Abstract Body (Do not enter title and authors here): Background: Pulmonary vein isolation (PVI), the gold-standard treatment for atrial fibrillation (AF), is often insufficient for persistent AF (PsAF). In this context, pulsed field ablation (PFA) has emerged as a key modality for PVI. However, PFA have been reported to create wider PVI lesions, dramatically narrowing left atrial (LA) posterior wall. Although the LA roofline lesion has been empirically added to prevent roof-dependent macroreentrant atrial tachycardia (RMAT) when the right and left PVI lines are in close proximity, it is intuitive that PFA lesions would increase the likelihood of RMAT occurrence. Recently, digital twins (DTs) have been utilized to test arrhythmia inducibility and assess the patient-specific substrates.
Hypothesis: DTs can be utilized to preoperatively identify the situation under which RMATs would occur after PVI, thereby avoiding unnecessary ablation or redo procedure for RMATs post-PVI.
Methods: From LGE-MRI scans of 51 consecutive PsAF patients, personalized biatrial DTs incorporating fibrosis distribution were generated. First, following virtual PVI with typical configuration of line lesions (7.5 mm), RMAT inducibility was tested via burst pacing from 12 sites at LA: roof, anterior wall (upper, middle and lower), posterior wall (upper, middle and lower), inferior wall, lateral wall, LA appendage ostium, and septum (upper and lower). Next, if no RMAT was induced, PVI was repeated, but this time wider lesions were executed by reducing the roof distance by 5 mm (2.5 mm to the right from the left PVI line and 2.5 mm to the left from the right PVI line). Then, the same inducibility test was performed. This process was repeated until the roof gap distance was reduced to below 5 mm. Finally, the fibrotic and electroanatomic features of DTs where RMAT was induced, as well as the occurrence timing, were investigated.
Results: Among 40 DTs generated from qualified images, RMATs were induced only in 20 DTs (cycle length: 366±65 ms): 9 after typical PVI and 11 after wider PVI. In 34 DTs, PsAF arrhythmogenicity was also induced after PVI. The LA fibrosis burden is the only determinant for RMAT occurrence (p=0.008). Furthermore, LA fibrosis burden—rather than initial roof distance—was an independent predictor of earlier RMAT induction (p=0.006).
Conclusions: LA fibrosis burden significantly contributed to RMAT occurrence post-PVI. DTs enable noninvasive prediction of the need for roofline ablation, diminishing unnecessary or redo ablation.