Factors associated with the release of cardiac troponin T following percutaneous transluminal coronary angioplasty

Background: Recent studies have suggested that immunoassay of cardiac troponin T (cTnT) provides a more sensitive measurement of myocardial necrosis than creatine kinase MB (CK-MB) mass concentration. Hypothesis: The purpose of this study was to compare the release of cTnT and CK-MB isoenzyme in patients undergoing percutaneous coronary angioplasty, and to investigate the clinical, procedural, and angiographic correlates of abnormal elevations of both of these markers. Methods: Total creatine kinase (total CK), CK-MB, and cTnT levels were measured immediately before and 12 h following intervention in 110 patients, including 100 consecutive patients undergoing coronary angioplasty and 10 control patients undergoing diagnostic cardiac catheterization. All patients had normal levels of all three markers at baseline. A postintervention total CK level >225 U/l, an increase in CK-MB >5.0 ng/ml, and/or an increase in cTnT >0.04 ng/ml were considered indicative of myocardial injury. Results: Coronary angioplasty was successfully performed in all 100 patients without emergency bypass surgery or death, although six patients required emergent placement of an intra-coronary stent for threatened closure. Eight patients demonstrated an abnormal increase in total CK, including six who were undergoing primary angioplasty for an acute myocardial infarction. One of these patients sustained a Q-wave infarction. Post angioplasty, 18 patients had elevations of both CK-MB and cTnT, 23 had elevations of only cTnT, and the remaining 59 patients had elevations of neither. All patients with CK-MB elevation also had cTnT elevation. Neither serologic marker increased in the diagnostic catheterization control patients. In comparison with patients without postintervention cTnT rise, patients with abnormal cTnT levels had a higher incidence of complex lesion morphology (p<0.01) and intra-coronary thrombus (p ≤0.0001) prior to coronary angioplasty, and a higher incidence of coronary dissection (p≤0.01), abrupt closure (p≤0.05), and side-branch occlusion (p≤0.01) during angioplasty. In patients with elevation of both cTnT and CK-MB, postintervention CK-MB levels were 12-fold higher and cTnT levels were 21-fold higher than in patients with isolated elevation of only cTnT (p<0.01). Conclusions: These data indicate that >40% of patients undergoing coronary angioplasty have evidence of minor degrees of myocardial damage, as evidenced by cTnT release. High-risk coronary lesions and both minor and major complications of angioplasty are associated with cTnT release. cTnT appears to be a more sensitive marker of myocardial injury than CK-MB under these circumstances. In comparison with isolated cTnT rise, elevation of both CK-MB and cTnT may be indicative of greater levels of myocardial injury.     

Heart-type fatty acid binding protein--a reliable marker of myocardial necrosis in a heterogeneous group of patients with acute coronary syndrome without persistent ST elevation

BACKGROUND: Myocardial infarction (MI) is one of the most serious challenges of contemporary cardiology. Among biochemical markers, heart-type specific fatty acid binding protein (h-FABP) has a high potential as a marker for the early diagnosis of acute MI. The h-FABP is released early to the bloodstream and may be useful for both rapid confirmation and exclusion of infarction. As opposed to patients with ST segment elevation MI (STEMI), patients with unstable angina (UA)/non-ST segment elevation MI (NSTEMI) present a heterogeneous group in which the confirmation of MI often meets diagnostic difficulties. A rapid, qualitative immunoenzymatic 'point of care' type test, revealing h-FABP in blood, has recently been made available (CardioDetect med). AIM: To evaluate diagnostic value of early measurements of h-FABP and other markers of necrosis (cTnT, CK-MB, CK-MB mass) in a group of 100 patients with an acute coronary syndrome (ACS) without persistent ST segment elevation (NSTE ACS). METHODS: We studied 100 consecutive patients (34 women, 66 men; mean age 61.6 years) with strong suspicion of NSTE ACS and chest pain lasting <24 h before admission. During admission and after 3 and 6 hours patients had measured a panel of conventional biomarkers as well as quantitative measurements of h-FABP (on admission and 3 hours later) using CardioDetect med. The ultimate diagnosis of infarction (NSTEMI) was confirmed in case of a second (6 h after admission) positive quantitative result of cardiac troponin. Non-ST segment elevation MI was finally diagnosed in 56 patients. RESULTS: The comparison of diagnostic utility of all analysed biomarkers of necrosis revealed that h-FABP was superior to other parameters, when measured on admission, and was characterised by 94.7% sensitivity, 100% specificity, 100% positive predictive value, 93.4% negative predictive value and 97% accuracy. Other biomarkers had on admission lower sensitivity - 70.1% for CK-MB mass, 66.7% for CK-MB, 64.9% for cTnT, whereas their specificity was 97.6% for CK-MB mass, 93% for CK-MB and 100% for cTnT. CONCLUSIONS: Qualitative h-FABP test (CardioDetect med) showed excellent sensitivity, higher than measurements of CK-MB mass, CK-MB, and cTnT on hospital admission, and high specificity in the patient group with NSTE ACS. The h-FABP seems to be an excellent biochemical cardiac marker for diagnosing NSTEMI, especially in its early phase, allowing exclusion of myocardial necrosis.     

