Abstract Body (Do not enter title and authors here): Background: Factor V Leiden (FVL) is a hereditary hypercoagulable state in which factor V is resistant to inactivation by activated protein C, causing activation of prothrombin and an increased propensity for thrombotic events. Coronary artery bypass grafting (CABG) is a procedure that restores adequate blood flow to the myocardium by harvesting vasculature from elsewhere in the body and using it to bypass atheromatous coronary arteries. Although thrombotic events are feared complications of a CABG procedure, little is known regarding the risk of CABG procedures in patients with FVL, given their increased propensity for thromboses.

Research Question: In this study, we aim to establish whether FVL increases in-hospital mortality following a CABG procedure.

Methods: The National Inpatient Sample database was used to extract data on patients who underwent a CABG procedure between 2017-2022. Patients were grouped based on a diagnosis of FVL (N=2,095) or no FVL (N=1,142,735). The Kruskal-Wallis test and Pearson’s Chi Squared with Rao-Scott adjustment were used for descriptive statistics. Differences in all-cause in-hospital mortality were evaluated using logistic regression models. Hospital length of stay and inflation-adjusted total hospital cost were evaluated using linear regression models. Results were propensity-matched, and differences in in-hospital mortality, length of stay, and total cost were assessed using logistic regressions.

Results: A higher proportion of patients with FVL were female and white (p’s ≤0.006). The FVL group had a higher proportion of patients with a previous history of DVT (36.0% versus 2.0%), PE (23.0% versus 1.2%), cardiovascular disease (14.0% versus 8.8%), and peripheral vascular disease (20.0% versus 15.0%) compared to the non-FVL group (p’s < 0.001). Additionally, the mean Elixhauser comorbidity index was higher in the FVL group (5.4) compared to the non-FVL group (4.7) (p<0.001). There was no significant difference in in-hospital mortality between those with and without FVL who underwent a CABG procedure (p=0.740). Those with FVL had longer hospital stays (p=0.002) but did not incur higher costs for their stay (p=0.150) compared to those without FVL.

Conclusion: FVL is not associated with increased in-hospital mortality following a CABG procedure, but it is associated with longer hospital stays. This finding can help guide providers considering CABG for revascularization in patients with FVL.