Assessment Of Acute Myocardial Infarction Research Articles

CytogeneticsComparability of Beckman Coulter Access Cardiac Troponin I Assays

Abstract Cardiac troponins (cTn) are the most sensitive and specific biomarkers of myocardial injury. The rise and/or fall of cardiac troponins above the 99th percentile of the upper reference limit (URL) is required in the assessment of acute myocardial infarction. In our institution, high sensitivity troponin I (hsTnI) is performed on four Access 2 Immunoassay Systems and three DXI 800 Access Immunoassay Systems. As a regional medical center, we accept patients from outside hospitals where contemporary cardiac troponin I (cTnI) were performed. The results from different assays and platforms may disagree and lead to incorrect explanation of the results as false rise and/or fall of cTn. To harmonize results among these assays, we analyzed the variation between the two assays of cTnI and hsTnI, and the concordance of same assay hsTnI on different instruments using patient specimens. To investigate the between-method variance, 424 patient specimens with troponin levels ranging from 0-23370 ng/L were used to measure both cTnI and hsTnI on DXI 800 instruments. To investigate the within-method agreement, 43 patient specimens with troponin levels ranging from 2-114394 ng/L were used to measure hsTnI on Access 2 and DXI instruments. The between-method comparison of cTnI and hsTnI on DXI showed a slope of 1.003 with intercept of -43.31 and correlation coefficient (CC) of 0.9590. The mean bias was -5.1%, which was within the analytical imprecision range determined in our laboratory (2.2%-10.7%). However, comparison of cTnI and hsTnI in patients with troponin <20ng/L (n=103), the 99th percentile of the URL for males, showed the slope was 1.325 with intercept of -0.97 and CC of 0.7462. The mean bias was 1.91 (21.53%), which was much larger than the analytical imprecision. This is consistent with the fact that cTnI results are not reliable at the lower level due to the imprecision problem. Comparison of cTnI and hsTnI in patients with troponin >20ng/L (n=321) showed the slope was 1.006 with intercept of –60.09 and CC of 0.9576. The mean bias was -54.30 (-5.23%), which was within the analytical imprecision range. The within-method comparison of hsTnI on Access 2 and DXI 800 showed the slope was 1.138 with intercept of -633.0 and CC of 0.9888. The mean bias was 2126.4 (10.6%), within the analytical imprecision range. These data indicate that cTnI results above the 99th percentile URL are comparable with hsTnI results if both are tested on DXI 800, and hsTnI results tested on Access 2 and DXI 800 are comparable. Thus, to use the cardiac troponins assay properly, we suggest the laboratory report cardiac troponins with the assay and instrument names to reduce confusion during results comparison.

B-281 Analytical Validation of the Mindray High Sensitivity Cardiac Troponin I Assay

