Role of mean platelet volume in triagging acute coronary syndromes

Background: Acute coronary syndromes, characterized by the rupture of unstable plaque and the subsequent thrombotic process involving platelets, have been increasing in relative frequency. The central role of platelet activation has long been noticed in this pathophysiology; hence, many therapies have been directed against it. In this study, we have aimed to search prospectively the value of mean platelet volume (MPV), which is a simple and accurate measure of the functional status of platelets, in patients hospitalized with diagnosis of acute coronary syndromes (ACS). Materials and methods: A total of 216 consecutive patients (156 male, 60 female) hospitalized with the diagnosis of non-ST segment elevation (NSTE) ACS within the first 24 h of their chest pain were enrolled. One hundred and twenty patients, matched according to sex and age, with stable coronary heart disease (CHD) (85 male, 35 female) were enrolled as a control group. Patients were classified into two group: those with unstable angina (USAP, n = 105) and those with non-ST segment elevation myocardial infarction (NSTEMI, n = 111). Results: MPVs were 10.4 +/- 0.6 fL, 10 +/- 0.7 fL, 8.9 +/- 0.7 fL consecutively for NSTEMI, USAP and stable CHD with significant differences. Patients with ischemic attacks in the first day of hospitalization accompanied by >0.05 mV ST segment shift had significantly higher MPV compared to those without such attacks (P = 0.001). Multivariable logistic regression analysis yielded that MPV (P = 0.016), platelet count (P < 0.001), and the presence of >0.05 mV ST segment depression at admission (P = 0.002) were independent predictors of development of NSTEMI in patients presenting with NSTE ACS. Conclusion: In patients presenting with NSTE ACS, higher MPV, though there are overlaps among subgroups, indicates not only more risk of having NSTEMI but also ischemic complications.     

肌钙蛋白T与降钙素基因相关肽对急性冠状动脉综合征患者危险分层及预后评估的价值

目的　探讨肌钙蛋白T(cTnT)与降钙素基因相关肽 (CGRP)对急性冠状动脉综合征 (ACS)患者危险分层及预后评估的价值。方法　选择ACS患者 15 8例 ,其中ST段抬高心肌梗死 (STEMI) 72例 ,非ST段抬高心肌梗死(NSTEMI) 2 3例 ,不稳定型心绞痛 (UA) 6 3例 ,入院后立即抽取肘静脉血采用ELISA法测定cTnT和CGRP水平 ,并观察患者住院期间和随访 6个月期间主要心血管事件 (MACE)。结果　NSTEMI组与STEMI组相比 ,cTnT及CGRP水平无显著性差异 ,但NSTEMI组CGRP水平高于STEMI组 ,cTnT水平低于STEMI组。与STEMI组相比 ,UA组患者cTnT水平明显降低 (P <0 .0 5 ) ,而CGRP水平显著增高 (P <0 .0 5 )。陈旧心肌梗死、左心室射血分数、cTnT及CGRP水平是ACS患者MACE发生的独立预测因子。结论　cTnT及CGRP水平在NSTEMI组与STEMI组相似 ,在心绞痛组cTnT亦有轻度增高 ;心肌梗死较心绞痛患者发病时CGRP水平低 ;cTnT及CGRP水平是ACS患者MACE发生的独立预测因子。     

老年人急性冠脉综合征介入治疗研究进展

老年人非ST段抬高急性冠脉综合征和ST段抬高性心肌梗死的共同问题包括症状不典型、合并危险因素多、临床证据不充分。老年人非ST段抬高急性冠脉综合征早期给予经皮冠状动脉介入治疗减少死亡或心肌梗死绝对和相对危险度,长期随访显示其改善生存和症状的优越性。老年人ST段抬高性心肌梗死介入治疗主要获益来自减少再次心肌梗死和重复血运重建;再灌注及时性和可行性是挽救濒危心肌和改善临床预后的重要因素;选择经皮冠状动脉介入治疗或溶栓取决于患者是否存在心源性休克、时间延搁、合并病等因素,多数情况下倾向选择经皮冠状动脉介入治疗。年龄是老年人急性冠脉综合征介入治疗临床疗效的重要影响因素。     

Impact of Acute Coronary Syndrome Classification and Procedural Technique on Clinical Outcomes in Patients With Coronary Bifurcation Lesions Treated With Drug‐Eluting Stents

Background:

We examined the impact of non–ST‐segment elevation acute coronary syndrome (NSTE‐ACS) on clinical outcomes in patients with bifurcation lesions treated with drug‐eluting stents.

