High Incidence of Thromboembolic Events in Left Ventricular Assist Device Patients Treated With Recombinant Activated Factor VII

Abstract

Dosing of recombinant activated factor VII (rFVIIa) is controversial and unstandardized, and there is growing concern about thromboembolic complications, especially in left ventricular assist device (LVAD)-supported patients. We reviewed our experience with rFVIIa administration in patients with LVADs and examined its effectiveness and adverse effects, including the incidence of thromboembolic events and its correlation with increasing doses. We retrospectively reviewed the records of 62 patients who received an LVAD and rFVIIa at our center between January 2004 and November 2006. Patients who received a single dose of 10 to 20 microg/kg (n = 32; 52%) constituted the "low-dose" cohort, and patients who received 30 to 70 microg/kg (n = 30; 48%) constituted the "high-dose" cohort. Laboratory values obtained before and after rFVIIa administration, as well as patients' transfusion requirements, were compared to determine the effectiveness of rFVIIa in reversing coagulopathy and reducing blood loss. We also compared the incidence of thromboembolic events in the low- and high-dose groups. Administration of rFVIIa was associated with significant decreases in prothrombin time, activated partial thromboplastin time and transfusion requirements. This association was seen in both the low- and high-dose groups. In addition, the incidence of thromboembolic events was significantly higher in the high-dose group (36.7%) than in the low-dose group (9.4%) (p < or = 0.001). Although rFVIIa administration seemed helpful in controlling life-threatening hemorrhage, patients requiring higher doses (30 to 70 microg/kg) had a dramatically higher incidence of serious thromboembolic events.