Comparison of cardiac troponin I and creatine kinase ratios in the detection of myocardial injury after aortic surgery

BACKGROUND: Perioperative myocardial infarction may not be diagnosed correctly because World Health Organization criteria are often not met and creatinine kinase myocardial fraction (creatinine kinase/creatinine kinase MB isoenzyme; CK/CK-MB) ratios can be difficult to interpret. Cardiac troponin (cTn) I and cTnT are the most sensitive and specific markers of myocardial cell necrosis currently available but are not widely used in surgical practice. The aim was to compare cTnI and CK/CK-MB ratios in the detection of myocardial injury following aortic surgery. METHODS: This was a prospective study of 59 patients undergoing elective (n = 28) or ruptured (n = 24) abdominal aortic aneurysm repair or elective aortofemoral bypass (n = 7). cTnI level was measured before operation and at 6, 24 and 48 h after surgery. The CK/CK-MB ratio was measured where cTnI was detectable. RESULTS: Some 14 of 24 emergency and ten of 35 elective patients had detectable cTnI (greater than 0.5 ng/ml) at one or more time-points. The CK/CK-MB ratio was greater than 5 per cent in only four of 24 patients having an emergency operation and in none of the elective patients with detectable cTnI. CONCLUSION: Over half of patients undergoing emergency operation and more than a quarter of those having elective aortic surgery suffered myocardial necrosis as determined by detectable cTnI levels. This was accompanied by a raised CK/CK-MB ratio in less than one-fifth of patients.     

血清心型肌酸激酶对判断电损伤后心脏损害的临床价值

目的探讨电损伤后心脏损害的发病情况及判断电损伤后心脏损害的血清酶学指标。方法研究了３２例电接触性损伤患者的心电图、血清肌酸激酶（ＣＫ）和心型肌酸激酶（ＣＫＭＢ）活性。结果１７例患者有心电图异常（Ａ组）,１５例患者心电图基本正常（Ｂ组）。将测定的血清ＣＫＭＢ减１１％总ＣＫ的差定义为ＣＫＭＢ差值。Ａ组ＣＫ、ＣＫＭＢ、ＣＫＭＢ／ＣＫ比率和ＣＫＭＢ差值明显高于Ｂ组（全部：Ｐ＜００５）。Ａ组８８％的患者ＣＫＭＢ差值大于２５Ｕ／Ｌ,Ｂ组为６７％（Ｐ＜００１）。结论（１）心脏损害是电损伤的常见并发症,高压电更易于导致心脏损害;（２）血清ＣＫＭＢ,特别是ＣＫＭＢ差值可用于评价电损伤患者的心脏损害。     

Do we still need CK-MB in coronary artery bypass grafting surgery?

AIM: The aim of this study was to evaluate the role of cardiac Troponin I (cTnI) and CK-MB for early prediction of outcome of patients undergoing coronary artery bypass grafting (CABG) surgery. METHODS: In 134 consecutive patients undergoing CABG-surgery blood samples were analyzed for cTnI concentration and CK-MB activity. ECG, hemodynamic parameters and the need for inotropic support, were continuously registered. Patients were divided into group A (uneventful course), group B (ischemia by ECG, hemodynamic stability) and group C (ischemia by ECG and IABP). RESULTS: After removal of X-clamp an increase cTnI and CK-MB was observed in all patients. Five hrs after stop of CPB group A (8.3+/-4.2 microg/L) had lower cTnI values compared to group B (14.8+/-5.3 microg/L) (p=0.035) and C (54+/-22.8 microg/L) (p=0.023). The cut off value was 14.8 microg/L. Sensitivity and specificity (99%/97%) was higher for cTnI than for CK-MB (90%/30%). The positive predictive value of outcome was better for cTnI (86%) than for CK-MB (33%). CONCLUSION: CTnI is a specific and sensitive marker for evaluation of perioperative myocardial ischemia (PMI). Additional determination of CK-MB activity does not provide further clinical information. CTnI should be the marker of first choice in CABG surgery.     

