Prognostic Value of Atrial Fibrillation Inducibility in Patients Without History of Clinical Atrial Fibrillation.

Purpose: During invasive electrophysiological studies (EPS), atrial fibrillation (AF) can be induced in patients without a history of AF. However, the prognostic value is not well evaluated in this population. Our aim was to investigate whether AF inducibility in those patients is associated with future clinical episodes of AF; whether non-inducibility is predictive of freedom from new-onset AF and finally, to examine clinical factors associated with inducibility.

Methods: Medical records from patients undergoing EPS between the years 2011 and 2014 were analysed retrospectively with 62 patients matching our inclusion criteria. Patients were divided into subgroups according to their inducibility status and underwent follow-up. Patients were assessed by a structured telephone interview, data from the further treating physicians and ECG recordings.

Results: AF was inducible in 19 patients ("induction group") and not inducible in the remaining 43 ("control group"). Inducibility was associated with a higher age (p=0.002), lower GFR (p=0.002), higher CHAD2S2-VASc score (p=0.004) and diagnosis of mitral (p=0.014), tricuspid (p=0.017) and pulmonary (p=0.026) valve insufficiency. Three months after EPS, 89.5% of all inducible patients were free of diagnosed AF, in contrast to 100% of those without inducibility (p=0.031). At three years, no significant difference was left (p=0.162).

Conclusion: AF inducibility was found more often in an older population with cardiac comorbidities. While inducibility was associated with an increased rate of diagnosed new-onset clinical AF in the months after testing, non-inducibility seemed to be associated with freedom from AF at least in the short to medium term. However, there was no significant difference in the long term follow-up.