Short-term (90 min) diagnostic performance for acute non-ST segment elevation myocardial infarction and 30-day prognostic evaluation of a novel third-generation high sensitivity troponin I assay

ObjectivesWe evaluated a third-generation high sensitivity “guidelines acceptable” troponin I assay (hs-cTnI) against a contemporary “clinically usable” troponin assay (cTnI).Design and methodsRemnant samples of undifferentiated emergency department (ED) patients with suspected acute coronary syndrome were enrolled. Baseline and 90-minute samples were analyzed for cTnI and hs-cTnI. Sensitivity, specificity, positive and negative predictive values for AMI and 30-day adverse cardiac events (ACE) were compared.ResultsOf 486 ED patients, there were 465 patients who had blood remaining at the presentation for the hs-cTnI assays, with 12 AMIs. At presentation, the clinical sensitivity and specificity for AMI was 75% and 97% for cTnI and 83.3 and 82.1% for hs-cTnI. There were 407 patients who had paired baseline and 90-minute blood samples for cTnI and hs-cTnI including 9 of the 12 AMI patients. The sensitivity and specificity was 77.7% and 96.5% for cTnI and 100% and 81.9% for hs-cTnI at 90 min. A Δ change of 30% increase from baseline to 90 min improved the specificity to 94.5% (95% CI 92%–96%) without lowering the sensitivity. When AMI was defined as a Δ30% change of hs-cTnI at t = 0 and 90 min and one hs-cTnI result > 99th percentile cutoff, more than 3 times as many patients met the diagnostic criteria for AMI compared to results from the normal sensitive troponin assay; 28 (6.9%) for hs-cTnI vs. 9 (2.2%) with cTnI. There were 37 in-hospital or 30-day events, producing an OR of 3.03, 95% CI: 0.86–9.59 for cTnI, and 2.54, 95% CI: 1.27–5.10 for hs-cTnI, which detected 11 more cases.ConclusionsThe hs-cTnI assay achieved a 90-minute rule out for AMI and detected more 3 times as many AMI cases. The specificity increased with the Δ30% criteria. The hs-cTnI assay also detected more cases of patient at risk for adverse cardiac events at 30 days.     

Clinical implications of the change of cardiac troponin I levels in patients with acute chest pain — An evaluation with respect to the Universal Definition of Myocardial Infarction

BackgroundThe Universal Definition of Myocardial Infarction incorporates elevated cardiac troponin levels (> 99th percentile) together with a significant rise/fall of troponins as biochemical criterion. We sought to evaluate the clinical implications of the relative change of cardiac troponin I (cTnI) levels with respect to the Universal Definition in patients with acute chest pain.MethodscTnI (Stratus CS) was measured serially in 454 patients within 24 h from admission. Acute myocardial infarction (AMI) was defined using the criteria adapted to the ESC/ACC consensus document, or corresponding to the Universal Definition together with prespecified cTnI changes of ≥ 20%, ≥ 50% and ≥ 100%. Follow-up was completed after 5.8 years.ResultsA peak cTnI level above the 99th percentile together with a cTnI change of ≥ 20% was found in 160 patients of whom 25 did not have AMI according to the ESC/ACC criteria. These 160 patients had a significantly raised mortality (HR 2.5 [95% CI 1.7–3.8]). Higher cTnI deltas were not associated with higher mortalities but identified smaller patient cohorts at risk.ConclusionsThe Universal Definition of AMI together with a ≥ 20% cTnI change appears to improve the discrimination of acute from chronic causes of cTnI release, and allows a reliable identification of patients at risk.     

