Background: Aortic stenosis (AS) is the most common acquired valvular disease. There are two methods of interventional treatment: surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI). The choice between SAVR and TAVI depends on the assessment of individual perioperative risk and long-term treatment outcomes. It is essential to identify factors that may influence the outcomes of the treatment to minimize their negative effects., Aims: The study aimed to identify the most important risk factor which affects treatment outcomes in patients with AS undergoing SAVR/TAVI., Methods: This study reviewed retrospectively patients with AS who underwent SAVR or TAVI. The primary outcomes included incidences of major adverse cardiovascular events (MACE) defined as cardiovascular death, stroke, and hospitalization for cardiovascular issues assessed over a one-year follow-up period. An occurrence of postprocedural AKI (acute kidney injury) was identified as an independent predictor of MACE., Results: The study included 78 patients, with the same number of subjects in each group (SAVR/TAVI [n = 39]). Twenty-nine patients developed AKI. It was similar in both groups (SAVR [n = 15]; TAVR [n = 14]). In the SAVR group, 13 (33%) patients developed at least one MACE compared to 5 (13%) patients in the TAVI group. AKI and the type of procedure (SAVR) were shown to be significantly and independently associated with the development of MACE (P = 0.01 and P = 0.03, respectively) as shown in the Cox multivariable regression model., Conclusions: Our study demonstrated that AKI is the strongest predictor of major adverse cardiovascular events after using both methods of aortic valve replacement (SAVR/TAVI).