Ischaemia modified albumin in the diagnosis of acute coronary syndromes

The early diagnosis of acute coronary syndrome remains problematic, despite recent improvements. Traditionally, the diagnosis of acute cardiac ischaemia relies on the combination of chest pain, electrocardiographic changes and elevation of serum markers. Troponins are currently the “gold standard” test for the detection of myocardial necrosis, but they are unsuitable for early diagnosis, as nearly 50% of patients may present to the emergency department with non-diagnostic concentrations. Ischaemia modified albumin increases within minutes after the onset of ischaemia, remains elevated for 6 to 12 h, and returns to normal within 24 h. Thus, it may be a valuable aid for the clinician enabling early detection of ischaemia before the development of myocardial necrosis. Its high sensitivity comes at the expense of a lower specificity because its increase may be due to ischaemia of other tissues such as gastrointestinal tissues or skeletal muscles tissues. This paper has focuses on the cardiology aspect of this biomarker, underlying its potential value in the emergency department.     

缺血修饰白蛋白与平板运动试验联合检查对早期冠状动脉综合征的临床诊断意义

目的探讨缺血修饰白蛋白(IMA)测定与平板运动试验联合诊断早期冠脉综合征的临床应用价值。方法以30例体检健康者做为对照,对80例心肌缺血、缺氧症状患者分别进行平板运动试验(TET)、冠状动脉造影(CAG)以及检测其运动前后的IMA值。比较运动试验前后患者与健康对照组IMA测定值的变化;以冠脉造影结果为标准,分别评价IMA、TET、IMA联合TET对于诊断早期冠状动脉综合征敏感性与特异性。结果运动试验前试验组IMA值与对照组差异显著(P0.05);运动试验后试验组IMA值显著升高(P0.01);IMA诊断早期冠脉综合征的特异性为85.3%,敏感性为93.5%;TET诊断早期冠脉综合征的特异性为67.6%,敏感性为89.1%;IMA联合TET诊断早期冠脉综合征的特异性为94.1%,敏感性为87.0%。结论IMA联合TET检查可显著提高早期冠状动脉综合征诊断的特异性,降低以IMA或TET单纯检查进行诊断时的假阴性和假阳性率,极大提高诊断的准确性。     

缺血修饰白蛋白在急性冠脉综合症（ACS）早期诊断中的价值探讨

目的 探讨缺血修饰白蛋白（IMA）诊断急性冠脉综合征（ACS）的价值.方法 测定37例ACS患者（实验组）和80例体检者（健康对照组）血清IMA浓度.建立IMA诊断ACS的ROC曲线,计算敏感度、特异度、阳性预测值、阴性预测值.结果 健康对照组与ACS组间血清IMA浓度有显著差异,差异有统计学意义.IMA诊断ACS的曲线下面积（AZ）为0.866（95%CI 0.791-0.941）,P〈0.001.cut-off值取80.0U/mL时,灵敏度和特异度分别为81.1%%和72.2%,阳性预测值PPV和阴性预测值NPV分别为61.0%%和89.0%.结论 缺血修饰白蛋白（IMA）诊断ACS具有高灵敏度和高阴性预测值的特点;可能在早期诊断心肌缺血及辅助排除ACS上具有较大的价值.     

Assay of ischemia-modified albumin and C-reactive protein for early diagnosis of acute coronary syndromes

Diagnosis of cardiac ischemia in patients coming to emergency departments (ED) with symptoms of acute chest pain is often difficult. Many markers are sensitive and specific for the detection of myocardial necrosis but may not rise during reversible myocardial ischemia. Ischemia-modified albumin (IMA) has recently been shown to be a sensitive and early biochemical marker of ischemia. The variation laws were observed by measuring IMA and C-reactive protein (CRP) of 113 patients in ED within 12 hr after onset of chest pain. In the observation, blood was taken for IMA and CRP. Patients underwent standardized triage, diagnostic procedures, and treatment. Results of IMA and CRP were correlated with final diagnoses of nonischemic chest pain (NICP) and acute coronary syndrome (ACS). There were obvious distinction of IMA and CRP levels between the NICP and ACS groups. Receiver operator characteristic (ROC) curve analysis was used to determine the optimal cutoff of this assay for identifying individuals with ACS patients from NICP. The area under the curves of IMA is 0.948. The sensitivity and specificity of albumin cobalt binding (ACB) at a cutoff value of 70.0 units/mL were 94.4% and 82.6%, respectively. The area under the curves of CRP is 0.746. Sensitivity and specificity of CRP at a cutoff value of 3.16 mg/L were 70.0% and 73.9%, respectively. Negative predictive value (NPV) of IMA and CRP for ischemia origin was 79.2% and 38.6%, respectively. IMA may make an early diagnosis of acute coronary ischemia, and will improve the early diagnostic sensitivity and specificity of ACS.     

