Early CK-MB Elevations Predict Ischemic Events in Stable Chest Pain Patients

ABSTRACT Objective : To demonstrate that creatine kinase-MB fraction (CK-MB) elevations within three hours of presentation in the emergency department (ED) are associated with subsequent ischemic events in clinically stable chest pain patients. Methods : Prospective cohort study at two university-affiliated teaching hospitals. Participants were consenting ED chest pain patients 25 years old or older without evidence of rhythm or hemodynamic instability (n = 449). Exclusions included ST-segment elevation ≥0.1 mV in ≥2 electrocardiogram leads, chest wall trauma, abnormal x-ray studies, and incomplete data collection. Measurements included presenting and three-hour CK-MB levels, presenting ECG, initial clinical impression of coronary care unit need, and clinical follow up. Monitored adverse events included myocardial ischemia necessitating coronary angioplasty or cardiac bypass surgery, recurrent in-hospital myocardial infarction, bradycardia requiring pacing, emergent cardioversion, cardiogenic shock, ventricular fibrillation, and death. Results : Overall, nine (2%) of 449 patients experienced an ischemic event within the first 48 hours. All nine patients required either coronary angioplasty or bypass surgery. Four (44%) of the nine patients with 48-hour ischemic events had elevated CK-MB levels. Of 23 patients who had complications within one week of ED presentation, seven (30%) had elevated ED CK-MB levels. An elevated CK-MB level was associated with an ischemic event both within 48 hours (risk ratio 9.5; 95% CI 2.7–33.7) and within one week (risk ratio 5.2; 95% CI 2.3–11.7). Conclusions : An elevated CK-MB level within three hours of ED presentation is associated with a subsequent ischemic event in the clinically stable chest pain patient without ST-segment elevation. However, the ED CK-MB identifies only a minority of otherwise low-risk patients who develop ischemic events; other markers for diagnosing myocardial ischemia in the ED are needed.     

Evaluation and risk stratification of acute coronary syndromes using a low cut-off level of cardiac troponin T, combined with CK-MB mass determination

OBJECTIVES: To study the usefulness of combined cardiac Troponin T (cTnT) and CK-MB mass determinations in risk stratification of acute coronary syndromes. DESIGN AND METHODS: Blood samples for cTnT and CK-MB mass were collected at arrival and 4, 8, and 12-24 later in 301 consecutive patients with recent acute chest pain (ACP). Data were also collected for cardiac events. RESULTS: Combined cardiac mortality/nonfatal myocardial infarction over a period of 15 months was lowest in patients with <0.04 microg/l cTnT and -<5.0 microg/l CK-MB mass intermediate in those with elevated cTnT but normal CK-MB mass and highest when both markers were elevated, in absence of early reperfusion. CONCLUSION: The use of a low cut-off point of cTnT, combined wit CK-MB mass determination, offers a good strategy for risk stratification of ACP patients.     

Risk stratification of chest pain patients by point-of-care cardiac troponin T and myoglobin measured in the emergency department

A prospective multicenter study including 1410 chest pain patients with suspected acute coronary syndromes was carried out to examine the predictive value of biological cardiac markers for adverse events measured by a point-of-care system. Admission cardiac troponin T (cTnT) and myoglobin were measured in parallel on a point-of-care system in the emergency department and -- together with CK-MB mass -- on lab analyzers. In a one-year follow-up, cardiac and non-cardiac death, acute myocardial infarction, unstable angina pectoris and need for revascularization were registered. Median time between onset of symptoms and admission was 285 min; 172 patients (12.2%) had no event during follow-up. If the cTnT, measured either by the point-of-care system or a conventional lab analyzer, was >0.05 microg/L, then the chance of a cardiac event during the follow-up period was doubled (18% vs. 9%). Serial cTnT measurement did not add any further value to the predictive power of the admission cTnT. Myoglobin and CK-MB mass identified increasing risk with increasing concentration quartiles; cardiac event rates were 2.8- to 4.4-fold higher between the quartiles with the lowest and those with the highest analyte concentration, respectively. There was no difference in non-cardiac death rates between any concentration quartiles. In conclusion, the prediction of clinical events by cardiac troponin T and myoglobin measured with a point-of-care analyzer in the emergency department was as good as that of the same cardiac markers and CK-MB mass measured on lab analyzers.     

