Ischemic stroke or systemic embolism after transseptal ablation of arrhythmias in patients with cardiac implantable electronic devices

Background-Incidental mobile thrombi are commonly found on endovascular leads of cardiac implantable electronic devices (CIEDs). Transseptal puncture for catheter ablation of arrhythmia poses a risk for paradoxical embolism. We examined risk of ischemic stroke, transient ischemic attack (TIA), or systemic embolism after transseptal ablation in patients with and without CIEDs. Methods and Results-Using a national administrative claims database, 31 720 patients who underwent a transseptal catheter ablation between January 2004 and September 2014 were identified. Two propensity-matched cohorts were created by matching demographic variables, administrative variables, Charlson Comorbidity Index, CHA₂DS₂-Vasc score, and year and indication for ablation (5533 and 11 300 patients with and without CIEDs). Incidence rates and Cox proportional hazards models were used to estimate risk of ischemic stroke, TIA, or systemic embolism for patients with and without CIEDs. Impact of oral anticoagulation (OAC) use on the endpoint was examined. Over a mean follow-up of 2.1 years, the incidence of the combined endpoint was 1.9 per 100 person-years in patients with CIEDs and 1.5 per 100 person-years in patients without CIEDs (P=0.03). Among patients not on OAC, presence of a cardiac device was associated with an increased risk (hazard ratio [HR], 1.71 [1.24-2.35]; P<0.01), whereas there was no association noted among patients treated with OAC (HR, 0.98 [0.75-1.28]). Conclusion-CIEDs are associated with an increased risk of stroke, TIA, or systemic embolism after transseptal ablation, but this risk is attenuated with postablation OAC use. Role of anticoagulation post-transseptal ablation in patients with CIED warrants further investigation.