Abstract Body (Do not enter title and authors here): Background: Mitral Valve Prolapse (MVP), also known as Barlow Syndrome, is one of the most common valve pathologies. As MVP progresses there is a propensity towards arrhythmias including Atrial Fibrillation (AF). AF is the most common arrhythmia seen among patients clinically. Although there is a known relationship between MVP and AF, there is limited data directly comparing MVP patients with AF and those without.

Methods: National Inpatient Sample 2017-2021 was used to compare outcomes between MVP patients with and without a concurrent diagnosis of Atrial Fibrillation. Logistic regression was used to compare characteristics and in-hospital outcomes.

Results: Of the 384,750 patients with MVP admitted, 61,895 had a concurrent diagnosis of AF. The majority of patients with AF had a diagnosis of paroxysmal vs. persistent vs. chronic (74.88 vs. 10.14 vs. 19.63%). Additionally, these patients had longer length of stay as well as total hospital cost. Compared to MVP patients without AF, these patients were predominantly male (37.21 vs. 23.65%, p<0.001) and Caucasian (90.51 vs. 84.45%, p<0.001). This group had a higher propensity of heart failure with preserved ejection fraction (22.07 vs. 7.29%, p=0.014), coronary artery disease (34.8 vs. 18.92%, p=0.003), and hyperlipidemia (55.76 vs 42.58%, p<0.001). Patients without AF had a higher proportion of hypertension (41.83 vs. 33.55%, p<0.001). Additionally, those with AF had more mitral valve repairs (4.88 vs. 1.94%, p<0.001) and mitral valve replacements (3.55 vs. 0.97%, p<0.001). [Table] The number of MVP patients without AF are downtrending and the number of MVP patients with AF are stable in these select years. Mitral valve repairs have consistently increased while replacement has stayed relatively the same in MVP patients. [Graph] Outcomes including mortality, mechanical ventilation, vasopressor requirement, and ICU admission were similar between the groups.

Conclusion: MVP patients with AF generally had more significant comorbidities while outcomes between the two groups are similar. Mitral valve repair and replacements are significantly more common among MVP patients with AF. Yearly trends appear to favor an increasing overall number of mitral valve repairs. These findings highlight the added burden that AF portrays in this patient population.