First-line treatment with oral anticoagulant predicts survival in acute cardiac patients with heparin-induced thrombocytopenia

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Heparin-induced thrombocytopenia (HIT) is a rare immune-mediated disorder related to the use of unfractionated heparin and low-molecular-weight heparin. Although thrombocytopenic, HIT is a paradoxical prothrombotic state associated with increased risk of vascular thrombosis and death. Non-heparin anticoagulants, parenteral and oral, are recommended for the treatment of HIT. As heparin is commonly used and thrombocytopenia is frequent in critically ill cardiac patients, HIT constitute a relevant clinical issue in the intensive cardiac care unit. Despite this, the incidence of HIT as well as factors influencing clinical outcomes in acute cardiac patients with HIT are unknown and have not been investigated so far. Purpose The purpose of our study was to evaluate the incidence of HIT in the population of cardiac patients and to determine if any predictor of survival for acute cardiac patients with HIT can be found. Methods We retrospectively collected data of all patients with HIT who were hospitalized in our intensive cardiac care unit in 2016 - 2021. We had used functionalized latex immunoassay to confirm the diagnosis of HIT in all patients. The choice of the non-heparin anticoagulant, oral or parenteral, for the first-line treatment of HIT had been left to clinical judgment of the physician. We performed statistical analysis including clinical and laboratory variables to find the predictors of survival in critically ill cardiac patients with HIT. Results Among 22 483 patients hospitalized in 2016 - 2021 in our department of cardiology 12 were diagnosed with HIT (incidence 1 : 1874). 5 of them were treated with parenteral non-heparin whereas 7 with oral anticoagulant as first-line treatment. 4 patients with HIT died during the index hospitalization. All of them were treated with parenteral non-heparin anticoagulant. 7 of 8 survivors were treated with oral anticoagulant as primary drug. First-line treatment with oral anticoagulant was the predictor of survival (p=0,0152) in our study group. There was no other neither clinical nor laboratory factor influencing outcomes in critically ill cardiac patients with HIT (Table 1). Conclusion First-line treatment with oral anticoagulant was the only one predictor of survival in acute cardiac patients with HIT. Oral anticoagulants may be preferred for the treatment of HIT in this population.