Non-inducibility of AF post electrophysiologically based PV isolation predicts freedom from AF

Background: Recently, various anatomic and electrophysiologic approaches to pulmonary vein (PV) isolation have shown variable efficacy in the management of patients with atrial fibrillation (AF). Whether inducibility of AF after achieving prespecified electrophysiologic endpoints of PV isolation is a useful predictor of AF recurrence is unknown. Methods: This study included 105 consecutive patients who underwent PV isolation for the treatment of symptomatic AF and were followed for a mean of 327 days. Patients were 54 /11 years of age, 72% were males, 46% had hypertension, 15% had valvular heart disease (VHD), 10% had cardiomyopathy, 40% had persistent or permanent AF, and 60% were on antiarrhythmic agents. Complete isolation of all 4 PVs was confirmed by demonstration of bi-directional block across the ablation lines: a) loss of PV potentials and b) failure to capture the LA by pacing 10-14 bipolar pairs of electrodes of the Lasso catheter placed at the entrance of the PV at 10 mA. Induction of AF by burst pacing from the HRA and/or CS on/off Isoproterenol (1-10mcg/min) was attempted after PV isolation. AF was inducible in 61% of patients and was sustained ( 1 minute) in 42% of patients. Clinical follow up included assessment of asymptomatic or symptomatic AF by 2 week event recorder and 24 hour holter monitor at 1, 3, 6, and 12 months. Predictors of freedom from AF recurrence at 6 and 12 months were analyzed using multivariable logistic regression. Results: Freedom from asymptomatic or symptomatic AF was present in 72% of patients at 6 months and 67% of patients at 12 months. Symptomatic improvement (90% reduction in symptoms) was present in 88% and 87% of patients at 6 and 12 months. In multivariable analysis, freedom from AF at 6 months was predicted by non-inducibility post PV isolation (OR: 5.48, p: 0.05) and absence of VHD (OR: 6.44, p: 0.03). Freedom from AF at 12 months was predicted by non-inducibility post PV isolation (OR: 39.32, p: 0.01), absence of VHD (OR: 8.28, p: 0.04), and absence of hypertension (OR: 10.73, p: 0.03). Conclusion: After complete PV isolation for AF, non-inducibility of AF in the electrophysiology laboratory predicts maintenance of sinus rhythm.