Myoglobin,creatine kinase MB isoforms and creatine kinase MB mass in early diagnosis of myocardial infarction in patients with acute chest pain

OBJECTIVES: Measurements of myoglobin and creatine kinase (CK)-MB isoforms have been suggested to be sensitive tests for the early diagnosis of myocardial infarction (MI). We have investigated the utility of myoglobin, creatine kinase (CK)-MB isoforms and creatine kinase MB mass (CK-MBm) in early diagnosis of MI using cardiac troponin T (cTnT) positivity as a reference. DESIGN AND METHODS: The study population comprised 440 patients who had had chest pain for less than 12 h. Patients were divided into cTnT negative (cTnT-) or cTnT positive (cTnT+) patients (concentration of cTnT >0.1 microg/L at two different time points during 72 h). RESULTS: At the time of admission to the emergency department receiver operating characteristics (ROC) curves of CK-MB isoforms and CK-MBm were not better than that of myoglobin. Six hours after admission CK-MB isoforms and CK-MBm provided statistically significantly larger areas under the curve (AUC) than myoglobin (p < 0.01). When ROC curves were related to the onset of chest pain (< 3 h, 3-6 h, and > 6 h) there were no significant differences between the cardiac markers studied. CONCLUSIONS: According to the present findings, CK-MB isoforms or myoglobin offer no advantage over CK-MBm as early markers of myocardial infarction.     

A rapid protocol to identify and exclude acute myocardial infarction: continuous 12-lead ECG monitoring with 2-hour delta CK-MB

A prospective observational study was performed in 706 chest pain patients who underwent our chest pain evaluation protocol which consists of continuous 12-lead ST-segment monitoring with automated serial ECG (SECG) and a 2-hour delta (delta) CK-MB level determination before ED physician making final disposition decision to determine the incremental value of our 2-hour protocol for identifying myocardial infarction (MI) as compared with the initial ECG in combination with a baseline CK-MB. The initial ECG was obtained on presentation and considered positive if it revealed injury or ischemia. SECGs were obtained at least every 10 minutes and considered positive if it revealed new injury or ischemia. The baseline CK-MB value was considered positive if it was > or =12 ng/mL and index > or =4%. ACK-MB was defined as a difference between the 2 hour and baseline CK-MB and was considered positive if the value was > or =+1.5 ng/mL. MI was defined as acute myocardial infarction (AMI) or recent AMI (ie, AMI patients presenting on falling curve of CK-MB). The incremental value of the 2 hour protocol (ie, SECG in conjunction with deltaCK-MB) was more sensitive for identification of MI than the baseline protocol (ie, initial ECG in conjunction with the baseline CK-MB) (94.0% versus 55.4%; P < .0001) and reliably both identified (+LR = 14.6) and excluded MI (-LR = 0.06). SECG monitoring in conjunction with the 2 hour deltaCK-MB allows for early identification and exclusion of MI, and can assist the ED physician in making appropriate treatment and disposition decisions.     

Myoglobin for Early Risk Stratification of Emergency Department Patients with Possible Myocardial Ischemia

OBJECTIVES: To determine and compare the prognostic abilities of early, single-sample myoglobin measurement with that of creatine kinase-MB (CK-MB), with cardiac troponin T (cTnT), and with physician judgment in the absence of marker results among emergency department (ED) patients with possible myocardial ischemia. METHODS: Prospective collection of clinical and serologic data using an identity-unlinked technique from patients with possible myocardial ischemia at two urban EDs. Outcome data concerning the occurrence of adverse events (AEs) during the 14 days after enrollment were used to calculate and compare the relative risks (RRs) and predictive values (with 95% confidence intervals) of the various markers for predicting AEs. RESULTS: Among 396 analyzed patients, 65 (16.4%) accrued 104 AEs, including 13 deaths (3.3%) and 31 (7.8%) myocardial infarctions. Myoglobin predicted AEs (RR = 3.36 [95% CI = 2.19 to 5.15]) with significantly higher sensitivity (50.8% [95% CI = 38.6 to 62.9]) than either CK-MB (15.4% [95% CI = 6.6 to 24.2]) or cTnT (24.6% [95% CI = 14.1 to 35.1]), but with lower specificity (81.9% [95% CI = 77.7 to 86.0]; CK-MB = 99.7% [95% CI = 99.1 to 100]; cTnT = 93.1% [95% CI = 90.3 to 95.8]). Myoglobin had prognostic ability among patients with chest pain (3.86 [95% CI = 2.39 to 6.22]) and atypical (non-chest pain) presentations (2.71 [95% CI = 1.09 to 6.71]), including those with a nondiagnostic electrocardiogram (3.11 [95% CI = 1.44 to 6.69]). The combination of myoglobin and physician decision making identified 63 of the 65 patients (96.9% [95% CI = 92.7 to 100]) with subsequent AEs. CONCLUSIONS: The early prognostic sensitivity of myoglobin may allow identification of some high-risk patients missed by physician judgment, CK-MB, and cTnT. Myoglobin should be considered for use in the ED based on both its diagnostic and prognostic abilities.     

