Abstract Body: Introduction
MitraClip has been shown to reduce heart failure readmissions in patients with moderate to severe mitral valve regurgitation. Likewise, beta-blocker (BB) therapy has been shown to reduce morbidity and mortality in select heart failure patients. At the cellular level, chronic myocardial insult from ongoing heart failure and mitral regurgitation leads to persistent overstimulation of myocardial beta-receptors, ultimately reducing cardiac inotropic reserve and contributing to myocardial injury. Thus, we hypothesized that patients on beta-blocker therapy before the MitraClip procedure would have fewer heart failure-related readmissions.

Hypothesis
We assessed the hypothesis that beta-blocker therapy before the MitraClip procedure would lead to fewer heart failure-related readmissions by conducting a retrospective cohort study. This would help us better understand the pathogenesis of re-admissions in this patient population as well as help us decide whether prophylactic initiation of BB therapy before the procedure would reduce the risk of heart failure readmissions.

Methods
We reviewed the records of patients who underwent the MitraClip procedure at our institution from January 2017 to July 2022. Patients without listed home medications, as well as non-heart failure-related readmissions and deaths, were excluded. Patients were split into those on BB therapy and those with no BB therapy. Of the 401 charts screened, 324 met the inclusion criteria.

Results
From those who met the inclusion criteria, 226 patients were on beta-blocker therapy, while 98 patients were not. Of those who had at least one heart failure-related readmission within 6 months of the MitraClip procedure, 18 patients were on beta-blocker therapy and 16 patients were not. Meaning a 7.96% readmission rate for patients on beta-blocker therapy, and a 16.32% readmission rate for those who were not (OR 2.05, 95% CI: 1.004 to 4.186, p<0.05), with the number needed to treat being 11.9.

Conclusions
Our data shows that the use of beta-blocker therapy was associated with a statistically significant decrease in 6-month heart failure readmissions in those undergoing the MitraClip procedure. This suggests that at the cellular level, cardiac beta receptor dysfunction plays an integral part in future hospitalizations in this population. In conclusion, beta-blocker therapy should be considered in heart failure patients planning to undergo the MitraClip procedure to reduce heart failure-related readmissions.