The Unique Impact of Blood Type O on Gastrointestinal Bleeding with Left Ventricular Assist Systems.

Acquired von Willebrand syndrome is implicated in the pathology of gastrointestinal bleeding (GIB) after implantation of continuous-flow left ventricular assist systems (CF-LVAS). Adults with blood type (BT) O have lower circulating levels of von Willebrand factor. In this analysis, we sought to explore the association between BT O and GIB following CF-LVAS implantation. We performed a single center, retrospective, observational cohort study in 200 consecutive adults implanted with a durable CF-LVAS over a 10-year period (2008-2018). Patients were grouped according to BT O (N = 97) vs Non-O (N = 103), and further stratified by the HAS-BLED score. Cumulative Kaplan-Meier event curves were constructed. Patients with at least 1 GIB event were generally older (60.8±10.1 vs 53.0±13.9 years, P <;0.001) and more likely to have chronic kidney disease (47.2 vs 23.8%, P = 0.001). Baseline characteristics were similar between BT groups. After a median follow-up of 10.4 months (IQR 2.7-18.4), univariate analysis showed no significant difference in rates of GIB by BT (HR, 1.23; 95% CI, 0.72-2.12) when unadjusted for bleeding propensity. However, among patients with a HAS-BLED score >;=3 (N = 87) the rates of GIB were significantly higher for BT O (HR, 2.36; 95% CI, 1.06-5.27; P = 0.036) (Figure). Our study suggests an important association of BT O with higher rates of GIB in CF-LVAS patients at high baseline risk for bleeding complications (HAS-BLED >;=3). These findings suggest that in this specific population characterized by BT O, a greater vigilance and targeted anticoagulation strategies may need to be investigated. [ABSTRACT FROM AUTHOR]