心肌标志物作用的系统分析

目的：获取心肌生化标记物的最佳应用证据。方法：查循、浏览对心肌肌酸激酶同工酶MB（CK－MB）、肌红蛋白、心肌肌钙蛋白T（cTnT）和心肌肌钙蛋白I（cTnI）用于诊断心肌梗塞（MI）和对急性冠状动脉综合症分级的系统评价和Meta－分析的文献资料。结果：在症状发生后的12－48小时采样分析CK－MB质量对于诊断MI的临床灵敏度和牧场划性分别是98．8％和89．6％。肌红蛋白有高的阴性预示值,在症状发生后的2－6小时采样分析有高的临床灵敏度。在症状发生后的12采样cTnI,诊断MI的临床灵敏度和特异性分别是98．2％和68．8％,其临床特异性降低与检测到微小心肌受损有关。结论：cTnT和cTnI比CK－MB对诊断心肌梗死和预测急性冠状动脉综合症危险性更有价值。     

Evaluation of a Bedside Whole-blood Rapid Troponin T Assay in the Emergency Department

Objective : To evaluate the performance of a new bedside whole-blood rapid assay for cardiac troponin T (cTnT) in patients presenting to the ED with symptoms consistent with acute coronary ischemia. Methods : A prospective, observational trial was performed in 8 participating medical centers. Serial blood samples were obtained on presentation to the ED and 3 and 6 hours later. The cTnT whole-blood rapid assays were performed immediately at the site. Treating physicians and patients were blinded to the results of the rapid assays. Serum samples were analyzed at the core laboratory for serum cTnT, creatine kinase (CK)-MB, and myoglobin. The sensitivity of the rapid assay for detecting acute myocardial infarction (AMI) was compared with the sensitivities of serum cTnT, CK-MB, and myoglobin assays. Results : Of 721 patients, 102 were diagnosed as having AMI. The median elapsed time from symptom onset to ED arrival was 3 hours. The sensitivities of the rapid assay for detecting AMI were 19.6%, 59.0%, and 69.7% at 0, 3, and 6 hours, respectively. The sensitivities of the serum cTnT assay (p-values for comparison with the rapid assay for cTnT) were 25.0% (p = 0.18), 69.6% (p = 0.04), and 79.8% (p = 0.02) at 0, 3, and 6 hours, respectively. The CK-MB and myoglobin sensitivities were 21.9%, 64.5%, and 81.0%; and 43.8%, 77.4%, and 71.4%, respectively. There were 7 patients with AMI who had negative rapid assay readings and positive serum cTnT levels; 4 of these patients were enrolled at the same site. Twenty patients not diagnosed as having AMI had at least one positive rapid assay. Fourteen of these 20 patients had a diagnosis of clinically relevant cardiac disease. Conclusions : The sensitivity of this whole-blood rapid cTnT assay for detecting AMI is comparable to that of current serum assays and offers the advantage of providing rapid bedside results. Discrepancies between serum and whole-blood assays for cTnT noted in this study may indicate the need for further education for the test reader prior to patient use.     