Hypothesis:

We hypothesized that NSTE‐ACS would be attributable to the increased risk of major adverse cardiac events (MACE) in bifurcation percutaneous coronary intervention.

Methods:

We enrolled 1668 patients, using data from a multicenter real‐world bifurcation registry. The primary objective was to compare the 2‐year cumulative risk of MACE in patients with NSTE‐ACS to those with stable angina. Major adverse cardiac events were defined as the composite endpoint of cardiac death, myocardial infarction (MI), and target‐lesion revascularization.

Results:

Non–ST‐segment elevation acute coronary syndrome was seen in 969 (58.1%) patients and stable angina in 699. Major adverse cardiac events occurred in 7.3% of NSTE‐ACS patients and in 5.2% with stable angina (P = 0.042). However, cardiac death, MI, and target‐lesion revascularization were similar between the 2 groups. We stratified patients with NSTE‐ACS into those with non–ST‐segment elevation MI and those with unstable angina. Cumulative risks of 2‐year MACEs were 7.0% in non–ST‐segment elevation MI patients and 7.5% in unstable angina patients (P = 0.87). In the NSTE‐ACS cohort, the baseline lesion length in the side branch (adjusted hazard ratio [HR]: 1.04, 95% confidence interval [CI]: 1.01‐1.07, P = 0.022), paclitaxel‐eluting stents in the main vessel (adjusted HR: 2.02, 95% CI: 1.21‐3.40, P = 0.008), and final kissing ballooning (adjusted HR: 1.88, 95% CI: 1.10‐3.21, P = 0.021) were independent predictors of MACE.

Conclusions:

Compared with stable angina patients, the NSTE‐ACS patients who underwent bifurcation percutaneous coronary intervention had an increased risk of MACE during the 2‐year follow‐up. Clin. Cardiol. 2012 doi: 10.1002/clc.22020 Drs Pil Sang Song and Dong Ryeol Ryu contributed equally to this work. Coronary Bifurcation Stenting (COBIS) Registry in South Korea, US Department of Health and Human Services, US National Institutes of Health, ClinicalTrials.gov no. NCT00851526. This work was supported by the Korean Society of Interventional Cardiology, Seoul, South Korea. The authors have no other funding, financial relationships, or conflicts of interest to disclose.     

Prognostic value of a qualitative test for heart-type fatty acid-binding protein in patients with acute coronary syndrome

Heart-type fatty acid-binding protein (h-FABP) is a novel diagnostic marker for myocardial infarction, but its prognostic value has not been established in patients with acute coronary syndrome (ACS). We sought to determine the value of qualitative analysis of h-FABP for predicting 30-day adverse events in patients with ACS. A retrospective observational study was conducted on patients at a community hospital, and 130 patients admitted through the emergency room (ER) for ACS were identified among 12,077 patients who presented to the ER between January and June 2003. Of these 130 patients, 90 (mean age, 66.8 years, 67 males) who had ACS were eligible for this study. Qualitative tests for serum h-FABP and troponin T (cTnT) were performed on presentation. Follow-up information on adverse events within 30 days after admission, defined as cardiac death or recurrent ACS, was obtained from the medical records. The qualitative tests for h-FABP and troponin T were positive in 62.2% and 36.7%, respectively. The cumulative adverse event rate at 30 days was 14.8% in the h-FABP-positive group and 3.2% in the negative group. The adjusted relative risk of a positive h-FABP test for adverse events was 44.98 (95% CI: 1.48 to 1,364.88). A positive h-FABP test was an independent predictor of adverse events within 30 days in these patients.     

