Baseline characteristics

Overall, 46,243 transfemoral TAVR procedures for aortic valve stenosis were performed in 2019 or 2020, with 19,910 balloon-expandable and 26,333 self-expanding valves (Table 1). Patients in the SE group had a significantly higher logistic EuroSCORE of 13.61 vs 12.66% in BE (p < 0.001), age of 81.55 vs 79.99a (p < 0.001), and proportion of women of 54.82 vs 40.06% (p < 0.001). Furthermore, there were significantly more patients in the BE group with coronary artery disease with 55.43 vs 52.57% in SE (p < 0.001), peripheral vascular disease with 10.22 vs 8.33% (p < 0.001), as well as carotid disease with 6.91 vs 5.40% (p < 0.001).

Unadjusted in-hospital outcomes of balloon-expandable or self-expanding TAVR in 2019/2020

Regarding the unadjusted in-hospital mortality (Table 2), both groups showed a similar mortality rate of 2.37% in BE and 2.35% in SE (p = 0.916). Patients treated with BE TF-TAVR had a significantly higher rate of major bleeding (2.81 vs 2.31%, p = 0.001). However, the BE group showed a lower rate of stroke (1.85 vs 2.55%, p < 0.001), delirium (7.22 vs 8.74%, p < 0.001), and permanent pacemaker implantation (12.13 vs 14.62%, p < 0.001). No difference was seen in acute kidney injury (9.49 vs 9.56%, p = 0.798) and mechanical ventilation > 48 h (2.24 vs 2.10%, p = 0.305).

Table 2 Unadjusted in-hospital outcomes of balloon-expandable or self-expanding TAVR in 2019/2020

Regarding resource utilization parameters, patients receiving SE TF-TAVR had a significantly shorter length of hospital stay (11.86 vs 11.61 days, p = 0.001). There was no difference in reimbursement (26,223 vs 26,131 €, p = 0.108).

Risk-adjusted in-hospital outcomes of balloon-expandable or self-expanding TAVR in 2019/2020

In-hospital mortality also did not differ significantly after risk adjustment (risk-adjusted OR = 0.98 [95% CI 0.86, 1.13], p = 0.799; Fig. 1). Patients receiving SE TF-TAVR had a significantly lower risk of major bleeding (OR = 0.83 [0.73, 0.95], p = 0.006). However, they had a significantly higher risk of stroke (OR = 1.38 [1.19, 1.59], p < 0.001), delirium (OR = 1.15 [1.06, 1.24], p = 0.001), and permanent pacemaker implantation (OR = 1.29 [1.21, 1.37], p < 0.001). There was no significant difference after risk adjustment for acute kidney injury (OR = 1.05 [0.98, 1.14], p = 0.180) and mechanical ventilation > 48 h (OR = 1.01 [0.88, 1.17], p = 0.871). Resource utilization parameters also did not differ regarding length of hospital stay (risk-adjusted Coefficient = 0.19d [− 0.01d, 0.39d], p = 0.066) and reimbursement (Coefficient = 117€ [− 22€, 257€], p = 0.099; Table 3).

Fig. 1

Risk-adjusted in-hospital outcomes of self-expanding instead of balloon-expandable TAVR in 2019 and 2020. BE balloon-expandable; CI confidence interval; SE self-expanding

Table 3 Risk-adjusted in-hospital outcomes as well as resource utilization parameters of self-expanding instead of balloon-expandable TAVR in 2019/2020

Primary risk factors regarding in-hospital mortality were higher grade renal disease (GFR < 15 ml/min: OR = 2.67 [2.04, 3.50], p < 0.001; GFR < 30 ml/min: OR = 1.59 [1.24, 2.04], p < 0.001), higher grade heart failure NYHA III/IV (OR = 1.81 [1.56, 2.10], p < 0.001), and atrial fibrillation (OR = 1.43 [1.26, 1.62], p < 0.001; Supplementary Appendix 1).

Risk-adjusted subgroup analysis for the endpoint in-hospital mortality comparing balloon-expandable and self-expanding TAVR

Furthermore, we performed a subgroup analysis for the endpoint in-hospital mortality. The full regression analysis can be found in the Supplementary Appendix 2. Looking at the endpoint in-hospital mortality (Table 4, Fig. 2), there were no significant differences between SE and BE TF-TAVR in any of the subgroups: age < 75a (SE instead of BE: OR = 1.02 [0.69, 1.50], p = 0.935), 75-79a (OR = 1.20 [0.89, 1.61], p = 0.225), 80-84a (OR = 0.89 [0.72, 1.11], p = 0.294), ≥ 85a (OR = 0.90 [0.72, 1.14], p = 0.386); EuroSCORE < 4 (OR = 1.27 [0.53, 3.04], p = 0.594), 4- < 9 (OR = 0.87 [0.67, 1.12], p = 0.280), ≥ 9 (OR = 1.01 [0.86, 1.18], p = 0.941); gender (OR = 0.89 [0.74, 1.07], p = 0.204); NYHA III/IV (OR = 1.00 [0.84, 1.17], p = 0.957); previous CABG (OR = 1.49 [0.96, 2.31], p = 0.073); peripheral vascular disease (OR = 1.10 [0.78, 1.55], p = 0.588); COPD (OR = 0.99 [0.67, 1.45], p = 0.957); pulmonary hypertension (OR = 0.96 [0.74, 1.25], p = 0.779); renal disease GFR < 30 ml/min (OR = 1.32 [0.96, 1.82], p = 0.091); diabetes mellitus (OR = 1.21 [0.95, 1.54], p = 0.128).

Table 4 Subgroup analysis for the endpoint in-hospital mortality: Self-expanding instead of balloon-expandable TAVR in 2019/2020Fig. 2

Risk-adjusted subgroup analysis for the endpoint in-hospital mortality of self-expanding instead of balloon-expandable TAVR in 2019 and 2020. BE balloon-expandable; CI confidence interval; SE self-expanding