Long term outcome (Table 4)
Success following cryoablation was in seen in 43% (30% off anti-arrhythmic medications), increasing to 59% (40% off anti-arrhythmic medications) with a subsequent redo procedure with RF ablation, at final follow up. There was no significant difference in success following cryoablation in those patients with paroxysmal AF (52%) compared with persistent AF (41%, p=0.36) at long term follow up (Figure 1). Twelve month overall freedom from atrial arrhythmia overall was 70% after a single procedure. Table 4 outlines procedure success at 1 year and final follow up stratified by AF phenotype.
A cox regression analysis was performed incorporating multiple variables including age, gender, hypertension, AF phenotype, heart failure aetiology, NYHA class, LVEF, LA diameter, and CHADS2VASc score to determine their impact upon long term single and multiple procedure success. There were no significant predictors of single or multi-procedure success (Table 1 supplementary tables).