Heparin-induced thrombocytopenia (HIT) is an immune-mediated reaction to heparin that provokes a prothrombotic state and causes a decline in platelet count. Data describing outcomes of HIT after cardiac surgery are limited. This study sought to determine the impact of HIT on short-term outcomes after cardiac surgery.
This was an observational study of cardiac surgeries from 2010 to 2018. Patients with HIT were matched against patients without HIT via 2:1 nearest neighbor propensity matching. Matching was performed to assess the impact of HIT on operative mortality (STS definition) and thromboembolic events (including deep vein thrombosis, pulmonary embolism, stroke, and/or acute limb ischemia) – the primary outcomes of interest.
Of 11,820 patients undergoing an (STS indexed) cardiac surgery, 131 (1.1%) developed HIT after their index operation. After matching, operative mortality was 21.8% in HIT patients, as compared to 5.3% in non-HIT patients. Thromboembolic events occurred in 29.1% of HIT patients, as compared to 2.9% in non-HIT patients. On sub-analysis, operative mortality was significantly higher for the HIT group without thromboembolic events (16.7%) and the HIT group with thromboembolic events (34.4%), compared to the non-HIT group (5.3%). However, operative mortality was not significantly higher in the HIT group with thromboembolic events, as compared to the HIT group without thromboembolic events, after Bonferroni correction.
Although uncommon, HIT is a highly morbid and potentially lethal complication, which should reinforce the importance of timely recognition and treatment of this adverse outcome.

Copyright © 2020. Published by Elsevier Inc.

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