Clinical significance of elevated troponin I levels in patients with nontraumatic subarachnoid hemorrhage

OBJECT: Aneurysmal subarachnoid hemorrhage (SAH) is associated with electrocardiographic abnormalities, regional or focal wall-motion abnormalities on echocardiograms, and/or increased creatine kinase MB isoenzyme (CK-MB) or cardiac troponin I (cTnI). The goal of this prospective study was to compare the sensitivity and specificity of cTnI with those of CK-MB in the prediction of left ventricular dysfunction on echocardiograms in patients with nontraumatic SAH. In addition, those patients with abnormal findings on their echocardiograms and elevated cTnI levels were further evaluated for the presence of coronary artery disease (CAD) by a cardiologist and to determine whether any left ventricular dysfunction that had been detected was reversible. METHODS: The authors obtained electrocardiograms and echocardiograms, and measured serial levels of cardiac enzymes (CK-MB and cTnI) in 43 patients with nontraumatic SAH. Patients with known CAD were excluded. Those patients found to have elevated enzyme levels and abnormal findings on their echocardiograms underwent additional evaluation for CAD. The sensitivity and specificity of both cTnI and CK-MB for detecting left ventricular function were determined. Twenty-eight percent of patients with SAH in the study had elevated cTnI levels within the first 24 hours after hemorrhage. Seven of the 12 patients had evidence of left ventricular dysfunction on echocardiograms. In all these patients a return to baseline function was found during follow-up examinations. The authors found that cTnI is much more sensitive than CK-MB (100% compared with 29%) in the detection of left ventricular dysfunction in patients with SAH. CONCLUSIONS: An elevated level of cTnI is a good indicator of left ventricular dysfunction in patients with SAH. In this study cardiac dysfunction was reversible and should not necessarily preclude these patients from undergoing operative interventions or becoming heart donors. Clinical management may require more aggressive hemodynamic monitoring until cardiac function returns to normal.     

Troponin I and myocardial injury in the ICU

Cardiac troponin I (cTnI) is a protein that is specific to heart muscle. Increased concentrations appear in serum after myocardial cell injury. cTnI was compared with creatinine kinase MB (CK MB), myoglobin and the 12-lead ECG for detection of myocardial injury in an unselected series of 109 medical and surgical ICU patients. Clinical observations and daily 12-lead ECG were recorded prospectively. Samples for cTnI, myoglobin and CK MB serum analysis were collected each day. Increased serum cTnI concentrations (> 0.1 microgram litre-1) were observed in 70.6% (n = 77) of the ICU group. Tachycardia, arrhythmia, hypotension and treatment with inotropic drugs were associated with higher concentrations. The standardized mortality ratio by APACHE III for the ICU sample was 0.98. All subjects in an unmatched control group of 98 medical unit emergency admissions without a primary cardiac diagnosis had serum cTnI concentrations < 0.1 microgram litre-1. We conclude that increased serum cTnI concentrations occur frequently in the ICU suggesting that there is a high incidence of cardiac injury in these patients.      

Serum levels of cardiac troponin I and other marker proteins in patients with chronic renal failure

Background Serum levels of biochemical markers for acute myocardial infarction (AMI) can be increased in patients with chronic renal failure (CRF) or skeletal muscle injury, creating diagnostic confusion. We evaluated the clinical utility of cardiac troponin I (cTnI) as a marker of AMI, particularly in patients with CRF.Methods Subjects consisted of 59 healthy volunteers and 102 patients: 61 with CRF undergoing hemodialysis (CRF-HD), 10 with CRF under conservative therapy (CRF-CT), 21 with renal disease (RD), and 10 with muscle disease (MD). Patients with RD, CRF, and MD were evaluated to verify the absence of myocardial injury. We developed an immunoradiometric assay to measure serum cTnI using monoclonal antibodies. The lower limit of detection was 0.33µg/l. Serum cTnI, creatine kinase (CK), CK-MB, cardiac troponin T (first-, second-, and third-generation assay: cTnT-I, cTnT-II, and cTnT-III), and cardiac myosin light chain 1 (cMLC1) were measured.Results cTnI was not detected in healthy volunteers or patients with CRF, RD, or MD. In patients with CRF-HD, elevated levels occurred in 4.9% (3/61) for CK, 0% (0/61) for CK-MB, 39.5% (15/38) for cTnT-I, 7.3% (3/41) for cTnT-II, 13.0% (3/23) for cTnT-III, and 77.0% (47/61) for cMLC1; and in patients with MD the levels were increased in 70% (7/10) for CK, 50% (5/10) for CK-MB, 44.4% (4/9) for cTnT-I, 20% (2/10) for cTnT-II, and 50% (5/10) for cMLC1.Conclusions cTnI is a highly specific marker for AMI and is particularly useful for detecting AMI in patients with CRF or MD.     

