增强型心肌肌钙蛋白I检测在急性冠状动脉综合征诊断中的应用

目的观察增强型心肌肌钙蛋白I(cTnI)[即高敏cTnI(hs-cTnI)]在正常人群及急性冠状动脉综合征(ACS)人群中的分布情况并探讨其在ACS诊断中的应用。方法选择胸痛12 h以内的ACS患者80例、同期入院稳定性心绞痛(SA)患者26例和正常对照者60名,检测外周血中hs-cTnI和上一代cTnI浓度,同时检测血常规、C反应蛋白(CRP)等指标。通过受试者工作曲线(ROC)评估hs-cTnI的诊断效能。结果 ACS组、SA组及正常对照组间hs-cTnI、cTnI差异均有统计学意义(P<0.05)。hs-cTnI的ROC曲线下面积(AUC)为0.986±0.014,高于cTnI的AUC(0.915±0.035)(P=0.034),而与hs-cTnI联合CRP、中性粒细胞百分率、中性粒细胞/淋巴细胞比值及白细胞计数的AUC(0.978±0.018)无差异(P>0.05)。当hs-cTnI取0.02 ng/mL为最佳临界值,此时诊断ACS的效率最高。结论 hs-cTnI对早期ACS的诊断效率较上一代cTnI有所提高,但联合炎症指标没有提高其诊断价值。     

高敏心肌肌钙蛋白Ⅰ水平变化对急性非ST段抬高型心肌梗死的诊断价值分析

目的 探讨高敏心肌肌钙蛋白Ⅰ(hs-cTnI)在急性非ST段抬高型心肌梗死(NSTEMI)中的诊断价值.方法 回顾性分析2018年1月至2020年10月以胸痛为主诉就诊于该院急诊科的疑似非ST段抬高型急性冠脉综合征(NSTE-ACS)患者资料.采用纯态氧介导化学发光法检测患者在就诊时(T0)及就诊3 h(T3)的血浆h...     

单次高敏肌钙蛋白I浓度对疑似急性冠状动脉综合征患者30天心血管不良事件的预测价值

目的探讨单次高敏肌钙蛋白I(hs-cTnI)浓度对疑似急性冠状动脉综合征(ACS)患者30 d心血管不良事件的预测价值。方法本研究为多中心、前瞻性、观察性研究。选择2017年1月至2020年9月中国医学科学院阜外医院、中山大学附属第一医院、南京市第一医院急诊科就诊的疑似ACS患者。对入选患者就诊时检测hs-cTnI, 并进行30 d随访, 以临床结局指标为标准分为发生事件组和未发生事件组, 计算单次hs-cTnI在不同浓度界值下对患者发生30 d心血管不良事件[急性心肌梗死(包括入院时)、计划外血运重建、心血管死亡]的敏感度、阴性预测值(NPV)及95%置信区间(CI), 以漏诊率<2%, NPV>99%为标准推测最佳界值。按照hs-cTnI的影响因素(性别、年龄、胸痛时间、估算的肾小球滤过率)进行分组, 采用卡方检验比较不同亚组间的敏感度及NPV。结果研究共完成随访1 461例患者, 其中发生30 d心血管不良事件者387例(26.5%), 未发生者1 074例(73.5%)。年龄(62±12)岁, 男905例(61.9%)。单次hs-cTnI浓度<2 ng/L(最...     