非ST段抬高急性冠状动脉综合征的预后危险因素与危险评分

目的：探讨非 ST 段抬高急性冠状动脉综合征的预后危险因素及不同危险评分的预测预后价值。方法：2003年1月至2004年4月期间,连续入院且资料完整的非 ST 段抬高急性冠状动脉综合征患者337例,随访 30天与1年的终点事件(心原性死亡和非致命性心肌梗死)。根据入院时的临床指标分别计算每例患者的心肌梗死溶栓治疗临床试验(TIMI)评分和全球急性冠状动脉事件注册(GRACE)评分,进行多变量回归分析,筛查30天和1年时心血管事件的预测危险因素(根据有无终点事件发生分为30天事件组、30天无事件组和1年事件组、1年无事件组)；分析 TIMI 评分和 GRACE 评分的预后价值,以及与血运重建的相互关系。结果：随访1年共发生终点事件57例(16.9%)。死亡19例(5.6%),非致死性心肌梗北38例(11.3%)。预测危险因素包括：年龄、血肌酐升高、入院时心率、左心室射血分数＜0.40和高血压。TIMI 评分和 GRACE 评分方法预测30天终点事件的敏感性和特异性相似,但 GRACE 评分预测1年终点事件的敏感性和特异性优于 TIMI 评分,GRACE 评分＞ 133分的患者进行血运重建治疗后远期终点事件发生率明显下降(P=0.01)。结论：除传统危险因素外,血肌酐水平升高是非 ST 段抬高急性冠状动脉综合征患者预后的重要危险因素；GRACE 评分较 TIMI 评分能更好的预测非 ST 段抬高急性冠状动脉综合征患者1年的终点事件危险,GRACE 评分＞133分的患者进行血运重建的获益更多。     

The role of heart-type fatty acid-binding protein in the diagnosis of acute coronary syndrome

BACKGROUND:

Heart-type fatty acid-binding protein (H-FABP) is a membrane-bound protein that facilitates transport of fatty acids from the blood into the heart. It is currently being used outside the United States for the early diagnosis of myocardial infarction (MI). However, previous studies have shown inconsistent correlation of H-FABP with standard cardiac biomarkers.

METHODS:

Fifty patients admitted with ST segment elevation MI (n=25), non-ST segment elevation MI (n=15) or unstable angina (n=10) were evaluated. The CardioDetect med cardiac infarction test (rennesens GmbH, Germany) was used to measure both qualitative and quantitative H-FABP.

RESULTS:

Of the 40 patients with acute MI, the initial troponin assay was positive in 35 patients (88%), the qualitative H-FABP assay was positive in 23 patients (58%) and the quantitative H-FABP assay was positive in 15 patients (38%) (P=0.001). No patient with MI had a positive H-FABP assay with a negative initial troponin assay.

CONCLUSION:

In the present study, the results of both the qualitative and quantitative H-FABP assays neither appeared earlier nor provided increased sensitivity compared with troponin in diagnosing acute MI. Accordingly, the use of H-FABP as a diagnostic tool for MI is limited.     

Cardiac magnetic resonance imaging study for quantification of infarct size comparing directly serial versus single time-point measurements of cardiac troponin T.

