INTRODUCTION: The objective of this study is to determine if cardiac damage based on hospital discharge codes is associated with in-hospital outcomes in patients with aortic stenosis (AS). METHODS: We conducted a retrospective cohort study of hospital admissions between 2016 and 2021 with a diagnosis of AS in the National Inpatient Sample (NIS). The cardiac damage stages 0-4 were determined based on hospital discharge codes. Logistic and linear regressions were used to determine the association between cardiac stage and in-hospital mortality, length of stay (LoS) and cost. RESULTS: A total of 2,980,150 hospital admissions were included in the analysis (82.5% conservative management, 11.2% transcatheter aortic valve replacement [TAVR], 6.3% surgical aortic valve replacement [SAVR]). The association between cardiac damage stage and in-hospital outcome was most significant for patients who had SAVR treatment (stage 4 vs. stage 0: mortality OR 27.70 95% CI 17.35-35.17, LoS 7.34 95% CI 6.34-8.35, cost 70,710 95% CI 65,110-76,310) compared to TAVR treatment (stage 4 vs. stage 0: mortality OR 9.15 95% CI 5.52-15.15, LoS 6.27 95% CI 5.63-6.90, cost 28,384 25,084 to 31,684) and conservative treatment (stage 4 vs. stage 0: mortality OR 3.55 95% CI 3.13-4.04, LoS 2.09 95% CI 1.87 to 2.31, cost 6362 95% CI 5642-7083). CONCLUSIONS: Cardiac damage can be evaluated using diagnostic codes in patients with AS and it is associated with in-hospital mortality, LoS and cost, and has more impact on these outcomes in patients treated with SAVR versus those treated with TAVR.