Measurements of baseline and follow-up concentrations of cardiac troponin-T and brain natriuretic peptide in patients with heart failure from various etiologies

Since chronic heart failure (CHF) is a complex clinical syndrome, a single biomarker may not reflect all of its characteristics. In this study, the clinical significance of combination and serial measurement of biochemical markers of myocyte injury and myocardial load in patients with CHF from various etiologies was examined. Serum concentrations of cardiac troponin-T (cTnT) and plasma concentrations of brain natriuretic peptide (BNP) were measured simultaneously in 190 patients with CHF, including dilated cardiomyopathy (DCM) (n = 41), ischemic heart disease (n = 40), valvular or congenital disease (n = 53), hypertensive heart disease (n = 16), and hypertrophic cardiomyopathy (HCM) (n = 22). Serum cTnT concentrations ≥0.01 ng/ml were found in 46/190 patients (24%) at baseline (20% in DCM, 42% in ischemic heart disease, 21% in valvular or congenital disease, 43% in hypertensive heart disease, and 9% in HCM). Follow-up samples were obtained in 137 patients after a mean treatment period of 31.8 days. Although BNP decreased significantly in each disease category (P < 0.0001: DCM; P < 0.005: ischemic heart disease; P < 0.05: valvular or congenital disease; P < 0.005: hypertensive heart disease; P < 0.05: HCM), cTnT remained high in 36/137 patients (26%) (19% in DCM, 39% in ischemic heart disease, 25% in valvular or congenital disease, 38% in hypertensive heart disease, and 19% in HCM). The rate of adverse cardiac events was significantly higher in patients with high cTnT than in patients with low cTnT concentrations (P < 0.0001) (P < 0.05: DCM; P < 0.05: ischemic heart disease; P < 0.01: valvular or congenital disease). Multivariate analysis showed that both cTnT and BNP are independent prognostic factors, and patients with elevations of both cTnT and BNP had the poorest prognosis (P < 0.0001). In patients with CHF, the evolution and prognostic value of cTnT and BNP are different. The combined measurements of these markers should refine our understanding of the state and evolution of CHF.     

Sialic acid or troponin T to detect perioperative myocardial damage in patients undergoing elective coronary artery bypass grafting.

Sialic acid (SA), a family of acetylated derivatives of neuraminic acid, is elevated in patients with coronary heart disease. Cardiac troponin T (cTnT), myoglobin (Mb), and creatine kinase-MB (CK-MB) are specific markers of myocardial injury and are, at present, widely used to detect perioperative myocardial damage during coronary artery bypass grafting (CABG) surgery. The present study investigated the net myocardial release of SA and the cardiac markers (cTnT, Mb, CK-MB) during reperfusion after hypothermic cardioplegic cardiac arrest in 25 patients undergoing elective CABG. Additional paired arterial, central venous, and coronary sinus blood samples were obtained after atrial cannulation before aortic cross-clamping (preischemic sample) and at 1 and 10 min after aortic declamping (reperfusion samples). There were no increase in the SA, cTnT, Mb and CK-MB concentrations before aortic cross-clamping, but there was considerable release of these markers within 10 min after aortic declamping: cTnT release was significantly higher compared with baseline values before aortic cross-clamping. In contrast to SA, Mb, and CK-MB, the difference between baseline and release values for cTnT at 1 min after aortic declamping was not significant. The rate of increase for SA was significantly higher than for Mb, CK-MB and cTnT. SA is a unique and novel marker that could be particularly useful in assessing myocardial cell damage in patients undergoing cardiac surgery.     

