Association of Blood Group O with Gastrointestinal Bleeding in Continuous-Flow LVAD Patients

Abstract

Background: Increasing use of mechanical circulatory devices for advanced heart failure therapy has led to challenges in managing complications that arise from device implantation for long term support either as a bridge to transplant or as destination therapy. Patients with continuous flow left ventricular assist devices (CF-LVADS) show increasing incidence of gastrointestinal (GI) bleeds.   Lack of pulsatality and narrow pulse pressure result in initiation and progression of arteriovenous malformations. High shear forces generated lead to destruction of von Willebrand factor (vWF) making it functionally inactive predisposing patients to increasing bleeding. Literature suggests that patients with blood type O have lower baseline levels of von Willebrand factor. It therefore seemed relevant to study the role of blood groups in this population. Methodology: Retrospective data analysis of 119 CF-LVADS patients discharged between 01/2005 and 07/2014. This study was approved by the Institutional Review Board on 08/01/2014. Results: Blood type (p=0.23), gender (p=0.16) and the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile (p=0.86) were not associated with significant incidence of GI bleeding. Blood group O was not associated with a higher incidence of GI bleeding (correlation coefficient =0.07) Patients supported on the HeartMate II (HMII) LVAD experienced more GI bleeding than patients supported on the HeartWare LVAD (HVAD) (p=0.009). HMII LVAD patients who experienced GI bleeding had a mean age of 59.8 years vs. 55.7 years for HMII LVAD patients in the Non-GI bleed group. Age was a significant factor for GI bleeding (p=0.016). Conclusion: Blood group and GI bleeding did not show any significant association in our study.  Patients with blood group O did not show increased incidence of GI bleeding despite reported lower baseline levels of von Willebrand factor suggesting contribution of additional factors leading to this complication. The HVAD had a decreased incidence of GI bleeding as compared to Heartmate II. This study is limited by the fact that it was a retrospective analysis in a small population.