations or poor reproducibility. Further technological advances have improved reliability and recent multicenter randomized trials showed the superiority of two distinct strategies over PVI alone: the anatomical approach combining PVI with vein of Marshall ethanol infusion and transection of three anatomical isthmuses (Marshall Plan), and the tailored approach combining PVI with AI-assisted ablation of spatiotemporal electrogram dispersion. Data is scarcer for repeat ablation of recurrent AF. Redo PVI proved superior to medical management, but there is no established adjunctive ablation strategy for repeat ablation. A reasonable approach involves redoing PVI in case of reconnection, completing previous lesion sets (e.g. gaps in linear lesions), and, in selected patients, pursuing adjunctive ablation strategies that proved beneficial for de novo ablation. The advent of pulsed field ablation and wide-spread availability of rapid high-density mapping will likely facilitate an era of re-evaluation of substrate modification strategies.