Serum markers in the emergency department diagnosis of acute myocardial infarction

No currently used cardiac-specific serum marker meets all the criteria for an "ideal" marker of AMI. No test is both highly sensitive and highly specific for acute infarction within 6 hours following the onset of chest pain, the timeframe of interest to most emergency physicians in making diagnostic and therapeutic decisions. Patients presenting to the ED with chest pain or other symptoms suggestive of acute cardiac ischemia therefore cannot make a diagnosis of AMI excluded on the basis of a single cardiac marker value obtained within a few hours after symptom onset. The total CK level is far too insensitive and nonspecific a test to be used to diagnose AMI. It retains its value, however, as a screening test, and serum of patients with abnormal total CK values should undergo a CK-MBmass assay. Elevation in CK-MB is a vital component of ultimate diagnosis of AMI, but levels of this marker are normal in one fourth to one half of patients with AMI at the time of ED presentation. The test is highly specific, however, and an abnormal value (particularly when it exceeds 5% of the total CK value) at any time in a patient with chest pain is highly suggestive of an AMI. There have been several improvements of CK-MB assay timing and subform quantification that appear highly useful for emergency physicians. Rapid serial CK-MB assessment greatly increases the diagnostic value of the assay in a timeframe suitable for ED purposes but unfortunately still misses about 10% of patients ultimately diagnosed with acute MI. Assays of CK-MB subforms have very high sensitivity, and, although unreliable within 4 hours of symptom onset, have excellent diagnostic value at 6 or more hours after chest pain begins. Automated test assays recently have become available and could prove applicable to ED settings. The cardiac troponins are highly useful as markers of acute coronary syndromes, rather than specifically of AMI, and abnormal values at any time following chest pain onset are highly predictive of an adverse cardiac event. The ED applicability of the troponins is severely limited, however, because values remain normal in most patients with acute cardiac events as long as 6 hours following symptom onset. Myoglobin appeared promising as a marker of early cardiac ischemia but appears to be only marginally more sensitive than CK-MB assays early after symptom onset and less sensitive than CK-MB at 8 hours or more after chest pain starts. Rapid serial myoglobin assessment, however, appears highly useful as an early marker of AMI. The marker has a very narrow diagnostic window. The clinician is left with several tests that are highly effective in correctly identifying patients with AMI (or at high risk for AMI), but none that can dependably exclude patients with acute coronary syndromes soon after chest pain onset. A prudent strategy when assessing ED patients with chest pain and nondiagnostic ECGs is to order CK-MB and troponin values on presentation in the hope of making an early diagnosis of AMI or unstable coronary syndrome. Although it is recognized that normal values obtained within 6 hours of symptom onset do not exclude an acute coronary syndrome, patients at low clinical risk and having normal cardiac marker tests could be provisionally admitted to low-acuity hospital settings or ED observation. After 6 to 8 hours of symptom duration has elapsed, the cardiac-specific markers are highly effective in diagnosing AMI, and such values obtained can be used more appropriately to make final disposition decisions. At no time should results of serum marker tests outweigh ECG findings or clinical assessment of the patient's risk and stability.     

Emergency Department CK-MB: A Predictor of Ischemic Complications

ABSTRACT
Objective : To demonstrate that a positive CK-MB in the emergency department (ED) predicts an increased risk for complications of myocar-dial ischemia in patients admitted to the hospital for evaluation of chest pain.
Methods : 53 academic and community hospital EDs participated in this prospective observational cohort analysis of 5,120 patients with chest pain without ST-segment elevation on the initial ED 12-lead electrocardiogram. All patients were admitted for evaluation of chest pain in one of the participating hospitals as part of the National Cooperative CK-MB Project. Patients were stratified by whether or not they had an elevated CK-MB level in the ED. CK-MB measurements were made on ED presentation and two hours later. Patient medical records were reviewed for inpatient diagnoses—myocardial infarction (MI) or other diagnosis —and for ischemic complications—cardiac-related death, recurrent or delayed in-hos-pital MI, significant ventricular arrhythmias, new conduction defects, congestive heart failure, and cardiogenic shock.
Results : 369 (7.2%) of the 5,120 patients had MI. The proportion of patients with any complication in the MI group was 24%, while the complication rate in the non-MI group was 0.4%. In all patients, regardless of final diagnosis, the relative risk of any complication was 16.1 (95% CI 11.0–23.6) in those with a positive ED CK-MB versus negative ED CK-MB patients. Similarly, the relative risk of death was 25.4 (95% CI 10.8— 60.2) in positive ED CK-MB versus negative ED CK-MB patients.
Conclusions : Multicenter data support the hypothesis that CK-MB measurements can help risk-stratify ED chest pain patients whose initial ECGs are without diagnostic ST-segment elevation.     

