Abstract Body (Do not enter title and authors here): Introduction:
Left Ventricular Assist Devices (LVADs) revolutionized the care of patients with advanced heart failure (AHF). Among AHF patients, atrial fibrillation (AF) is a common arrhythmia. Despite its prevalence, the impact of pre-existing AF on outcomes in post-LVAD recipients is poorly understood.

Hypothesis:
LVAD recipients with preexisting AF have higher all-cause mortality.

Methods:
This is a single-center, retrospective review of 573 LVAD recipients. Patients with LVADs implanted elsewhere, implants prior to 2011, implantation of an unconventional LVAD (e.g. artificial heart), and those with insufficient records were excluded. Univariate descriptive statistics and multivariate logistic & linear regression analyses of patient all-cause mortality, as appropriate, were performed using STATA. Significance was determined at alpha < 0.05.

Results:
Pre-implant AF was seen in 54% of LVAD recipients. Participants with AF were more likely to be male and older. They had higher rates of hyperlipidemia, prior stroke or TIA, prior CABG, pre-existing ICD at time of implant, and pre-LVAD sustained VT (Table 1). After a median follow-up time of approximately 2 years, 57% of patients died, 22% were transplanted, 9% were explanted, and 12% were lost to follow up. Irrespective of incidence of pre-LVAD AF, worse survival was seen in ischemic cardiomyopathy (HR 2.0 [1.5-2.7]), RV failure necessitating RVAD (HR 2.6 [1.9-3.6]), and pre-LVAD ICD shocks (HR 1.3 [1.0-1.7]). Pre-LVAD AF was associated with increased mortality (61% vs 47%, p= 0.001). This finding remained significant on multivariate analysis while controlling for other comorbidities (Table 2). Additionally, presence of AF was significantly associated with an increased occurrence of both post-implant VT (63% vs 43%, p <0.001) and post-implant RV failure necessitating RVAD (19% vs 10%, p< 0.001).

Conclusions:
A history of prior AF is associated with worse survival and higher incidence of complications following LVAD placement when compared to LVAD recipients without prior AF. This association is maintained even when controlling for possible confounders. However, this study is limited by its retrospective design, and further prospective randomized studies would better determine the impact of pre-implant AF on survival in LVAD recipients.