急性ST段抬高心肌梗死患者白细胞计数与肌酸激酶同工酶及肌钙蛋白T峰值的相关分析

目的探讨急性ST段抬高心肌梗死(ST-elevation myocardial infarction,STEMI)患者入院即刻WBC计数与肌酸激酶同工酶(CK-MB)及肌钙蛋白T(cTnT)峰值的相关性,及WBC作为心肌坏死面积大小指标的可靠性。方法连续入选2010年1月～2011年6月就诊于北京友谊医院的初发STEMI患者212例,按入院即刻外周血WBC水平分为正常组(WBC<10×10~9/L)120例,升高组(WBC≥10×10~9/L)92例。比较2组患者CK-MB及cTnT峰值的差异,并分析WBC与CK-MB、cTnT峰值的相关性。结果与正常组比较,升高组患者舒张压、TG、CK MB及cTnT峰值明显升高,差异有统计学意义(P<0.05,P<0.01);多元逐步回归分析显示,WBC与CK-MB和cTnT峰值呈正相关(r=0.636,r=0.539,P<0.05)。结论 STEMI的入院即刻WBC水平与CK-MB及cTnT峰值升高程度呈显著线性正相关,WBC是反应STEMI患者心肌坏死面积大小的良好指标。     

心肌型脂肪酸结合蛋白对心外科围术期心肌缺血与损伤的预测价值

目的 通过观察冠状动脉旁路移植术和室间隔缺损修补术围手术期不同时间人类心肌型脂肪酸结合蛋白(h-FABP)的动态变化,评价h-FABP在术中对心肌缺血及损伤的预测作用.方法 随机选取2008年2月至12月行冠状动脉旁路移植术和室间隔缺损修补术者各30例,分别于术前、主动脉夹闭时及主动脉开放后10 min、2 h.6 h、12 h、24 h取静脉血,检测h-FABP、缺血修饰白蛋白(IMA)、心肌肌钙蛋白I(cTnI)和肌酸激酶同工酶(CK-MB)的含量.结果 h-FABP与IMA变化趋势一致.h-FABP与cTnI和CK-MB变化趋势相似,但是h-FABP在心肌缺血与损伤后血中高峰时间出现得更早,维持时间较短,在2 h后即明显下降,24 h回复基线水平.经线性相关分析,冠状动脉旁路移植术组h-FABP的峰值与IMA、CK-MB和cTnI的峰值高度呈正相关(P<0.05),相关系数r分别为0.948、0.964和0.961.室间隔缺损修补术组有类似的结果,h-FABP的峰值与IMA、CK-MB和cTnI的峰值高度呈正相关(P<0.01),相关系数r分别为0.986、0.978和0.957.结论 h-FABP是心外科围手术期心肌缺血和损伤的早期诊断指标.h-FABP血中水平的定量监测可以有效地预测术中心肌缺血与损伤情况.     

射频消融治疗对局部心肌组织损伤的研究

目的　研究射频消融术 (RFCA)患者术前及术后不同时间血清心肌肌钙蛋白T(cTnT) ,肌酸激酶 (CK) ,肌酸肌酶同功酶 (CK MB)及天冬氨酸转氨酶 (AST)浓度变化及与RFCA诸因素的关系。探讨RFCA对心肌组织损伤程度。方法　采用ELISA一步夹心免疫测定法 ,分别测定 40例阵发性室上性心动过速 (PSVT)患者RFCA术前及术后即刻 ,6h ,12h ,2 4h血清cTnT以及上述心肌酶浓度。结果　RFCA患者cTnT ,CK ,CK MB ,AST均于术后即刻升高 ,术后 6h达到峰值 ,12h下降 ,2 4h除CK外 ,其余均恢复正常 (P均 <0 0 5 )。经相关分析表明cTnT活性变化的峰值升高程度与消融时间 ,平均功率及累计能量均无线性关系 (r=0 .33 ,r =0 .2 5 ,r=0 .2 9,P均 >0 0 5 ) ,而与消融靶点个数高度正相关(r=0 .81,P <0 0 0 1) ,与消融次数也有显著关系 (r=0 .5 1,P <0 0 1)。结论　RFCA对心肌组织确有不同程度的损伤 ,但持续时间短 ,损伤轻 ,恢复快。提示RFCA系安全有效的治疗快速心律失常的方法。测定cTnT可作为临床判断RF CA对心肌损伤的监控指标。     