缺血修饰白蛋白在急性冠状动脉综合征早期诊断中的价值

目的 探讨缺血修饰白蛋白(IMA)对急性冠状动脉综合征(ACS)的早期诊断价值.方法 103例疑似ACS患者[非心肌缺血性胸痛(NICP)45例(NICP组),ACS 58例(ACS组)]在胸痛发作5 h内取血测定IMA、肌钙蛋白I(cTnI)、肌酸激酶同工酶MB(CK-MB)并在入院后即刻描记12导联心电图(ECG),同时选择30例健康对照(对照组)进行检测,经ROC曲线分析获得区分NICP与ACS最佳,临界值点(Cut-off值).IMA、cTnI、CK-MB及ECG结果分别与最终诊断结果(NICP,ACS)进行综合分析,评价其诊断ACS的敏感性.结果 ACS组与NICP组IMA值分别是(89.66±25.82)、(46.79±17.20)U/ml,2组间比较IMA值差异有统计学意义(P＜0.05);ROC曲线下面积0.935,最佳临界值为71.6 U/ml,此时IMA检测的敏感性、特异性、阳性预测值和阴性预测值分别为90.6%、71.4%、82.8%和83.3%.而同步测定cTnI、CK-MB、ECG诊断ACS的阳性率分别为29.3%、27.6%、48.3%.结论 IMA是诊断急性心肌缺血早期灵敏指标,可明显提高ACS早期诊断的敏感性.     

缺血修饰白蛋白在急性冠状动脉综合征早期诊断中的应用价值研究

目的观察急性冠状动脉综合征(ACS)患者血清缺血修饰白蛋白(IMA)水平的变化,探讨IMA在ACS早期诊断中的价值。方法连续监测97例ACS患者[包括急性心肌梗死(AMI)43例、不稳定型心绞痛(UAP)54例]急性胸痛发作后2、6、12、24、48 h血清IMA、肌酸激酶MB同工酶(CK-MB)和心肌肌钙蛋白T(c Tn T)水平的变化,并与42例疑似ACS最终确诊排除诊断的患者(对照组)比较;评价各项标志物在ACS早期诊断中的应用价值。结果 UAP及AMI患者发病后2 h血清IMA水平明显高于对照组(P0.05),AMI患者发病12 h时达高峰,24 h时下降到和对照组水平基本持平。UAP患者CK-MB及c Tn T各检测时间点与对照组比较差异均无统计学意义(P0.05)。受试者工作特征(ROC)曲线显示AMI患者发病2 h时,IMA、CK-MB、c Tn T诊断AMI的曲线下面积(AUC)分别为0.812、0.781、0.648。结论 IMA可作为ACS心肌缺血的敏感标志物,可用于早期诊断AMI。     

Application of albumin-adjusted ischemia modified albumin index as an early screening marker for acute coronary syndrome

BACKGROUND: Existing cardiac markers are not sensitive for reversible myocardial ischemia. Ischemia modified albumin (IMA) has recently been shown to be an early and sensitive marker of myocardial ischemia. We established a newly standardized, albumin-adjusted IMA index that was more sensitive and accurate than the conventional IMA value. METHODS: We enrolled 413 consecutive patients with symptoms suggestive of acute coronary syndrome (ACS). All patients were classified to either the ACS group (n=129) or 4 other groups (n=284). The ideal cutoff value of IMA was calculated by the receiver operating characteristic (ROC) curve analysis. The albumin-adjusted IMA index was calculated from the results of correlation assay between serum albumin concentration and IMA value and re-applied. RESULTS: The sensitivity and specificity of IMA for ACS were 93.0% and 35.6%, respectively, at 85.0 U/ml. IMA had a negative linear relationship with serum albumin and albumin-adjusted IMA index was calculated by using the following equation [IMA index=serum albumin conc. (g/dl) x 23+IMA (U/ml)-100]. The sensitivity and specificity were 98.4% and 34.5%, respectively, at IMA index of 83.4. CONCLUSIONS: The use of the calculated albumin-adjusted IMA index is recommended to increase the sensitivity of the ACS diagnosis although IMA is a sensitive marker for the identification of ACS.     