hs-cTnI与cTnI在远端冠脉阻塞后的微小心肌损伤诊断中的价值比较

目的研究肌钙蛋白I(cTnI)和高敏肌钙蛋白I(hs-cTnI)在远端冠脉阻塞后微小心肌损伤(MMD)中的诊断价值。方法随机选取240例胸痛入院患者作为观察组,其中175例已确诊有冠脉阻塞的心肌损伤患者(ZMMD组)、39例无冠脉阻塞的心肌损伤患者(WMMD组),26例非缺血性胸痛患者(NICP组),入院后抽血并测定ZMMD组、WMMD组、NICP组三组入院即刻(0 min),入院后30 min、90 min、120 min血清中cTnI和hs-cTnI的水平,另选90例健康体检者作为对照组。采用胶体金免疫层析法(GICA)检测血清cTnI水平,荧光免疫层析法检测hs-cTnI水平。结果观察组血清cTnI和hs-cTnI水平均明显高于对照组,差异有统计学意义(P 0. 05); ZMMD组和WMMD组中cTnI和hs-cTnI水平均高于NICP组和对照组,差异有统计学意义(P 0. 05),ZMMD组与WMMD组cTnI和hs-cTnI水平无显著差异。ZMMD组和WMMD组入院即刻血清样本hs-cTnI的阳性率分别为92. 6%和93. 1%,高于c Tn T阳性率69. 2%和65. 3%,差异有统计学意义(P 0. 05)。ZMMD组hs-cTnI入院4个不同时间点(0 min、30 min、90 min、120min)阳性率高于cTnI阳性率,hs-cTnI阳性率最高为99. 5%(入院30min后),cTnI阳性率最高为98. 2%(入院90 min后)。结论 cTnI和hs-cTnI是诊断远端冠脉阻塞后MMD的生理指标,且在远端冠脉阻塞MMD患者早期血清中hscTnI比cTnI更敏感。     

敏感型心肌钙蛋白Ⅰ早期诊断急性心肌梗死的应用研究

目的:评估敏感型心肌钙蛋白Ⅰ早期诊断急性心肌梗死(AMI)临床应用价值.方法:应用发光免疫法分别测定疑似心梗患者症状发生后3h内就诊的67例AMI患者和58例非AMI患者同一份血清标本中敏感型心肌肌钙蛋白Ⅰ (hs-cTnI)、标准型心肌钙蛋白Ⅰ(cTnI).结果:两种检测方法对AMI患者检测的敏度和特异性:cTnI为68.7％和53.4％; hs-cTnI为71.6％和63.8％.hs-cTnI检测的接受者操作特征(ROC)曲线的曲线下面积为0.755,诊断灵敏度为67.2％均高于标准cTnI检测(0.639,59.7％).结论:hs-cTnI检测早期诊断AMI的准确性和灵敏度优于标准型cTnI检测.     

高敏cTnI在急性心肌梗死患者中的诊断阈值与影响因素分析

目的研究急性心肌梗死(AMI)患者高敏肌钙蛋白I(hs-cTnI)的测定阈值及其影响因素。方法选取2014~2015年来该院内科急诊就诊,初次检测hs-cTnI患者9 236例(9 099例诊断为非AMI患者和137例诊断为AMI患者),将非AMI的患者按年龄分为老年组(60岁)和年轻组(≤60岁),并且分析性别对hs-cTnI的影响;根据确诊为AMI的cTnI值做ROC曲线来确定本地区诊断AMI最佳阈值,并按年龄和性别分组,做出诊断AMI的适合阈值。结果非AMI人群中,老年男性患者组hs-cTnI平均水平39.21ng/L[(37.48~40.93)ng/L],高于年轻男性患者组的平均水平22.38ng/L[(21.16~23.6)ng/L],差异有统计学意义(P0.05);老年女性患者组的hs-cTnI平均水平为33.84ng/L[(32.13~35.54)ng/L],高于年轻女性组的hs-cTnI平均水平17.41ng/L[(16.46~18.36)ng/L],差异有统计学意义(P0.05);总体男性患者hs-cTnI平均水平为31.26ng/L[(30.17~32.34)ng/L],高于总体女性患者26.8ng/L[(25.73~27.86)ng/L],差异有统计学意义(P0.05)。AMI患者中,利用ROC曲线分析整体患者的hs-cTnI诊断AMI最佳阈值为45ng/L,在老年男性和老年女性组中分别为135和45ng/L,均不同于试剂生产商给出的AMI诊断cut off值120ng/L。结论 hs-cTnI水平与性别有关,男性高于女性,与年龄呈正相关,建立本地区人群诊断AMI的hs-cTnI阈值应考虑到这些影响因素。     

高敏肌钙蛋白I低水平表达在冠心病中的诊断价值

目的 探讨高敏肌钙蛋白I(hs-cTnI)低水平表达的胸痛患者冠状动脉造影情况,了解hs-cTnI的低水平表达在冠心病诊断中的价值.方法 选择hs-cTnI水平为0.006～0.04 ng/mL的胸痛患者,根据冠脉造影结果分为冠心病组与非冠心病组,比较两组的hs-cTnI水平及其与冠状动脉Gensini积分的相关性.结果 冠心病组hs-cTnI水平高于非冠心病组,差异有统计学意义(P＜0.01).冠心病组患者hs-cTnI水平与冠状动脉Gensini积分呈正相关(r=0.426,P<0.05).结论 hs-cTnI有助于冠心病的诊断,且hs-cTnI水平可能与冠状动脉的病变范围和程度有关.     

