Early Diagnosis of Myocardial Infarction With Point-of-Care High-Sensitivity Cardiac Troponin I

BackgroundUntil now, high-sensitivity cardiac troponin (hs-cTn) assays were mainly developed for large central laboratory platforms.ObjectivesThis study aimed to assess the clinical performance of a point-of-care (POC)-hs-cTnI assay in patients with suspected myocardial infarction (MI).MethodsThis study enrolled patients presenting to the emergency department with symptoms suggestive of MI. Two cardiologists centrally adjudicated the final diagnosis using all clinical data including cardiac imaging. The primary objective was to directly compare diagnostic accuracy of POC-hs-cTnI-TriageTrue versus best-validated central laboratory assays. Secondary objectives included the derivation and validation of a POC-hs-cTnI-TriageTrue–specific 0/1-h algorithm.ResultsMI was the adjudicated final diagnosis in 178 of 1,261 patients (14%). The area under the curve (AUC) for POC-hs-cTnI-TriageTrue at presentation was 0.95 (95% confidence interval [CI]: 0.93 to 0.96) and was at least comparable to hs-cTnT-Elecsys (AUC: 0.94; 95% CI: 0.93 to 0.96; p = 0.213) and hs-cTnI-Architect (AUC: 0.92; 95% CI: 0.90 to 0.93; p < 0.001). A single cutoff concentration <3 ng/l at presentation identified 45% of patients at low risk with a negative predictive value (NPV) of 100% (95% CI: 99.4% to 100%). A single cutoff concentration >60 ng/l identified patients at high risk with a positive predictive value (PPV) of 76.8% (95% CI: 68.9% to 83.6%). The 0/1-h algorithm ruled out 55% of patients (NPV: 100%; 95% CI: 98.8% to 100%), and ruled in 18% of patients (PPV: 76.8%; 95% CI: 67.2% to 84.7%). Ruled-out patients had cumulative event rates of 0% at 30 days and 1.6% at 2 years. This study confirmed these findings in a secondary analysis including hs-cTnI-Architect for central adjudication.ConclusionsThe POC-hs-cTnI-TriageTrue assay provides high diagnostic accuracy in patients with suspected MI with a clinical performance that is at least comparable to that of best-validated central laboratory assays. (Advantageous Predictors of Acute Coronary Syndromes Evaluation Study [APACE]; NCT00470587)     

Biochemical Validation of Patient-Reported Symptom Onset Time in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

ObjectivesThis study evaluated a biochemical validation of patient-reported symptom onset time in patients with ST-segment elevation myocardial infarction (STEMI).BackgroundSymptom onset time is an important metric but has never been formally validated.MethodsThe Mayo Clinic Percutaneous Coronary Intervention (PCI) Registry was interrogated to obtain baseline, procedural, and outcome data on 607 STEMI patients undergoing primary PCI. Biochemical onset time was determined by backward extrapolation of serial increasing cardiac troponin T (cTnT) measurements.ResultsThe median patient-reported onset time was 12 min later than the calculated time of first cTnT increase and was therefore estimated to be 4.2 h later than the biochemical onset time (interquartile range: 1.9 to 11.1 h; p < 0.001), assuming a 4-h interval between coronary occlusion and first cTnT increase. Conventional ischemic time showed no association with infarct size (correlation with peak cTnT: r = 0.023; p = 0.61) or 1-year mortality (hazard ratio: 0.97 per doubling; 95% confidence interval: 0.68 to 1.40; p = 0.88). However, after recalculation of ischemic time with biochemical onset time, significant associations with infarct size (r = 0.14; p = 0.001) and 1-year mortality (hazard ratio: 1.70 per doubling; 95% confidence interval: 1.20 to 2.40; p = 0.003) were found. When underestimation of ischemic time by patient-reported onset time increased, so did the risk of mortality.ConclusionsAlthough our point estimate should be interpreted with caution, our study indicates that the actual onset of STEMI is likely to be earlier than the patient-reported onset time. Recalculation of ischemic time with biochemical onset time greatly enhanced its prognostic value. Underestimation of ischemic time by patient-reported onset time occurred more often in high-risk patients.     

缺血性心力衰竭中医证候与NT-proBNP及心肌损伤的相关性研究

目的：探索缺血性心力衰竭气虚血瘀证和阳虚水停证与N端钠尿肽前体（N-terminal pro-brain natriuretic peptide,NTproBNP）及心肌损伤的相关性。方法：收集2011年11月至2012年12月于中国中医科学院西苑医院心血管科住院的缺血性心力衰竭患者36例,气虚血瘀证和阳虚水停证各18例,检测患者血中NT-proBNP及心肌肌钙蛋白T（Cardiac troponin T,cTnT）的含量,比较气虚血瘀证和阳虚水停证NT-proBNP及cTnT含量的差异,进一步对差异指标进行ROC曲线分析,计算ROC曲线下面积,分析差异指标与阳虚水停证的相关性。结果：缺血性心力衰竭阳虚水停证较气虚血瘀证NT-proBNP及cTnT含量升高（P〈0.05）;阳虚水停证与气虚血瘀证NT-proBNP及cTnT的ROC曲线分析显示,NT-ProBNP曲线下面积0.91,cTnT曲线下面积0.79（P〈0.05）;cTnT及NT-ProBNP与阳虚水停证呈正相关,相关系数为分别为0.50、0.72（P〈0.05）。结论：NTproBNP及cTnT可以为缺血性心力衰竭气虚血瘀证和阳虚水停证的辨证分型提供检测依据。     