Abstract Background According to recent global guidelines for patients presenting with ischemia, high sensitivity cardiac troponin I and T (hs-cTn) are the preferred biomarkers for the diagnosis and risk assessment of acute myocardial infarction (MI) and myocardial injury. The purpose of our study was to perform an analytical validation study of the Mindray hs-cTnI assay. Methods Analytical studies were designed according to Clinical and Laboratory Standards Institute protocols (CLSI). We used one reagent lot and one CL1200i chemiluminescence Immunoassay Analyzer (Mindray Bio Medical Electronics Co., Shenzhen, China). Following the CLSI EP17 A2 document, the limit of blank (LoB) and limit of detection (LoD) were assessed following analysis of a) Mindray controls without cTnI concentrations added for the LoB and b) 4 lithium heparin (LiHep) fresh samples with low cTnI concentrations, for 3 days for LoB and LoD, with 5 replicates per day (60 replicates per study). For the precision study, according to the CLSI EP15-A3 protocol, we used 12 LiHep fresh samples, measured for 10 days, with 2 runs per day (separated by a minimal time of 2 h) and in replicates of 3 (n = 720). For the 12 samples for the precision study, 7 were chosen with hs-cTnI concentrations close to the manufacturer sex-specific 99th percentile upper reference limits (URL; 31 ng/L for males and 15 ng/L for females). The CLSI EP06 protocol was followed to study linearity, using 9 fresh LiHep samples analyzed the same day in replicates of 7 (n = 63). A blank sample between every sample was used to avoid carryover. Our analytical specification for linearity was an allowable deviation <10%. Analyses were performed with Analyze it for Excel (Method Validation edition, version 6.15). Results Using both parametrical and non-parametrical analyses, LoB was <0.1 ng/L, with a relative light unit (RLU) of 5394. LoD was 0.1 ng/L according to the parametrical analysis. Regarding imprecision, for samples ranging from cTnI concentrations of 1 to 106 ng/L, repeatability had a coefficient of variation (%CV) from 1.15% to 3.83%, and within-laboratory imprecision ranging from 1.69% to 5.03%. Using samples with hs-cTnI concentrations close to the manufacture’s sex-specific upper reference limits (9–36 ng/L), the repeatability and within-laboratory precision was 1.27%–1.61% and 1.92%–2.52%, respectively. The measuring interval for the linearity study ranged from 1.1 to 30 772 ng/L. All analytical parameters met CLSI limits of acceptable performance. No carry over was detected. Conclusion Our analytical observations of the Mindray hs-cTnI assay demonstrate excellent LoB, LoD, imprecision and linearity, that were in alignment of with the manufacturer’s claims and published guidelines for hs-cTnI.

Cardiac Magnetic Resonance Assessment of Acute Myocardial Infarction Involving the Right Ventricle.

Cardiac Magnetic Resonance Assessment of Acute Myocardial Infarction Involving the Right Ventricle.

Risk Assessment of Acute Myocardial Infarction and Stroke Associated with Long-Acting Muscarinic Antagonists, Alone or in Combination, versus Long-Acting beta2-Agonists.

BackgroundThe long-acting muscarinic antagonist (LAMA) aclidinium was approved in Europe in 2012 to relieve symptoms in adult patients with chronic obstructive pulmonary disease (COPD). A post-authorization safety study was initiated to assess potential cardiovascular risks associated with LAMAs versus long-acting beta2-agonists.PurposeTo estimate incidence rates and adjusted incidence rate ratios (IRRs) for acute myocardial infarction (AMI), stroke, and major adverse cardiac events (MACE) in new users of aclidinium, aclidinium/formoterol, tiotropium, other LAMA, long-acting beta-agonists/inhaled corticosteroids (LABA/ICS), and LAMA/LABA compared with initiators of LABA.Patients and MethodsThis population-based cohort study included patients with COPD aged ≥40 years initiating COPD medications in the UK Clinical Practice Research Datalink (CPRD) Aurum database from 2012 to 2019. Poisson regression models were used to estimate the IRR for AMI, stroke, and MACE in users of COPD medications versus LABA, adjusting for clinically relevant covariables.ResultsThe study included 11,121 new users of aclidinium, 4804 of aclidinium/formoterol, 56,198 of tiotropium, 23,856 of other LAMA, 17,450 of LAMA/LABA, 70,289 of LABA/ICS, and 13,716 of LABA. During periods of continuous medication use after initiation (current use), crude incidence rates per 1000 person-years for AMI ranged from 8.7 (aclidinium/formoterol) to 12.4 (LAMA/LABA), for stroke ranged from 4.8 (aclidinium/formoterol) to 7.2 (LAMA/LABA), and for MACE ranged from 13.5 (aclidinium/formoterol) to 19.3 (LAMA/LABA). Using LABA as reference, adjusted IRRs [95% confidence intervals] were close to 1 for all study drugs for AMI (lowest for aclidinium/formoterol, 0.95 [0.60–1.52], and highest for LAMA/LABA, 1.23 [0.91–1.67]), stroke (lowest for aclidinium/formoterol, 0.64 [0.39–1.06], and highest for tiotropium, 1.02 [0.81–1.27] for tiotropium) and for MACE (lowest for aclidinium, 0.93 [0.75–1.16], and highest for LAMA/LABA, 1.24 [0.97–1.59]).ConclusionRisks of AMI, stroke, and MACE in current users of aclidinium, aclidinium/formoterol, tiotropium, other LAMA, LAMA/LABA, or LABA/ICS were similar to the risks among current users of LABA.

