Concentrated Factor Administration and Subsequent Pump Thrombosis on HeartMate II LVAD Support

Purpose Limited data exists regarding concentrated factor administration during continuous flow left ventricular assist device (CF-LVAD) implantation and subsequent rates of pump thrombosis. While the hemocompatability profile of CF pumps are presently changing, this is the largest concentrated factor experience reported in CF-LVAD patients to date. Methods Patients with first time HeartMate II implantation (n=328) were identified from a single center continuous-flow (CF-LVAD) database (n=400). Patients were coded as receiving concentrated factor if prothrombin 4 factor complex or recombinant factor VIIa was charted intra-operatively or within 48 hours of device implantation. Laboratory and hospitalization data were reviewed to determine time to first suspected or confirmed pump thrombosis. Suspected pump thrombosis was defined as a sustained rise in lactate dehydrogenase (LDH) > 2.5 the upper limit of normal. Confirmed pump thrombosis was defined as a pump exchange, cardiac transplant, or death associated with a hemolysis event. Multivariable cox regression was utilized to determine the association between concentrated factor administration and the time to suspected or confirmed pump thrombosis. Results Eighteen percent of patients (59/328) received concentrated factor intra-operatively or within 48 hours of device implantation. On multivariate analysis, concentrated factor administration was not significantly associated with time to first suspected pump thrombosis (HR 1.17, 95 % CI 0.62-2.20, p = 0.62) or confirmed pump thrombosis (HR 1.19, 95 % CI 0.43-3.3, p = 0.73). All models were adjusted for discharge pump speed, age, bridge to transplant status, diabetes, and INTERMACS profile. Conclusion While no statistical association was observed between concentrated factor administration and subsequent pump thrombosis in this large single center analysis, further data will be needed to answer this question in the contemporary continuous flow era.