Time-dependent diagnostic performance of a rapid troponin T version 2 bedside test in patients with acute coronary syndromes

In a prospective trial, the diagnostic performance of the second version of the troponin T rapid assay (Trop T; cutoff 0.2 microg/L) was compared with the quantitative cardiac-specific troponin T assay (cTnT ELISA; cutoff 0.1 microg/L) and other established cardiac markers such as CK, CK-MB activity, CK-MB mass and myoglobin. Additionally, a 30-day follow-up was performed to determine the suitability of the Trop T assay and the reference markers for short-term risk stratification. Two-hundred-and-eighty-six consecutive patients with chest pain and suspected acute myocardial infarction (AMI) were enrolled in two CCU departments. Serial blood specimens were taken at admission and at 3, 6, 12, 24, 48, 72 and 96 h after admission. According to the biochemical criterion CK-MB mass, the patients were classified as having AMI in 154 patients (54%), unstable angina (UAP) in 72 patients (27%) and no evidence for acute cardiac ischemia in 55 patients (19%). Analytical method comparison of Trop T with cTnT ELISA (cutoff 0.1 microg/L) showed a good agreement, Trop T yielded only 4% false-negative and 3% false-positive results. The diagnostic performance of Trop T for the detection of AMI was only slightly inferior compared to cTnT ELISA. Beyond 12 h after admission, Trop T and cTnT ELISA maintained a sensitivity close to 100%, whereas the sensitivity of the other cardiac markers decreased sharply. The diagnostic sensitivity of Trop T for the detection of minor myocardial damage in UAP patients was the same as for cTnT ELISA. Death within 30 days' follow-up occurred only in AMI patients with a positive Trop T test result within the first 6 h after admission. The admission Trop T and cTnT ELISA were the only significant biochemical predictors of major cardiac events. In conclusion, these data show that Trop T has similar diagnostic sensitivity as cTnT ELISA and is a useful tool to confirm acute or subacute myocardial infarction. Trop T is an excellent marker in detecting minor myocardial damage in UAP patients and is suitable for short-term risk stratification.     

A multi-marker approach for the prediction of adverse events in patients with acute coronary syndromes

BACKGROUND: Cardiac troponin T (cTnT), high sensitivity C-reactive protein (hs-CRP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) have emerged as strong predictors of adverse events among patients presenting with acute coronary syndromes (ACS). We evaluated the prognostic performance of each of these markers, individually, and in combination in patients presenting to the emergency department (ED) with ACS symptoms. METHODS: Serum samples were obtained from 422 consenting patients presenting to the ED with symptoms of acute coronary syndrome (ACS) and subsequently tested for cTnT, NT-proBNP, myoglobin, CK-MB, and hs-CRP. Adverse events (AEs) occurring within 30 days (death, myocardial infarction, unstable angina and the need for revascularization procedures) were recorded and ROC curves were constructed. RESULTS: AEs occurred in 42 patients (10%). Relative risk, cut-off, and predictive values for each biomarker were determined statistically, with the exception of cTnT, where the concentration meeting the 99th percentile of a healthy population with a 10% coefficient of variation (0.03 ng/ml) was used. These cut-off values, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and relative risk (RR) were calculated. Sensitivity and RR for a panel of cTnT and NT-proBNP were 78.6% (66.2-91.0) and 4.7 (2.3-9.5), respectively. CONCLUSIONS: If used alone, cTnT appeared to have greater prognostic value when compared to hs-CRP, NT-proBNP, myoglobin or CK-MB. The combination of cTnT and NT-proBNP performed better than the combination of cTnT and hs-CRP. When cTnT, NT-proBNP and hs-CRP were used as a panel, there was no significant improvement in prognostic performance over using cTnT and NT-proBNP together. Thus, in patients with suspected ACS, the measurement of both cTnT and NT-proBNP may have enhanced prognostic performance over using either marker in isolation.     

