Background: Transcatheter aortic valve implantation (TAVI) has shown lower procedural risk compared to surgical aortic valve replacement (SAVR). However, bleeding complications may require the administration of packed red blood cell units (PRBCs). The aim of this study was to investigate the prevalence of bleeding complications and PRBC administrations over the last 13 years, and their impact on long-term outcomes in patients with severe AS undergoing TAVI.

Methods: All patients undergoing TAVI in Switzerland have been consecutively included in a nationwide prospective registry, the Swiss TAVI Registry. PRBC-administration was tracked until hospital discharge. The primary outcome of the present analysis was all-cause mortality at five years. Secondary outcomes included all-cause mortality at one year, as well as in-hospital complications.

Results: In total, 14'765 patients who underwent TAVI from 2011 to December 2023 were included. A total of 1411 patients (9.5%) received PRBCs during hospitalization. All-cause mortality was significantly higher among patients receiving PRBC at one year (16.8% vs. 8.4%, HR 2.1, 95% CI 1.8 - 2.5) and five years (58.5% vs. 44.2%, HR 1.67, 95% CI 1.5 - 1.8, p<0.001). PRBC was identified as an independent predictor of mortality at five years (aHR 1.20, 95% CI 1.10 - 1.32, p<0.001).

Conclusions: Bleeding complications remain prevalent in patients undergoing TAVI. Patients requiring PRBC-administration during their hospitalization for TAVI had a 1.5-fold higher mortality up to five years.