Myocardial injury after off-pump coronary artery bypass grafting operation.

OBJECTIVE: Perioperative myocardial ischemia is less pronounced in off-pump coronary artery bypass (OPCAB) compared to on-pump coronary artery bypass; however, the threshold over which the postoperative release of cardiac troponin I (cTnI) release and creatine kinase-MB (CK-MB) after OPCAB should be considered clinically relevant is unknown. The study was designated to evaluate if perioperative myocardial damage, measured by means of postoperative release of cTnI and CK-MB, has an influence on short- and mid-term outcome after OPCAB operations. METHODS: Two hundred and sixty-one unselected patients undergoing OPCAB had cTnI and CK-MB measured preoperatively and nine times postoperatively. Postoperative peak values were evaluated and the 80th percentiles were used to segregate the population into two groups for each marker. The following cut-offs were used: 7.1 ng/dl for cTnI peak and 36.3 ng/dl for CK-MB peak. RESULTS: Patients with cTnI>7.1 ng/ml (n=51) and CK-MB>36.3 ng/ml (n=48) had a longer mechanical ventilation and ICU length of stay. Nevertheless, hospital mortality did not differ between groups. Survival after 3 years was 92.8+/-2.3% and 81.8+/-6.2 for patients with postoperative cTnI peak7.1 ng/ml, respectively (p=0.003). It was 93+/-2.2% and 80+/-6.8% for patients with CK-MB36.3 ng/ml, respectively (p=0.005). Adjusted hazard ratios for mid-term mortality were HR 2.7 (CI 1-7.6), p=0.05 for cTnI>7.1 ng/dl and HR 3.1 (CI 1-9.1), p=0.04 for CK-MB>36.3 ng/ml. CONCLUSION: Perioperative myocardial damage should not be considered an innocuous event following OPCAB operations since the survival rate over 3 years is significantly worse in patients with the highest postoperative peak release of cTnI and CK-MB.     

The value of echocardiography in blunt chest trauma

All victims of blunt injury to the chest or precordium admitted to a Level I trauma center in a 1-year period were evaluated prospectively with two-dimensional echocardiography on the day of admission, serial determinations of creatine kinase (CK) and MB isoenzyme radioimmunoassay (CK-MB) over the first 24 hours, continuous electrocardiographic monitoring over at least the first day, and serial 12-lead electrocardiography (ECG) over the first 3 days. The patients were divided into four groups based upon the results of echocardiography. Group A (n = 35) had normal ECHO and ECG; Group B (n = 16), normal ECHO and abnormal ECG; group C (n = 14), ECHO showing abnormal wall motion and/or pericardial fluid; group D (n = 8), ECHO showing a nontraumatic valvular or wall motion abnormality. Nineteen patients required an operation under general anesthesia. Group C patients had significantly higher CK, CK-MB, numbers of associated injuries, and Injury Severity Scores; seven required invasive hemodynamic monitoring. No cardiac morbidity of general anesthesia was seen. We conclude that echocardiography is an important tool for diagnosis and triage which may be used to stratify a homogeneous patient population into groups with acute, chronic, and no cardiac disease. Cardiac injury occurs in a setting of multisystem trauma. Patients with normal echocardiogram and ECG on admission do not require intensive care monitoring.     

大剂量磷酸肌酸钠预先给药对心脏瓣膜置换术患者心肌缺血再灌注损伤的影响

目的 探讨大剂量磷酸肌酸钠预先给药对心脏瓣膜置换术患者心肌缺血再灌注损伤的影响.方法 择期拟行二尖瓣-主动脉瓣置换术患者246例,年龄42～71岁,体重45～80 kg,随机分为2组:对照组(NS组,n=122)和磷酸肌酸钠预先给药组(CP组,n=124).CP组切皮时开始中心静脉输注磷酸肌酸钠10g(溶于100ml生理盐水),输注时间60 min,NS组静脉输注等容量生理盐水,分别于麻醉前、术后第1天和第5天采集颈内静脉血样,检测血清磷酸肌酸激酶、乳酸脱氢酶、肌酸激酶同工酶的活性,测定心肌肌钙蛋白I浓度,观察心律失常、心肌梗塞的发生情况及自动复跳情况,记录使用正性肌力药多巴胺(≥5 μg·kg-1·min-1)和肾上腺素的患者例数及左室射血分数.结果 与NS组比较,CP组术后第1天和第5天血清磷酸肌酸激酶、乳酸脱氢酶、肌酸激酶同工酶的活性及心肌肌钙蛋白I浓度降低,使用多巴胺和肾上腺素的患者例数减少,术后心律失常和心肌梗塞的发生率降低,自动复跳率及左室射血分数升高(P<0.05).结论 大剂量磷酸肌酸钠(10 g)预先给药可减轻二尖瓣-主动脉瓣置换术患者的心肌缺血再灌注损伤,改善心脏功能.     