OBJECTIVES: We compared single-point cardiac troponin T (cTnT) measurements with parameters from serial sampling during 96 h after acute myocardial infarction with magnetic resonance imaging measured infarct mass. BACKGROUND: Contrast-enhanced magnetic resonance imaging (CE-MRI) allows exact quantification of myocardial infarct size. Clinically, measurement of cardiac biomarkers is a more convenient alternative. METHODS: The CE-MRI infarct mass was determined 4 days after primary percutaneous coronary intervention in 31 ST-segment elevation myocardial infarction (STEMI) and 30 non-ST-segment elevation myocardial infarction (NSTEMI) patients. All single-point, peak, and integrated area under the curve (AUC) cTnT values were plotted against CE-MRI infarct mass. RESULTS: All single-point and serial cTnT values were significantly higher in STEMI than in NSTEMI (p < 0.01) patients. Except for the admission values, all single-point values on any of the first 4 days, peak cTnT and AUC cTnT were found to correlate comparably well with infarct mass. Among single-point measurements, cTnT on day 4 (cTnTD4) showed highest correlation and performed as well as peak cTnT or AUC cTnT (r = 0.66 vs. r = 0.65 vs. r = 0.69). Receiver-operator characteristic analysis demonstrated that cTnTD4 >0.84 microg/l predicted infarct mass above median as well as peak cTnT >1.57 microg/l or AUC cTnT (receiver-operator characteristic for AUC: 0.839 vs. 0.866 vs. 0.893). However, estimation of infarct mass with cTnTD4, peak cTnT, and AUC cTnT was worse in patients with NSTEMI (r = 0.36, r = 0.5, r = 0.36) than in STEMI (r = 0.75 vs. r = 0.65 vs. r = 0.76). CONCLUSIONS: All single-point cTnTs, except on admission, give a good estimation of infarct size and perform as well as peak cTnT or AUC cTnT. Infarct estimation by single-point measurements, particularly cTnTD4, may gain clinical acceptance because the measurement is easy and inexpensive.     

Diagnostic accuracy of cardiac markers for myocardial damage after radiofrequency catheter ablation

Aims This study compares serum markers of myocardial damage incurred during radiofrequency catheter ablation (RFCA). Methods and results Blood was sampled from 34 patients with atrial flutter (n = 16), atrioventricular nodal reentrant tachycardia (AVNRT; n = 13), and Wolff–Parkinson–White syndrome (WPW; n = 5) to measure creatine kinase MB subfraction (CK-MB), human heart-type fatty acid protein (h-FABP), and cardiac troponin T (cTnT) values at baseline and after RFCA. The controls comprised 12 patients without significant elevation of all myocardial markers during electrophysiological study (EPS) without RFCA. h-FABP values did not elevate significantly, whereas CK-MB and cTnT demonstrated significant change after RFCA (P < 0.001). Neither peak h-FABP nor CK-MB correlated with following RFCA parameters: delivery duration, number of RFCA discharges, and cumulative RFCA energy. In contrast, correlations were significant between mean peak values of cTnT and these RFCA parameters (all P < 0.05). The sensitivity (71.6%) and specificity (35.6%) of h-FABP were inferior to those of cTnT (93.3% and 89.8%, respectively). Conclusion h-FABP is an insensitive and less specific marker of myocardial damage in RFCA much along the lines of CK-MB and when compared with the proven accuracy of cTnT.     

Peripheral arterial disease, acute coronary syndromes, and early invasive management: the TACTICS TIMI 18 trial

BACKGROUND: Patients with peripheral arterial disease (PAD) represent a high-risk patient subset in the setting of non-ST-segment elevation acute coronary syndromes (NSTE ACS). The efficacy and safety of early invasive management for such patients remains unclear. Hypothesis: Early invasive management would be well tolerated and effective among patients with NSTE ACS and PAD. METHODS: Patients from the Treat angina with Aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction (TACTICS-TIMI) 18 trial were stratified by the presence or absence of PAD and assessed with respect to baseline clinical factors. The outcomes of patients with PAD and NSTE ACS were examined with respect to treatment assignment to either early invasive therapy or conservative treatment of NSTE ACS. Finally, the bleeding and stroke rates of patients with PAD managed invasively were compared with patients with PAD managed conservatively. RESULTS: Of 2219 patients with NSTE ACS overall, 166 (7.5%) had concomitant PAD. Compared with those patients without PAD, those with PAD were older (75 vs. 62 years, p < 0.001) and were more likely to have high-risk clinical features, including prior histories of bypass surgery (39 vs. 20%, p < 0.001) or diabetes mellitus (38 vs. 27%, p = 0.002), and more ST-segment depression on their 12-lead electrocardiogram (43 vs. 29%, p < 0.001). Among such patients, early invasive management was associated with significant reductions in the risk of myocardial infarction (MI) at 30 days (11.4 vs. 2.3%, p = 0.03). At 180 days, compared with early conservative management, early invasive treatment for patients with PAD and NSTE ACS was associated with similar reductions in MI (12.7 vs. 3.5%, p = 0.04), and was also accompanied by significant reductions in risk of death (10.1 vs. 2.3%, p = 0.05). No excess in bleeding or stroke rates was noted among patients with PAD managed invasively. CONCLUSIONS: Among patients with NSTE ACS and a history of PAD, early invasive management is well tolerated and accompanied by significant reductions in morbidity and mortality when compared with a more conservative, ischemia-driven approach.     

