2025 Southeastern Residency Conference

Title: 
Impact of aPTT versus Anti-Xa monitoring of unfractionated heparin during Impella support
 
Authors:
Seneca Williams
Lyndsay Gormley
Logan McCulloh
Bryan Love
Jenna Cox
 
Background:
Receipt of heparin during Impella mechanical circulatory support (MCS) to prevent thromboembolic complications and maintain purge reliability must be balanced with minimizing bleeding risk. Heparin may be administered through the purge solution and intravenously. The device manufacturer recommends the use of heparin via the purge solution and intravenously as needed to attain an activated clotting time (ACT) target of 160 to 180 seconds.  A 2019 survey by Reed et. al found that the majority of high-volume Impella institutions across the United States utilized activated partial thromboplastin time (aPTT) monitoring, followed by ACT and anti-Xa. In 2023, anti-Xa 0.2-0.4 IU/mL became the default heparin dosing strategy for patients receiving Impella support at Prisma Health. An aPTT goal of 50-70 seconds was our default strategy prior to this time and remains an option for providers to choose within our current order sets. Outcomes data comparing anticoagulation targets during Impella support are extremely limited.
 
Methods:
This multicenter, retrospective, cohort study aims to evaluate safety outcomes between aPTT (50-70 seconds) and anti-Xa (0.2-0.4 IU/mL) heparin monitoring strategies in patients receiving Impella support. Adult patients admitted to Prisma Health Richland or Greenville Hospitals between January 1, 2023 to December 31, 2024 who received Impella support for greater than six hours and intravenous heparin were included. Patients were excluded who received non-heparin anticoagulants during Impella support or heparin outside of specified target ranges. The primary outcome is the incidence of bleeding (utilizing major and minor per ISTH criteria). Secondary objectives include comparison of: the incidence of thrombotic events, time to onset of bleeding or thrombotic event, time to therapeutic aPTT or anti-Xa, total heparin exposure, length of Impella support, percentage of laboratory monitoring values (aPTT or anti-Xa, respectively) within target range.
 
Results:
In-Progress
 
Conclusions:
In-Progress