心肌型脂肪酸结合蛋白对心外科围术期心肌缺血与损伤的预测价值

目的 通过观察冠状动脉旁路移植术和室间隔缺损修补术围手术期不同时间人类心肌型脂肪酸结合蛋白(h-FABP)的动态变化,评价h-FABP在术中对心肌缺血及损伤的预测作用.方法 随机选取2008年2月至12月行冠状动脉旁路移植术和室间隔缺损修补术者各30例,分别于术前、主动脉夹闭时及主动脉开放后10 min、2 h.6 h、12 h、24 h取静脉血,检测h-FABP、缺血修饰白蛋白(IMA)、心肌肌钙蛋白I(cTnI)和肌酸激酶同工酶(CK-MB)的含量.结果 h-FABP与IMA变化趋势一致.h-FABP与cTnI和CK-MB变化趋势相似,但是h-FABP在心肌缺血与损伤后血中高峰时间出现得更早,维持时间较短,在2 h后即明显下降,24 h回复基线水平.经线性相关分析,冠状动脉旁路移植术组h-FABP的峰值与IMA、CK-MB和cTnI的峰值高度呈正相关(P<0.05),相关系数r分别为0.948、0.964和0.961.室间隔缺损修补术组有类似的结果,h-FABP的峰值与IMA、CK-MB和cTnI的峰值高度呈正相关(P<0.01),相关系数r分别为0.986、0.978和0.957.结论 h-FABP是心外科围手术期心肌缺血和损伤的早期诊断指标.h-FABP血中水平的定量监测可以有效地预测术中心肌缺血与损伤情况.     

Correlation between serum miR-122 and myocardial damage and ventricular function in patients with essential hypertension

BackgroundMyocardial damage and decreased ventricular function are risk factors leading to a bad prognosis in patients with essential hypertension (EH). MicroRNAs play important roles in myocardial function impairment in patients with hypertension. The purpose of our research was to investigate the correlation between serum miR-122 and myocardial damage and ventricular functions in EH patients.MethodsThe clinic data of EH patients (group A, n=60) and healthy individuals (group B, n=60) from December 2016 to December 2019 in our hospital were collected and analyzed. Serum miR-122, myocardial damage markers [B-type brain natriuretic peptide (BNP), homocysteine (Hcy), cardiac troponin T (cTnT) and creatine kinase MB isoenzyme (CK-MB)] and cardiac function indicators [ejection fraction (EF), left ventricular septal thickness (IVST), left ventricular isovolumic relaxation time (IVRT), left ventricular end-diastolic diameter (LVEDD), left ventricular posterior wall thickness (LVPWT), and left ventricular end-systolic diameter (LVESD)] were assessed in both groups. The correlation between serum miR-122 and myocardial damage markers and ventricular function indicators was analyzed.Results(I) The mean serum miR-122 concentration in group A and group B was 6.86±1.23 and 3.36±1.87 µmol/L, respectively. The serum miR-122 concentration in group A was evidently increased compared with that in group B. (II) The levels of BNP, Hcy, cTnT, and CK-MB in the peripheral blood in group A were evidently increased compared with those in group B (P<0.05). (III) EF and IVRT were evidently decreased in group A compared with that in group B (P<0.05). (IV) Serum miR-122 concentration was positively correlated with the myocardial damage markers BNP, Hcy, cTnT and CK-MB, and serum miR-122 concentration was negatively correlated with the ventricular function indicators EF and IVRT but not significantly correlated with other ventricular function indicators (IVST, LVEDD, LVPWT and LVESD).ConclusionsThe serum miR-122 concentration in EH patients was higher than that in healthy individuals, and miR-122 concentration was positively correlated with myocardial damage markers. Serum miR-122 level was negatively correlated with the ventricular function indicators EF and IVRT but was not significantly correlated with other ventricular function indicators (IVST, LVEDD, LVPWT, and LVESD).     

心肌型脂肪酸结合蛋白对心外科围术期心肌缺血与损伤的预测价值

目的 通过观察冠状动脉旁路移植术和室间隔缺损修补术围手术期不同时间人类心肌型脂肪酸结合蛋白(h-FABP)的动态变化,评价h-FABP在术中对心肌缺血及损伤的预测作用.方法 随机选取2008年2月至12月行冠状动脉旁路移植术和室间隔缺损修补术者各30例,分别于术前、主动脉夹闭时及主动脉开放后10 min、2 h.6 h、12 h、24 h取静脉血,检测h-FABP、缺血修饰白蛋白(IMA)、心肌肌钙蛋白I(cTnI)和肌酸激酶同工酶(CK-MB)的含量.结果 h-FABP与IMA变化趋势一致.h-FABP与cTnI和CK-MB变化趋势相似,但是h-FABP在心肌缺血与损伤后血中高峰时间出现得更早,维持时间较短,在2 h后即明显下降,24 h回复基线水平.经线性相关分析,冠状动脉旁路移植术组h-FABP的峰值与IMA、CK-MB和cTnI的峰值高度呈正相关(P<0.05),相关系数r分别为0.948、0.964和0.961.室间隔缺损修补术组有类似的结果,h-FABP的峰值与IMA、CK-MB和cTnI的峰值高度呈正相关(P<0.01),相关系数r分别为0.986、0.978和0.957.结论 h-FABP是心外科围手术期心肌缺血和损伤的早期诊断指标.h-FABP血中水平的定量监测可以有效地预测术中心肌缺血与损伤情况.     