Cardiac troponin I versus creatine kinase-MB in the detection of postoperative cardiac events after coronary artery bypass grafting surgery

AIM: Several studies suggest that postoperarive concentrations of cardiac troponin-I (cTnI) may increase in patients undergoing aorto-coronary bypass grafting (CABG). The degree and pattern of release appears to be associated with perioperative myocardial damage. METHODS: This was a prospective observational study with serial sampling conducted at the Departments of Cardiothoracic Surgery and Anesthesiology, University Hospital of Ioannina, Ioannina, Greece. The levels of cTnI and creatine kinase-MB (CK-MB) preoperatively, upon admission to the intensive care unit and at 12, 24, 36 and 48 hours after surgery, as well as daily from postoperative days 3-7 were determined in 41 consecutive patients (33 males and 8 females, aged 64.8+/-6.1 years) who underwent CABG with cardiopulmonary bypass. The Authors compared the patterns and variation of cTnI and creatine kinase (CK)-MB after CABG in patients with or without postoperative cardiac events (PCEs). RESULTS: Eleven patients experienced a PCE (postoperative ventricular and supraventricular arrhythmia, need for intra-aortic balloon pump (IABP) for >12 hours, or postoperative myocardial infarction, [MI]). In patients without PCE the elevation of cTnI peaked at 24 hours after surgery, while in patients with PCE maximal values of cTnI occurred after 36 hours. CTnI levels correlated with CK-MB after the procedure. Receiver-operating characteristic (ROC) curve analysis indicated that cTnI is superior to CK-MB with regard to PCE diagnosis following CABG (area under the ROC curve, 0.73, 95% CI (0.53-0.93) versus 0.54, 95% CI, (0.25-0.83). CONCLUSION: CTnI seems to be more valuable compared to CK-MB in the detection of PCEs in patients undergoing coronary surgery.     

Role of troponin I, myoglobin, and creatine kinase for the detection of early graft failure following coronary artery bypass grafting.

OBJECTIVE: The detection of early graft failure following coronary artery bypass grafting (CABG) enables immediate reintervention and may significantly limit myocardial damage, thus potentially improving outcome. To date, non-invasive indicators of early graft failure following coronary surgery are still of uncertain diagnostic value. METHODS: In a prospective study, patients following isolated CABG with a postoperative serum cardiac troponin I (cTnI) above 20 ng/ml or significant ECG-changes underwent acute repeat angiography. cTnI, myoglobin (Myo), and creatine kinase (CK) were measured preoperatively and at 1, 6, 12, and 24 h after aortic unclamping. Peak values of cTnI, Myo, CK and isoenzyme CK-MB were determined postoperatively. Receiver operating curves (ROC) for cTnI, Myo and CK/CK-MB were constructed at 6, 12, and 24 h after aortic unclamping to differentiate between patients with and without early graft failure. Based on these curves, the area under curve+/-standard deviation (AUC+/-SD), the sensitivity and specificity were calculated. RESULTS: Out of 2078 consecutive patients having undergone isolated CABG from January 2001 to April 2003, 55 fulfilled the inclusion criteria and underwent acute repeat angiography. Early graft failure was found in 35 patients (group 1), whereas 20 patients did not show graft failure (group 2). CTnI and Myo, but not CK and CK-MB levels were significantly increased in group 1 compared to group 2 at 12 and 24 h after aortic unclamping. ROC analysis of cTnI, Myo and CK/CK-MB indicated cTnI as the best discriminator between the groups with 21.5 ng/ml at 12 h (AUC, 0.82+/-0.06; sensitivity, 82%; specificity, 66%) and 33.4 ng/ml at 24 h (AUC, 0.95+/-0.03; sensitivity, 98%; specificity, 82%) and Myo with 887 microg/ml at 12 h (AUC, 0.72+/-0.07; sensitivity, 73%; specificity, 57%) after aortic unclamping. In contrast, CK/CK-MB as well as the appearance of ECG-changes could not separate between the groups. CONCLUSIONS: cTnI, but not Myo and CK served as a reliable marker for the identification of patients with early graft failure following CABG.     

