Prospective analysis of bleeding events in left ventricular assist device patients

Bleeding is a major cause of morbidity in patients with continuous flow left ventricular assist devices (LVADs). We sought to identify clinical predictors of bleeding within the first year of LVAD implantation.

A prospective study was performed on 30 patients with HeartMate II implantation at the University of Rochester Medical Center, Rochester, New York, United States. Blood was collected within 1 week before implantation, and at 1, 3, and 30 ± 10 days after implantation. Blood samples were analyzed for prothrombin time (PT), international normalized ratio (INR), von Willebrand factor (vWF) activity, vWF antigen, vWF multimers, collagen binding assay, factor VIII, and epinephrine closure time. The first bleeding event within 1 year of implantation was recorded.

There were 17 (57%) patients with a bleeding event. The cumulative incidence of bleeding was 50% at 304 days. Age at the time of LVAD implantation was associated with higher risk of bleeding (hazard ratio (HR) = 1.05, 95% confidence interval (CI) = 1.01-1.10, p = 0.013). Higher baseline INR was also associated with increased risk of bleeding after adjusting for age at the time of implant (HR = 6.58, 95% CI = 1.21-35.70, p = 0.028). The bleeders and non-bleeders had similar hemostatic markers at all four time points. Prior to LVAD, mean epinephrine closure time was similar between bleeders and non-bleeders. However, post LVAD measurement of epinephrine, closure time was frequently limited by platelet clumping.

Older age and baseline INR are associated with higher risk of bleeding in LVAD patients. Platelet clumping may suggest underlying platelet dysfunction and associated high risk of bleeding.