缺血修饰白蛋白和C反应蛋白在急性冠脉综合征诊断中的作用

嗜酸粒细胞性胃肠炎 误诊 嗜酸粒细胞增高 嗜酸粒细胞增多 临床表现 腹部不适 病例分析 误漏诊 目的：探讨缺血修饰白蛋白（IMA）及C反应蛋白（CRP）检测对急性冠咏综合征（ACS）的早期诊断评价。方法：监测急诊稳定型心绞痛（SA）和ACS患者共113例，入院后即刻取血测定IMA及CRP，观察其变化同时选择76例门诊体检者作对照．经受试者工作特征曲线（ROC曲线）分析获得区分SA与ACS最适界值点（cutoff值）.结果：ACS组与对照组、SA组间IMA、CRP值差异均具有统计学意义。IMA ROC曲线下面积为0．948，在最适cutoff值为70．5U／ml．时敏感性和特异性分别为94.4％和82．6％．阳性预测值和阴性预测值分别95．5％和79.2％，CRPROC曲线下面积为0．746，在最适cutoff值为4．905mg／L时敏感性和特异性分别为55．6％和87．0％，阳性预测值和阴性预测值分别78．1％和18.4％.结论：IMA可对急性心肌缺血作出早期诊断．且明显提高对ACS早期诊断敏感性     

急性冠状动脉综合征的早期诊断指标

ACS是由一系列连续发生的病理生理事件所导致的临床综合征,它包括了UA、NSTEMI和STEMI.这3种病症的共同病理基础均为存在不稳定的粥样斑块,只是伴发了不同程度的继发性病理改变.     

心肌标志物在急性心肌梗死诊断中的临床应用研究

目的应用临床诊断性能曲线(ROC)评价心肌肌钙蛋白T(cTnT)、肌红蛋白(Myo)和肌酸激酶同工酶质量(CK MBmass)在急性心肌梗死诊断中的临床决定限。方法电化学发光免疫分析法测定病例组及对照组的血清cTnT、Myo和CK MBmass,所得数据用ROC曲线统计软件进行分析。结果入院即刻血清cTnT诊断急性心肌梗死(AMI)的最佳临界值为0.042μg/L,诊断特异性93%、敏感性92%;CK MBmass的临界值为5.37μg/L,诊断特异性88%;Myo的临界值为62.8μg/L,诊断特异性为74%、敏感性为72%。急性心肌梗死(AMI)患者胸痛发作6h内Myo的诊断敏感性较高(90.0%),cTnT其次(76.7%),CK MBmass最低(73.3%);6h后Myo诊断敏感性仅为58.3%;cTnT上升为91.7%,CK MBmass仍为75.0%。结论cTnT不论是曲线下面积、诊断敏感性、特异性及准确性等方面都明显优于CK MBmass和Myo,是诊断急性心肌损伤的“金标准”。     

缺血修饰清蛋白测定对急性心肌梗死的诊断意义

目的：探讨缺血修饰清蛋白对临床早期诊断急性心肌梗死的价值。方法选择2013年1～10月宝鸡市第三人民医院确认为急性心肌梗死的60例患者设为试验组,选择同期健康体检者60为对照组,分别测定两组的血清缺血修饰清蛋白、乳酸脱氢酶、肌酸激酶及肌酸激酶同工酶的浓度水平,试验组患者同时进行心电图检查,综合分析检测结果。结果试验组患者在发生胸痛后6h内的血清缺血修饰清蛋白的浓度与6h后比较,差异有统计学意义（P＜0．01）,而其他血清学指标6 h前后比较差异无统计学意义（P＞0．05）;急性心肌梗死发作早期（0～6 h）患者的血清缺血修饰清蛋白阳性检出率为86．7％,与其他血清学指标和心电图结果比较,差异有统计学意义（ P＜0．05）;与对照组比较,试验组患者的血清学指标测定结果均有明显升高（P＜0．05）,联合缺血修饰清蛋白和心电图进行检测的特异性为100．0％。结论缺血修饰清蛋白对急性心肌梗死的早期诊断有重要价值,联合心电图进行检测,可以有效提高检测特异性。     

Evaluation of ischaemia-modified albumin as a marker of myocardial ischaemia in end-stage renal disease

