Creatine kinase-MB mass concentration versus creatine kinase-B activity for the detection of acute myocardial infarction in patients with slightly elevated total creatine kinase activity in serum

Abstract. Objective . The diagnostic value of creatine kinase-MB mass concentration (CK-MB mass) was compared with that of creatine kinase-B (CK-B) activity in patients with suspected acute myocardial infarction (AMI) but with total serum CK activity only slightly above the reference range. Design . One hundred consecutive blood samples with total CK activity between 120 and 360 U I^-1 and CK-B activity ≥ 9 U I^-1 were analysed. Electrophoresis of CK isoenzymes was also performed. Setting . Patients from all departments of the hospital were included. About half of the patients originated from the coronary care unit. Subjects . The blood samples derived from 49 patients. Thirteen patients had at least one serum sample with total CK activity above 360 U I^-1. These and another three patients were omitted from the study. Results . Acute myocardial infarction had been diagnosed clinically (with CK and CK-B methods) in 12 of 33 patients. However, using the CK-MB mass concentration of the reference method, five of these 12 patients did not have myocardial infarction whereas nine patients with small infarctions were undetected. A good correlation was seen between the results from CK-MB mass concentration and CK isoenzyme electrophoresis, but there was a poor correlation between these methods and CK-B activity including the CK-B/CK ratio. A relatively high proportion (24%) of the selected patients had increased levels of macro CK. Conclusion . CK-B activity was inaccurate for the detection of probable myocardial infarction in patients with slightly elevated total CK activity. Increased levels of macro CK interfering with the CK-B assay was one explanation for this observation.     

Detection of acute myocardial infarction by a new, sensitive and rabid method for determination of creatine kinase B-subunit activity

An immunoinhibition method for the assay of creatine kinase(CK) isoenzymes by continuous monitoring of the ATP formationin the CK reaction by a purified firefly luciferase reagenthas been developed. The sensitivity of the firefly assay ofATP makes it possible to assay CK-B subunit activity (CK-B)in serum down to 1 U/l. In healthy individuals CK-B varied between 2 and 12, mean 3U/l. A wide range of CK-B activity was observed after acutemyocardial infarction (AMI), intramuscular injection and surgerywith overlapping between these different categories. Thereforethe maximal change in CK-B activity (CK-B) was studied in 98patients admitted to a coronary care unit. In all 57 patientswithout a subsequent diagnosis of AMI according to conventionalcriteria CK-B was < 5 U/l. In all 41 patients with AMI CK-Bwas 5 U/l. In all healthy individuals CK-B was < 2 U/l.CK-B 5 U/l was found after i.m. injection and different kindsof surgery in three out of 60 patients. Thus, the present method for determination of CK activity hasbeen shown to possess high precision in low activities, to beas rapid as conventional methods and to be simple enough tobe used in a routine laboratory. With these properties the methodshould be suited for early diagnosis and early exclusion ofeven very small AMIs.     

Myoglobin, creatine Kinase-B isoenzyme, and myosin light chain release in patients with unstable angina pectoris

In 27 patients presenting with angina pectoris at rest and normalserum creatine kinase (CK) activity, cardiac myosin light chains(CM-LC), myoglobin (MG), and CK-B isoenzyme were determinedin 7 serial blood samples by radioimmunoassays. Measurable amountsof CM-LC were found in at least one serum sample in 13 patients.MG was found to be elevated in 9, and CK-B in 8 of these patients.In the 189 serum samples determined, CM-LC were found more frequentlyelevated (21.7%) than MG (13.2%, P <0.05) or CK-B (12.2%,P <0.05). Coronary angiograms were obtained in 21 of the27 patients. Elevated marker protein concentrations were foundonly in patients with coronary artery stenosis 70% of at leastone coronary artery. The incidence of elevated serum concentrationsof any of the 3 marker proteins determined was higher in patientswith 3 vessel disease than in those with 1 or 2 vessel disease(33.9% vs 15.6%, P <0.05), and it was higher in patientswith a history of previous myocardial infarction than in thosewithout (34.5% vs 11.4%. P <0.001).The findings suggest thanin a subgroup of patients with angina pectoris at rest but withoutevidence of acute myocardial infarction, ischaemic damage ofsmall myocardial areas can be detected by serological assaysof high sensitivity. Among the marker proteins studied. CM-LCwere found the most sensitive.     

