Evaluation of anticoagulation management in patients with suspected heparin-induced thrombocytopenia awaiting diagnosis confirmation.

The 2018 American Society of Hematology (ASH) guidelines recommend discontinuation of heparin products upon suspicion of heparin-induced thrombocytopenia (HIT) and initiation of therapeutic non-heparin anticoagulation. This practice may be influenced by various factors, including diagnostic method. Our institution recently switched from an enzyme-linked immunosorbent assay (ELISA) that was run once daily to a chemiluminescence immunoassay (CLIA) that is run on-demand to detect anti-platelet factor 4 (PF4)/heparin antibodies. The objective was to evaluate if implementation of an on-demand anti-PF4/heparin antibody CLIA assay changed the timing of initiating a non-heparin anticoagulant compared with the traditional ELISA assay. A retrospective analysis was performed at our single academic medical center. Eligible subjects included patients ordered for an ELISA or CLIA anti-PF4/heparin assay upon suspicion of HIT. The major endpoint was the percentage of patients transitioned to a therapeutic non-heparin anticoagulant at the time of testing. Minor endpoints included the development of new or worsening thrombosis and/or bleeding within 72 h of testing. Overall, 227 patients were included in the analysis (n = 123 (ELISA), n = 104 (CLIA)). Significantly fewer patients in the CLIA group were switched to non-heparin anticoagulation at the time of testing as compared to the ELISA group (10.4% vs. 23.6%, p = 0.006). There were no differences between groups for the development of the minor endpoints. Significantly fewer patients were switched to therapeutic non-heparin anticoagulation at the time of testing after converting to an on-demand anti-PF4/heparin antibody CLIA assay. These findings may aid in optimizing institutional guidelines.