Cardiovascular Journal of Africa: Vol 26 No 6 (November/December 2015)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 6, November/December 2015 234 AFRICA
High-sensitivity cardiac troponin T is more helpful in
detecting peri-operative myocardial injury and apoptosis
during coronary artery bypass graft surgery
Emel Fatma Kocak, Cengiz Kocak, Ahmet Aksoy, Ozden Ozben Isiklar, Raziye Akcilar, Ibrahim Fevzi
Ozdomanic, Cevher Unsal, Merve Celenk, Irfan Altuntas
Abstract
Aim: To determine whether there is a correlation between
cardiac markers and peri-operative myocardial injury (PMI)
and apoptosis in coronary artery bypass graft (CABG)
surgery and to compare the efficacy of cardiac markers to
detect PMI.
Methods: The study population consisted of 37 patients (24
male, 13 female, mean age 63.4 ± 8.9 years) undergoing elec-
tive CABG. Arterial and coronary sinus blood samples were
collected just before aortic cross-clamping (pre-ACC) and
after aortic declamping (post-ACC). Creatine kinase-MB
isoenzyme (CK-MB) activity, and high-sensitivity cardiac
troponin T (hs-cTnT), creatine kinase-MB isoenzyme mass
(CK-MB mass) and cardiac troponin I (cTnI) concentrations
were measured in blood samples. Myocardial injury and
apoptosis were examined in atrial biopsies.
Results: CABG caused PMI and apoptosis in all cases.
Concentrations and net releases of cardiac markers signifi-
cantly increased after aortic declamping (p < 0.001 for
CK-MB and CK-MB mass, p < 0.01 for cTnI, p < 0.05 for
hs-cTnT). A positive correlation was found between apop-
totic index ( r = 0.611, p < 0.001 for cTnI; r = 0.806, p < 0.001
for hs-cTnT), myocardial injury score ( r = 0.544, p < 0.001
for cTnI; r = 0.719, p < 0.001 for hs-cTnT) and cTnI and
hs-cTnT values in the post-ACC period. A positive correla-
tion was found between apoptotic index ( r = 0.507, p < 0.001),
myocardial injury score (r = 0.416, p = 0.010) and net release
of hs-cTnT. Furthermore, a positive correlation was found
between aortic cross-clamp (ACC) time (r = 0.448, p = 0.007),
cardiopulmonary bypass (CPB) time ( r = 0.342, p = 0.047) and
net release of hs-cTnT.
Conclusion: Although both cTnI and hs-cTnT may be specific
and efficacious markers of myocardial apoptosis and injury
occurring during CABG with CPB, hs-cTnT may be a more
useful marker than cTnI to detect peri-operative myocardial
apoptosis and injury.
Keywords: apoptosis, creatine kinase, MB form, coronary artery
bypass, myocardial reperfusion injury, troponin
Submitted 19/4/15, accepted 14/6/15
Published online 14/7/15
Cardiovasc J Afr 2015; 26: 234–241
DOI: 10.5830/CVJA-2015-052
Coronary artery bypass grafting (CABG) accompanied by
cardiopulmonary bypass (CPB) is a safe, routine procedure for the
surgical treatment of various heart diseases, including coronary
artery disease. Cardiopulmonary bypass and cardioplegic arrest
enable the performance of coronary artery anastomosis in a
bloodless and motionless field during CABG surgery.1,2 However,
peri-operative myocardial injury (PMI) is a major problem and
the most common cause of morbidity and mortality during
CABG surgery.3
Despite optimal myocardial protective techniques, a certain
amount of myocardial injury may occur in the majority of
patients undergoing CABG surgery. Various factors can cause
myocardial injury during CABG surgery, most importantly
CPB, surgical technique, suture placement or manipulation of
the heart, coronary dissection, aortic cross-clamping (ACC), and
inadequate cardiac protection. 4-6
During CPB, the heart is arrested and protected by
cardioplegia. This period is associated with oxygen deprivation
and the heart is ischaemic during this time. At the end of CPB, the
heart is reperfused and cardiac action resumes. These ischaemic
and subsequent reperfusion periods cause myocardial injury and
Department of Medical Biochemistry, Faculty of Medicine,
Dumlupinar University, Kutahya, Turkey
Emel Fatma Kocak, MD,
Irfan Altuntas, MD
Department of Pathology, Faculty of Medicine, Dumlupinar
University, Kutahya, Turkey
Cengiz Kocak, MD
Department of Cardiovascular Surgery, Evliya Celebi
Education and Research Hospital, Dumlupinar University,
Kutahya, Turkey
Ahmet Aksoy, MD
Ibrahim Fevzi Ozdomanic, MD
Department of Medical Biochemistry, Evliya Celebi
Education and Research Hospital, Dumlupinar University,
Kutahya, Turkey
Ozden Ozben Isiklar, MD
Department of Physiology, Faculty of Medicine,
Dumlupinar University, Kutahya, Turkey
Raziye Akcilar, PhD
Department of Anesthesiology and Reanimation, Evliya
Celebi Education and Research Hospital, Dumlupinar
University, Kutahya, Turkey
Cevher Unsal, MD
Department of Medical Biochemistry, Evliya Celebi
Education and Research Hospital, Dumlupinar University,
Kutahya, Turkey
Merve Celenk, MD