Myoglobin, creatine Kinase-B isoenzyme, and myosin light chain release in patients with unstable angina pectoris

In 27 patients presenting with angina pectoris at rest and normalserum creatine kinase (CK) activity, cardiac myosin light chains(CM-LC), myoglobin (MG), and CK-B isoenzyme were determinedin 7 serial blood samples by radioimmunoassays. Measurable amountsof CM-LC were found in at least one serum sample in 13 patients.MG was found to be elevated in 9, and CK-B in 8 of these patients.In the 189 serum samples determined, CM-LC were found more frequentlyelevated (21.7%) than MG (13.2%, P <0.05) or CK-B (12.2%,P <0.05). Coronary angiograms were obtained in 21 of the27 patients. Elevated marker protein concentrations were foundonly in patients with coronary artery stenosis 70% of at leastone coronary artery. The incidence of elevated serum concentrationsof any of the 3 marker proteins determined was higher in patientswith 3 vessel disease than in those with 1 or 2 vessel disease(33.9% vs 15.6%, P <0.05), and it was higher in patientswith a history of previous myocardial infarction than in thosewithout (34.5% vs 11.4%. P <0.001).The findings suggest thanin a subgroup of patients with angina pectoris at rest but withoutevidence of acute myocardial infarction, ischaemic damage ofsmall myocardial areas can be detected by serological assaysof high sensitivity. Among the marker proteins studied. CM-LCwere found the most sensitive.     

血栓前体蛋白和糖原磷酸化酶同工酶BB对急性心肌梗死早期诊断的价值

目的 评价血栓前体蛋白(TpP)和糖原磷酸化酶同工酶BB(GPBB)对急性心肌梗死(AMI)早期诊断的潜在价值。方法 选择168例确诊或疑似AMI的患者，以酶联免疫吸附法(ELISA)测定干预前其血浆TpP和GPBB浓度，同期常规检测肌酸激酶同工酶：MB(CK-MB)、门冬氨酸氨基转移酶(AST)牙和心脏肌钙蛋白I(CTnI)，比较这些生化指标对AMI的诊断价值。结果 这五种生化标志物中，TpP和GPBB诊断AMI优势明显，两者灵敏度分别为100％和96．5％：特异度分别为85．5％和90．9％；真实度分别为95．2％和94．1％；阳性预测值分别为93．4％和95．6％；阴性预测值分别为100％和192．6％。结论 血浆TpP和GPBB是有价值的早期诊断AMI的生化指标。     

Early positive technetium-99m stannous pyrophosphate images as a marker of reperfusion after thrombolytic therapy for acute myocardial infarction

Fourteen patients with transmural acute myocardial infarction (AMI) were treated with intravenous streptokinase a mean of 4 +/- 1 hours after chest pain and underwent technetium-99m stannous pyrophosphate (Tc-99m-PPi) imaging 7 +/- 2 hours after the onset of chest pain. The early Tc-99m-PPi images were obtained to test the hypothesis that an early, strongly abnormal Tc-99m-PPi image suggests reperfusion. Eleven of 14 patients had early peaking (within 16 hours) serum creatine kinase isoenzyme levels (CK-B) at a mean of 11 +/- 3 hours. Ten of 14 patients had 3+ or 4+ acute Tc-99m-PPi images. Eight of 11 patients had patent infarct-related vessels at cardiac catheterization 15 days after AMI. One patient who had both an early positive Tc-99m-PPi image and CK-B peak level had an occluded infarct-related artery at catheterization. Acute left ventricular (LV) ejection fraction (EF) by radionuclide ventriculography was compared with LVEF on day 15, and improved from 0.37 +/- 0.13 to 0.50 +/- 0.16 (p = 0.004) in the 10 patients with strongly positive acute Tc-99m-PPi images. LVEF also improved from 0.37 +/- 0.12 to 0.49 +/- 0.15 (p = 0.003) in the 11 patients with early peaking serum CK-B values. Three patients without evidence of reperfusion failed to improve the LVEF from the initial value to the one obtained at hospital discharge. Six control patients had acute Tc-99m-PPi images 10 +/- 2 hours after chest pain; none had strongly positive acute Tc-99m-PPi images, and the mean time to peak CK-B was 19 +/- 5 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Early estimation of acute myocardial infarct size soon after coronary reperfusion using emission computed tomography with technetium-99m pyrophosphate