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.     

Long-term outcomes in high-risk patients with non-ST-segment elevation myocardial infarction

Greater use of evidence-based therapies has improved outcomes for patients with acute coronary syndromes (ACS) in recent decades. Consequently, more ACS patients are surviving beyond 12 months; however, limited data exist to guide treatment in these patients. Long-term outcomes have not improved in non-ST-segment elevation myocardial infarction (NSTEMI) patients at the same rate seen in ST-segment elevation myocardial infarction patients, possibly reflecting NSTEMI patients’ more complex clinical phenotype, including older age, greater burden of comorbidities and higher likelihood of a previous myocardial infarction (MI). This complexity impacts clinical decision-making, particularly in high-risk NSTEMI patients, in whom risk–benefit assessments are problematical. This review examines the need for more effective long-term management of NSTEMI patients who survive ≥12 months after MI. Ongoing risk assessment using objective measures of risk (for bleeding and ischemia) should be used in all post-MI patients. While 12 months appears to be the optimal duration of dual antiplatelet therapy for most patients, this may not be the case for high-risk patients, and more research is urgently needed in this population. A recent subgroup analysis from the DAPT study in patients with or without MI who had undergone coronary stenting (31 % presented with MI; 53 % had NSTEMI) and the prospective PEGASUS-TIMI 54 trial in patients with a prior MI and at least one other risk factor (40 % had NSTEMI) demonstrated that long-term dual antiplatelet therapy improved cardiovascular outcomes but increased bleeding. Further studies will help clarify the role of dual antiplatelet therapy in stable post-NSTEMI patients.     

缺血修饰白蛋白在老年急性冠状动脉综合征中的应用价值

目的探讨缺血修饰白蛋白(IMA)在老年急性冠状动脉综合征(ACS)早期诊断中的应用价值。方法收集急诊老年患者共153例作为病例组,年龄>65岁,入选患者均有胸痛、呼吸困难、或恶心呕吐上腹不适等典型(或不典型)症状的疑似ACS,所有患者在就诊即刻、12 h抽血检测IMA、肌酸激酶同工酶(CK-MB)和心肌肌钙蛋白T(cTnT),入院后常规查18导联心电图(ECG)、心脏彩色B超、胸部X线、腹部彩色B超和冠状动脉造影。随机选择同期在本院进行健康体检的健康者80例作为对照组,空腹抽血检测IMA水平。分别评价IMA、cTnI、ECG指标对老年ACS患者缺血早期诊断的敏感度和特异度以及三者联合应用对ACS患者缺血早期诊断的敏感度和特异度。评估IMA对老年急性冠状动脉综合征的危险分层的应用价值。结果 153例病例中,12 h cTnT阳性86例,最终诊断ACS 95例,95例包括急性ST抬高心肌梗死(STEMI)36例、急性非ST抬高急性心肌梗死(NSTEMI)48例、不稳定型心绞痛(UA)11例、非ACS 58例;来诊即刻IMA对12 h cTnT阳性及最终诊断ACS的敏感度[95.3%(82/86)、96.8%(92/95)]、阴性预测值[92.7%(51/55)、94.5%(52/55)]最高,cTnT即刻的敏感度[26.7%(23/86)、25.3%(24/95)]、阴性预测值[50.8%(65/128)、44.5%(57/128)]很低,ECG对12 h cTnT阳性及最终诊断ACS的敏感度[40.7%(35/86)、41.1%(56/67)]、阴性预测值[52.3%(56/107)、47.7%(51/107)],3个指标联合应用对12 h cTnT阳性及最终诊断ACS的敏感度[98.8%(85/86)、97.9%(93/95)]、阴性预测值[98.1%(50/51)、96.1%(49/51)],在4组中ACS组IMA明显高于非ACS组且有统计学意义,AMI组高于UA组且有统计学意义(均为P<0.05)。结论 IMA在急症患者中对ACS的早期诊断和鉴别诊断应用价值很高,对危险分层有应用价值。     

