Impact of anatomical features of the left atrial appendage on outcomes after cryoablation for atrial fibrillation

Aims: Pulmonary vein isolation (PVI)using cryoballoon has been accepted as a safe and effective method for treatment of atrial fibrillation (AF). Despite advances in catheter-based technologies, some patients still experience AF recurrence. In this study, we aimed to compare left atrial appendage (LAA)morphology in AF patients and subjects with sinus rhythm and also investigate the association between LAA morphology and success of PVI using cryoballoon in subjects with AF. Methods: In this prospective study, 359 AF patients who underwent pre-ablation computed tomographic angiography (CTA)scan between January 2013–March 2016 were included as the patient group. 100 age and gender-matched subjects in sinus rhythm who had no AF episodes in 24-h Holter monitoring that underwent CTA were included as the control group. Results: Non-chicken wing LAA morphology was more common in AF patients (p < 0.001). LAA was significantly deeper (p < 0.001)and short-axis diameter of LAA orifice and LAA orifice area were significantly larger (p < 0.001)in AF patients. Low take-off type morphology of LAA was more common in controls compared to AF patients (p = 0.006). At a median follow-up of 37 months, only longitudinal-axis left atrial diameter on CT (p = 0.003)and cauliflower-type LAA morphology (p = 0.004)were independent predictors of AF recurrence. Conclusion: This is the first study in the literature that investigates the relationship between anatomical variations of LAA and AF recurrence following cryoablation. Our findings demonstrate that cauliflower-type LAA morphology is associated with two-fold increased risk of AF recurrence.