肌钙蛋白T在心源性胸痛鉴别诊断中的价值

因急性胸痛而就诊于急诊科的患者日益增多,早期、快速、准确地检出急性心肌梗死(AMI)患者显得尤为重要.本文采用德国Boehringer Mannheim公司的肌钙蛋白T(cTnT)全血快速灵敏定性检测试纸条对50例急性胸痛患者进行观察,并作出评价.     

即时床旁超声心动图在诊断急性高危胸痛病人中的应用

目的:总结即时床旁经胸超声心动图(TTE)在急性高危胸痛患者诊断中的应用。方法:回顾性分析2019年3月至2021年5月广东省河源市人民医院诊治的244例急性胸痛患者的临床资料,并分为急性高危胸痛组63例,非急性高危胸痛组181例(对照组),比较TTE的诊断率及其在不同病因胸痛中的检测指标。结果:TTE诊断急性高危胸痛的检出率为90.5%,明显高于心电图(ECG)检出率的69.8%,P<0.05;急性心肌梗死(AMI)、主动脉夹层(AD)患者的左室舒张末容积、左室射血分数(LVEF)及AD患者的升主动脉直径与对照组均有明显差异,肺栓塞(PE)患者的右室舒张末期容积和三尖瓣环收缩期运动幅度(TAPSE)与对照组有明显差异,P均<0.05。结论:即时床旁TTE能及时快速有效辅助诊断常见急性高危胸痛,建议临床推广应用。     

急诊环节质量控制对急性心肌梗死患者肌酸激酶同工酶、高敏肌钙蛋白、脑钠肽值的影响

目的:研究急诊环节质量控制对急性心肌梗死(AMI)患者肌酸激酶同工酶(CK-MB)、高敏肌钙蛋白(hs-cTnI)、脑钠肽(BNP)值的影响。方法:总结分析2012-01-01-2016-06-30在我院进行治疗的175例AMI患者的临床资料。结果:92例对照组患者CK-MB、hs-cTnI、BNP在即刻、4~6h、12~24h、72h4个时间段的均值均显著高于83例研究组患者三者的均值(P0.05);研究组CK-MB、hs-cTnI、BNP数值上升幅度较对照组小,而恢复时间早于对照组。结论:急诊环节质量控制对AMI患者CK-MB、hs-cTnI、BNP数值有显著影响,结合动态联合检测CK-MB、hs-cTnI、BNP可以较早确诊AMI,提高AMI的诊断率,有助于判断AMI的疗效及预后。     

Diagnostic performance of initial salivary alpha-amylase activity for acute myocardial infarction in patients with acute chest pain

Background

To rule out acute myocardial infarction (AMI) in chest pain patients constitutes a diagnostic challenge to emergency department (ED) physicians.

Study Objectives

To evaluate the diagnostic value of measuring salivary alpha-amylase (sAA) activity for detecting AMI in patients presenting to the ED with acute chest pain.

Methods

sAA activity was measured in a prospective cohort of 473 consecutive adult patients within 4 h of onset of chest pain. Comparisons were made between patients with a final diagnosis of AMI and those with non-AMI. Univariate analysis and multiple logistic regression model were used to identify independent clinical predictors of AMI.

Results

Initial sAA activity in the AMI group (n = 85; 266 ± 127.6 U/mL) was significantly higher than in the non-AMI group (n = 388; 130 ± 92.8 U/mL, p < 0.001). sAA activity levels were also significantly higher in patients with ST elevation AMI (n = 53) compared to in those with non-ST elevation AMI (n = 32) (300 ± 141.1 vs. 210 ± 74.1 U/mL, p < 0.001). The area under the receiver operating characteristic curve of sAA activity for predicting AMI in patients with acute chest pain was 0.826 (95% confidence interval [CI] 0.782–0.869), with diagnostic odds ratio 10.87 (95% CI 6.16–19.18). With a best cutoff value of 197.7 U/mL, the sAA activity revealed moderate sensitivity and specificity as an independent predictor of AMI (78.8% and 74.5%).

Conclusions

High initial sAA activity is an independent predictor of AMI in patients presenting to the ED with chest pain.     