Autoantibodies to cardiac troponin in acute coronary syndromes

BackgroundsIn a recent small study, patients with autoantibodies to cardiac troponin (cTnaAb) had higher cardiac troponin I (cTnI) release during an episode of acute coronary syndrome (ACS) than patients without cTnaAb and continued to have higher long-term levels of cTnI. However, the prognostic importance of the occurrence of cTnaAb is unknown.MethodsIn 957 nonST-elevation ACS patients cTnaAb and cTnI were analyzed at randomization and after 6 months. Outcomes were assessed through 5 years.ResultsSeven and 11% of the patients were cTnaAb positive at inclusion and 6 months, respectively. The cardiac troponin I (cTnI) concentration at inclusion was independently associated with the development of cTnaAb (OR 1.53, 95% CI 1.25–1.88). The presence of cTnaAb was associated with an increased cTnI level at 6 months (OR 2.39, 95% CI 1.50–3.81). cTnaAb was not independently associated with death and AMI during follow-up (HR 0.97, 95% CI 0.61–1.54).ConclusionDevelopment of cTnaAb after an episode of nonST-elevation ACS is associated with the acute myocardial damage, but occurs only in a minority of patients. Furthermore, the presence of cTnaAb is associated with chronically elevated cTnI concentrations. However, the occurrence of cTnaAb is not associated with an adverse long-term prognosis.     

Delta changes for optimizing clinical specificity and 60-day risk of adverse events in patients presenting with symptoms suggestive of acute coronary syndrome utilizing the ADVIA Centaur TnI-Ultra assay

ObjectivesWe determined diagnostic accuracy and risk stratification using delta changes for the cardiac troponin I (cTnI) Centaur Ultra assay for ruling out acute myocardial infarction (AMI) and for risk prediction of adverse events in patients with symptoms of acute coronary syndrome.Design and methodscTnI was measured on admission and 6–24 h in 371 patients. Optimal deltas (percent change, absolute value of percent change, change, absolute value of change) were determined from ROC curve analysis. Risk stratification was performed for cardiac events and death within 60 days.ResultsAMI during hospitalization occurred in 49 patients and endpoints in 11 patients. Diagnostic accuracy by ROC curve was optimal (0.96) using the absolute value of change delta. Diagnostic specificities utilizing the 99th percentile (40 ng/L) for admission and follow-up samples were 84% and 81%, compared to: [90% percent change delta] 89.7%; [66.7% absolute value of percent change delta] 85.5%, [217 ng/L change delta] 99.0% and [55 ng/L absolute value of change delta] 93.7%. All four delta values showed substantially greater risk when the initial cTn value was normal.ConclusionsUtilizing delta cTnI values improves clinical specificity, diagnostic accuracy and risk assessment in patients presenting with symptoms of ACS.     

Clinical performance of a new point-of-care cardiac troponin I assay compared to three laboratory troponin assays

BackgroundStudies of cardiac markers in diagnosing acute myocardial infarction (AMI) have mostly been performed using central laboratory platforms. The AQT90 FLEX TnI (troponin I) assay is designed for quantitative point of care testing (POCT). This study evaluated clinical performance in diagnosing AMI of the AQT90 FLEX TnI POCT assay compared with central laboratory troponin assays.MethodsThe study included 458 chest pain patients. Blood samples were obtained on admission and after 6–9 h. Blood was analyzed using the following assays: AQT90 FLEX TnI, Access AccuTnI, Abbott AxSYM ADV, Roche cTnT, Roche CKMBmass. Patients were diagnosed with AMI according to the new universal definition of AMI.ResultsThe performance of the AQT90 FLEX TnI assay on admission was equivalent to the Abbott AxSYM ADV cTnI but inferior to the AccuTnI. After 6–9 h both laboratory based assays were superior. The AQT90 FLEX TnI had a negative predictive value (NPV) of 90 and 96% (admission; 6–9 h). No statistical differences were seen in receiver operating characteristics analysis.ConclusionsThe AQT90 FLEX TnI POCT assay was marginally inferior to the two laboratory based assays of cTnI in diagnosing AMI. A high (NPV) may make this assay suitable as a rule out marker.     