Elevated concentrations of cardiac troponins are associated with severe coronary artery calcification in asymptomatic haemodialysis patients.

BACKGROUND: Elevated concentrations of cardiac biomarkers, such as troponins and natriuretic peptides, have been shown to be predictive of poorer long-term cardiovascular outcomes in stable patients with end-stage renal disease (ESRD). However, little is known about the relationship between elevated concentrations of these cardiac markers and underlying coronary artery pathology in these patients. The aim of the present study was to investigate associations between coronary artery calcification (CAC) and the concentrations of cardiac biomarkers in ESRD patients. METHODS: We conducted a cross-sectional study of 38 asymptomatic patients (median age, 54 years; 26 males, 12 females; diabetic, 39%) who were undergoing chronic haemodialysis. In these patients, pre-dialysis circulating concentrations of cardiac troponin T (cTnT), cardiac troponin I (cTnI), creatine kinase-MB (CK-MB) and B-type natriuretic peptide (BNP) were measured. We quantified the level of CAC by multirow spiral computed tomography to obtain a CAC score. CAC scores > or = 400 were defined as being indicative of severe CAC. RESULTS: Severe CAC was detected in 17 patients (45%). The degree of CAC severity was positively associated (P < 0.05) with cTnT concentrations. Thus, 15% of patients had severe CAC in the lowest tertile of cTnT, 50% had severe CAC in the middle third, and 69% in the highest third. Similarly, the degree of severity of CAC was positively associated (P < 0.01) with cTnI concentrations across concentration categories. In contrast, there was no association between the degree of CAC severity and the concentrations of either BNP or CK-MB. A logistic regression analysis revealed that elevated concentrations of cTnT (> or = median vs or = 0.1 ng/ml vs 相似文献   

Significance of mildly elevated creatine kinase (myocardial band) activity after elective abdominal aortic aneurysmectomy

The clinical significance of mildly elevated creatine kinase (CK) myocardial band (MB) enzyme levels in patients undergoing elective repair of an abdominal aortic aneurysm was evaluated retrospectively in 348 patients. For each patient, preoperative and postoperative electrocardiograms (ECGs) were interpreted blindly for left ventricular hypertrophy, ST segment abnormality, left bundle branch block, right bundle branch block, left axis deviation, atrial fibrillation, T wave abnormality, and Q waves. A total of 107 patients (31%) had postoperative CK-MB elevations of trace or greater; 37 had trace, 35 had 1% to 4%, and 35 had greater than or equal to 5% elevation. There was no difference in survival between those with trace and no CK-MB elevation. Patients with increased CK-MB (greater than or equal to 1%) values were more likely to have ECG abnormalities. The following ECG (either preoperative or postoperative) abnormalities were univariately related to decreased postoperative survival: left ventricular hypertrophy (P less than 0.001), ST segment abnormalities (P less than 0.001), left bundle branch block (P less than 0.001), the combination of right bundle branch block and left axis deviation (P = 0.006), Q wave infarction (P less than 0.001), and atrial fibrillation (P less than 0.001). There were 15 in-hospital deaths, and 333 patients were discharged and followed-up for a median of 4.6 years. There were 97 posthospitalization deaths, 61% of which were due to cardiac causes. Overall survival was associated with the degree of CK-MB elevation; the higher the CK-MB, the worse the survival.(ABSTRACT TRUNCATED AT 250 WORDS)     