95例急性心肌梗死患者血清肌钙蛋白测定分析与探讨

目的探讨急性心肌梗死（AMI）患者血清肌钙蛋白测定分析与价值。方法95例AMI患者,同时设健康对照组50例,观察AMI患者及健康体检者血清肌钙蛋白T（cTnT）和肌酸激酶同工酶（CK—MB）变化。结果AMI组与对照组相比,cTnT和CK—MB结果差异有统计学意义（P〈0．05）。且cTnT和CK—MB在各时间点阳性率不同,cTnT血清活性升高快,在AMI发作后4h其阳性率比较差异有统计学意义（P〈0．05）。结论cTnT可有效监测病情的发展、治疗及预后,有助于判断溶栓的疗效,并且能提示患者的预后,可以在临床推广应用。     

心肌肌钙蛋白Ⅰ和肌钙蛋白T对急性缺血性心脏病预后相关性分析

目的探讨心肌肌钙蛋白I(cTnI)和肌钙蛋白T(cTnT)对急性缺血性心脏病转归的影响。方法对就诊的急性缺血性心脏病患者定性测定入院时及距胸痛发作间隔10h的cTnI和定量测定相同时点的cTnT。同时随访患者发病后1、3、6、12个月的疾病转归,以心绞痛、心肌梗死、心力衰竭、心源性猝死为终点评价指标。结果cTnI或cTnT异常患者与正常者相比较,不稳定型心绞痛、心肌梗死、心力衰竭、心源性猝死的发生率具有显著性差异(P<0.01)。cTnI或cTnT异常与终点事件(不稳定型心绞痛、心肌梗死、心力衰竭、心源性心源性猝死)发生率呈正相关。结论cTnI或cTnT对急性心肌梗死,尤其是微小心肌坏死诊断具有高度的敏感性和特异性,并与急性缺血性心脏病的预后密切相关。     

Correlation of antemortem serum creatine kinase, creatine kinase-MB, troponin I, and troponin T with cardiac pathology

BACKGROUND: Spurious increases in serum troponins, especially troponin T, have been reported in patients with and without acute myocardial syndromes. METHODS: We studied 78 autopsied patients without clinical myocardial infarction (MI) and correlated histologic cardiac findings with antemortem serum creatine kinase (CK), its MB isoenzyme (CK-MB), cardiac troponin I (cTnI), and cardiac troponin T (cTnT). RESULTS: There was no significant myocardial pathology in 15 patients. Cardiac pathologies were in five groups: scarring from previous MI or patchy ventricular fibrosis (n = 9), recent MI (n = 27), healing MI (n = 7), degenerative myocyte changes consistent with congestive heart failure (CHF; n = 12), and other cardiac pathologies (n = 8). The median concentrations in the five groups were not significantly different for either CK or CK-MB. Compared with the no-pathology group, only the MI group was significantly different for cTnI, and the MI and other pathology groups were significantly different for cTnT. For patients with MI, 22%, 19%, 48%, and 65% had increased CK, CK-MB, cTnI, and cTnT, respectively; for CHF and other cardiac pathologies combined, the percentages were 28%, 17%, 22%, and 50%. For patients with increased cTnI, 72% and 28% had MI and other myocardial pathologies, respectively; patients with increased cTnT had 64% and 36%, respectively. Patients without myocardial pathology had no increases in CK-MB, cTnI, or cTnT. CONCLUSIONS: All patients with increased serum CK-MB, cTnI, and cTnT had significant cardiac histologic changes. The second-generation cTnT assay appears to be a more sensitive indicator of MI and other myocardial pathologies than the cTnI assay used in this study.     

cTnT与CK--MB在胸痛危险分层中的作用

目的评价心肌肌钙蛋白T(cTnT)与肌酸激酶同工酶-MB(CK-MB)蛋白量在胸痛危险分层中的作用。方法对所有病例进行12h床边动态监测，包括基线、4、8、12h的连续心律监测和12导联心电图(ECG)测试；与此同时分别于基线、4、8、12h对入选胸痛组的其中383例患者测定cTnT、CK-MB。结果383例CPU患者只有8例(2．1％)CK-MB阳性，39例cTnT阳性。cTnT状态与随访的结果表明，cTnT阳性明显早于CK-MB。89％cTnT阳性患者血管造影术显示发生冠状动脉疾病(CAD)及多支血管病。结论cTnT比CK-MB在评估伴心肌坏死和多支血管病的胸痛危险分层中具有更高的敏感性与特异性；常规测定cTnT更便于胸痛的危险分层与处理。     

