Outcomes With Heparin-Induced Thrombocytopenia After Cardiac Surgery

Background

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.

Methods

This was an observational study of cardiac surgeries from 2010 to 2018. Patients with HIT were matched against patients without HIT using 2:1 nearest-neighbor propensity matching. Matching was performed to assess the impact of HIT on operative mortality (The Society of Thoracic Surgeons definition) and thromboembolic events (including deep vein thrombosis, pulmonary embolism, stroke, and/or acute limb ischemia), which were the primary outcomes of interest.

Results

Of 11,820 patients undergoing a Society of Thoracic Surgeons indexed cardiac surgery, 131 (1.1%) developed HIT after their index operation. After matching operative mortality was 21.8% in HIT patients compared with 5.3% in non-HIT patients. Thromboembolic events occurred in 29.1% of HIT patients compared with 2.9% in non-HIT patients. On subanalysis operative mortality was significantly higher for the HIT group without thromboembolic events (16.7%) and the HIT group with thromboembolic events (34.4%) compared with the non-HIT group (5.3%). However operative mortality was not significantly higher in the HIT group with thromboembolic events compared with the HIT group without thromboembolic events, after Bonferroni correction.

Conclusions

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.