Cangrelor -Safe and Effective Agent for Treating Pump Thrombosis in LVAD Patients

Abstract

Background Pump thrombosis (PT) is a major complication of Left Ventricular Assist Device (LVAD). One of the early markers of PT is elevation in Lactate Dehydrogenase (LDH). Aggressive anti coagulation regimen can sometimes decrease LDH levels and prevent surgical need for pump exchange. Several treatment strategies have been utilized including escalating anti thrombotic therapy. There is minimal data regarding the role of Cangrelor for treatment of PT. Purpose Cangrelor, which is a novel antiplatelet agent in the treatment of PT. Method Review of cases of suspected pump thrombosis as evidenced by elevated LDH and Plasma free hemoglobin, who were treated with Cangrelor at University Medical Center from October 2018 to March 2019. We found two cases that were treated with Cangrelor. Results First patient had Heart Mate implanted 02/01/2017. She had undergone pump exchange for pump thrombosis 03/16/2018. She was not a candidate for further pump exchange or transplant due to socioeconomic issues. She was admitted with elevated LDH of 1400. She was initially started on heparin and integrillin drips with no significant change in LDH for 3 days (1097,1466,1541). There was also ongoing increase in Plasma free hemoglobin (62,82, 107). At this point it was decided to discontinue Integrilin and start Cangrelor. The LDH level started decreasing immediately and was back to baseline level of nearly 600 in 4 days. Free hemoglobin normalized in 5 days. She had no major bleeding complications. She was discharged from the hospital without any major events. Second patient had Heart Mate II implanted January 2017. He had suffered subarachnoid hemorrhage, when treated with heparin and Integrilin drip for elevated LDH. He subsequently underwent LVAD exchange on 8/29/2018. Patient did well for few months after the pump exchange. However, he started having intermittent flash pulmonary edema, power fluctuations and was subsequently hospitalized for transplant evaluation. While admitted he was noted to have elevated LDH to more than 1000 with increase in plasma free hemoglobin. Due to his history of subarachnoid hemorrhage with Integrilin, we chose to use Cangrelor with standard dose heparin drip for treatment of pump thrombosis. He was initially given 4mcgm/kg/min with rapid reduction in LDH and free hemoglobin. He was then maintained on 0.75mcgm/kg/min. This dose was increased to 1.5mcg/kg/min as LDH started to rebound. Patient went on to get heart transplant and did well without any bleeding complications. Conclusions Cangrelor can be used along with heparin for pump thrombosis. It has been used effectively in decreasing the LDH levels without any major bleeding complications. It may be considered as safe alternative to other modalities of anticoagulation.