BACKGROUND: Transcatheter aortic valve replacement (TAVR) has transformed the management of patients with severe symptomatic aortic stenosis who are unfit for surgical aortic valve replacement. Atrial fibrillation is one of the most common arrhythmias observed in patients with aortic stenosis undergoing TAVR. Our study explores the impact of Afib on perioperative outcomes in patients undergoing TAVR. METHODS: We queried the National Inpatient Sample from 2016 to 2021 for TAVR hospitalizations. We compared baseline features and outcomes between patients undergoing TAVR with and without Afib. We used the Pearson-Chi Square and Wilcoxon Rank Sum tests to compare categorical and continuous variables, respectively. We used multivariate logistic regression analysis to study the effect of Afib on outcomes. RESULTS: Among 393,195 weighted hospitalizations for TAVR, 28.7 % had Afib. These patients were older (median age: 82 y vs. 79 y, p <
0.002) and predominantly males (58.6 % vs. 54.9 %, p <
0.002) compared to those without Afib. Multivariate analysis suggested that Afib was associated with greater odds of acute heart failure (aOR 1.27, p <
0.002), ventricular arrhythmia (aOR 1.33, p <
0.002), cardiogenic shock (aOR 1.38, p <
0.002), major adverse cardiac events (aOR 1.14, p = 0.002), acute kidney injury (aOR 1.27, p <
0.002), and acute bleeding (aOR 1.20, p <
0.002) compared to those without Afib in patients undergoing TAVR. CONCLUSION: Afib was associated with increased odds of acute heart failure, ventricular arrhythmia, cardiogenic shock, major adverse cardiac events, acute kidney injury, and acute bleeding in patients undergoing TAVR. However, the odds of in-hospital mortality in these patients were not significantly different from the group without Afib.