Early appearance of positive findings on a technetium-99m pyrophosphate scan has been shown to be associated with the presence of a reperfused acute myocardial infarction (AMI). Early technetium-99m pyrophosphate imaging was performed by emission computed tomography to evaluate reperfusion and to test the feasibility of estimating infarct size soon after coronary reperfusion based on acute positive tomographic findings. Twenty-seven patients with transmural AMI who were treated with intracoronary urokinase infusion followed by percutaneous transluminal coronary angioplasty underwent pyrophosphate imaging 8.7 +/- 2.1 hours after the onset of AMI. None of the 8 patients in whom reperfusion was unsuccessful had acute positive findings. Of 19 patients in whom reperfusion was successful, 17 had acute positive findings (p less than 0.001). In these 17, tomographic infarct volumes were determined from reconstructed transaxial images. The threshold for areas of increased pyrophosphate uptake within the infarct was set at 60% of peak activity by the computerized edge-detection algorithm. The total number of pixels in all transaxial sections showing increased tracer uptake were added and multiplied by a size factor and 1.05 g/cm3 muscle to determine infarct volume. The correlations of tomographic infarct volumes with peak serum creatine kinase (CK) levels (r = 0.82) and with cumulative release of CK-MB isoenzyme (r = 0.89) were good. Moreover, the time to positive imaging was significantly shorter than that to peak CK level (8.5 +/- 2.3 vs 10.4 +/- 2.2 hours, p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)     

Late estimation of myocardial infarct size by total creatine kinase nomogram

We studied the possibility of enzymatic estimation of myocardial infarct size in patients late (between days 2 and 6) after the onset of acute myocardial infarction (AMI), in whom estimation of infarct size was difficult by analysis of time-activity curves of serum creatine kinase (CK) because of the lack of the enzymatic information during the initial 48 hours. Serial determinations of serum enzymes were performed in 32 patients within 6 hours after the onset of AMI and significantly close correlations were observed between cumulative total CK release and the cardiac fraction of lactate dehydrogenase isoenzyme (LDH1) activities from day 2 to day 6 after the onset of AMI (r = 0.863 to 0.870; p less than 0.001). We developed a nomogram to estimate cumulative total CK release by serum LDH1 activities obtained between days 2 and 6 after AMI and evaluated the reliability of the nomogram. Cumulative total CK release obtained from serial serum CK activities correlated closely with total CK release obtained from the nomogram in the second group of patients with AMI (r = 0.923 to 0.946; n = 24; p less than 0.001). Our total CK nomogram requiring few blood samples was useful in late estimation of infarct size in patients who were admitted to the hospital between days 2 and 6 after the onset of AMI.     

A clinical and experimental study on early diagnosis of myocardial infarct extension by measuring the activity of serum pyruvate kinase

To explore the early diagnostic effects of serum pyruvate kinase (PK) on myocardial infarct extension (MIE), the activity of serum PK, glutamate oxalacetate transaminase (GOT), creatine kinase (CK) and its isoenzyme (CK-MB) were measured in 102 cases of acute myocardial infarction (AMI). The results showed that the dynamic changes of PK were similar to that of CK-MB, but serum PK was 9.2 hours earlier than CK-MB in the determination of the onset of MIE. Furthermore we introduced MIE and AMI model by ligating the branch of coronary arteries in conscious dogs. Compare the pathologic findings with the PK dynamic changes showed that the double peak and plateau types were brought about by MIE. We believe that serial measuring of serum PK was helpful in the early diagnosis of MIE.     

Isoenzyme profiles of creatine kinase, lactate dehydrogenase, and aspartate aminotransferase in the diabetic heart: comparison with hereditary and catecholamine cardiomyopathies