Role of ischemia-modified albumin in estimating the extent and scope of cardiac ischemia in patients with ST elevation myocardial infarction

Ischemia-modified albumin (IMA) is a laboratory biomarker of cardiac ischemia. Our study aims to determine whether IMA can estimate or represent to any degree the extent of myocardial ischemia. We expect that the higher the marker of cardiac necrosis (maximum value after serial measurements) the greater the preceding cardiac ischemia, indicated by IMA in patients diagnosed with STEMI prior to direct percutaneous coronary intervention (PCI). We studied 216 patients indicated for direct PCI with a diagnosis of ST elevation myocardial infarction. Biochemical analysis of IMA was carried out using the albumin cobalt binding (ACB^?) test. We also obtained relevant values for markers of myocardial necrosis (CK, CK-MB, cTnT). In all patients, there was an increased level of IMA prior to the procedure (116 ± 16.9 kU/l); also raised were levels of CK (17.32 μkat/l), CK-MB (4.85 μkat/l) and cTnT (2.97 μg/l) taken as the maximum values obtained after serial measurements at 12, 18, and 24 h after the procedure. We observed that there was no significant association between increase in IMA and cTnT (R ² = 0.0068, p = 0.483). This was also the case for CK-MB (R ² = 0.0011, p = 0.637). IMA does not estimate the extent of ischemia in patients with ST elevation myocardial infarction. However, its absence can be used qualitatively to rule out cardiac ischemia.     

联合测定心型脂肪酸结合蛋白、肌钙蛋白T诊断早期急性心肌损伤

目的:联合测定心型脂肪酸结合蛋白(h-FABP)、肌钙蛋白T(cTnT)对早期诊断急性心肌损伤的意义.方法:对76例急性冠脉综合征(ACS)患者,自胸痛发生后1 h开始每小时连续监测心型脂肪酸结合蛋白、肌钙蛋白T至胸痛发生后6 h,共6次.结果:在早期急性心肌损伤中,h-FABP阳性结果出现的时间早于cTnT,二者对比有统计学意义(P＜0.05).在cTnT升高患者中,h-FABP升高率为98.7%,二者对比无统计学差异(P＞0.05).结论:在诊断早期急性心肌损伤时,h-FABP出现阳性结果时间早于cTnT,而联合测定h-FABP、cTnT对提高ACS患者早期确诊率,指导临床急救具有重要的价值.     

Creatine kinase isoforms as circulating markers of deterioration in idiopathic dilated cardiomyopathy

Background: A proportion of patients with dilated cardiomyopathy (DCM) may have ongoing myocardial damage secondary to viral or immune mediated myocardial inflammation. Hypothesis: The prognostic determinants identify patients with decreased survival but do not provide a measure of myocardial damage. To obtain an objective assessment of myocardial damage in DCM, we measured plasma levels of creatine kinase (CK), its isoenzymes (CK-MM and CK-MB), and separated the isoforms of CK-MM and CK-MB. Methods: The cohort consisted of 77 consecutive patients (61 men, 16 women) with DCM (World Health Organization criteria), aged 49 ± 14 years (range 19–60). Patients had been symptomatic for 29 ± 38 months (range 0.5–200 months) with 48 in New York Heart Association class I/II and 29 in class III/IV at the time of diagnosis. During median follow-up of 27 months from diagnosis (range 0.6–165), 50 patients remained clinically stable and 27 had deteriorated. Results: A significantly higher proportion of patients with DCM had abnormal MB2/MB1 ratio compared with normal volunteers (11,14% vs. 1, 1%, p = 0.003). Patients who deteriorated had higher MB2/MB1 ratio, (1.22 ± 0.62 vs. 0.85 ± 0.56;p = 0.01), and more frequently had abnormal MB2/ MB1 ratio (8,30% vs. 3,6%;p=0.004) and CK and CK-MM activities (5, 19% vs. 2, 4%;p = 0.03) than those who remained stable. Patients with DCM with high CK-MB activity had 3.13-fold increased odds of sudden death or need for cardiac transplantation (95% confidence interval 1.53–6.40, p = 0.008). Thus, CK measurements, in particular CK-MB isoforms, are markers of myocardial damage in a subset of patients with DCM and could be useful in investigating the possibility of persistent myocardial damage in these patients.     