Cardiac troponin I for stratification of early outcomes and the efficacy of enoxaparin in unstable angina: a TIMI-11B substudy

OBJECTIVES: We sought to evaluate cardiac troponin I (cTnI) for predicting early clinical outcomes and the efficacy of enoxaparin among patients with non-ST segment elevation acute coronary syndrome (ACS) and negative creatine kinase, MB fraction (CK-MB) levels. BACKGROUND: Cardiac TnI identifies patients with unstable angina who are at higher risk of death or myocardial infarction (MI) by 30 days. The utility of cTnI for predicting very early clinical events, including recurrent ischemia, and the efficacy of enoxaparin are not yet established. METHODS: At baseline and 12 h to 24 h after enrollment in the Thrombolysis in Myocardial Infarction (TIMI)-11B trial, samples were collected for cTnI determination. RESULTS: Among 359 patients with negative serial CK-MB values, 50.1% had a cTnI result > or =0.1 ng/ml within the first 24 h. Patients with elevated cTnI were at higher risk of death or MI at 48 h (3.9 vs. 0%, p = 0.01) and 14 days (13.9 vs. 2.2%, p<0.0001). Elevated cTnI also correlated with higher risk of recurrent ischemia requiring urgent revascularization by 48 h (10.0 vs. 1.7%, p = 0.001) and 14 days (20.6 vs. 5.6%, p< or =0.0001). Enoxaparin had a greater benefit among patients with elevated vs. normal cTnI (p = 0.03), achieving a 47% reduction in the risk of death, MI or urgent revascularization by 14 days in cTnI-positive patients (p = 0.007). CONCLUSIONS: Elevation of cTnI among patients with non-ST segment elevation ACS and negative levels of CK-MB identifies those at higher risk for very early adverse outcomes, including severe recurrent ischemia. Treatment with enoxaparin reduces the risk associated with elevated cTnI.     

Frequency and clinical implications of discordant creatine kinase-MB and troponin measurements in acute coronary syndromes.

OBJECTIVES: We sought to evaluate the association between discordant cardiac marker results and in-hospital mortality and treatment patterns in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS). BACKGROUND: Creatine kinase-MB (CK-MB) and cardiac troponins (cTn) are often measured concurrently in patients with NSTE ACS. The significance of discordant CK-MB and cTn results is unknown. METHODS: Among 29,357 ACS patients in the CRUSADE initiative who had both CK-MB and cTn measured during the first 36 hours, we examined relationships of four marker combinations (CK-MB-/cTn-, CK-MB+/cTn-, CK-MB-/cTn+, and CK-MB+/cTn+) with mortality and American College of Cardiology/American Heart Association guidelines-recommended acute care. RESULTS: The CK-MB and cTn results were discordant in 28% of patients (CK-MB+/cTn-, 10%; CK-MB-/cTn+, 18%). In-hospital mortality was 2.7% among CK-MB-/cTn- patients; 3.0%, CK-MB+/cTn-; 4.5%, CK-MB-/cTn+; and 5.9%, CK-MB+/cTn+. After adjustment for other presenting risk factors, patients with CK-MB+/cTn- had a mortality odds ratio (OR) of 1.02 (95% confidence interval [CI] 0.75 to 1.38), those with CK-MB-/cTn+ had an OR of 1.15 (95% CI 0.86 to 1.54), and those with CK-MB+/cTn+ had an OR of 1.53 (95% CI 1.18 to 1.98). Despite variable risk, patients with CK-MB+/cTn- and CK-MB-/cTn+ were treated similarly with early antithrombotic agents and catheter-based interventions. CONCLUSIONS: Among patients with NSTE ACS, an elevated troponin level identifies patients at increased acute risk regardless of CK-MB status, but an isolated CK-MB+ status has limited prognostic value. Recognition of these risk differences may contribute to more appropriate early use of antithrombotic therapy and invasive management for all cTn+ patients.     