STUDY OBJECTIVE--The aim was to investigate the redistribution of isoenzymes, clinically important markers of myocardial necrosis, in the diabetic heart and compare it with that investigated in other types of cardiomyopathies. DESIGN--Myocardial isoenzyme activity of creatine kinase (CK), lactate dehydrogenase (LD) and aspartate aminotransferase (AST) was measured in animals with diabetic, hereditary, and catecholamine cardiomyopathies. SUBJECTS--Diabetic rats (4 and 8 weeks after intravenous streptozotocin, n = 21), Bio 14.6 hamsters (30, 90, 160 and 240 days old, n = 29), and rats injected with isoprenaline (0.25, 0.5 and 1.0 mg.kg-1.d-1 for 3 weeks, n = 20) were used. Controls were age matched intact animals (n = 8-11). MEASUREMENTS AND MAIN RESULTS--Total CK and CK MM activity decreased in all groups. CK MB and BB decreased by 62 and 52% in diabetic rats, but increased by 40 and 33% in Bio hamsters and by 9 and 96% in isoprenaline treated rats. Thus the CK-B subunit decreased by 61% in diabetics and increased by 33 and 38% in Bio and isoprenaline groups, while the CK-M subunit decreased in all groups. Mitochondrial CK decreased in diabetic and isoprenaline groups. Total LD activity increased in diabetics and decreased in Bio. LD-H subunit increased by 21% in diabetics and decreased by 19 and 18% in Bio and isoprenaline groups. Accordingly the proportion of LD-M subunit, an index of anaerobic metabolism, decreased in diabetics and increased in Bio and isoprenaline groups. Changes in CK-M and CK-B subunits and the LD-M proportion in diabetic heart were normalised by insulin. Total AST activity decreased in diabetics because of the reduction in mitochondrial AST. CONCLUSIONS--Increased LD-M proportion and CK-B observed in Bio and isoprenaline groups may be a metabolic "compensation" to decreased myocardial perfusion and substrate. Decreased LD-M proportion and CK-B in the diabetic heart was insulin dependent and may indicate either lack of "compensation" to myocardial ischaemia or absence of ischaemia per se. Decreased myocardial CK and CK MB activity possibly causes underestimation of enzymatically assessed infarct size in the diabetic heart.     

The importance of creatine kinase determination in identifying acute myocardial infarction among patients complaining of chest pain in an emergency room

The contribution of serum creatine kinase (CK) levels to the diagnosis of acute myocardial infarction (AMI) in an emergency room was studied in 252 patients presenting with chest pain. Thirty percent were ultimately diagnosed as having AMI. The electrocardiogram (ECG) identified 66% of patients with AMI who were evaluated within 4 h of onset of symptoms; while CK serum levels were elevated in only 9%. Among patients evaluated more than 4 h after the onset of symptoms, the ECG was helpful in diagnosing AMI in only 36.6%, while serum CK levels were high in 63.4%. CK testing added significantly to the diagnosis of AMI in patients already studied by ECG. We suggest that determination of serum CK levels in the emergency room is of value in the evaluation of patients complaining of chest pain 4 or more hours after the onset of symptoms.     

不稳定性心绞痛和急性心肌梗塞肌钙蛋白T变化的比较

目的 :比较不同急性冠状动脉综合征患者肌钙蛋白 T(Tn T)变化。　　方法 :不稳定性心绞痛 (UAP)、Q波型和非 Q波型急性心肌梗塞 (AMI)患者于急诊就诊时、住院后第 2、第 3和第 6日取血测定 Tn T水平。　　结果 :35 %的 UAP患者 Tn T表现为升高 ,其升高的幅度 (均 <3.0 ng/ ml)明显 <非 Q波型 AMI(2 4% >3.0 ng/ml)和 Q波型 AMI(90 % >3.0 ng/ ml) ,且一般 3天后即转为阴性 ,而 AMI患者 6天后多数仍为阳性。非 Q波型 AMI和Q波型 AMI急诊就诊时 Tn T的阳性率分别为 79.1%和 90 .7% ,住院后第 2日均达 10 0 % ,均明显高于同时间谷草转氨酶和肌酸激酶同工酶的阳性率 ,两组 Tn T阳性在持续时间上相似 ,但在升高幅度上有明显的区别。再灌注治疗可能会影响 Q波型 AMI患者 Tn T的自然变化规律。　　结论 :UAP患者 Tn T的变化与非 Q波型 AMI和 Q波型 AMI有显著的不同。     

Myocardial creatine kinase expression after left ventricular assist device support