Analytical and clinical performance of a fully automated cardiac multi-markers strategy based on protein biochip microarray technology

OBJECTIVES: The analytical and clinical performance of the Evidence Cardiac Panel were evaluated. DESIGN AND METHODS: The Evidence Cardiac Panel, an automated protein biochip microarray system, allows the simultaneous determination of creatine kinase MB (CK-MB), myoglobin (MYO), glycogen phosphorylase BB (GPBB), heart-type fatty acid-binding protein (H-FABP), carbonic anhydrase III (CA III), cardiac troponin I (cTnI). Precision: 3 levels of quality control (QC) and 2 in house pools (P) were assayed. Method comparison: MYO and cTnI concentrations measured on Evidence (E) and on Dimension RxL (D) analyzers were compared. Clinical study: 132 non-consecutive patients admitted to the Emergency Department for chest pain were enrolled. RESULTS AND CONCLUSIONS: The between-day imprecision was CK-MB=6.80-10.08%; MYO=5.36-16.50%; GPBB=6.51-12.12%; H-FABP=6.26-12.63%; CA III=6.98-13.61%; cTnI=6.02-9.80%. Method comparison: E-MYO vs. D-MYO, Bias=-29.22, 95% CI from -40.25 to -18.18; E-cTnI vs. D-cTnI, Bias=-2.75, 95% CI from -4.04 to -1.46. In patients studied (at discharge: AMI, acute myocardial infarction n=42; non-AMI, n=90) H-FABP showed the highest accuracy (ROC analysis, AUC=0.92) and "cTnI+H-FABP" the greatest diagnostic efficacy (89.4%) in AMI diagnosis.     

Critical review and meta-analysis on the combination of heart-type fatty acid binding protein (H-FABP) and troponin for early diagnosis of acute myocardial infarction

An early diagnosis is crucial for effective triage and management of patients with suspected acute myocardial infarction (AMI). Although troponin testing is the cornerstone of diagnosis, the sensitivity of this biomarker is still suboptimal at patient admission. The heart-type fatty acid binding protein (H-FABP) is an early and sensitive biomarker of myocardial ischemia, whose appropriate setting is in combination with troponin testing. We performed a systematic review and meta-analysis of articles that have assessed the combination of troponin and H-FABP in the early diagnosis of AMI. Eight studies, totaling 2735 patients, met the inclusion criteria but none of them used a high-sensitivity troponin immunoassay. The between-study variation was high (98.5%), and attributable to heterogeneity. When considered alone, troponin exhibited a significantly greater pooled area under the curve (AUC) than H-FABP alone (0.820 versus 0.784; p < 0.001). The pooled specificity was also higher for troponin alone than for H-FABP alone (0.94 versus 0.83; p < 0.001), whereas the cumulative sensitivity was lower for troponin than for H-FABP (0.73 versus 0.80; p = 0.02). The combination of both biomarkers exhibited a greater AUC than troponin alone (0.881; p < 0.001), as well as a higher pooled sensitivity (0.91; p < 0.001), which was however counterbalanced by a lower specificity (0.82; p < 0.001). These results attest that the combination of H-FABP with a conventional troponin immunoassay seems advantageous for increasing the sensitivity of the former biomarker, at the expense of a lower specificity. The introduction of H-FABP testing would hence require careful assessment of laboratory data or clinical signs and symptoms for excluding sources of elevation different from AMI. Further studies are needed to assess the diagnostic effectiveness of combining H-FABP with a high-sensitivity troponin immunoassay.     

Diagnostic performance of four point of care cardiac troponin I assays to rule in and rule out acute myocardial infarction

ObjectiveThis study evaluated the diagnostic performance of four point-of-care (POC) cardiac troponin I (cTnI) assays compared to a central laboratory cTnI assay for detecting myocardial injury and diagnosing acute myocardial infarction (AMI).Design and methodsPlasma obtained at admission, 3 h, and 6 h post-admission in 169 patients presenting with symptoms suggestive of acute coronary syndrome (ACS) was studied. cTnI concentrations were measured on the Instrumentation Laboratory prototype GEM Immuno, Radiometer AQT90, Mitsubishi PATHFAST, Abbott i-STAT and the Ortho-Clinical Diagnostic Vitros assays. MI was determined based on 99th percentiles according to Universal MI guidelines.ResultsFor ruling in MI at presentation (0 h), the GEM Immuno (sensitivity 63%, specificity 85%) and PATHFAST (sensitivity 53%, specificity 86%) were comparable to the OCD (sensitivity 68%, specificity 81%), and significantly better (p < 0.05) than the AQT90 (sensitivity 26%, specificity 93%) and i-STAT (sensitivity 32%, specificity 92%). cTnI concentrations and serial rising patterns after MI differed by each assay. Negative predictive values were > 90% and ROC AUCs were > 0.90 after 6 h for all assays. Detection of myocardial injury in non-ischemic pathologies accounted for lower than 100% specificity for MI.ConclusioncTnI is a sensitive biomarker for detection of myocardial injury. The analytical variability that exists between POC cTnI assays demonstrates substantial diagnostic differences for ruling in and ruling out MI in patients presenting with symptoms suggestive of ACS.     