Quantitative proteomics reveal three potential biomarkers for risk assessment of acute myocardial infarction

ABSTRACT Acute myocardial infarction (AMI) is the one of the main cause of death worldwide. Exosomes carry important information about intercellular communication and could be diagnostic marker for many diseases. Here, we aimed to find potential key proteins for the early diagnosis of AMI. A label free proteomics strategy was used to identify the differentially expressed proteins (DEPs) of AMI patients’ plasma exosome. By bioinformatics analysis and enzyme-linked immunosorbent assay to validate the candidate proteins. Compared to healthy control plasma exosome, we totally identified 72 differentially expressed proteins (DEPs) in AMI patients. Also, we found that complement and coagulation cascades was activated by KEGG analysis and GSEA. PLG, C8B and F2 were selected as candidate molecules for further study, and then validated another 40 plasma samples using enzyme-linked immunosorbent assay. Finally, we found that the expression levels of these three proteins (PLG, C8B and F2) were significantly higher than those of healthy controls (P < 0.05). ROC analysis revealed that PLG, C8B and F2 had potential value for AMI early diagnosis. In conclusion, our study identified three potential biomarkers for AMI diagnosis. But there remains a need to further study the mechanism of the biomarkers.

S100A1 is a sensitive and specific cardiac biomarker for early diagnosis and prognostic assessment of acute myocardial infarction measured by chemiluminescent immunoassay

BackgroundA member of the S100 family of Ca2+-binding proteins, S100A1 is highly expressed in cardiac muscle tissue. Although this protein is considered an indicator of acute myocardial infarction (AMI), high-throughput and sensitive detection methods are still urgently needed. We constructed a rapid and sensitive method for detecting S100A1 and to investigate the clinical utility of S100A1 as a biomarker for the early diagnosis of AMI and subsequent prognostic assessments. We developed an automated chemiluminescent immunoassay to detect S100A1. We then analyzed the performance of the newly developed assay including evaluation of the analytical sensitivity, analytical selectivity, linear range, accuracy and repeatability. MethodsWe recruited 87 patients with AMI or angina pectoris to explore the value of this marker for the early diagnosis and prognostic assessment. ResultsThe chemiluminescent-immune-based S100A1 assay had functional analytical sensitivity with a detection limit of 0.13 ng/ml, and a wide linear range of 0.13–31.66 ng/ml. It also exhibited good repeatability with intra-assay and inter-assay findings of <5% and <15%, respectively. Plasma S100A1 was found to have a higher diagnostic sensitivity than conventional cardiac biomarkers (creatine kinase-MB and cardiac troponin T). The survival analysis showed that a higher concentration of plasma S100A1 (>1.02 ng/ml) was notably associated with the poor prognosis of AMI patients after first PCI. ConclusionsMeasurement of circulating S100A1 concentrations with our newly developed chemiluminescent-immune-based assay shows potential for use in the clinic. This assay could enable early identification and prognostic assessment of AMI.

The Value of Low-Dose Dynamic Myocardial Perfusion CT for Accurate Evaluation of Microvascular Obstruction in Patients With Acute Myocardial Infarction.

