Comparison of Unfractionated Heparin and Bivalirudin for Treatment of Suspected Device Thrombosis during Heart Mate II Support

Purpose Although intravenous anticoagulation is the mainstay medical therapy employed during CF LVAD thrombosis, the comparative impact of indirect thrombin inhibition with unfractionated heparin (UH) and direct thrombin inhibition with bivalirudin (BV) is unknown. Methods We conducted a single center review of all patients with a Heart Mate(HM) II who were admitted for suspected device thrombosis (SDT) from September 2011 to September 2018. Device thrombosis was suspected due to elevated outpatient lactate dehydrogenase (LDH), evidence of systemic emboli, or device alarms. After admission, patients were categorized into those receiving UH or BV. Crossovers were excluded. Freedom from device exchange was calculated with Kaplan Meier analysis. Results Twenty-three patients were admitted for SDT, of whom 13 received UH and 10 received BV. There were no differences in age (UH: 49.2 vs. BV: 46.9 years, p=0.60) and time from implant to SDT (UH: 10.3 vs. BV: 10.4 months, p=0.98). LDH remained elevated after UH (879, IQR: 755-1049 to 1028, IQR: 550-1438 U/L, p=0.34) but dropped with BV (839, IQR: 733-914 to 453, IQR: 352-465 U/L, p=0.002). During the follow up period, there was a lower likelihood of a device exchange in patients treated with BV (HR: 0.28, 95% CI: 0.09-0.89, p=0.04, figure 1). Conclusion In this sample of HM II patients, intravenous direct thrombin inhibition was more effective in treating device thrombosis.