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

Abstract

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. 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. 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). 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.