Objective: Individual case analysis of in-hospital mortality after catheter ablation for atrial fibrillation (AF), atrial flutter (AFlu), and ventricular tachycardia (VT) in administrative data.

Methods: We determined the incidences of in-hospital mortality of AF, AFlu, and VT ablations in four German large ablation centers between 2005-2020. All cases were coded by the G-DRG- and OPS-systems. Uniform code search terms were applied defining both the types of ablation for AF, AFlu, and VT and the occurrence of in-hospital death. After administrative data analysis all cases were individually reviewed based on patient-level source records.

Results: Overall, 43,031 ablations were analyzed (30,361 AF; 9,364 AFlu; 3,306 VT). A total of 72 (0.17%) patients (65.9 ±11.6 years, 61 % male; one patient with VT and AFlu ablation during the same hospital stay) died after catheter ablation of AF (n=11, median age 68.0, IQR: 60.8; 73.0), AFlu (n=13; median age 65.0, IQR: 55.0; 71.0), or VT (n=49; median age 69.0, IQR: 63.0; 74.0). After individual patient adjudication, the likely ablation-related mortality was lower than the coded mortality rate from the administrative data: AF: 0.03% vs. 0.04%; AFlu: 0.04% vs. 0.14%; VT: 0.42% vs. 1.48%. The main causes of ablation-related deaths were thromboembolic (n=8) and hemorrhagic (n= 13) adverse events. Thirty-seven patients (51.4%) were identified with an unlikely association of their in-hospital death with the catheter ablation. Here, the main reasons for death included infection (n=12) present before ablation or occurring late after ablation due to severe co-morbidities, malignancies (n=1), cardiac decompensation (n=6), or therapy-refractory electrical storm (n=10).

Conclusion: Individual case analysis demonstrates a lower than coded ablation-related in-hospital mortality. This highlights the importance of individual case adjudication when analyzing administrative data to avoid overestimation of ablation-related in-hospital mortality.