1552
Idraparinux , a Factor Xa inhibitor , is being evaluated in patients with atrial fibrillation .
 Idraparinux, atrial fibrillation
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Idraparinux, atrial fibrillation