OBJECTIVE. The purpose of this study was to investigate the diagnostic performance of quantitative parameters generated from dynamic myocardial perfusion CT for assessment of acute myocardial infarction (AMI) and microvascular obstruction (MVO) using cardiac MRI as a reference standard. SUBJECTS AND METHODS. Patients who underwent successful reperfusion treatment within 1 week after AMI between January 1, 2018, and May 31, 2018, were prospectively enrolled. All patients were referred for cardiac MRI and dynamic myocardial perfusion CT on the same day. Various quantitative parameters and late iodine enhancement (LIE) were analyzed for the evaluation of AMI and MVO using cardiac MRI findings as a reference standard. RESULTS. Twenty-seven patients with 442 vascular segments were ultimately included in the analysis. The mean radiation doses ± SD for dynamic myocardial perfusion CT and LIE were 3.3 ± 1.1 mSv and 2.0 ± 0.6 mSv, respectively. Myocardial blood flow (MBF) was significantly lower in segments with MVO than in those without MVO and in reference segments (23.08 ± 7.95 mL/min/100 mL vs 44.60 ± 14.97 mL/min/100 mL and 75.07 ± 7.34 mL/min/100 mL; p < 0.001). According to ROC curve analysis, MBF had the largest AUC of all parameters for identifying AMI with and without MVO as determined by late gadolinium enhancement (LGE) (AUC = 0.941 and 0.996; p < 0.001). The diagnostic accuracy of MBF-based assessment for identifying MVO was 99.2%, which outperformed other quantitative parameters and LIE. We found good correlation between the AMI area and MVO area estimated by MBF and LGE (r = 0.95 and 0.99; p < 0.001). CONCLUSION. MBF derived from dynamic myocardial perfusion CT is accurate and outperforms other quantitative parameters and LIE in diagnosis of AMI and MVO. Area of AMI and MVO can also be accurately estimated using MBF.

Validating the Manchester Acute Coronary Syndromes (MACS) and Troponin-only Manchester Acute Coronary Syndromes (T-MACS) rules for the prediction of acute myocardial infarction in patients presenting to the emergency department with chest pain

BackgroundThe Manchester Acute Coronary Syndromes (MACS) rule and the Troponin-only MACS (T-MACS) rule risk stratify patients with suspected acute coronary syndrome (ACS). This observational study sought to validate and compare...

Letter to the Editor: Assessment of Acute Myocardial infarction by the use of special biochemical markers

With great interest I read the article titled Assessment of Acute Myocardial infarction by the use of special biochemical by Rihab Akasha et al. The work done was commendable. Biochemical markers used as AMI diagnostic tests are often used in patients with acute chest pain. According to the World Health Organization, AMI diagnosis is based on at least 2 of the following three criteria: Chest pain, ECG changes, cardiac enzyme increase.

Assessment of Acute Myocardial infarction by the use of special biochemical markers

Assessment of Acute Myocardial infarction by the use of special biochemical markers

Identification of peptides that selectively bind to myoglobin by biopanning of phage displayed-peptide library

Biopanning of phage displayed-peptide library was performed against myoglobin, a marker for the early assessment of acute myocardial infarction (AMI), to identify peptides that selectively bind to myoglobin. Using myoglobin-conjugated magnetic beads, phages that bound to myoglobin were collected and amplified for the next round of screening. A 148-fold enrichment of phage titer was observed after five rounds of screening relative to the first round. After phage binding ELISA, three phage clones were selected (3R1, 3R7 and 3R10) and the inserted peptides were chemically synthesized. The analysis of binding affinity showed that the 3R7 (CPSTLGASC) peptide had higher binding affinity (Kd=57nM) than did the 3R1 (CNLSSSWIC) and 3R10 (CVPRLSAPC) peptide (Kd=125nM and 293nM, respectively). Cross binding activity to other proteins, such as bovine serum albumin, troponin I, and creatine kinase-MB, was minimal. In a peptide-antibody sandwich ELISA, the selected peptides efficiently captured myoglobin. Moreover, the concentrations of myoglobin in serum samples measured by a peptide–peptide sandwich assay were comparable to those measured by a commercial antibody-based kit. These results indicate that the identified peptides can be used for the detection of myoglobin and may be a cost effective alternative to antibodies.

Detection of acute myocardial infarct with T1-mapping post ferumoxytol contrast administration

Background Gadolinium-enhanced CMR can be a useful adjunct in the diagnosis and assessment of acute myocardial infarction (AMI). However, gadolinium contrast is contraindicated in severe renal impairment. Alternative, non-gadolinium contrast agents for AMI assessment and contrast-enhanced CMR in general would be of substantial clinical importance. Ferumoxytol, an intravenous iron-supplementation drug, was approved in 2009 by the FDA for treatment of iron-deficiency anemia in patients with chronic kidney disease, and is known to have T1 shortening properties. The utility of T1-weighted ferumoxytol-enhanced CMR for detecting AMI has not been previously evaluated.

