22039
Mean N - terminal pro B - type natriuretic peptide was above normal in both groups but within normal range in 5 patients with abnormal echo and above normal range in 24 patients with normal echo - missing sensitivity and specificity .
 N
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 N