心型脂肪酸结合蛋白在急性心肌梗死早期诊断中价值

目的探讨血浆心型脂肪酸结合蛋白(heart-type fatty acid-binding protein,H-FABP)对早期诊断急性心肌梗死(acute myocardial infarction,AMI)的意义。方法发病6h内以急性胸痛就诊的疑似AMI患者83例,根据出院诊断分为AMI组32例与非AMI组51例,非AMI组又分为不稳定型心绞痛33例(UAP组)与非心源性胸痛18例(NCCP组),选择体检健康者40名为对照组,采用ELISA法检测各组血清H-FABP水平,并与传统心肌标志物的诊断效能进行比较。结果 AMI组血清H-FABP水平明显高于非AMI组和对照组(P均<0.01);ROC曲线显示,H-FABP的AUC为0.954(95%CI:0.912～0.997),H-FABP诊断AMI的最佳截断值为6.65ng/mL;H-FABP诊断发病6h内AMI的敏感度、特异度、阴性预测值及准确率分别为90.26%,80.39%,93.18%,84.34%;敏感度、阴性预测值及准确率明显高于传统心肌标志物肌红蛋白、肌酸激酶同工酶和肌钙蛋白I(P<0.05)。结论 H-FABP对发病早期的AMI有较好诊断价值。     

Rapid rule out of acute myocardial infarction in the observe zone using a combination of presentation N-terminal pro-B-type natriuretic peptide and high-sensitivity cardiac troponin I

Background and aimsThe release of N-terminal pro-B-type natriuretic peptide (NT-proBNP) is strongly triggered by myocardial ischemia. We aimed to investigate whether the addition of NT-proBNP to high-sensitivity cardiac troponin (hs-cTnI) at presentation could provide better performance in risk stratification and thus early rule-out of acute myocardial infarction (AMI) in patients of the “observe zone”.MethodsEmergency department (ED) patients presenting with symptoms suspicious for AMI were consecutively enrolled. Blood samples were obtained at presentation and tested for hs-cTnI and NT-proBNP. All available medical records pertaining to the patient from ED presentation to 30-day follow-up were used for adjudication of the primary outcome. The incremental diagnostic value added by NT-proBNP to hs-cTnI was evaluated by receiver operating characteristic (ROC) analysis, continuous net reclassification improvement (cNRI), and integrated discrimination improvement (IDI). Sensitivity, specificity, positive and negative predictive values were used to assess the diagnostic accuracy of different approaches for early rule out.ResultsOf the 165 patients we analyzed, 55 (33.3%) had index AMI. For hs-cTnI alone, area under the curve for index AMI was not significantly increased after adding NT-proBNP (0.773 vs 0.809; p = .076). Adjustment of hs-cTnI by NT-proBNP improved the predictive value of hs-cTnI, showed by cNRI (0.418, 95%CI 0.102–0.735, p = .009) and IDI (0.055, 95%CI 0.017–0.092, p = .004). Compared to hs-cTnI, the combined test identified 14% more patients as low-risk and safe for early discharge.ConclusionsCombination of presentation hs-cTnI and NT-proBNP provided better predictive performance for AMI in patients of the observe zone presenting with symptoms of chest pain as compared to hs-cTnI alone. The combined test outperformed hs-cTnI by correctly identifying nearly 14% more patients as low-risk and safe for early discharge. Future multi-center studies are needed to verify the results and to determine the best clinical use of the combination of NT-proBNP and hs-cTnI in the early diagnosis of AMI.     

Single test rule-out of acute myocardial infarction using the limit of detection of a new high-sensitivity troponin I assay