ECONOMIC IMPACT OF THE UNIVERSAL DEFINITION OF ACUTE MYOCARDIAL INFARCTION ON AN INNER CITY TEACHING HOSPITAL

i p The universal definition of myocardial infarction provides criteria for the diagnosis and classification of the type of acute myocardial infarction (AMI) and recommends the measurement of cardiac troponin (cTn) for the detection of myocardial necrosis. Despite this, many institutions still use creatinine kinase-MB as part of the standard laboratory evaluation for AMI. The aim of this study was to ascertain the cost benefit of using only cTn for the diagnosis of acute coronary syndromes. A survey was done of Kansas City hospitals and the University HealthSystem Consortium list server for comparison of whether other institutions use 1 or both biomarkers. Locally, most of the responding hospitals in Kansas City and 57% of responding university hospitals surveyed use the 2 biomarkers for the diagnosis of AMI. After initiating medical staff education, the investigators’ institution’s standard order sets were changed to use only cTnI for the assessment of AMI. The cost savings by eliminating creatine kinase-MB on the order sets was based on the annual volume of processed specimens. The cost of supplies, equipment, and materials was determined on a per test basis. After initiation of the new standard order sets, the creatine kinase-MB testing rate decreased to 50 per month, from 1,098, for an annualized savings of $86,786. In conclusion, as the health care system is challenged to improve care while containing cost, the use of a single biomarker (cTn) in the diagnosis of AMI fulfills this promise without sacrificing patient care. The diagnostic value of cardiac troponin (cTn) measurement is well established. However, less well appreciated is the potential economic benefit from using a single marker instead of a panel of biomarkers that traditionally have included creatine kinase-MB (CK-MB). Expert consensus underscores using cTn determinations only for better clinical care and a reduction in cost. The elimination of muliple biomarkers, including CK-MB, in the diagnosis of cute coronary syndromes (ACS) relies on evidence-based edicine consistent with the universal definition of acute yocardial infarction (AMI). We report our experience in ost savings after developing standard order sets with cTnI s the only marker on chest pain, ACS, and post–percutaeous coronary intervention orders. Our hypothesis was that significant cost savings would be realized without comromising patient care.

Economic Impact of the Universal Definition of Acute Myocardial Infarction on an Inner City Teaching Hospital

i p The universal definition of myocardial infarction provides criteria for the diagnosis and classification of the type of acute myocardial infarction (AMI) and recommends the measurement of cardiac troponin (cTn) for the detection of myocardial necrosis. Despite this, many institutions still use creatinine kinase-MB as part of the standard laboratory evaluation for AMI. The aim of this study was to ascertain the cost benefit of using only cTn for the diagnosis of acute coronary syndromes. A survey was done of Kansas City hospitals and the University HealthSystem Consortium list server for comparison of whether other institutions use 1 or both biomarkers. Locally, most of the responding hospitals in Kansas City and 57% of responding university hospitals surveyed use the 2 biomarkers for the diagnosis of AMI. After initiating medical staff education, the investigators’ institution’s standard order sets were changed to use only cTnI for the assessment of AMI. The cost savings by eliminating creatine kinase-MB on the order sets was based on the annual volume of processed specimens. The cost of supplies, equipment, and materials was determined on a per test basis. After initiation of the new standard order sets, the creatine kinase-MB testing rate decreased to 50 per month, from 1,098, for an annualized savings of $86,786. In conclusion, as the health care system is challenged to improve care while containing cost, the use of a single biomarker (cTn) in the diagnosis of AMI fulfills this promise without sacrificing patient care. The diagnostic value of cardiac troponin (cTn) measurement is well established. However, less well appreciated is the potential economic benefit from using a single marker instead of a panel of biomarkers that traditionally have included creatine kinase-MB (CK-MB). Expert consensus underscores using cTn determinations only for better clinical care and a reduction in cost. The elimination of muliple biomarkers, including CK-MB, in the diagnosis of cute coronary syndromes (ACS) relies on evidence-based edicine consistent with the universal definition of acute yocardial infarction (AMI). We report our experience in ost savings after developing standard order sets with cTnI s the only marker on chest pain, ACS, and post–percutaeous coronary intervention orders. Our hypothesis was that significant cost savings would be realized without comromising patient care.