褪黑素对慢性间歇性缺氧性心肌cTnT及Ca~(2+)-ATPase的影响

目的探讨褪黑素(MLT)对常压下慢性间歇性缺氧SD大鼠心肌的保护作用。方法将24只雄性SD大鼠(5周龄)随机分成3组:对照组、实验A组、实验B组。对照组在空气中正常饲养,实验A组和实验B组在常压慢性间歇性低氧箱内,对照组和实验B组灌服生理盐水,实验A组灌服褪黑素。8周后用光电比色法测定血清肌钙蛋白T(cTnT)的浓度和心肌钙离子ATP酶(Ca2+-ATPase)的活性,取大鼠右心室做病理切片。结果 1实验B组与实验A组比较:实验B组的cTnT明显增加(P0.05),心肌组织的Ca2+-ATPase的活性明显降低(P0.05)。病理切片显示,个别心肌细胞核消失,心肌细胞肥大,心肌之间有大量出血;2实验A组与对照组比较:cTnT和Ca2+-ATPase均无明显差异(P0.05)。病理切片显示,心肌细胞之间有少量出血;3实验B组与对照组比较:实验B组的cTnT明显增加(P0.05),心肌组织的Ca2+-ATPase的活性明显降低(P0.05)。病理切片显示,个别心肌细胞核消失,心肌细胞肥大,心肌之间有大量出血。结论褪黑素对慢性间歇性缺氧心肌具有保护作用。     

急性心梗时肌钙蛋白检测临床意义分析

目的 了解急性心梗(AMI)病人肌钙蛋白(cTnT)升高、升高程度的临床指导意义.方法 将因急性心痛确诊为AMI的病人,按cTnT升高程度分成升高、异常两组,每组各40例.入院即刻、入院第2、3天晨起抽静脉血,测心肌酶,且以酶联免疫法测定其cTnT值,取3次中最高值做统计学分析.观察住院期间心脏事件.结果 30天内病死4例,其cTnT都高于1.0ng/ml.Q波出现与室壁痛形成也都在cTnT>1.0ng/ml组中.cTnT的特异性高于心肌酶学指标.结论 cTnT测定值对AMI预后、诊断的临床价值较高.     

h-FABP、hs-CRP、cTnT对急性心肌梗死诊断临床价值分析

[目的]通过对h-FABP、hs-CRP、cTnT 3项指标的联合检测为急性心肌梗死(AMI)的诊断提供可靠依据.[方法]cTnT检测采用金标记免疫渗滤法;hs-CRP检测采用免疫散射比浊法;h-FABP检测采用96T ELISA方法.[结果]健康组与AMI组比较,h-FABP:(5.46±0.19),(23.27±1.77)ng/mL,P＜0.01;cTnT:(0.10±0.01),(0.64±0.11)ng/mL,P＜0.01;hs-CRP:(0.85±0.10),(17.39±4.69)mg/L,P＜0.01;cTnT、hs-CRP、h-FABP在40例AMI患者发作0～3 h阳性率分别为50%、55.26%、85%.3项指标联合分析阳性率可达98%.[结论]h-FABP、hs-CRP与cTnT联合检测对AMI早期诊断具有高灵敏性和特异性.     

肌钙蛋白两个亚单位在急性心肌梗死诊断中的应用分析

目的:探讨肌钙蛋白I(cTnI)和肌钙蛋白T(cTnT)在急性心肌梗死(AMI)诊断中的意义.方法:对89例 AMI 患者和 25 例非AMI患者以及 48 例 AMI 患者胸痛发作后不同时间cTnI、cTnT、肌红蛋白(MYO)检测值及阳性率进行比较,并比较不同浓度组cTnI、cTnT检测值和阳性率.结果:AMI组患...     

电针内关对心肌缺血再灌注损伤大鼠cTnT及bax基因表达的影响

目的通过研究电针内关对心肌缺血再灌注损伤过程中肌钙蛋白T(cTnT)及细胞凋亡调控基因bax的影响,阐明电针内关对心肌缺血再灌注损伤的作用机制。方法在大鼠冠状动脉左前降支根部穿线结扎建立心肌缺血再灌注损伤模型,电针内关穴,检测血清中cTnT含量、分析凋亡细胞基因bax的表达。结果内关穴组血清中cTnT含量低于模型组(P<0.01);模型组bax蛋白表达的阳性率明显增高,电针内关组阳性表达率明显降低,与模型组比较有非常显著性意义(P<0.01)。结论电针内关穴可减少心肌缺血再灌注损伤过程中cTnT的释放,且对凋亡的调控基因bax的生成有抑制作用,从而在一定程度上对心肌缺血再灌注损伤心肌起到保护作用。     

cTnT、MYO和CK-MBmass对AMI的诊断价值

目的检测急性心肌梗死发生时血清中cTnT、MYO和CK-MBmass的水平变化及分析三者之间的相关性,以探讨其对AMI的诊断价值.方法用电化学发光法检测.结果检测40例AMI病人血清和50例健康人血清cTnT、MYO和CK-MBmass 的浓度,并进行分析:(1)病人组cTnT在AMI胸痛后升高时间较CK-MBmass早,但以MYO升高时间最早,cTnT与CK-MBmass达高峰时间相比无显著性差异;正常对照组cTnT、MYO和CK-MBmass均在正常参考范围内;(2)在检出率方面cTnT的阳性率最高,其次是MYO和CK-MBmass.结论 MYO和cTnT在AMI早期诊断中有较好的应用价值,而cTnT、MYO和CK-MBmass三者结合可以提高对AMI诊断的准确性.