The early diagnosis of myocardial ischaemia is problematic in patients with ESRD (end-stage renal disease). The aim of the present study was to determine whether IMA (ischaemia-modified albumin) increases during dobutamine stress and detects myocardial ischaemia in patients with ESRD. A total of 114 renal transplant candidates were studied prospectively, and all received DSE (dobutamine stress echocardiography). IMA levels were taken at baseline and 1 h after cessation of DSE. A total of 35 patients (31%) had a positive DSE result. Baseline IMA levels were not significantly different in the DSE-positive and -negative groups. The increase in IMA was significantly higher in the DSE-positive group compared with those with no ischaemic response (26.5 +/- 19.1 compared with 8.2 +/- 9.6 kU/l respectively; P = 0.007; where kU is kilo-units). From ROC (receiver operator charactertistic) curve analysis, the optimal IMA increase to predict an ischaemic response was 20 kU/l, with a sensitivity of 81% and a specificity of 72% [area under the curve, 0.80 (95% confidence interval, 0.44-0.94); P = 0.03]. There were 18 deaths, ten of which were cardiac in nature over a follow up period of 2.25 +/- 0.71 years. An increase in IMA > or = 20 kU/l was associated with significantly worse survival (P = 0.02). In conclusion, IMA is a moderately accurate marker of myocardial ischaemia in ESRD. Patients with an increase in IMA > or = 20 kU/l during DSE had significantly worse survival.     

缺血修饰白蛋白在诊断急性冠状动脉综合征中的临床意义

目的:探讨血清缺血修饰白蛋白(IMA)在心肌缺血早期诊断中的价值。方法:采用白蛋白钴结合法检测52例急性心肌梗死(AMI)患者、48例不稳定性心绞痛(UA)患者及120名健康体检者(健康对照组)血清中的IMA水平,并分析IMA检测对于急性冠状动脉综合征(ACS)的诊断价值。结果:当临界值为68.4 u/mL时,血清IMA检测诊断ACS的灵敏度、特异度、阳性预测值和阴性预测值分别为80.61%、85.13%、84.63%和85.35%。AMI组患者的血清IMA水平明显高于健康对照组(P<0.05);UA组患者的血清IMA水平亦明显高于健康对照组(P0.05)。有1支或2支冠状动脉(冠脉)病变者的血清IMA水平均显著低于3支病变者(P<0.05),冠脉病变Gensini积分40分者(P<0.05)。结论:血清IMA水平是提示ACS早期且灵敏的指标,可作为早期诊断心肌缺血的标志物。     

缺血修饰性白蛋白在急性缺血性胸痛中的诊断价值

目的 评价缺血修饰性白蛋白（ischemia modified albumin，IMA）对急性缺血性胸痛（ICP）的早期诊断价值。方法 时206例发病〈12h、表现为急性胸痛的患者立即行12导联心电图（ECG）检查，并抽血进行IMA、肌钙蛋白I（cTnI）、肌酸激酶同工酶MB（CK-MB）测定。将ECG、IMA、cTnI、CK-MB的结果单独或结合与最终诊断为非缺血性胸痛（NICP）及ICP的相互关系进行比较。结果 最后诊断为ICP98例，NICP108例，ICP发病〈3h和3-6h组IMA水平明显升高，与NICP组比较差异有统计学意义（P〈0．001）；ICP发病〉6h组IMA水平与NICP组比较差异无统计学意义（P〉0．05）。IMA诊断发病〈3hICP的敏感性和阴性预测值（NPV）为89．1％和88．8％，明显高于ECG、cTnI和CK-MB，四者结合为97．6％和96．9％；IMA诊断发病3～6hICP的敏感性和NPV为71．7％和74．5％，也高于ECG、cTnI、CK-MB，四者结合为95．5％和94．2％；但IMA对于发病〉6h的ICP则无诊断作用。结论 IMA是诊断ICP的早期敏感生化指标，对于发病〈6h（尤其是〈3h）的ICP诊断具有较高的敏感性和NPV，优于ECG、CK-MB、cTnI；将IMA与其他指标结合，可进一步提高对ICP的诊断价值。     

心脏型脂肪酸结合蛋白与缺血修饰白蛋白在急性心肌梗死早期的诊断价值

目的：探讨心脏型脂肪酸结合蛋白（H-FABP）及缺血修饰蛋白（IMA）在急性心肌梗死（AMI）早期的诊断价值。方法测定AMI患者 H-FABP、IMA及CK-MB、cTnT、Mb各指标在入院即刻、4 h、8 h、12 h、24 h 5个时间点的水平。结果在入院即刻（0 h）,H-FABP 和 IMA 的敏感性优于 CK-MB、cTnT、Mb,差异有统计学意义（P＜0.05）;在入院4 h时间点时,H-FABP、IMA、Mb的敏感性高于CK-MB、cTnT （P＜0．05）。5种指标特异性无统计学差异（P＞0．05）;在入院12 h及24 h,CK-MB、cTnT的敏感性达到峰值,与IMA、H-FABP敏感性相比,有统计学差异（P＜0．05）。结论新的心肌损伤标志物 H-FABP、IMA在发病8 h以内的早期胸痛患者中,诊断 AMI的敏感性和特异性均较高,具有较高的临床应用前景。     