心型脂肪酸结合蛋白在急性心肌梗死患者早期诊断中的应用价值

目的: 探讨血清心型脂肪酸结合蛋白（heart-type fatty acid-binding protein,H-FABP）在急性心肌梗死（acute myocardial infarction,AMI）早期诊断中的应用价值。方法: 应用乳胶凝集法检测105例因胸痛疑似AMI就诊患者的血清H-FABP,同时测定患者血清中肌酸激酶同工酶MB（creatine kinase isoenzyme MB,CK-MB）、肌红蛋白（myoglobin, MYO）和心肌钙蛋白I（cardiac troponinc I,cTnI）。根据最终的临床诊断将患者分为AMI组和非AMI组（对照组）,并对2组检测结果的阳性率、诊断效率等进行分析比较。结果: 105例疑似AMI患者中,最终诊断为AMI患者45例,其余60例排除AMI诊断作为对照组。AMI组的H-FABP、cTnI、MYO、CK-MB平均水平及阳性率分别为（49.32±10.29） ng/mL、84.4%,（1.62±0.76） ng/mL、44.4%,（156.14±54.23） ng/mL、82.2%,（13.01±6.08） ng/mL、42.2%,均高于对照组（P<0.05）;AMI组中H-FABP阳性率与MYO阳性率间无统计学差异（P>0.05）,但明显高于cTnI及CK-MB的阳性率（P<0.05）。H-FABP与CK-MB诊断AMI的特异度相似（P>0.05）,但低于cTnI（P<0.05）,高于MYO（P<0.05）。H-FABP与cTnI的阳性预测值相似（P>0.05）,均高于MYO、CK-MB（P<0.05）。在阴性预测值方面,H-FABP与MYO相似（P>0.05）,明显高于cTnI和CK-MB（P<0.05）。4项指标检测结果进行组合分析,H-FABP+ cTnI、H-FABP+ CK-MB、H-FABP+ MYO、H-FABP+ cTnI+MYO、H-FABP+ cTnI+CK-MB、H-FABP+ cTnI+MYO+CK-MB诊断AMI的灵敏度均为100.0%,特异度分别为82.0%、72.0%、61.2%、59.3%、68.1%和56.5%。结论: H-FABP在AMI早期诊断中具有较好的灵敏度和特异度,与cTnI联合检测,可显著提高AMI早期诊断效能。     

Serum free L-carnitine in association with myoglobin as a diagnostic marker of acute myocardial infarction

BackgroundEarly diagnosis of acute myocardial infarction (AMI) in patients with chest pain is necessary to initiate appropriate treatment. Elevation of ST-segment in ECG is the only marker that cardiologists depend on in diagnosis. The aim of this study was to monitor the level of serum free L-carnitine in combination with myoglobin (Myo) and creatine kinase (total activity and CK-MB level) for usefulness as a predictor of AMI in ICU patients.Design and methodsIn the present study serum total CK activity and CK-MB, Myo, and free L-carnitine levels were determined in 90 patients admitted to the ICU at Ain Shams University Hospital and correlated the sensitivity and specificity of each parameter.ResultsObtained data revealed that, 47/90 who were diagnosed as AMI showed a highly significant reduction in serum free L-carnitine level in all cases as compared to normal control (P < 0.001), 24/90 diagnosed as unstable angina showed a non significant reduction of serum carnitine and 19/90 who were diagnosed as noncardiac showed non significant changes in the level of serum free carnitine as compared to normal control. In addition, serum free L-carnitine level was negatively correlated to CK-MB and Myo (r = ? 0.61 and ? 0.52) respectively. The sensitivity of carnitine assay was considerably higher (95.5%) compared to CK-MB (87%) and Myo (89.5%) even considering patients with a short delay until admission.ConclusionComparing the changes in serum total CK, levels of CK-MB, Myo and carnitine, the sensitivity and specificity were significantly higher for serum free L-carnitine. For this reason, serum free L-carnitine can be used as a good predictor for AMI diagnosis from other diseases.     