Classification and risk stratification of patients with acute chest pain using a low discriminatory level of cardiac troponin T

BACKGROUND: Cardiac troponins are the biochemical markers of choice for the evaluation of acute coronary syndromes (ACS). Using the first-generation test, most studies related adverse outcome to > 0.20 or 0.10 microg/l cardiac troponin T (cTnT) levels. With the highly sensitive and specific second- and third-generation assays, cTnT is undetectable in most healthy individuals. HYPOTHESIS: We evaluated whether a lower cTnT level, within 24 h of admission, could indicate an increased risk of future complications. METHODS: During 1998-1999, clinical data were collected in 260 patients with ACS. Cardiac troponin T was measured at arrival, and 4, 8, and 12-24 h thereafter. The maximum cTnT value was then used to assess, over a 15-month follow-up period, the cumulative risk of death or myocardial infarction (MI), as well as rates of events according to quartiles of cTnT values. RESULTS: Patients with < or = 0.03 microg/l cTnT levels had the lowest rate of adverse events and the best Kaplan-Meier event-free survival curve. Increasing cTnT levels were associated with stepwise increases in mortality rates and with a constant 10-fold increase in MI rates during follow-up. CONCLUSIONS: A low threshold cTnT elevation is recommended to assess the risk of ACS. All cTnT elevations > 0.03 microg/l predict a higher risk of MI during follow-up, whereas increasing values predict mortality in relation to the amount of elevation.     

冠状动脉旁路移植术后ST-T改变的临床意义及评价

目的:探讨冠状动脉旁路移植术(CABG)后ST-T改变的临床意义. 方法:对2001年12月～2002年7月500例CABG患者术后进行心电图检测,每天1次,连续3天.如果有心电图改变,则每天两次,连续3天,并记录出院时的心电图.术后4～6小时,术后第1天上午7点,检查心肌酶谱和肌钙蛋白T(cTnT),如果有不正常,则连续检查3天,每天1次.结果:在500例患者中心电图出现ST-T改变有37例,同时cTnT阳性有10例.ST段抬高合并QRS波群改变5例中4例有cTnT阳性,ST段抬高合并高尖T波8例,2例cTnT阳性.右束支阻滞2例,都有cTnT阳性改变,ST段下移1例,广泛ST段抬高1例.肌酸激酶MB同工酶高于正常3倍只有5例,其中ST段抬高合并QRS波群改变3例,ST段下移1例,右束支阻滞1例.异常T波8例,单纯ST段抬高都不合并cTnT改变.ST段抬高合并QRS波群改变5例中3例进行了再次手术并应用了主动脉球囊反搏(IABP),这3例出院时心电图表现为陈旧性心肌梗死.广泛ST段抬高2例证实有急性心包积液,在出院时,ST段恢复到基线.结论:CABG后ST-T改变需综合分析,心电图的动态表现和心肌坏死的血清心肌标记物浓度的动态变化可诊断围手术期心肌梗死.     