The role of cardiac troponin t and other new biochemical markers in evaluation and risk stratification of patients with acute chest pain syndromes

Background and hypothesis: Increased serum creatinine kinase (CK) and CK-MB enzyme levels have been used for years to detect myocardial infarction (MI). However, serum myoglobin and CK-MB mass or protein levels may indicate MI earlier; cardiac troponin T is the most specific marker of myocardial injury and it can detect even minor myocardial necrosis. The diagnostic and prognostic utility of the traditional and new markers of cardiac injury in the emergency evaluation of patients with acute chest pain syndromes were therefore compared. Methods: One hundred and fifteen consecutive patients with an acute coronary syndrome, and 64 controls recruited during the same period, were examined. The time elapsed from onset of symptoms to blood collection was recorded. Cardiac markers were measured in specimens collected upon arrival (0 h), and 2 and 5–9 h, and later in cases of longer observation. The major cardiac events occurring up to 40 months after the index examination were recorded. Results: cTnT levels provided unique information: they were the most specific indicators of myocardial damage and identified unstable angina patients at high risk of future major events. Up to 6 h after the onset of chest pain, the new markers were elevated more frequently than the traditional ones and permitted earlier MI recognition. The worst prognosis (nonfatal myocardial infarction or death) was noted in subjects with chest pain at rest within 48 h before the index examination and elevated cTnT levels. Conclusions: The new markers, particularly cardiac troponin T, offer considerable advantages and they should be more widely used in the diagnosis and risk stratification of acute coronary syndromes.     

Cardiac troponin T and I and creatine kinase-MB as markers of myocardial injury and predictors of outcome following percutaneous coronary intervention

AIMS: This study was performed to determine the most sensitive biochemical marker for the detection of cardiac myocyte damage potentially sustained during percutaneous coronary intervention (PCI) and to assess whether such a marker can be used to identify patients at increased risk of poor subsequent clinical outcome. METHODS AND RESULTS: We studied 109 consecutive patients presenting with clinical stable and unstable angina and undergoing PCI at our institution. Blood was sampled for creatine kinase-MB (CK-MB), cardiac Troponin T (cTnT) and I (cTnI) immediately before and at 6, 14 and 24 h post-PCI. Five patients with raised cardiac markers pre-PCI were excluded from further analysis. The occurrence of major adverse cardiac events (MACE) was documented in-hospital, at 30 days and at long-term clinical follow up of up to 20 months. MACE occurred in 26/109 (24%) patients: death=1, QWMI=4, NQWMI=5, repeat PCI=16 (nine target vessel revascularisations and seven de-novo lesions), CABG=5. cTnI had the highest detection rate for myocardial damage, with 58 cTnI-positive patients, 38 cTnT-positive patients and 28 CK-MB-positive patients in the 24 h following PCI (Pearson's Chi square test, P<0.01). The type of interventional strategy per se was not significantly associated with post-procedural cardiac marker concentrations (Kruskal-Wallis ANOVA, P>0.05). There was a significant association between post-procedural cardiac marker concentrations of CK-MB, cTnT and cTnI and the occurrence of procedural angiographic complications (P=0.0003, 0.0002, 0.001, respectively). All three markers, at each sampling time point between 6 and 24 h post-PCI, showed a significant predictive relationship with MACE in-hospital and at long-term follow up (ROC curve AUC analysis, P<0.05). All three markers provided equally predictive information at each of the three post-procedural sampling time points between 6 and 24 h following PCI. All levels of cardiac marker elevation above the clinically discriminant cut-off values were significantly predictive of outcome at long-term follow up. CONCLUSIONS: cTnI proved to be the most sensitive marker in detecting myocardial necrosis following PCI. CK-MB, cTnT and cTnI all provided similarly reliable prognostic information, with cTnT and cTnI being marginally superior in predicting MACE at follow up.     

射频消蚀术前后血清心肌酶变化的研究

对３３例患者射频消蚀术（简称ＲＦＣＡ）前后的血清心肌酶（ＣＫ、ＣＫ－ＭＢ．ＡＳＴ、ＬＤＨ、ＬＤＨ１）进行动态观察。结果表明：ＲＦＣＡ后血清心肌酶活性均有不同程度的升高（Ｐ＜０．０１）；ＣＫ及ＣＫ－ＭＢ于术后６小时达到峰值，２４小时恢复至正常水平，ＡＳＴ于术后１２小时达峰值、时达峰值，７２小时恢复正常，ＬＤＨ及ＬＤＨ，的达峰及恢复时间分别为２４小时和１２０小时；多元线性相关分析显示心肌酶活性的升高程度与消蚀靶点个数呈高度正相关（ｒ＝０．８１３６，Ｐ＜０．００１）．揭示ＲＦＣＡ对心肌组织有不同程度的损伤，影响心肌损伤范围的主要因素是消蚀靶点的多少。因此，在ＲＦＣＡ中，应力求标测定位准确，尽量减少试探性放电，以最大限度地减少心肌损伤。     

