Comparative outcomes of balloon-expandable versus self-expanding transcatheter aortic valves: insights from a large-scale German registry.

BACKGROUND: While transcatheter aortic valve replacement (TAVR) has become an established alternative to surgical aortic valve replacement (SAVR), the comparative outcomes of balloon-expandable (BE) and self-expanding (SE) valve technologies remain an area of ongoing investigation. METHODS: Using the German DESTATIS database, we analyzed 48,565 transfemoral TAVR procedures performed between 2021 and 2022. Outcomes were compared between BE (n = 23,412) and SE (n = 25,153) valves using a double/debiased machine learning estimator to account for potential confounding. Key endpoints included in-hospital mortality, major bleeding, stroke, acute kidney injury, mechanical ventilation > 48 h, postoperative delirium, permanent pacemaker implantation (PPI), length of hospital stay, and reimbursement. RESULTS: Descriptively, SE valves were associated with significantly lower in-hospital mortality (1.6% vs. 2.0%, p < 0.001) and major bleeding (1.4% vs. 2.1%, p < 0.001) but a higher risk of stroke (2.4% vs. 1.9%, p < 0.001). A trend towards higher risk of PPI was observed (p = 0.078). After adjustment, patients with SE valves are at lower risk for in-hospital mortality (RR 0.85, p = 0.049) and major bleeding (RR 0.78, p = 0.006), but had a higher risk of stroke (RR 1.35, p < 0.001) and permanent pacemaker implantation (RR 1.09, p = 0.028). Subgroup analysis indicated that older and high-risk patients, particularly those aged ≥ 85 years, showed a stronger association with lower in-hospital mortality for SE valves, whereas younger patients exhibited a trend favouring BE valves. BE valves were also associated with a modestly higher reimbursement (€209 per case, p = 0.004). CONCLUSION: In this large, real-world cohort, self-expanding valves were associated with lower in-hospital mortality and major bleeding but a higher risk of stroke and permanent pacemaker implantation compared with balloon-expandable valves. Because prosthesis choice in routine practice is highly individualized and driven by anatomical and procedural factors not captured in administrative data, these associations are hypothesis-generating and cannot support device-selection recommendations.