Non ST segment elevation acute coronary syndromes: A simplified risk-orientated algorithm

Non-ST segment elevation acute coronary syndromes (NSTE ACS) include a clinical spectrum that ranges from unstable angina to NSTE myocardial infarction. Management goals aim to prevent recurrent ACS and improve long-term outcomes by choosing a treatment strategy according to an estimate of the risk of an adverse outcome. Recent registry data suggest that patients with NSTE ACS frequently do not receive recommended treatment, and that risk stratification is not used to determine either the choice of treatment or the speed of access to coronary angiography. The present article evaluates the evidence for recommended treatment using information from recent trials and guidelines published by the major cardiac organizations in Europe and North America. Using this information, a multidisciplinary group developed a simplified algorithm that uses risk stratification to select an optimal early management strategy. Long-term outcomes are improved by a multi-faceted vascular protection strategy that is initiated at the time of hospitalization for NSTE ACS.     

Metabolic syndrome is associated with extension of coronary artery disease in patients with non-ST segment elevation acute coronary syndromes

BACKGROUND: Metabolic syndrome (MS) comprises a group of factors that are associated with increased risk for cardiovascular events. Acute coronary syndromes account for the most important part of cardiovascular events with considerable morbidity and mortality. We aimed to investigate the association of MS with extension of coronary artery disease in patients presenting with non-ST segment elevation (NSTE) acute coronary syndromes (ACS). METHODS: Three hundred and six consecutive patients (220 men, 86 women patients) with the diagnosis of NSTE ACS, who were hospitalized within the first 24 h of their chest pain in the coronary care unit, were prospectively enrolled into our study. Patients with elevation of troponins (T or I) were classified as NSTE myocardial infarction (MI) and otherwise as unstable angina pectoris (USAP). Components of MS were noted as previously identified. Coronary angiograms were evaluated by two authors, who were blinded to the study plan and each other, via Sullivan's method. RESULTS: MS was noted in 49% of all patients, and was significantly more common in women than in men (62.8 versus 43.6%, P=0.003). The mean total stenosis score of patients with MS was significantly higher than for those without MS (16+/-6 versus 12+/-5, P<0.001), and the mean extension score of patients with MS was significantly higher than for those without MS (63+/-29 versus 44+/-26, P<0.001). The presence of MS together with some clinical factors and poor total cholesterol/high-density lipoprotein cholesterol ratio, hypertension and diabetes mellitus, was found to be independently predictive of extension of coronary artery disease (CAD) in a group of patients presenting with NSTE ACS. CONCLUSIONS: MS is independently associated with CAD extension, and hence, might account for poor cardiovascular outcomes through CAD extension in patients with NSTE ACS.     

Creatine kinase-MB elevation after coronary artery bypass grafting surgery in patients with non-ST-segment elevation acute coronary syndromes predict worse outcomes: results from four large clinical trials.

AIMS: To assess the significance of creatine kinase (CK)-MB elevations in outcomes of patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) who have undergone coronary artery bypass grafting (CABG) surgery. METHODS AND RESULTS: This analysis includes data from 26 465 patients with NSTE ACS enrolled in four major trials. In total, 4626 (17.5%) of patients had CABG within 30 days. Patients were excluded if CK-MB was elevated within 24 h before surgery and there was no CK-MB measured after surgery. Overall, 4401 patients were included in these analyses. The incidence of mortality increased with peak CK-MB ratios of 0-1, >1-3, >3-5, >5-10, and>10x the upper limit of normal measured at the local lab (P<0.001 across categories): 1.1, 2.8, 2.4, 3.1, and 10.8% in hospital; 1.1, 3.0, 2.9, 3.5, and 10.2% at 30 days; and 1.6, 4.4, 4.7, 6.0, and 10.9% at 180 days. Multivariable predictors of 6-month mortality included age, heart rate and randomization, peak CK-MB ratio, time to CABG, prior angina, signs of congestive heart failure and randomization, three- and two-vessel coronary disease, enrolment infarction, ST-segment depression at enrolment, female sex, experimental treatment, and systolic blood pressure. CONCLUSION: CK-MB elevations after CABG are independently associated with increased risk of mortality in patients with NSTE ACS.