OBJECTIVES: We examined whether unloading of the left ventricle with a ventricular assist device (LVAD) can result in normalization of the creatine kinase (CK) abnormalities in the failing human heart. BACKGROUND: Left ventricular failure is associated with a decrease of myocardial total CK activity and a fetal shift in CK isoform expression that results in an increase in the cytosolic brain type homodimeric-creatine kinase (CK-B) subunit and decreases of the cytosolic muscle-creatine kinase (CK-M) and CK-mitochondrial (CK-Mt) isoforms. The mechanisms of this abnormality are not known. METHODS: Total CK activity and CK protein isoform expression (Western blotting) were examined in 11 patients with end-stage cardiomyopathy. In 7 patients, myocardial tissue was also obtained after 4.1 +/- 1.1 months of left ventricular assist device (LVAD) support. RESULTS: Left ventricular unloading produced by LVAD implantation resulted in a 270% +/- 114% increase in total CK activity (p < 0.01) that was associated with a 69% +/- 18% increase in CK-M protein expression (p < 0.01) and a 121% +/- 69% increase in CK-Mt protein expression (p < 0.01), but no significant change in CK-B expression. CONCLUSIONS: Systolic and diastolic unloading provided by the LVAD resulted in increases of total CK activity as well as CK-Mt and CK-M protein expression. The failure of CK-B expression to decrease suggests that abnormalities other than increased loading are responsible for the increase in CK-B expression in the failing heart.     

Serial determinations of serum enzymes following aorta-coronary bypass surgery and acute myocardial infarction

Serial determinations of serum creatine kinase (CK), cardio-specific isoenzyme of CK (CK-MB), glutamic oxaloacetic transaminase (GOT) and alpha-hydroxybutylate dehydrogenase (HBD) were made in 29 consecutive patients undergoing aorta-coronary (AC) bypass grafting, and the results were compared with those in 31 patients with acute myocardial infarction (AMI). Postoperatively, all patients had an uneventful postoperative course and there was no evidence of AMI. The time course of enzyme activity following surgery was characterized by 1) shortening of peak activity time of all enzymes except CK, 2) rapid disappearance of CK-MB, 3) prolonged normalization of GOT and HBD. Peak activities of CK, CK-MB, GOT and HBD in AC bypass patients were 801 +/- 77, 46 +/- 6, 100 +/- 9 and 718 +/- 32 IU (mean +/- SEM), respectively, which were equivalent to 46%, 12%, 22% and 47% of those in AMI. The degree of postoperative CK-MB elevation was influenced by the duration of the operation and the extracorporeal circulation, and the number of grafts bypassed. The peak CK-MB activity did not correlate with the CK peak. The ratio of CK-MB to CK was much smaller in AC bypass than in AMI (6.5 +/- 1.8 vs. 20.1 +/- 1.4%). It was concluded that serum enzyme elevations after AC bypass surgery largely reflected enzyme release from the skeletal muscle rather than the myocardium.     

Nitric oxide production by neutrophils obtained from patients during acute coronary syndromes: expression of the nitric oxide synthase isoforms

OBJECTIVES: To analyze the differences in the nitric oxide (NO) forming system between neutrophils obtained from patients during unstable angina (UA) and during acute myocardial infarction (AMI). BACKGROUND: Neutrophils are involved in the regulation of thrombus formation through the release of active substances such as NO. Acute myocardial infarction is the result of an occlusive thrombus; unstable angina is attributed to intermittent thrombus formation. METHODS: We studied 49 patients admitted to hospital within 24 h after the onset of chest pain: 31 experienced AMI and 18 experienced UA. Acute myocardial infarction was defined as CK greater than two-fold the upper limit of normal value of biochemical laboratory, with CK-MB >10% total CK. Unstable angina was defined as transient ST segment changes without significant increases in CK and CK-MB. RESULTS: The amount of NO generated by neutrophils from AMI patients was significantly higher than that generated by neutrophils from UA patients. Neutrophils from UA and AMI patients showed low levels of endothelial-like NO synthase protein expression and a marked expression of the inducible NO synthase (iNOS) isoform. Although neutrophils from patients during acute coronary syndromes generated high amounts of NO, they did not demonstrate an increased ability to stimulate cyclic guanosine monophosphate (cGMP) synthesis in platelets. This lack of activity to release NO by neutrophils from patients during AMI was unrelated to a defect in the platelet cGMP-forming system; sodium nitroprusside, an exogenous NO donor, similarly increased cGMP levels in platelets from AMI patients and healthy donors. CONCLUSIONS: Neutrophils from patients during AMI and UA showed an increased production of NO and a marked expression of the iNOS isoform. However, NO released from these neutrophils showed a deficient functionality. These findings could have clinical implications because they show differences in thrombus growth in patients with UA versus patients with AMI.     

