(149) Complications of Heparin With Intra-Aortic Balloon Counterpulsation

Introduction: Given improvements in intra-aortic balloon pump (IABP) technology, the use of anticoagulation (AC) with unfractionated heparin (UFH) to prevent limb ischemia in patients with an IABP remains debated. Further, risks of AC with UFH in the absence of an indication, such as venous thromboembolism (VTE) or atrial fibrillation (Afib), include heparin induced thrombocytopenia (HIT) and potential bleeding events. The purpose of this study is to evaluate the use of UFH in patients that receive an IABP at NYU Langone Health (NYULH) and assess anti-factor Xa (anti-Xa) targets along with any complications of UFH.

Methods: At NYULH, following implantation of an IABP, all patients are initiated on UFH, titrated to target an anti-Xa between 0.15-0.5 IU/mL, and/or an activated partial thromboplastin time (aPTT) of 40-70 second(s). In patients with underlying indication(s) for AC, the anti-Xa target is higher at 0.3-0.5 IU/mL. This is a retrospective cohort study of adult patients that received an IABP and UFH for ≥ 24 hours from January 1, 2018 to October 31, 2021. Electronic medical records were reviewed for pertinent data. The primary outcome was the incidence of limb ischemia. Secondary outcomes included the incidence of HIT testing, anti-Xa targets, and rates of any bleeding or thromboembolic event including myocardial infarction, thrombus on the IABP, VTE, or stroke. All outcomes were evaluated up to 7 days after IABP removal.

Results: Our cohort consisted of 159 patients with 88% receiving an IABP for cardiogenic shock. The median duration of IABP support was 118 hours (IQR 67, 196). Limb ischemia occurred in 4/159 patients (2.5%), strokes in 3.8%, and VTE in 11%, with the majority identified upon asymptomatic screening due to concerns for HIT. Bleeding events occurred in 33% of our cohort. No differences in outcomes occurred with a hybrid anti-Xa and aPTT versus aPTT monitoring alone.

Conclusions: The incidence of limb ischemia with the use of IABP remains low, even when UFH is titrated to anti-Xa levels of 0.15-0.5 IU/mL. However, the use of UFH leads to complications, including HIT screening and bleeding events. Future studies should evaluate the optimal anti-Xa target and consider lower intensity strategies for AC during IABP support.