Incidence and Predictors of Stroke and Silent Cerebral Embolism Following Very High-Power Short-Duration Atrial Fibrillation Ablation

Abstract Background and aims Cerebral thromboembolism is a dreaded complication of pulmonary vein isolation (PVI) for atrial fibrillation (AF); its surrogate, silent cerebral embolism (SCE) can be detected by diffusion-weighted brain magnetic resonance imaging (bMRI). Initial investigations have raised a concern that very high-power, short-duration (vHPSD; 90W/4 sec) temperature-controlled PVI with the QDOT Micro catheter may be associated with a higher incidence of SCE compared to low-power long-duration ablation (LPLD). We aimed to assess the incidence of procedural complications of vHPSD PVI with an emphasis on cerebral safety. Methods We enrolled 328 consecutive patients undergoing their PVI procedure using vHPSD. A subgroup of 61 consecutive patients underwent diffusion-weighted bMRI within 24 hours of the procedure, and incidence and predictors of SCE were studied. Results The mean procedure time and left atrial dwell time for the overall cohort was 69.6 ± 24.1 min and 46.5 ± 21.5 min, respectively. First-pass isolation was achieved in 82%. No stroke or transient ischemic attack occurred. SCE was identified in 5 out of 61 patients (8.2%). SCE following procedures was significantly associated with lower baseline generator-impedance (105.8 vs 112.6 Ω, p < 0.0001), and with intermittent loss of catheter-tissue contact during ablation (14.1% vs 6.1%, p < 0.0001). Conclusion vHPSD PVI is a safe technique with an excellent acute success rate. SCE incidence in our cohort was below the previously reported range, with no clinically overt cerebral complications. Lower baseline generator-impedance and loss of contact during ablation may contribute to a higher risk of SCEs.