Objective and Background: Data on incidences of symptomatic pulmonary arterial embolism (PAE) after catheter ablation of cardiac arrhythmias is scarce. To gain further insights on safety of ablation procedures we sought to provide data through multicentric individual case-based analyses of administrative data. 

Methods: We determined the incidences of PAE after supraventricular tachycardia (SVT), atrial fibrillation (AF), typical atrial flutter (AFlu), and ventricular tachycardia (VT) ablations in three German tertiary centers between 2005-2020. All cases were coded by the G-DRG- and OPS-systems. A uniform administrative search was performed among all participating centers with consecutive individual case-based analysis. 

Results: Overall, 47,344 ablations were analyzed (SVT: 10,037; 28,048 AF; 6,252 AFlu; 3,007 VT). PAE occurred in a total of 14 (0.03%) patients. Patients were mostly female (n= 9; 64.3%) with a mean age of 66±12  years, mean BMI of 27.7 ± 5.0 kg/m² and LVEF of 55 ± 12%. PAE incidences were 0.05% (n=5) for SVT ablations, 0.02% (n=5) for AF, and 0.13% (n=4) for VT ablations. No patient suffered PAE after AFlu ablation. If prescribed prior to the procedure, oral anticoagulation was paused the day of the procedure in most cases (n= 10). Mean preprocedural INR was 1.04 ± 0.5 and pTT 29 ± 5.6 seconds. Most patients with PAE presented with sudden shortness of breath or chest discomfort the day after the procedure (n=9) after a mean intraprocedural heparin application of 1200 ± 3511 IU. No protamine was applied in any of the patients. Upon diagnosis of PAE all patients received effective anticoagulation treatment with either phenprocoumone (n=5) or non-Vitamin K dependent drugs (NOAC, n= 9). Mean length of hospital stay was 11.5 ± 9.8 days with two patients dying during the same hospital stay after VT ablation. All other patients were discharged on oral anticoagulation with no PAE residuals.

Conclusion: Over a 15-years period, the overall incidence of PAE after catheter ablation is low and particularly low in patients with ablation for AF and AFlu. This is most likely related to stricter anticoagulation during and after ablation as compared to SVT and VT ablations.  Optimizing periprocedural anticoagulation to reduce thrombembolic complications should be subject of further prospective trials.