Background: Although transcatheter aortic valve implantation (TAVI) outcomes are well-documented, predictors of mortality beyond conventional surgical risk scores and valve-related factors in real-world, high-risk cohorts require further elucidation. This study aimed to identify the key determinants of 30-day and 1-year mortality following TAVI, with a focus on both patient-specific and procedure-specific complications.

Methods: The KOSUTAVI study is a single-center, retrospective cohort analysis of 859 consecutive high-risk individuals with severe aortic stenosis undergoing TAVI between 2020 and 2025. Primary endpoints were 30-day and 1-year all-cause mortality. Multivariate Cox regression and Kaplan–Meier analyses were used to identify independent risk factors.

Results: Mean age was 78.7 ± 6.5 years, and mean Society of Thoracic Surgeons score was 7.4 ± 2.2. The 30-day and 1-year mortality rates were 6.5% (n = 56) and 12.4% (n = 107), respectively. The 5-year all-cause mortality rate was 26.3%. In multiple Cox’s analysis, chronic renal failure (hazard ratio [HR] = 7.75, P = .008, 95% CI = 1.29-16.54), presentation with cardiogenic shock (HR = 5.83, P = .028, 95% CI = 1.19-15.41), major vascular injury (HR = 22.7, P = .019, 95% CI = 1.89-45.91), and cardiac tamponade (HR = 17.9, P = .012, 95% CI = 8.13-52.62) were independently associated with 30-day mortality. While these factors were all significant in univariate analysis for 1-year mortality, they did not retain independence in the multiple model. Valve type, access route, and sex were not associated with increased mortality.

Conclusion: In a high-risk TAVI population, early mortality is predominantly driven by pre-existing renal dysfunction and acute procedural complications (shock, vascular injury, and tamponade), rather than valve-specific factors. These findings underscore the critical importance of optimizing renal function before the procedure and implementing advanced vascular protection strategies to improve early survival after TAVI.