Assessment of acute myocardial infarction: current status and recommendations from the North American society for cardiovascular imaging and the European society of cardiac radiology

There are a number of imaging tests that are used in the setting of acute myocardial infarction and acute coronary syndrome. Each has their strengths and limitations. Experts from the European Society of Cardiac Radiology and the North American Society for Cardiovascular Imaging together with other prominent imagers reviewed the literature. It is clear that there is a definite role for imaging in these patients. While comparative accuracy, convenience and cost have largely guided test decisions in the past, the introduction of newer tests is being held to a higher standard which compares patient outcomes. Multicenter randomized comparative effectiveness trials with outcome measures are required.

Superparamagnetic microsphere-assisted fluoroimmunoassay for rapid assessment of acute myocardial infarction

Rapid assessment of acute myocardial infarction (AMI) was successfully demonstrated using an improved superparamagnetic polymer microsphere-assisted sandwich fluoroimmunoassay to detect two early cardiac markers—myoglobin and human heart-type fatty acid binding protein (H-FABP). This assay used a preparation of superparamagnetic poly(styrene-divinylbenzene-acrylamide) microspheres, glutaraldehyde-coupled capture antibodies (monoclonal anti-myoglobin 7C3 and anti-H-FABP 10E1) grafted onto the polymer microspheres, and a sequential sandwich fluoroimmunoassay using detection antibodies (FITC-labeled anti-myoglobin 4E2 and FITC-labeled anti-H-FABP 9F3). Characterization of the polymer microspheres by TEM, SEM and Fourier transform infrared spectroscopy (FT-IR) showed that the microspheres were uniformly round with an average diameter of 1.12 μm, and had a Fe 3O 4-polymer core–shell structure (shell thickness was about 84 nm) with 0.22 mmol/g amino groups on their surfaces. The magnetic behavior of the Fe 3O 4-polymer microspheres was superparamagnetic ( M s = 13 emu/g, H c = 13.1 Oe). Fluorescence images of the post-immunoassay microspheres recorded using a confocal laser-scanning microscope showed that the average fluorescence intensity was correlated with the concentration of cardiac markers, in agreement with the results obtained by an F-4500 FL spectrophotometer; this indicated that the fluoroimmunoassay could be used to semi-quantitatively detect both myoglobin and H-FABP. The detection limit was 25 ng/mL for myoglobin and 1 ng/mL for H-FABP.

On-chip detection of myoglobin based on fluorescence

A disposable immunosensor cartridge was developed that allows antibodies to be immobilized on the surface for the detection of myoglobin, a marker for the early assessment of acute myocardial infarction (AMI) using fluorescence techniques. The anti-myoglobin antibody was immobilized on a polystyrene substrate based on covalent bonding via silanization. The immunosensor chip layers were fabricated from sheets by CO 2-laser ablation. The functionalized polystyrene surfaces were characterized by contact angle measurement, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). After the antigen–antibody reaction as a sandwich enzyme-linked immunosorbent assay (ELISA) with a horseradish peroxidase-conjugated secondary antibody (HRP-anti-myoglobin), addition of fluorogenic substrate produced a fluorescent dye which was quantified on-chip using fluorescent technique. The immunosensor response was linear for myoglobin concentrations between 20 and 230 ng/ml ( r = 0.991, n = 3). The detection limit was found to be 16 ng/ml, which is lower than the clinical cut-off value for myoglobin in healthy patients. This protocol could be extended to the detection of other important cardiac markers simultaneously in microchannels.