Creatine kinase as a prognostic indicator in electrical injury

Serial serum creatine kinase (CK) and creatine kinase myocardial band isoenzyme (CK-MB) levels were obtained from 116 of 125 electrical burn patients admitted from 1976 through 1986. We divided patients into three groups (peak CK within 2 days after admission) as follows: group 1, CK less than 400 U/L; group 2, CK = 400 to 2500 U/L; group 3, CK greater than 2500 U/L. Clinical myocardial infarction (MI) was determined by ischemic ECG changes, LDH isoenzyme patterns, and clinical course. Skin grafts occurred in 2 of 24 patients from group 1, in 15 of 31 from group 2, and in 37 of 61 from group 3. Hospital stay (mean +/- SEM) was 4.6 +/- 1.3 days for group 1, 20.2 +/- 5.4 for group 2, and 37.7 +/- 3.6 for group 3. Group 1 patients required no amputations; group 2 had 1 limb and 5 digit amputations; group 3 had 22 limb and 16 digit amputations. Only three clinical MIs were found (all in group 3), although 1 of 31 patients from group 2 and 32 of 61 from group 3 had CK-MB greater than 4%. Highly elevated CK and CK-MB are associated with longer hospitalization, and a greater risk of skin grafting or amputation, than with levels less than 400 U/L. Clinical MI is rare and cannot be diagnosed by elevated CK-MB alone.     

Biochemical markers of myocardial injury in the pericardial fluid of patients undergoing heart surgery

The purpose of this study was to compare cardiac markers in the pericardial fluid and serum in order to evaluate preoperative myocardial injury. Thirty patients were divided into three groups. The first group (AVR; n=10) received an aortic valve replacement. The second group (SA; n=10) included patients with stable angina who underwent elective coronary artery bypass grafting (CABG). The third group (ACS; n=10) included patients with acute coronary syndrome who underwent urgent CABG. Pericardial fluid and venous samples were taken after opening the pericardium and 24 h postoperatively. Serum and pericardial concentration of troponin I (cTnI), creatine kinase (CK), its MB isoenzyme (CK-MB) and myoglobin were determined. Preoperative pericardial cTnI was significantly (P<0.01) higher than in serum in all groups. Preoperative pericardial CK, CK-MB and myoglobin were significantly (P<0.01) lower than in serum in groups AVR and SA. Preoperative pericardial and serum cTnI were significantly higher in the ACS than in AVR and SA groups (P<0.01). Postoperative pericardial concentration of all markers was significantly higher (P<0.01) than in serum in all groups. We conclude that preoperative pericardial accumulation of cTnI may reflect subclinical injury which may not be demonstrated by the usual laboratory tests.     

右美托咪定预处理对心脏瓣膜置换术患者心肌肌钙蛋白Ⅰ和心肌酶学的影响

【摘要】〓目的〓观察右美托咪定预处理对脏瓣膜置换术患者心肌肌钙蛋白Ⅰ和心肌酶学的影响,探讨其对缺血再灌注损伤心肌的保护作用。方法〓拟择期行瓣膜置换术患者50例随机分为右美托咪定组(D组,n=25)和对照组(C组,n=25)。D组在麻醉诱导前经15 min静脉泵注右美托咪定0.5 μg/kg,随后以0.5 μg·kg^-1·h^-1速率泵注至阻断主动脉。C组泵注等容量生理盐水。所有患者手术前(T₀),主动脉阻断30 min(T₁)、主动脉开放1 h(T₂),术毕(T₃)和术后24小时(T₄)抽血测定磷酸肌酸激酶(CK)、磷酸肌酸激酶同工酶(CK-MB)的活性及心肌肌钙蛋白I(cTnI)的浓度。观察自动复跳率、心律失常发生率、左室射血分数(LVEF)以及血管活性药物使用情况。结果〓与C组相比,D组的cTnI浓度、CK和CK-MB的活性、多巴胺和肾上腺素用量低于C组;两组自动复跳率和心律失常发生率无统计学差异;D组术后LVEF值高于C组。结论〓右美托咪定预处理可减轻瓣膜置换患者的心肌损伤。     

Effect of topic defibrillation on serum markers of myocardial damage

Serum levels of cardiac enzymes and troponins after external cardioversion (ECV) for atrial defibrillation and atrial flutter, and after endocardiac cardioverter defibrillation by implantable cardioverter defibrillator (ICD), have been well investigated. The aim of this study was to assess the effects of topic defibrillation (TD), after cardiac surgery, on cardiac enzymes in patients with uncomplicated clinical course. Biochemical markers were analyzed prospectively for 20 patients after TD (group A) and for 20 patients that were not defibrillated (Control group). We obtained serum concentrations of cardiac Troponin I (cTnI), total creatine-kinase (CK), CK MB isoenzyme (CK-MB), Myoglobin (Myo) in both groups. The difference in cTnI plasma level and curve of raise was not statistically significant between the two groups, but there was a difference in the CK-MB and Myoglobin curve of raise between the two groups. Topic defibrillation does not influence the increase of cTnI, so a high cTnI should be correlated to myocardial damage and not to TD. In patients that received TD, it would be preferable to use cTnI as a marker of myocardial disease than CK-MB which is influenced by the TD.     

