(132) Bivalirudin Compared to Unfractionated Heparin in Patients Supported With Impella Devices

Introduction: Impella devices are temporary mechanical circulatory support (tMCS) devices used in patients with cardiogenic shock to support organ perfusion. Impella devices have risks including clotting and bleeding. Therefore, anticoagulation strategies are utilized to prevent device-related thrombosis. Unfractionated heparin (UFH) is the anticoagulant recommended by the manufacturer and international guidelines. Direct thrombin inhibitors (DTIs), such as bivalirudin, are becoming more commonly used with several reports of using DTIs as an initial strategy for patients on Impella devices. There are no clinical data published that directly compare UFH with a DTI in patients requiring Impella support.

Methods: This retrospective cohort study included adult patients receiving either UFH or bivalirudin for greater than 24 hours with an Impella in place, from January 2017 – January 2024. The primary outcome was major bleeding based on ELSO and ISTH criteria during Impella use. Secondary outcomes included rate of device thrombosis, systemic thrombosis, time in therapeutic range (TTR), and on-device mortality.

Results: A total of 129 patients were screened with 69 patients included (n=39 UFH, n=30 bivalirudin). Major bleeding occurred in 23.1% vs 16.7% in the UFH and bivalirudin groups, respectively, but this difference was not statistically significant (p=0.561). There was a statistically higher percentage of TTR in the bivalirudin group vs the UFH group (median 66.5% vs 50.0%) with an absolute percentage difference of 16 (95% CI 4-27; p=0.012). Median duration of anticoagulation was longer in the bivalirudin group compared to the UFH group at 13.70 vs 4.33 days (median difference 5.07 days; 95% CI 0.59-13.13). No significant differences in mortality on the device, device-related thrombosis, or systemic thrombosis were observed.

Conclusions: Compared to UFH, bivalirudin had a similar risk of major bleeding for patients on tMCS with Impella. There were also no significant differences in device-related thrombosis or mortality. Patients in the bivalirudin group had a higher time in goal range with therapeutic monitoring. Further research is needed to determine the applicability of these results and optimize anticoagulation strategies for patients on Impella devices.