心型脂肪酸结合蛋白在急性心肌梗死早期诊断中的价值

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

Elevated levels of myeloperoxidase, white blood cell count and 3-chlorotyrosine in Taiwanese patients with acute myocardial infarction

ObjectivesInflammation, a major risk factor for acute myocardial infarction (AMI), is associated with leukocytic activation, secretion of myeloperoxidase (MPO) and generation of the oxidative damage marker, 3-chlorotyrosine (3-Cl-Tyr). To study their association with AMI and their value in diagnosis of AMI, white blood cell (WBC) count, plasma MPO, plasma 3-Cl-Tyr, and conventional risk factors such as cardiac troponin I and CK-MB were examined in AMI patients during the onset of chest pain.MethodsAfter obtaining informed consent, blood samples were collected from 77 AMI patients during the onset of chest pain and from 53 normal controls. The samples were analyzed for WBC count using SE-9000 automated analyzer. Plasma MPO was measured by an enzyme-linked immunosorbent assay. Plasma levels of 3-Cl-Tyr, a product of MPO, were analyzed by HPLC coupled with Coularray electrochemical detection.ResultsThe WBC, plasma MPO and 3-Cl-Tyr levels were significantly elevated in AMI patients than in normal controls (p < 0.001). The levels of WBC, MPO and 3-Cl-Tyr alone were strongly associated with the prevalence of AMI. Plasma MPO was correlated with 3-Cl-Tyr (r = 0.389, p < 0.01) and WBC counts (r = 0.405, p < 0.01) respectively. The ROC curve analyses suggested that MPO had the best specificity and sensitivity among these oxidative stress-related markers.ConclusionPlasma MPO value should be considered as a better marker for early diagnosis of AMI, as compared with WBC count or 3-Cl-Tyr.     

Effect of population selection on 99th percentile values for a high sensitivity cardiac troponin I and T assays

ObjectiveUsing objective laboratory and clinical criteria to more accurately determine the 99th percentile values for cardiac troponin I and T.Design and methodsWe measured cardiac troponin T and cardiac troponin I with high-sensitivity assays in a large cohort of apparently healthy community subjects and calculated 99th percentiles for different sexes and ages. Subjects with possible subclinical disease were eliminated based on objective laboratory criteria, eGFR and NT-proBNP, and clinical criteria, history and examination and echocardiogram.ResultsFor men and women of all ages, separately, more than 50% of subjects were excluded using these criteria, with a lesser proportion of younger subjects being excluded. In men aged < 75 years, the 99th percentile for cTnI decreased by more than 50% from 22.9 ng/L to 10.3 ng/L. In other age groups and for cTnT the decrease was smaller (%) but still considerable.ConclusionsFor establishing cardiac troponin 99th percentiles, simply using self-reporting of health is insufficient. Objective laboratory measures and clinical and echocardiographic assessments are essential to define a healthy population, especially in older persons.     

Performance of cardiac troponins within the HEART score in predicting major adverse cardiac events at the emergency department

BackgroundThis study compared the performance of a single blood draw of high-sensitivity troponin T (hsTnT), high-sensitivity troponin I (hsTnI) and conventional troponin I (cTnI) within a modified HEART score for predicting 30-day MACE at Emergency Department (ED) presentation, and established local reference norms for all three assays by determining the cut-off point which yielded the highest sensitivity and negative predictive value for acute myocardial infarction and 30-day MACE.MethodsThis single-center prospective cohort study recruited chest pain patients at the ED, whose hsTnT, hsTnI and cTnI were taken on admission. Subjects were classified into low and non-low risk group according to their modified HEART score, with MACE as the primary endpoint. Receiver-operating characteristic (ROC) curves were generated, area under the curves (AUCs) were calculated; the performance characteristics were determined.ResultsThe performance of modified HEART scores was comparable among the three assays for 30-day MACE (84.9–87.0% sensitivity, 95.6–96.0% NPV, 95%CI) and none of these had very high AUC and specificity (AUC 0.70–0.71, 53.7–56.7% specificity, 95% CI). The modified HEART score using a single blood draw of either hsTnT (3.9 ng/L), hsTnI (0.9 ng/L) or cTnI (0.0 ng/L) at presentation yielded a sensitivity of 100% for 30-day MACE.ConclusionThe modified HEART score using a single blood draw of either hsTnT, hsTnI or cTnI was equally effective in risk-stratifying chest pain patients for safe discharge. The theoretical cut-off points yielding 100% sensitivity are potentially useful (when achieved) for safely discharging low risk patients with undifferentiated chest pain in the ED.     

