Arrhythmia Termination During Radiofrequency Delivery Improves Outcomes after Catheter Ablation for Persistent and Long Standing Persistent Atrial Fibrillation

Abstract

Background: Achieving long-term successful outcomes with catheter ablation (CA) of persistent atrial fibrillation (PsAF) remains a challenge. Multiple attempts to determine effective ablation strategies besides the pulmonary veins (PV) were made but, so far, there is no agreed standard approach and no clear consensus as to which is the best one. Among the most frequently used techniques was ablation of complex atrial fractionated electrograms (CFAE) but studies showed contradictory results. The optimal procedural endpoint also needs further refinement. Objectives: We sought to evaluate outcomes in regard to patient characteristics and procedural termination. We also aimed to assess whether continuation of antiarrythmic therapy in the blanking period (1 to 3 months after the procedure) influences long term results. Methods: We enrolled consecutive patients with persistent and long-standing PsAF (LS-PsAF) who underwent one or more radiofrequency catheter ablations (RF CA) - pulmonary vein antral isolation (PVAI), followed by CFAE or resultant atrial tachycardia/flutter elimination, were retrospectively analyzed. Procedural objective was tachyarrhythmia (AF or resultant atrial flutters/tachycardias) termination (TT) to sinus rhythm (SR) during RF delivery. If after extensive substrate based or activation guided ablation sinus rhythm was not restored, conversion was performed with antiarrhythmic drugs (AAD), overdrive pacing or electrical shock. Screening for arrhythmia recurrence was performed via clinical interview and 48 hours Holter monitoring at 1,3 and 6 months and then every 6 months. Results: The cohort included 94 patients (age 54.5±11.4, 67 (71%) males, CHADSVASc 2.3±2, 11 (12%) LS-PsAF) Acute restoration of sinus rhythm (SR) was achieved in 93.4% of the cases, 43% by ablation of CFAE or resultant atrial tachycardia/fl utter(AT/AFL), 36.2% by electric cardioversion, 7.4% by chemical conversion, 3.1 % overdrive pacing, 3.7 % spontaneuous / mechanical. The long term success rate after a mean of 1.7±0.8 procedures was 59% at a mean follow-up period of 80±28 months. Freedom from AF was significantly higher when arrhythmia termination was obtained during RF delivery (p – 0.003). Short-term use of AAD in the blanking period did not lead to improved long term outcomes. Conclusions: In patients with PsAF and LS-PsAF restoration of sinus rhythm during RF delivery for pulmonary vein isolation, ablation of CFAE or resultant atrial tachyarrhythmia predicts long term procedural success. Further research to determine the best strategy to achieve this outcome is necessary.

Keywords

• arrhythmia
• radiofrequency
• catheter ablation
• atrial fibrilation