Changes of Serum Troponin-T Concentrations in Patients with Open Heart Surgery

Park, Dong Wook; Choi, Suk Chul; Kim, Yoon Gyu; Park, Jong Wean; Jo, Kwan Hyun

Abstract

This study was designed to identify the efficiency of serum troponin-T (s-TnT) level as a diagnostic indicator for the perioperative myocardial damage with open heart surgery (OHS) and to compare with the conventional myocardial enzyme tests such as isoenzyme fraction of creatine kinase (% CK-MB) and isoenzyme ratio of lactate dehydrogenase (LDH1/LDH2 ratio). The study was performed on 30 adult patients who underwent OHS from Jan. 1996 to June 1996 at Inje University Pusan Paik Hospital, and they were divided into two groups accorfding to aortic clamping time (ACT) duration : group I (ACT<60 minutes, n=15); group II (ACT>60 minutes, n=15). S-TnT, % CK-MB, and LDH1/LDH2 ratio were measured in serial blood samples from all subjected patients. The results were obtained as follows. 1. In both groups, s-TnT concentrations increased gradually during OHS and elevated significantly at CPB-10 (p<0.001). The peak level was noticed at POD 1 in group I (1.10 +/-0.19 ng/ml), whereas, at CPB-off in group II (1.88+/-0.42 ng/ml). The elevated levels remained until POD 7 in both groups. 2. %CK-MB was risen significantly with the initiation of operations (p<0.001) and the peak levels were noticed at CPB-off in both groups (7.14+/-0.86% in group I, 10.69+/-1.27% in group II). Thereafter, these levels returned to normal values at POD 3. 3. There were no significant changes in the values of LDH1/LDH2 ratio during and after OHS compared with the control levels (p>0.05). 4. The serial changes of s-TnT were relatively well correlated with those of changes of % CK-MB (r=0.64, p<0.05). 5. The serial s-TnT levels were significantly higher in group II than group I from B-ACR to POD 1 (p<0.05), suggesting that duration of aortic clamping time was a major factor concerned with perioperative myocardial injury. In conclusion, measurement of s-TnT is a very useful indicator in assessing the myocardial cell damage and therefore it is expected that serial checking and evaluation of the s-TnT is very available for identification of the perioperative myocardial damage and for postoperative cares in patients with OHS.