Comparison of the prognostic value of peak creatine kinase-MB and troponin levels among patients with acute myocardial infarction: a report from the Acute Coronary Treatment and Intervention Outcomes Network Registry-get with the guidelines

Background:

Although peak creatine kinase‐myocardial band (CK‐MB) and troponin levels have been correlated with mortality among patients with acute myocardial infarction (AMI), the independent prognostic implications of these markers have not been compared.

Hypothesis:

We hypothesized that in patients with AMI, peak troponin levels (as compared to peak CK‐MB levels) would have greater prognostic value.

Methods:

We examined AMI patients in the National Cardiovascular Data Registry ACTION Registry–GWTG (Acute Coronary Treatment and Intervention Outcomes Network Registry–Get With The Guidelines) with CK‐MB and troponin I levels recorded, excluding patients who were transferred in or out. Peak marker levels, standardized by the local laboratory upper limit of normal and assay standard deviation, were fitted into the previously validated ACTION Registry–GWTG mortality model to compare prognostic value.

Results:

Between January 2007 and March 2009, 16 009 ST‐segment elevation myocardial infarction (STEMI) and 26854 non–ST‐segment elevation myocardial infarction (NSTEMI) patients were identified. Peak marker ratios were directly associated with in‐hospital mortality in both STEMI and NSTEMI patients. Peak CK‐MB had slightly greater discrimination compared with peak troponin I in predicting mortality in both STEMI (model C‐statistic 0.881 vs 0.877, P = 0.011) and NSTEMI (C‐statistic 0.831 vs 0.824, P = 0.001) patients.

Conclusions:

Both peak CK‐MB and peak troponin I levels are independently associated with in‐hospital mortality in this large contemporary database of AMI patients treated in routine practice. Peak marker values slightly improved model performance in prognosticating in‐hospital mortality; the incremental value was higher with CK‐MB than with troponin I. These findings may help to guide future risk stratification algorithms and contribute to more efficient use of serial cardiac marker measurements in clinical practice. Clin. Cardiol. 2011 DOI: 10.1002/clc.21980 This project was supported by grant number U18HS016964 from the Agency for Healthcare Research and Quality (AHRQ). The content is solely the responsibility of the authors and does not necessarily represent the official views of the AHRQ. The funding source had no role in the design or implementation of the study, or in the decision to seek publication. The authors have no other funding, financial relationships, or conflicts of interest to disclose.     

体外电复律对恶性心律失常患者心肌酶谱及肌钙蛋白Ⅰ的影响

目的探讨临床体外电复律对恶性心律失常患者心肌酶谱及肌钙蛋白I的影响。方法院前及院内恶性心律失常患者,排除胸廓及心脏外伤患者以及既往心梗患者,经体外电复律成功后,根据冠脉造影和电复律成功后心电图表现分为非急性心梗组和急性心梗组。分析体外电复律对两组电复律前或即刻和12h血清CK、CK—MB、cTnI的影响。结果非急性心梗组及急性心梗组分别有22例和30例患者,两组电复律累积次数及能量差异无统计学意义[（3．0±1．2）次比（3．0±1．3）次;（446±275）J比（450±293）J,P〉0．05];体外电复律前或即刻及12h,非急性心梗组与急性心梗组相比,CK12[（452．3±204．2）U／L比（562．2±234．1）U／L]、CK—MB0[（10．6±7．5）U／L比[27．1±12．3）U／LJ、CK—MB12[（30．0±20．5）U／L比（180．5±62．3）U／L]、cTnI0[（0．04±0．04）ng／ml比（0．58±0．86）ng／ml]、cTnI12[（0．06＋0．04）ng／ml比（17．47±12．07）ng／ml]差异有统计学意义（P〈0．01）,除外CK0[（129．2±90．5）U／L比（135．3±94．8）U／L,P〉0．05]。体外电复律后12h较电复律前或即刻CK、CK—MB、cTnI均显著升高（P〈0．05或P〈0．01）。CK—MB0、CK—MB12、cTn10、cTnI12阳性率,非急性心梗组分别为9．1％、54．5％、0、0,急性心梗组分别为53．3％、90．0％、20．0％、93．3％。结论体外电复律可导致恶性心律失常患者CK、CK—MB、eTnI升高,但eTnI升高程度并不影响急性心梗的诊断。     