Plasma markers of activated hemostasis in the early diagnosis of acute coronary syndromes

BACKGROUND: Because acute coronary syndromes (ACS) are caused by intracoronary thrombosis, plasma markers of coagulation have relevance for early diagnosis. AIMS AND OBJECTIVES: To provide a critical review of these studies and specific attempts to close the diagnostic time gap left by traditional plasma markers of heart injury. METHODS: Studies of ACS patients, with at least one control group, were included when blood samples were taken within 24 h after first symptoms prior to medication or intervention. Special attention was paid to studies reporting diagnostic performance, or combination of several markers into a single diagnostic index. RESULTS: Markers with short plasma half-life (FPA, TAT, etc.) reflect ongoing thrombosis and may identify patients at increased risk. Markers with longer half-life (F1+2, D-Dimer, etc.) may be more useful to indicate a single acute thrombotic event. However, results are highly variable and depend on sampling time, clot property, degree of coronary obstruction and physiological condition. Early diagnostic performance of hemostatic markers was poor even when combined with heart injury markers. CONCLUSIONS: Early measurement of hemostatic plasma markers in ACS patients provides pathophysiological information and may be helpful in risk stratification or to monitor anticoagulant therapy, but does not seem useful in routine clinical diagnosis of ACS.     

缺血修饰白蛋白在急性心肌梗死早期诊断中的价值

目的 探讨缺血修饰白蛋白(IMA)对急性心肌梗死(AMI)的早期诊断价值.方法 103例胸痛发作患者分别于入院即刻及4、6、12、24h连续监测IMA、肌钙蛋白I(cTnI)、肌酸激酶同工酶MB(CK-MB)三项指标,观察其变化规律,同时选择30例健康对照进行检测.结果 23例患者最终诊断为AMI;入院即刻IMA、CK-MB、cTnI检测的敏感性、特异性分别为IMA 89.3％、91.3％,CK-MB 48.4％、92.3％,cTnI 30.6％、93.7％;入院6h内,IMA、CK-MB、cTnI的敏感性分别为91.3％、34.8％、52.2％,联合检测敏感性为100.0％,三者比较差异有统计学意义(x2=15.99,P＜0.01).结论 IMA对AMI的早期诊断有较高的价值,IMA联合cTnI、CK-MB检测诊断AMI,其敏感性明显优于单项检测,具有重要的临床应用价值.     

缺血修饰清蛋白在冠心病早期诊断中的应用研究

目的评价缺血修饰清蛋白（IMA）检测对冠脉综合征（ACS）早期诊断的应用价值。方法连续监测急性胸痛患者发病后2、6、12、24h的血清IMA、肌酸激酶同工酶（CK—MB）、肌钙蛋白I（cTnI）水平，并与健康人群对照，观察其变化规律。用ACB法测定IMA含量，免疫比浊法测定cTnI含量，免疫抑制酶动力学法测定CK-MB活性。结果IMA在稳定型心绞痛患者组无明显升高（P〉0．05）；在不稳定型心绞痛组可升高，发病后2～12h内IMA水平与健康对照组比较有明显升高（P〈0．05）。急性心肌梗死组IMA、CK-MB、cTnI均有不同程度的升高，心肌梗死发生后2h其阳性率分别为85％、71％和55％，3项指标联合检测阳性率为92％；急性心肌梗死发生后6h时，其阳性率分别为96％、87％和81％；当3项指标联合检测时，阳性率上升到99％。敏感性和特异性的受试者工作特征（ROC）曲线显示，急性心肌梗死发生后2h和6h时，IMA、CK—MB、cTnI的AUC值则分别为0．821、0．692、0．632和0．984、0．861、0．816。结论IMA在急性心肌梗死发生以前即不稳定型心绞痛时即可升高，IMA、CK-MB、cTnI 3项指标联合检测诊断急性心肌梗死，其敏感性明显优于单项检测，对急性心肌梗死的早期诊断具有较好的临床应用价值。