2573
BACKGROUND : Direct thrombin inhibitors ( DTIs ) provide an alternative method of anticoagulation for patients with a history of heparin - induced thrombocytopenia ( HIT ) or HIT with thrombosis ( HITT ) undergoing cardiopulmonary bypass ( CPB ) .
 heparin, thrombocytopenia, HIT, HIT, thrombosis, HITT
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 heparin, thrombocytopenia, HIT, HIT, thrombosis, HITT