Markers of myocardial ischemia after minimally invasive and conventional coronary operation

Background. The purpose of this study was to evaluate the course of serum markers of myocardial tissue damage after two different types of minimally invasive coronary surgical procedures (MICS) as compared with conventional coronary artery bypass grafting (CABG).

Methods. We enrolled 87 patients with one- or two- vessel disease scheduled for one of the three procedures: minimally invasive direct coronary artery bypass grafting (MIDCABG) by lateral thoracotomy (n = 29), the OCTOPUS method by median sternotomy (n = 27), and CABG (n = 31). Creatine kinase activity (CK), creatine kinase MB activity (CK-MB act), creatine kinase MB mass concentration (CK-MB mass), myoglobin concentration (MG), and cardiac troponin I concentration (cTnI) were measured perioperatively until the second postoperative day.

Results. Creatine kinase-MB, CK-MB mass, and cTnI were significantly higher after CABG and were nearly maintained within the normal range in MICS. Creatine kinase and MG were significantly lower in the OCTOPUS group than in the MIDCABG or CABG groups.

Conclusions. Minimally invasive coronary surgical procedures cause less myocardial injury than CABG as indicated by specific serum markers. However, higher CK and MG reflect more substantial skeletal muscle trauma during MIDCABG operation compared with Octopus procedures.     

Serum troponin-I as an indicator of clinically significant myocardial injury in paediatric trauma patients

Myocardial injury is a cause of mortality in paediatric trauma, but it is often difficult to diagnose. The objectives of this pilot study were to (1) determine the prevalence of elevated cardiac troponin I (TnI) in paediatric trauma patients and (2) to determine whether elevated TnI correlates with clinically significant myocardial injury, defined as abnormalities on echocardiogram (ECHO) and/or electrocardiograms (ECG). To this end, we investigated a convenient sample size of 59 paediatric trauma patients with an Injury Severity Score (ISS)>12. TnI and creatine kinase-MB (CK-MB) were measured on admission, at then at regular intervals until TnI had normalized. Patients with elevated TnI levels had an ECHO performed within 24h of admission and underwent daily ECGs until TnI normalized. Elevated serum TnI was found in n=16/59 (27%; 95% CI: 18-40%) patients and was associated with elevated CK-MB in all cases. Abnormal ECHOs were seen in 4/16 patients with elevated TnI, but peak TnI values did not correlate with abnormalities on ECHO (p=0.23). Only 1 patient had a clinically significant, albeit mild, decrease in cardiac function. All ECGs were normal. Patients with elevated TnI were more likely to be intubated (p=0.04), to have higher Injury Severity Scores (p=0.02), required more resuscitation fluid (p=0.001), and to have thoracic injuries (p<0.001). Our data indicates that the prevalence of elevated TnI in paediatric trauma patients is 27%; and whilst elevated TnI reflects overall trauma severity, it is frequently elevated without a clinically significance myocardial injury. Hence, large scale studies are required to determine if an elevated threshold TnI value can be identified to accurately diagnose severe myocardial injury in paediatric trauma.     

烧伤患者血清心肌钙蛋白T变化的临床意义

目的　评估血清心肌钙蛋白T(cardiactroponinTcTnT)对烧伤患者心肌损伤的诊断价值。　方法　 6 2例烧伤患者按伤情分为轻中度、重度和特重度 3组 ,于伤后 1、3、7、14d用放免法分别测定血清cTnT和肌酸磷酸激酶同功酶 (CK -MB) ,同期进行超声心动图和心电图检查并与 2 0例正常人员对照。　结果　 (1)与正常组比较 ,重度和特重度各时相点的cTnT均显著升高 (P <0 0 1) ,最高值可达 6 0倍 ,而且升高幅度与伤情相一致。 (2 )CK -MB的变化与cTnT大致相似 ,其最大值只有正常对的 6倍。 (3)特重度组中 9例、5例患者超声心动图和心电图表现异常。　结论　cTnT与CK -MB的动态变化均能较好反映烧伤患者的心肌损伤程度 ,cTnT的特异性和敏感性更高 ,因而更为可靠