Usefulness of rapid bedside cardiac troponin T assay for the diagnosis of acute myocardial infarction

Cardiac troponin T(cTnT) is one of the most myocardial-specific markers for the diagnosis of acute myocardial infarction(AMI). Recently, the rapid bedside cTnT assay(Trop T rapid assay sensitive version), which can provide qualitative determinations within 15 min, has been developed for the emergency clinical setting. To evaluate the usefulness of rapid bedside cTnT assay, we performed the Trop T test and measured serum levels of myoglobin(Mb), creatine kinase MB isoenzyme(CK-MB) and cTnT in 256 consecutive emergency patients with suspected AMI(65 found to have AMI and 191 without AMI). The diagnostic sensitivities for AMI of Trop T, Mb and CK-MB measurements were 66%, 92% and 52%, respectively, whereas the specificities were 80%, 18% and 74%, respectively. The diagnostic accuracy for AMI of Trop T(77%) was significantly higher than that of Mb(37%, p < 0.001) and CK-MB(69%, p < 0.05). The sensitivity for AMI of Mb(86%) was significantly(p < 0.001) higher than that of Trop T (31%) and CK-MB(31%) in patients admitted < or = 3 hr after the onset of AMI. In contrast, the sensitivities of Trop T(80% and 100%) in patients admitted at 3-6 hr and > 6 hr showed no significant differences from those of Mb(100% and 96%). Furthermore, Trop T in patients admitted > 6 hr had significantly(p < 0.01) higher sensitivity compared with CK-MB(69%). The mortality rate in the non-AMI group during hospitalization in patients with positive Trop T test(39%) was significantly(p < 0.001) higher than that in patients with negative test(9%). When the positive Trop T test was regarded as > or = 0.10 ng/ml of serum cTnT, Trop T test had the best concordance of 92% with a quantitative of cTnT assay.     

The use of human heart-type fatty acid-binding protein as an early diagnostic biochemical marker of myocardial necrosis in patients with acute coronary syndrome, and its comparison with troponin-T and creatine kinase–myocardial band

Heart-type fatty acid-binding protein (H-FABP), a new biochemical marker of sarcolemmal injury due to acute myocardial ischemia, can be used as a tool in early diagnosis and management of patients at high risk. The aim of this study was to determine the early diagnostic value of H-FABP in acute coronary syndrome (within 6–24 h of chest pain) and to compare it with troponin-T (TnT) and creatine kinase–myocardial band (CK-MB) for accuracy. The study consisted of 40 consecutive patients with chest pain admitted to the coronary care unit with the diagnosis of suspected acute coronary syndrome. The patient population consisted of two groups according to the time of admission; the first group (26 patients) included patients admitted within 6 h of chest pain, and the second group (14 patients) included patients admitted within 6–24 h of chest pain. The blood samples for H-FABP, TnT, and CK-MB were obtained at admittance, at the 6th, and at the 24th hours for the first group, and at admittance and at the 24th hours for the second. Statistical analysis was performed among the 26 patients for the first 6 h values, and among all 40 patients for the values obtained within 6–24 h and at the 24th hour. The patients were then divided into groups according to the changes in the electrocardiogram (ECG) and cardiac enzymes as unstable angina pectoris, non-ST elevation myocardial infarction (MI), and ST-elevation MI. Coronary angiography was performed in 38 (95%) patients. Sensitivity of TnT, CK-MB, and H-FABP in the first group (within 6 h of chest pain) were 38%, 76%, and 95% respectively. The sensitivity of H-FABP was significantly higher than TnT (P = 0.014). Sensitivity of TnT, CK-MB, and H-FABP tests in the second time period (within 6–24 h of chest pain) were 100%, 90%, and 91% respectively. In this time period, the sensitivity of TnT was higher than H-FABP, but it was statistically insignificant. At the 24th hour, sensitivity of TnT was 100%, CK-MB 90%, and H-FABP 27.3%, and TnT and CK-MB were more sensitive than H-FABP for the whole group (P = 0.002). In the first group (within 6 h of chest pain) H-FABP positivity was slightly but insignificantly higher in patients with two- and three-vessel disease compared with those with one-vessel disease (60.7% and 33.3%, P = 0.19) and in the same group, patients who underwent primary coronary intervention had a significantly higher H-FABP positivity than others (80%, 32%, P = 0.02). Within 6–24 h of chest pain, H-FABP positivity was 80% in patients with one-vessel disease and 71.4% in patients with two- and three-vessel disease (P = 0.69). Within 6–24 h, positivity of H-FABP reached a peak value of 100% in patients who underwent primary coronary intervention, while H-FABP was positive in 60% of the others (P < 0.001). We conclude that within the 6 h of acute coronary syndrome, H-FABP seems to be a more sensitive biochemical marker than TnT in the early detection of ischemic myocardial necrosis. But after the first 6 h of the onset of chest pain the sensitivity of H-FABP decreases, and this marker should not be used alone in patients admitted 24 h after the onset of chest pain.     

