Heparin-induced thrombocytopenia in patients readmitted after open cardiac surgical procedures: A case series

Michael A Catalano; Vikram Prasad; Alexander M Spring; Hugh Cassiere; Tylis Y Chang; Alan Hartman; Pey-Jen Yu

doi:10.1016/j.xjon.2020.07.009

Heparin-induced thrombocytopenia in patients readmitted after open cardiac surgical procedures: A case series

JTCVS Open. 2020 Aug 3:4:36-42. doi: 10.1016/j.xjon.2020.07.009. eCollection 2020 Dec.

Authors

Michael A Catalano¹, Vikram Prasad¹, Alexander M Spring¹, Hugh Cassiere¹, Tylis Y Chang², Alan Hartman¹, Pey-Jen Yu¹

Affiliations

¹ Division of Cardiovascular and Thoracic Surgery, Zucker School of Medicine at Hofstra/Northwell, Manhasset, NY.
² Department of Pathology, Zucker School of Medicine at Hofstra/Northwell, Manhasset, NY.

Abstract

Objectives: Heparin-induced thrombocytopenia (HIT) is an immune-mediated complication that occurs in a small percentage of patients exposed to heparin. Concerns of HIT are particularly high in patients undergoing cardiac procedures requiring cardiopulmonary bypass, as they are exposed to high doses of heparin intraoperatively. Our aim was to identify and assess the hospital courses of patients who were diagnosed with HIT during readmission following cardiac surgery.

Methods: A retrospective review of patients who underwent open cardiac surgical procedures from June 2017 through October 2019 was performed. Of these, we identified patients who were newly diagnosed with HIT upon readmission. HIT positivity was defined as a positive anti-PF4 antibody screening test, plus a positive serotonin release assay.

Results: Of the 2496 patients identified, 13 patients were HIT positive on index admission and were excluded. Of the remaining 2483 patients, 351 were readmitted within 30 days. Six were newly diagnosed with HIT during readmission, 5 of whom presented with thrombotic complications. One patient was readmitted with thrombocytopenia and was started on argatroban; the remaining 5 did not have a significantly lower platelet count on readmission. Of the 12 patients readmitted for venous thromboembolism, 4 tested positive for HIT.

Conclusions: HIT can have a delayed appearance following open heart surgery. Venous thromboembolism appears to be a significant indicator for HIT during readmission, even in the absence of thrombocytopenia. This may support the use of non-heparin anticoagulation for cardiac surgery patients readmitted with thromboembolism until HIT status is determined.

Keywords: CPB, cardiopulmonary bypass; DVT, deep-vein thrombosis; ELISA, enzyme-linked immunosorbent assay; HIT; HIT, heparin-induced thrombocytopenia; HITT, heparin-induced thrombocytopenia and thrombosis; PE, pulmonary embolus; PF4, platelet factor 4; UFH, unfractionated heparin; VTE, venous thromboembolism; cardiac surgery; thrombotic complications.