ObjectivesTo determine the diagnostic accuracy of a high-sensitivity cardiac troponin I (hs-cTnI) assay in patients presenting to the Emergency Department (ED) with suspected acute coronary syndromes. Specifically, we evaluated the use of a single blood test at the time of arrival in the ED, using low hs-cTnI cut-offs.MethodsIn a prospective diagnostic test accuracy study at 14 centers, we included patients presenting to the ED with suspected ACS within 12 h of symptom onset. We drew blood for hs-cTnI (Siemens ADVIA Centaur, overall 99th percentile 47 ng/L, limit of quantification [LoQ] 2.50 ng/L) on arrival. Patients underwent serial cardiac troponin testing over 3–6 h. The primary outcome was an adjudicated diagnosis of acute myocardial infarction (AMI). We evaluated the incidence of major adverse cardiac events (MACE: death, AMI or revascularization) after 30 days. Test characteristics for hs-cTnI were calculated using previously reported cut-offs set at the LoQ and 5 ng/L.ResultsWe included 999 patients, including 131 (13.1%) with an adjudicated diagnosis of AMI. Compared to the LoQ (100.0% sensitivity [95% CI 95.9–100.0%]), 99.7% negative predictive value [NPV; 95% CI 97.6–100.0%]), a 5 ng/L cut-off had slightly lower sensitivity (99.2%; 95% CI 95.8–100.0%) and similar NPV (99.8%; 95% CI 98.6–100.0%) but would rule out more patients (28.6% at the LoQ vs 50.4% at 5 ng/L). MACE occurred in 2 (0.7%) patients with hs-cTnI below the LoQ and 7 (1.4%) patients with hs-cTnI < 5 ng/L. Accounting for time from symptom onset or ECG ischemia did not further improve sensitivity.ConclusionThe Siemens ADVIA Centaur hs-cTnI assay has high sensitivity and NPV to rule out AMI with a single blood test in the ED. At the LoQ cut-off a sensitivity > 99% can be achieved. At a 5 ng/L cut-off it may be possible to rule out AMI for over 50% patients.     

心型脂肪酸结合蛋白在急性心肌梗死早期诊断中的价值

目的探讨心型脂肪酸结合蛋白(H-FABP)在急性心肌梗死(AMI)早期诊断中的价值。方法选择以胸痛为主要表现、疑似AMI就诊的患者144例(有90例确诊为AMI,其余54例为疑似组),使用酶联免疫吸附试验(ELISA)测定发病3 h内、6 h后的血清H-FABP、心肌肌钙蛋白I(cTnI)、肌酸激酶同工酶(CK-MB),比较其在AMI早期的敏感性、特异性、诊断正确性。同时选取年龄、性别相仿的60名健康体检者作为正常对照组。结果在发病3 h内,AMI组H-FABP水平为(56.13±19.17)ng/mL,明显高于疑似组[(11.46±4.85)ng/mL]和正常对照组[(3.14±1.52)ng/mL](P<0.01),并且其阳性率(91.11%)、敏感性(91.11%)、特异性(98.33%)、诊断正确率(94.67%)、阳性预测值(98.80%)和阴性预测值(88.24%)均明显优于cTnI(13.33%、13.33%、96.67%、48.00%、85.71%、43.48%)和CK-MB(21.11%、21.11%、95.00%、52.67%、86.36%、48.80%)(P<0.05、P<0.01)。而cTnI及CK-MB水平在发病6 h后AMI组才明显高于疑似组和正常对照组(P<0.01)。结论在AMI发病早期(3 h内),H-FABP具有较高的敏感性、诊断正确率及阴性预测值,可以用于AMI的早期诊断。     

床边敏感性肌钙蛋白Ⅰ对急性心肌梗死的早期诊断价值

目的 评估床边敏感性肌钙蛋白Ⅰ(point-of-care testing for sensitive cardiac troponin Ⅰ,POCT-cTnⅠ)对早期诊断急性心肌梗死(acute myocardial infarction,AMI)的分析性能.方法 检测中山大学附属第一医院急诊科收治的127例疑诊AMI的急诊胸痛患者在入院3个不同时间点(入院即刻、入院后3h和6h)POCT-cTnI和中心实验室高敏肌钙蛋T(central laboratory testing for high sensitive cardiac troponin T,CLT-hscTnT)水平,由两名临床医师根据90 d内所获得的全部临床资料各自独立地给出胸痛病因的最终诊断,并将患者分为AMI组和非AMI组.应用受试者工作特征曲线(receiver operating characteristic curve,ROC曲线)比较POCT-cTnI和CLT-hscTnT两种检测方法对AMI的诊断性能,采用DeLong检验比较ROC曲线下面积(area under the curve,AUC);并计算使用不同诊断界值时的敏感性、特异性、阴性预测值(negative predictive value,NPV)和阳性预测值(positive predictive value,PPV).结果 127例胸痛患者中,有40例(31.5％)最终诊断为AMI.POCT-cTnI和CLT-hscTnT在入院即刻水平诊断AMI的准确性用AUC表示,分别为0.901 (95％CI:0.901～0.947)和0.907 (95％CI:0.842～0.951),两者差异无统计学意义(Z=0.235,P=0.745).POCT-cTn在入院后3h的AUC增加至0.931,与入院即刻相比(AUC,0.858)差异有统计学意义(Z=-2.038,P=0.042),但较入院后6 h(AUC,0.949)差异无统计学意义(Z=-1.435,P=0.151).POCT-cTn使用正常人群参考范围上限的第99百分位数为诊断界值(0.023 ng/mL),入院即刻水平的诊断敏感性为77.5％,特异性为94.2％;入院后3h诊断特性进一步提高,敏感性为96.4％,特异性为92.0％,NPV为98.6％,PPV为81.8％.而CLT-hscTnT使用第99百分位数为诊断界值(0.014 ng/mL),在入院3h水平的NPV为100％.结论 POCT-cTnI可在急诊胸痛患者入院后3h快速准确地识别或除外AMI,诊断性能与CLT-hscTnT相近.     