心脏肌钙蛋白T在急性心肌梗死中的应用价值

目的 探讨血清肌钙蛋白T(cTnT)在急性心肌梗死(AMI)后的释放特点及其对AMI溶栓后的疗效判定。方法 采用酶联免疫法对28例AMI患者进行动态血清cTnT观察,同时测定CK及CK-MB。结果 溶栓2小时阳性率为67.9％、发病8小时至5天为100％、发病7、9、11、13、15、17、19天分别为92.9％、82.1％、67、9％、60.7％、39.3％、21.4％、7.1％。明显比CK和CK-MB持续时间长。cTnT诊断急性心肌梗死的敏感性为100％。溶性再通组15例呈双峰曲线,4例呈单峰曲线,双峰者首峰与次峰比大于2,单峰都在24小时以内出现。未通组双峰3例,单峰6例,双峰者首峰与次峰比不大于2,单峰多在4～5天内出现。把首峰与次峰之比(或第24小时内峰值与第4日峰值之比)大于2,作为溶栓再通指标的敏感性为89.5％,特异性为100％。结论 血清中cTnT动态变化对AMI的诊断及溶栓治疗效果的评定均有一定的价值。     

Detection of coronary disease patients at high risk for recurrent myocardial infarction by elevated plasma inactive creatine kinase B protein levels

The diagnostic and prognostic significance of plasma inactive creatine kinase B protein (CK-Bi) levels measured by radioimmunoassay was determined in various ischemic myocardial syndromes. In 120 stable angina patients free of pain at time of blood sampling, mean CK-Bi level was 114 ± 42 (SD) μg-equiv/ml; 195 μg-equiv/ml (95% confidence interval) represented upper limit of normal. In seven coronary artery disease (CAD) patients atrial pacing-induced ischemia was not associated with increased coronary sinus CK-Bi. Of 201 consecutive patients with suspected acute infarction (AMI), 45 developed ECG criteria of transmural AMI with concomitant increased plasma CK-Bi levels (498 ± 133, range 372–718 μg-equiv/ml). Elevated CK-Bi levels in evolving transmural AMI were detected before raised CK enzyme activity. Elevated plasma CK-Bi levels also occurred in acute pericarditis and in unstable angina. In the 84 patients not developing ECG changes or elevated plasma CK activity, their plasma CK-Bi levels were also normal and no coronary events occurred in the next 6 months. The remaining 55 patients had nontransmural AMI, with 15 also having elevated plasma CK and CK-Bi levels, of whom six developed re-AMI in the next 3 months. In the other 40 nontransmural AMI patients, plasma CK-Bi levels (350 ± 65 μg-equiv/ml, range 228 to 445) increased significantly without associated CK activity rise, and 24 developed re-AMI (three fatal) in the next 6 months. These data suggest that: (1) plasma CK-Bi protein radioimmunoassay measurement provides a sensitive means for detecting myocardial necrosis or inflammation and (2) elevated plasma CK-Bi levels in coronary disease patients during myocardial ischemic pain may afford identification of a CAD clinical subset at high risk of subsequent AMI.     

血清脂蛋白(a)浓度与急性心肌梗死病情程度相关性初探

目的　探讨血清脂蛋白 (a) [L p(a) ]与急性心肌梗死 (AMI)严重程度的相关性。方法　对 113例急性心肌梗死患者 (AMI组 )及 5 5例健康人 (对照组 )采用酶联免疫吸附法检测 L p(a)浓度 ,用速率法检测 AMI患者血清肌酸磷酸激酶(CK)及其同功酶 (CK - MB)的高峰浓度 ,比较两组的结果。结果　 AMI组平均血清 L p(a)浓度显著高于对照组 ,L p(a)浓度越高 ,CK及 CK- MB水平也越高 ,两者呈正相关。结论　 AMI患者存在着血清 L p(a)的异常升高 ,且血清 L p(a)浓度愈高 ,则 AMI时心肌坏死面积愈大 ,病情相应严重。