心型脂肪酸结合蛋白在早期急性心肌梗死中的诊断价值

目的 探讨心型脂肪酸结合蛋白（H-FABP）在早期急性心肌梗死中的诊断价值.方法 选择我院收治的疑为AMI胸痛患者126例,进行H-FABP、cTnT及CK-MB检测.结果 34例AMI患者发病3h内血液H-FABP检测灵敏度和准确性显著高于cTnT和CK-MB,差异有统计学意义（P＜0.05）;48例AMI患者发病3-6 h血液HFABP检测灵敏度和准确性显著高于cTnT,差异有统计学意义（P＜0.05）,但与CK-MB比较,差异无统计学意义（P＞0.05）.非AMI患者H-FABP在以上两个时间段均为正常值.结论 H-FABP用于早期诊断急性心肌梗死准确性高,值得临床推广.     

Electrocardiographic ST-segment Elevation The Diagnosis of Acute Myocardial Infarction by Morphologic Analysis of the ST Segment

Acute myocardial infarction (AMI) is one of many causes of ST-segment elevation (STE) in emergency department (ED) chest pain (CP) patients. The morphology of STE may assist in the correct determination of its cause, with concave patterns in non-AMI syndromes and non-concave waveforms in AMI. OBJECTIVES: To determine the impact of STE morphologic analysis on AMI diagnosis and the ability of this technique to separate AMI from non-infarction causes of STE. METHODS: The electrocardiograms (ECGs) of consecutive ED adult CP patients (with three serial troponin I determinations) were interpreted in two-step fashion by six attending emergency physicians (EPs): 1) the determination of STE by three EPs followed by 2) STE morphologic analysis (either concave or non-concave) in those patients with STE. The impact of STE morphology analysis was investigated in the identification of AMI and non-AMI causes of STE. Acute myocardial infarction 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. Interobserver reliability concerning STE morphology was determined. Study inclusion criteria included at least three troponin values performed in serial fashion no more frequently than every three hours, initial ED ECG, ED diagnosis, and final hospital diagnosis. RESULTS: Five hundred ninety-nine CP patients were entered in the study, with 171 (29%) individuals having STE on their ECGs. Of the 171 patients who had STE, 56 had AMI, 50 had unstable angina pectoris (USAP), and 65 had non-coronary final diagnoses. Forty-nine patients had non-concave STE, 46 with AMI and three with USAP; no patient with a non-coronary diagnosis had a non-concave STE morphology. The sensitivity and specificity of the non-concave STE morphology for AMI diagnoses were 77% and 97%, respectively; the positive and negative predictive values for non-concave morphology in AMI diagnoses were 94% and 88%, respectively. Interobserver reliability in the STE morphology determination revealed a kappa coefficient of 0.87. CONCLUSIONS: A non-concave STE morphology is frequently encountered in AMI patients. While the sensitivity of this pattern for AMI diagnosis is not particularly helpful, the presence of this finding in adult ED chest pain patients with STE strongly suggests AMI. This technique produces consistent results among these EPs.     

Lipoprotein analysis in the evaluation of chest pain in the emergency department

Apolipoproteins were measured in a prospective blinded fashion in blood specimens from patients with chest pain in the emergency department. A definitive diagnosis for the chest pain (non-cardiac-related in 32% and angina or myocardial infarction in 68%) was available in 136 of the 162 patients originally enrolled in the study. Logistic regression and multivariate analysis failed to show any usefulness of apolipoprotein determinations in distinguishing patients with cardiac ischemia from those without it. The clinician's initial impression of the chest pain, the electrocardiogram, a history of previous angina, myocardial infarction, or peripheral atherosclerosis, and male sex were strongly associated with the final diagnosis. We conclude that, although apolipoprotein analysis has proved useful in epidemiologic studies, the most reliable indicators of ischemic pain remain the medical history, the electrocardiogram, and the clinician's overall initial impression.