BACKGROUND: Pulmonary vein isolation (PVI) can be performed using radiofrequency (RF) or cryoballoon (CB) ablation. Guidelines do not favor one technique and knowledge about complication rates is limited. OBJECTIVE: To report the procedural safety of RF and CB ablation using data from a German nation-wide real-world registry. METHODS: Using health records, all left atrial catheter ablation procedures using RF or CB ablation in Germany from 2013-2021 were analyzed. After adjustment for confounders, safety performance endpoints were compared. RESULTS: From 2013 to 2021, RF ablation was performed in 184,613 patients and CB ablation in 118,980 patients with increasing trends in patient numbers and performing centers for both procedures. Patients with RF ablation had slightly more comorbidities. In-hospital mortality (RF 0.08%
CB: 0.06%) and other investigated complications were rare. After adjustment for patient baseline characteristics, the risk of in-hospital mortality, serious bleeding, stroke, intracerebral bleeding and acute kidney injury did not differ. The risk of pericardiocentesis (RR 0.50
95% CI: 0.46-0.55
p<
0.001), vascular complication (0.36
0-33-0.39
p<
0.001) and ventilation >
48h (0.81
0.66-0.99
p=0.042) was significantly lower for CB ablation. Pericardiocentesis risk negatively correlated with annual procedure numbers per center with a faster learning curve for CB ablation (both p<
0.01). CONCLUSION: RF and CB ablation had low overall procedural complication rates, with CB ablation showing a 50% reduced risk of pericardiocentesis. Centers with higher volume provided a better in-hospital safety with a faster learning curve for CB ablation.