Assessment of Acute Myocardial Infarction Using MDCT After Percutaneous Coronary Intervention: Comparison with MRI

Imaging to determine myocardial infarct size is difficult in the emergency setting because the current gold standards, MRI and nuclear medicine techniques, are difficult to perform in unstable patients. Delayed enhanced MDCT has recently been proposed as a technique to study contrast uptake in infarcted myocardium. In this study, we compared the extent of acute myocardial infarction as measured by delayed enhanced MDCT performed immediately after percutaneous coronary intervention (PCI) without an additional iodine injection with that measured by delayed gadolinium-enhanced MRI. Nineteen consecutive patients presenting with primary acute myocardial infarction underwent delayed enhanced MDCT immediately after coronary angioplasty and underwent delayed enhanced MRI within 8 days of angioplasty. Only patients with a thrombolysis in myocardial infarction (TIMI) score of 0 or 1 of the culprit coronary artery before endovascular angioplasty and TIMI score of 2 or 3 after angioplasty were selected. Comparison of delayed enhanced MDCT and delayed enhanced MRI was performed by three observers and focused on identifying the involved segments and determining the transmural extent of enhancement and infarct size. The mean signal intensity was significantly higher in the involved territory than in healthy myocardium: 197 +/- 81 H versus 71 +/- 20 H, respectively (p < 0.0001). We found significant agreement between delayed enhanced MDCT and delayed enhanced MRI for the number of involved segments, transmural extent of enhancement, and infarct size (r(2) = 0.74, 0.76, and 0.67, respectively; p < 0.0001) with good interobserver reproducibility (kappa = 0.8). The results of our study show that delayed enhanced MDCT allows accurate visualization of early myocardial contrast uptake compared with delayed enhanced MRI and does not require an additional contrast injection after PCI.

Assessment of Myocardial Viability in Reperfused Acute Myocardial Infarction Using 16-Slice Computed Tomography in Comparison to Magnetic Resonance Imaging

The aim of this study was to examine if contrast-enhanced multislice spiral computed tomography (MSCT) is comparable to contrast-enhanced magnetic resonance imaging (MRI) for depiction of acute myocardial infarction (MI). Delayed-enhancement MRI of MI is well established, but there are no clinical reports about MSCT for this indication. Early perfusion deficit on MSCT has been reported to correlate with the presence of MI. A total of 28 consecutive patients (23 men; 55.9 +/- 11.4 years) with reperfused MI underwent contrast-enhanced cardiac 16-slice MSCT. Images were acquired in the arterial phase and the late phase 15 min after administration of 120 ml contrast material. Within 5 days, patients underwent MRI after administration of 0.2 mmol Gd-dimeglumine/kg/bodyweight. All examinations were completed within two weeks after MI. The area of MI was compared between the different imaging techniques using Bland-Altman method and multivariate analysis. Agreement of the contrast enhancement patterns was evaluated with a weighted kappa test. Mean infarct size on MRI was 31.2 +/- 22.5% per slice compared with 33.3 +/- 23.8% per slice for late-enhancement MSCT and 24.5 +/- 18.3% per slice for early-perfusion-deficit MSCT. Bland-Altman data showed a good agreement between late-enhancement MRI and late-enhancement MSCT. Contrast enhancement patterns demonstrated an excellent agreement between late-enhancement MRI and late-enhancement MSCT (kappa = 0.878). The results were worse comparing MRI and early-phase MSCT (kappa = 0.635). Multislice spiral computed tomography allows for the assessment of acute MI. Late-enhancement MSCT appears to be as reliable as delayed contrast-enhanced MRI in assessing infarct size and myocardial viability in acute MI.

Echocardiography for risk stratification of myocardial infarction in the reperfusion era

The prediction of functional recovery or ventricular remodeling plays a central role in the prognostic assessment of acute myocardial infarction (MI) in the reperfusion era. This article reviews the advances of echocardiographic techniques, focusing on the role of low-dose dobutamine stress echocardiography, contrast echocardiography, transthoracic Doppler of the left anterior descending coronary artery, and transmitral Doppler in detecting myocardial viability and predicting outcome after an acute MI. Moreover, the definition of risk for further ischemic events is another major objective in conservatively managed patients post infarction. As such, the prognostic and economic implication of stress echocardiography compared with that of traditional exercise electrocardiography was considered.