Electrocardiographic ST segment elevation: a comparison of AMI and non-AMI ECG syndromes

Chest pain (CP) patients presenting to the ED may manifest electrocardiographic ST segment elevation (STE). AMI (acute myocardial infarction) is a less frequent cause of such abnormality and one of many patterns responsible for ST segment elevation in ED CP patients. We performed a retrospective comparative review of the electrocardiographic features of various STE syndromes, focusing on differences between AMI and non-AMI syndromes. The electrocardiograms (ECGs) of consecutive ED adult CP patients (with 3 serial troponin I determinations) were interpreted by 3 attending emergency physicians. These ECGs with STE represented the study population used for analysis. Various electrocardiographic features such as STE, ST segment depression (STD), STE morphology, anatomic distribution of STE, and the number of leads with STE were recorded; derived values such as total STE, total ST segment deviation, and average STE per lead were calculated. Interobserver reliability concerning STE morphology was determined. AMI was diagnosed by abnormal serum troponin I values (>0.1 mg/dL) followed by a rise and fall of the serum marker; STE diagnoses of non-AMI causes were determined by medical record review. Five hundred ninety-nine CP patients were entered in the study with 212 (35%) individuals showing STE, 55 (26%) with electrocardiographic AMI and 157 (74%) with non-AMI electrocardiographic syndromes. Anatomic location within the AMI group included 32 inferior and inferior variants, 18 anterior and anterior variants, and 5 lateral; non-AMI anatomic locations included 56 inferior and inferior variants, 98 anterior and anterior variants, and 3 lateral; anterior STE occurred significantly more often in non-AMI syndromes. Total STE was 15.3 mm in AMI patients and 7.4 mm in non-AMI patients (P =.0004). The number of leads with STE was not significantly different between the two groups, 3.4 mm in AMI and 4.1 in non-AMI syndromes. ST segment elevation per lead was not significantly different in the 2 groups, 4.4 mm in AMI versus 1.8 mm in non-AMI syndromes. Total ST segment deviation (sum of STE and STD) was significantly greater in AMI syndromes, 17.8 mm in AMI compared with 10.5 mm in non-AMI syndromes (P =.00009). The presence of STD occurred at statistically similar rates in both groups. The morphology of the STE occurred in significantly different rates between AMI and non-AMI patterns, concave more often in non-AMI patterns (P <.00001) and nonconcave more often in AMI (P <.00001). Non-AMI causes of STE account for the majority of electrocardiographic syndromes encountered in ED chest pain patients. These findings alone are not adequate to determine the electrocardiographic cause of the ST segment elevation in chest pain patients. When determining AMI versus non-AMI with the ECG, these various findings should be used in the consideration of the overall clinical picture (history, examination, and electrocardiogram) in chest pain patients with ST segment elevation.     