The relationship of ST segment elevation shape with preserved myocardium and signal-averaged electrocardiography in acute anterior myocardial infarction

Although a relation between magnitude of ST segment elevation and myocardial damage has been shown in the early period of acute myocardial infarction (AMI), such a relation between the shape of the ST segment elevation, myocardial damage, and the clinical course remains obscure. For this purpose 62 first anterior AMI patients admitted in the first 6 h were enrolled for the study. On the basis of precordial V3 derivation prior to thrombolytic therapy, the shape of the ST elevation was separated into three groups: concave (n = 26), straight (n = 24), or convex types (n = 12). The relation between the shape of the ST elevation recorded on admission, and the results of predischarge low-dose dobutamine stress echocardiography (LDE) performed (n = 53) and signal-averaged ECG values were investigated. The basal wall motion score index (WMSI) and response to LDE in the concave group were better in the infarct zone. Additionally, the average akinetic segment number in the infarct zone was higher, and improvement in these segments was less in the convex and straight groups (concave 3.78 ± 2 vs 2.17 ± 2.1, P < 0.01; straight 5.15 ± 2.7 vs 4.45 ± 2.8, not significant (NS); convex 5.4 ± 2.3 vs 4.8 ± 2.1, NS; basal vs LDE). While only 13% (3/23) of the patients did not respond to LDE (P < 0.05 vs group B and P < 0.01 vs group C), 35% (7/20) of group B and 60% (6/10) of group C patients did not respond to LDE. Although no relation was found between better left ventricular function (WMSI < 2) and shape of the ST elevation in basal evaluation by multiple logistic regression analysis (P = 0.06), an independent relation was found between them following LDE (P = 0.01, odds ratio (OR) 4.5, 95% Confidence Interval (CI) 1.3–14.7). The incidence of ventricular late potential (LP) positivity was 11% (3/26) in the concave group, 16% (4/24) in the straight group, and 58% (7/12) in the convex group (P < 0.001 vs concave and P < 0.05 vs straight groups). We found that shape of the ST elevation could significantly predict the presence of late potentials in multiple logistic regression analysis (P = 0.003, OR 10.7, 95% CI 2.2–51.7). There was no in-hospital death in the concave group, whereas five patients died in either the straight or the convex group. Furthermore, arrhythmia was lower in the concave group during this period (P < 0.05), and exercise capacity was lower. In conclusion, we determined that there was a higher viable myocardium, and lower LP(positivity) and in-hospital mortality in patients with concave ST elevation on admission. Received: August 6, 2001 / Accepted: December 18, 2001     

Sensitivity and long-term prognostic value of cardiac troponin-i increase shortly after percutaneous transluminal coronary angioplasty

Background: After successful coronary interventions, minor elevations of creatine kinase MB (CK-MB) identified a population with a worse long-term prognosis than that in patients without enzyme elevations. In that setting, cardiac troponin-I (cTn-I), a highly specific marker for myocardial injury, was considered for a small study; the results did not support the view that significant myocardial damage occurred during successful percutaneous transluminal coronary angioplasty (PTCA). Hypothesis: The present study was designed to assess the rate of elevated values of cTn-I after successful PTCA and to determine its prognostic value. Methods: CTn-I and CK-MB were measured in 44 patients before and daily for 3 days after PTCA. Two groups of patients were considered according to the presence or absence of elevated levels of cTn-I. The rate of free-event survival was estimated for the two groups using the Kaplan-Meier method and was compared with the log rank test. Results: Globally, 36% of patients had an increase in cTn-I (normal values 0.35 ng/ml) and 9% had an increase in CK-MB, p = 0.002. The mean time to maximal enzyme level was 1.8 days for cTn-I and 2.2 days for CK-MB. Over a follow-up of 1375 ± 416 days, 18% of patients experienced adverse events, and cTn-I did not identify a population of worse longterm prognosis. Conclusion: These results suggest that cTn-I is more sensitive than CK-MB in identifying minor myocardial damage after PTCA, but these elevated concentrations of cTn-I in the short-term aftermath of angioplasty do not seem to be a marker of worse long-term prognosis.