心脏型脂肪酸结合蛋白定性检测对急性心肌梗死早期诊断的价值

目的:探讨心脏型脂肪酸结合蛋白(H-FABP)在急性心肌梗死(AMI)早期诊断中的价值。方法:运用胶体金免疫层析技术定性检测104例发病3h内胸痛患者的血H-FABP,比较其与心肌肌钙蛋白(cTnI)、肌酸激酶同功酶MB(CK-MB)、肌红蛋白(MYO)诊断早期AMI的敏感度、特异度。结果:入选患者中最终确诊为AMI患者50例,非AMI54例。H-FABP、cTnI、CK-MB和MYO检出AMI的敏感度分别为88.00%、68.00%、64.00%和84.00%,H-FABP显著高于cTnI和CK-MB(均P<0.05),与MYO比较无显著差异(P>0.05);检测特异度分别为90.74%、87.04%、85.19%和70.37%,H-FABP显著高于MYO(P<0.05),分别与cTnI和CK-MB比较均无显著差异(均P>0.05)。在四种心肌损伤标志物中,H-FABP的准确诊断指数最高。结论:H-FABP用于AMI早期诊断具有快速、简便,灵敏度和特异度高的特点,值得临床推广应用。     

A FABP-ulous 'rule out' strategy? Heart fatty acid binding protein and troponin for rapid exclusion of acute myocardial infarction

Objective

Many Emergency Departments (EDs) utilise ‘triple marker’ testing with CK-MB, myoglobin and troponin I (cTnI) to exclude acute myocardial infarction (AMI) within hours of presentation. We evaluated the ability of 8 biomarkers to rapidly exclude AMI at the point of presentation and investigated whether ‘triple marker’ testing represents the optimal multimarker strategy.

Methods

We recruited patients who presented to the ED with suspected cardiac chest pain occurring within 24 h. Blood was drawn at the time of presentation. Diagnostic value was assessed by calculating the area under the ROC curve (AUC) and a multivariate model was constructed by logistic regression. The primary outcome was a diagnosis of AMI, established by ≥12-h troponin testing in all patients.

Results

705 included patients underwent venepuncture a median of 3.5 h after symptom onset. Heart fatty acid binding protein (H-FABP) had an AUC of 0.86 (95% CI 0.82-0.90), which was significantly higher than any other biomarker including cTnI. While no single biomarker could enable exclusion of AMI, multivariate analysis identified cTnI and H-FABP as the optimal biomarker combination. Combined with clinical risk stratification, this strategy had a sensitivity of 96.9%, specificity of 54.7%, PPV 32.4% and NPV 98.8%.

Conclusions

We have derived an algorithm that would enable AMI to be immediately excluded in 315 (44.7%) patients at the cost of missing 6 AMIs per 1000 patients treated. While the risk is likely to be unacceptable for clinical implementation, we have highlighted an area for future development using serial testing and increasingly sensitive assays.     

