Direct synchronized cardioversion not independently associated with infarcts on cerebral magnetic resonance imaging and clinical outcomes in patients with atrial fibrillation

Abstract Background Direct synchronized cardioversion (DCV) is frequently performed in atrial fibrillation (AF). In general, DCV is considered a safe procedure. A rare, but feared complication following DCV is an overt ischemic stroke resulting from embolization of a left atrial clot to the cerebral circulation. Purpose The aim of the present study was to assess the association of DCV with infarcts on brain magnetic resonance imaging (bMRI) and clinical outcomes. Methods 2386 patients of the Swiss AF cohort were included. 1731 patients were evaluated by bMRI. DCVs were recorded by questionnaire. Patients were categorized by number of DCVs performed before enrollment (0,1,≥2). BMRI were conducted at baseline and after 2 years (n=1227) and analyzed for large noncortical or cortical infarcts (LNCCI) and small noncortical infarcts (SNCI). Clinical outcomes were recorded during follow-up. Associations of DCV and outcome-measures were assessed by multivariate analyses. Results There was no independent association between the number of DCV and infarct prevalence (LNCCI + SNCI) on baseline bMRI (DCV 1 vs. 0: OR 0.95 [95% CI 0.73-1.26]; DCV ≥2 vs. 0: OR 1.04 [0.73-1.51]) or between DCV performed during follow-up and new infarcts on bMRI at 2 years (OR 1.46 [0.54-3.31]). DCVs were not associated with overt stroke or transient ischemic attack (DCV 1 vs. 0: HR 1.35 [0.87-2.03]; DCV ≥2 vs. 0: HR 1.54 [0.95-2.49]), hospitalization for heart failure (DCV 1 vs. 0: HR 1.03 [0.80-1.33]; DCV ≥2 vs. 0: HR 1.03 [0.77-1.37]), or death (DCV 1 vs. 0: HR 0.85 [0.67-1.09]; DCV ≥2 vs. 0: HR 0.92 [0.70-1.22]). Conclusions There was no association between DCV performed before enrollment and cerebral infarcts on baseline bMRI or between DCV performed during follow-up and new infarcts at 2 years. Moreover, DCV were not associated with clinical events.