Delta CK-MB outperforms delta troponin I at 2 hours during the ED rule out of acute myocardial infarction

It has been shown that a rise in creatine kinase MB bank (CK-MB) of > or = + 1.6 ng/mL in 2 hours is more sensitive and equally specific for detection of acute myocardial infarction (AMI) as compared with a 2-hour CK-MB > or = 6 ng/mL during the emergency department (ED) evaluation of chest pain. Because cardiac specific troponin I (cTnI) is thought to have similar early release kinetics as compared with CK-MB mass, we undertook a retrospective cohort study in 578 chest pain patients whose baseline CK-MB and cTnI was less than two times the hospital's upper limits of normal and who underwent a 2-hour CK-MB and cTnI to compare sensitivities and specificities of the 2-hour delta CK-MB (deltaCK-MB) and delta cTnI (delta cTnI) for AMI and 30-day Adverse Outcome (AO). Thirty day AO was defined as AMI, life-threatening complication, death, or percutaneous transluminal coronary angioplasty (PTCA)/coronary artery bypass graft (CABG) within 30 days of ED presentation. Optimum delta values were determined by choosing the smallest cutoff value greater than the assay precision where the deltaCK-MB and delta cTnI had a positive likelihood ratio for 30-day AO of > or = 15. A deltaCK-MB > or = +1.5 ng/mL was more sensitive than a deltaTnI > or = +0.2 ng/mL for AMI (87.7% versus 61.4%; P < .0005) and 30-day AO (56.7% versus 42.3%; P < .005). There were no differences in specificities for AMI and 30-day AO. Combining the two tests (MBdelta > or = +1.5 ng/mL and/or a deltaTnI > or = +0.2 ng/mL) resulted in an incremental increase in sensitivity of 89.5% for AMI and 61.9% for AO (P < .005). Patients with either a rise in CK-MB of > or = +1.5 ng/mL or rise in cTnI of > or = +0.2 ng/mL in 2 hours should receive consideration for aggressive antiischemic therapy and further diagnostic testing before making an exclusionary diagnosis of nonischemic chest pain.     

Human heart-type cytoplasmic fatty acid-binding protein (H-FABP) for the diagnosis of acute myocardial infarction. Clinical evaluation of H-FABP in comparison with myoglobin and creatine kinase isoenzyme MB.

Heart-type fatty acid-binding protein (H-FABP) is a low molecular weight cytoplasmic protein and present abundantly in the myocardium. When the myocardium is injured, as in the case of myocardial infarction, low molecular weight cytoplasmic proteins including H-FABP are released into the circulation and H-FABP is detectable in a blood sample. We have already developed a direct sandwich-ELISA for quantification of human H-FABP using two distinct types of monoclonal antibodies specific for human H-FABP. In this study we investigated the clinical validity of H-FABP as a biochemical diagnostic marker in the early phase of acute myocardial infarction (AMI). To evaluate the diagnostic usefulness of H-FABP in the early phase of AMI, blood samples were obtained from the following patients within 12 hours after the appearance of symptoms, and serum levels of H-FABP were compared with those of conventional diagnostic markers, such as myoglobin and creatine kinase isoenzyme MB (CK-MB). Blood samples were collected from patients with confirmed AMI (n=140), patients with chest pain who were afterwards not classified as AMI by normal CK-MB levels (non-AMI) (n=49) and normal healthy volunteers (n=75). The serum concentration of H-FABP was quantified with our direct sandwich-ELISA. The concentration of myoglobin mass was measured with a commercial RIA kit. The serum CK-MB activity was determined with an immuno-inhibition assay kit. The overall sensitivity of H-FABP, within 12 hours after the appearance of symptoms, was 92.9%, while it was 88.6% with myoglobin and 18.6% with CK-MB. The overall specificity of H-FABP was 67.3%, while it was 57.1% with myoglobin and 98.0% with CK-MB. The diagnostic efficacy rates with these markers were 86.2% (H-FABP), 80.4% (myoglobin) and 39.2% (CK-MB), respectively. The diagnostic validity of H-FABP was further assessed by receiver operating characteristic (ROC) curve analysis. The area under the curve (AUC) of H-FABP was 0.921, which was significantly greater than with myoglobin (AUC: 0.843) and CK-MB (AUC: 0.654). These parameters, such as sensitivity, specificity, diagnostic efficacy and diagnostic accuracy, obtained for patients with chest pain within 3 hours and/or 6 hours after the onset of symptoms were almost the same as those for patients within 12 hours after symptoms. H-FABP is more sensitive than both myoglobin and CK-MB, more specific than myoglobin for detecting AMI within 12 hours after the onset of symptoms, and shows the highest values for both diagnostic efficacy and ROC curve analysis. Thus, H-FABP has great potential as an excellent biochemical cardiac marker for the diagnosis of AMI in the early phase.