Cardiovascular disease testing on the Dimension Vista® system: Biomarkers of acute coronary syndromes

ObjectivesPerformance characteristics of the LOCI® cTnI, CK-MB, MYO, NTproBNP and hsCRP methods on the Dimension Vista® System were evaluated.Design and methodsImprecision (following CLSI EP05-A2 guidelines), limit of quantitation (cTnI), limit of blank, linearity on dilution, serum versus plasma matrix studies (cTnI), and method comparison studies were conducted.ResultsMethod imprecision of 1.8 to 9.7% (cTnI), 1.8 to 5.7% (CK-MB), 2.1 to 2.2% (MYO), 1.6 to 3.3% (NTproBNP), and 3.5 to 4.2% (hsCRP) were demonstrated. The manufacturer's claimed imprecision, detection limits and upper measurement limits were met. Limit of Quantitation was 0.040 ng/mL for the cTnI assay. Agreement of serum and plasma values for cTnI (r = 0.99) was shown. Method comparison study results were acceptable.ConclusionsThe Dimension Vista® cTnI, CK-MB, MYO, NTproBNP, and hsCRP methods demonstrate acceptable performance characteristics for use as an aid in the diagnosis and risk assessment of patients presenting with suspected acute coronary syndromes.     

心型脂肪酸结合蛋白在诊断急性心肌梗死中的临床意义

目的 探讨血清心型脂肪酸结合蛋白(H-FABP)在急性心肌梗死(AMI)诊断中的价值.方法 采用双抗体夹心酶联免疫法测定78例AMI、52例不稳定性心绞痛(UA)、65例稳定性心绞痛(SA)患者及70名健康对照者血清H-FABP水平,同时测定心肌肌钙蛋白I(cTnI)、肌酸激酶质量(CK-MB mass)并作比较.测定...     

Acute ischemic heart disease alters ventricular fibrillation waveform characteristics in out-of hospital cardiac arrest

BackgroundAlthough ventricular fibrillation waveform characteristics (VFWC) correlate with coronary perfusion pressure and may predict defibrillation outcome, recent animal data indicate that these waveform characteristics are altered in both acute myocardial infarction (AMI) and chronic coronary heart disease (CHD). We wanted to confirm these recent animal data in humans and explore the possibility for such characteristics to identify acute ischemia during cardiac arrest.MethodsData from all adult patients admitted to hospital after out-of-hospital VF cardiac arrest in Oslo between May 2003 and July 2007 were prospectively collected. Patients were categorized into one of four pre-defined etiologic groups: patients with AMI (AMI only), patients with AMI and CHD (AMI and CHD), patients with previous CHD without evidence for a new AMI (CHD only), and patients with primary arrhythmia (PA). VFWC were analyzed from prehospital ECG tracings, and the different etiologic groups compared using ANOVA.ResultsOne-hundred-and-one patients with ECG recordings usable for VF analysis could confidently be categorized; 16 with AMI only, 34 with AMI and CHD, 41 with CHD only and 10 with PA. The two VFWC median slope (MS) and amplitude spectral area (AMSA) were significantly depressed in patients with AMI only compared to both PA (MS p = 0.008, AMSA p = 0.035) and CHD only patients (MS p = 0.008, AMSA p = 0.006).ConclusionsAMI patients have depressed MS and AMSA compared to patients without AMI during VF cardiac arrest. VFWC might be helpful in identifying patients with AMI during cardiac arrest, but prospective clinical studies are warranted to assess its feasibility and clinical benefit.     

血清心肌型脂肪酸结合蛋白检测在急性心肌梗死诊断中的应用

目的探讨血清心肌型脂肪酸结合蛋白（H-FABP）在急性心肌梗死（AMI）诊断中的应用价值。方法选择95例疑似急性心肌梗死的胸痛患者,用快速检测试剂盒检测患者发病0～3、3～6h和6h后血清的H-FABP,并和心肌肌钙蛋白I（cTnI）、肌酸激酶同工酶（CK-MB）的检测结果进行比较,分析3种心肌标志物在AMI不同发病时间段诊断中的敏感性和特异性。结果 3种指标在所有胸痛患者中检出率差异无统计学意义（P〉0.05）,但在AMI组患者中,H-FABP的阳性率为72.9%,显著高于cTnI（66.7%）及CK-MB（62.5%）,差异有统计学意义（P〈0.05）。H-FABP检测诊断AMI的敏感性在0～3h（70.00%）和3～6h（82.61%）时间段显著高于cTnT（20.00%与65.22%）和CK-MB（10.00%与65.22%）;在诊断特异性上,H-FABP高于CK-MB,但比cTnI低。结论 H-FABP对于诊断早期AMI具有较高的敏感性和良好的特异性,适合于临床AMI的早期诊断。