Objective: To establish the reference value of high sensitive cardiac troponin T (hs-cTnT) and the efficiency of reference value in the diagnosis of chest pain.
Methods: Volunteers from eight independent communities in Chengdu,Sichuan were selected with detailed records of physical examination,electrocardiogram,ultrasound examination. The level of hs-cTnT for healthy volunteers was tested to determine ninety-ninth percentile references according to sex and ages. 2 249 patients with chest pain in the emergency department of Western China Hospital from July 2009 to July 2014 were enrolled to measure the efficiency of reference value for diagnosing acute myocardial infarction (AMI).
Results: There were 1 305 volunteers included finally. Among them,the mean hs-cTnT level of male was 4.3 (3.2-5.9) ng/L,which was significantly higher than that of female 3.0 (3.0-3.1) ng/L ( P<0.01) . The correlation coefficient between age and hs-cTnT level was 0.43 (male) and 0.29 (female),and the P-value was less than 0.01. The 99th percentile values of male were 10.8 ng/L,15.4 ng/L and 19.7 ng/L for <45 yr.,45-<60 yr. and ≥60 yr.,respectively. Those values of female were 4.6 ng/L,8.9 ng/L,18.8 ng/L,respectively. There was no difference in sensitivity and specificity between the value we figured out and manufactures provided (14.0 ng/L) for those<60 yr.. For the patients ≥60 yr.,the sensitivity and negative predictive value did not show diversity ( P>0.05) but the specificity and positive predictive value showed significant difference (male: 0.67 vs. 0.56 and 0.83 vs. 0.79, P<0.05;female:0.75 vs. 0.68 and 0.74 vs. 0.69, P<0.05).
Conclusion: We recommends that the ninety-ninth percentile reference value of patients<60 yr. should be 14.0 ng/L,while 20.0 ng/L for those patients≥60 yr.
Keywords: Acute myocardial infarction; Chest pain; High sensitive cardiac troponin T; Ninety-ninth percentile reference value.