Availability of Cardiac Troponin T as a Marker for Detecting Perioperative Myocardial Damage in Patients with Open Heart Surgery

개심술후 발생한 심근손상에서 진단 표지자로서의 Troponin T의 임상적 유용성

  • 김태이 (영남대학교 의과대학 흉부외과학교실) ;
  • 정태은 (영남대학교 의과대학 흉부외과학교실) ;
  • 이동협 (영남대학교 의과대학 흉부외과학교실) ;
  • 이정철 (영남대학교 의과대학 흉부외과학교실) ;
  • 한승세 (영남대학교 의과대학 흉부외과학교실)
  • Published : 1998.01.01

Abstract

It is well known that troponin T(below TnT) is present in the myocardial cells and released during myocardial damage, so it`s very specific enzyme to myocardium. Availability of cardiac specific TnT in assessing perioperatively myocardial damage was evaluated from 34 open heart surgery patients. They consisted of 11 ischemic heart, 13 acquired valvular heart and 10 congenital heart cases. Patients were divided into two groups, group A(patients with myocardial damage) and group B(patients without myocardial damage), according to the symptom of chest pain suspecting angina and the ECG findings of ST segment and T wave changes which show myocardial ischemia and injury. Serum TnT levels were measured by enzyme immunoassay method preoperatively, immediately postoperatively, postoperative day 1, day 2, day 3, and day 7. We observed and analyzed the changes of serum TnT levels in two groups and compared the serum TnT levels with CK-MB levels measured at the same time. In group A, serum TnT levels showed 1.37$\pm$0.26$\mu$g/L, 3.16$\pm$0.66$\mu$g/L, 2.39$\pm$0.74$\mu$g/L, 2.49$\pm$0.76$\mu$g/L, and 1.23$\pm$0.60$\mu$g/L, immediate postoperatively, postoperatively day1, day2, day3, and day7, respectively. It was observed there were significant differences compared with those of group B(0.38$\pm$0.04$\mu$g/L, 0.34$\pm$0.05$\mu$g/L, 0.25$\pm$0.03$\mu$g/L, 0.24$\pm$0.04$\mu$g/L, and 0.11$\pm$0.03$\mu$g/L) during identical periods(P<0.01). Serum CK-MB level in group A significantly elevated to 145.04$\pm$35.08 IU/L on the postoperative day 1 compared to group B(31.28$\pm$5.87 IU/L, P<0.05), However, it stiffly decreased from day 2 and returned to preoperative level at day 3. When serum TnT level more than 1.0$\mu$g/L is thought to reflect myocardial damage, serum TnT had 100% of sensitivity and 87% of specificity in diagnosing the postoperative myocardial damage(p<0.01). I conclusion, serum TnT levels increased significantly at very early stage of myocardial damage and persisted much longer period than CK-MB. This suggests that serum TnT has more advantage and availability in assessing the perioperatively myocardial damage than any other tests.

Troponin T(이하 TnT)는 주로 심근세포에 존재하며 심근손상 시에만 유리되는 심근특이 효소이다. 저자들은 개심술을 시행한 34명의 환자들을 대상으로 수술 전후 심근손상에 대한 지표로서 TnT의 유용성에 대해 조사하였다. 환자들은 허혈성 심질환에 의한 관동맥 우회술이 11례, 후천성 판막 질환이 13례, 그리고 선천성 심질환이 10례였다. 이들은 술후 흉통과 심전도의 ST분절과 T파의 변화 등에 의거하여 심근손상이 의심되는 환자들(A군, 11례)과 정상 소견을 가진 환자들(B군, 23례)로 구분하였다. TnT의 측정은 효소 면역법을 이용하여 술 전, 수술 직후와 술후 1, 2, 3, 7일에 각각 측정하여 수술 전후의 수치 변화를 각 군간에 서로 비교하였고, 같은 시기에 측정한 CK-MB의 변화와 비교 분석하였다. A군에서는 수술 직후와 술후 1, 2, 3, 7일에 각각 1.37$\pm$0.26 $\mu$g/L, 3.16$\pm$0.66 $\mu$g/L, 2.39$\pm$0.74 $\mu$g/L, 2.49$\pm$0.76 $\mu$g/L, 그리고 1.23$\pm$0.60 $\mu$g/L로 변화하였으며, B군에서는 0.38$\pm$0.04 $\mu$g/L, 0.34$\pm$0.05 $\mu$g/L, 0.25$\pm$0.03 $\mu$g/L, 0.24$\pm$0.04 $\mu$g/L, 그리고 0.11$\pm$0.03 $\mu$g/L로 두 군간에 전기간에 걸쳐서 유의한 차이를 가졌다(P<0.01). 이에 반하여 CK-MB는 술후 1일째만 A군과 B군간에 145.04$\pm$35.08 IU/L과 31.28$\pm$5.87 IU/L로 유의한 차이가 있었고(P<0.05), 2일째부터 급격히 감소하여 3일 이후에는 술전치로 환원하였다. 혈청 TnT치가 1.0 $\mu$g/L이상인 경우를 술후 심근손상의 기준으로 볼 때 TnT는 심근손상의 진단에 있어서 100%의 민감도와 87%의 특이도를 보였다(P<0.01). 따라서 TnT는 심근손상 환자에 있어서 CK-MB와 달리 수술 직후부터 증가하여 지속됨으로써 심근손상의 정도를 더욱 민감하게 반영하고, 장기간 유의한 차이를 보여줌으로써 술후의 심근손상을 진단하는데 있어서 기존의 방법들보다 더욱 유용한 것으로 사료된다.

Keywords

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