Assessment of cardiac parameters after the administration of nicorandil before primary percutaneous coronary intervention.

Objective: To assess cardiac troponin I and creatine kinase-myocardial band levels, electrocardiogram changes and major adverse cardiac events after treatment with nicorandil before primary percutaneous coronary intervention. METHODS: The comparative, analytical study was conducted from October to November 2022 at the Pharmacology Department of Army Medical College, National University of Medical Sciences, Rawalpindi, Pakistan, in collaboration with the Rawalpindi Institute of Cardiology, Rawalpindi. The sample comprised ST-elevated myocardial infarction patients of either gender aged at least 30 years with an ejection fraction of at least 35% undergoing primary percutaneous coronary intervention. Participants were selected based on the above-mentioned inclusion and informed consent was taken before their enrolment in this research study. The sample was randomised into control group A receiving conventional acute coronary syndrome treatment, and intervention group B receiving nicorandil in addition to the conventional treatment. Cardiac troponin I and creatine kinase-myocardial band levels, electrocardiogram changes, and major adverse cardiac events noted and compared. Data was analysed using SPSS 26. RESULTS: Of the 140 patients, 70(50%) were in each of the 2 groups. In group B, 60(85.7%) patients achieved a completely settled ST segment on electrocardiogram compared to 25(35.7%) in group A (p=0.001). There was a significant inter-group difference with respect to cardiac troponin I value 6 hours after percutaneous coronary intervention and major adverse cardiac events (p<0.05), but creatine kinase-myocardial band level was no significantly different between the groups (p=0.761). Conclusion: Prophylactic use of nicorandil in ST-elevated myocardial infarction patients decreased the incidence of reperfusion injury.

A capillary-based microfluidic chip with the merits of low cost and easy fabrication for the rapid detection of acute myocardial infarction.

Point-of-care testing methods currently utilize rapid, portable, inexpensive, and multiplexed on-site detection. Microfluidic chips have become a very promising platform with broad development prospects due to their breakthrough improvement in miniaturization and integration. However, the conventional microfluidic chips still have disadvantages, such as difficulty in fabrication processing, long production time and high cost, which hinder its applications in the fields of POCT and in vitro diagnostics. In this study, a capillary-based microfluidic chip with the characteristics of low cost and easy fabrication was developed for the rapid detection of acute myocardial infarction (AMI). Several short capillaries, which were already conjugated with the capture antibodies respectively, were connected by peristaltic pump tubes and then formed the working capillary. Two working capillaries were encapsulated in the plastic shell and ready for the immunoassay. Multiplex detection of Myoglobin (Myo), cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) were chosen to demonstrate the feasibility and analytical performance of the microfluidic chip, which requires rapid and accurate detection during diagnosis and therapy for AMI. The capillary-based microfluidic chip required tens of minutes to prepared, and its cost was less than $1. The limit of detection (LOD) was 0.5 ng/mL for Myo, 0.1 ng/mL for cTnI and 0.5 ng/mL for CK-MB respectively. The capillary-based microfluidic chips with easy fabrication and low cost hold promise for the portable and low-cost detection of target biomarkers.

Analysis of the Application Value of Echocardiography Combined with CK-MB, Alb, and CysC in the Prognosis Assessment of Patients with Chronic HF.

In order to evaluate the diagnostic and prognostic value of echocardiography combined with serum creatine kinase-MB (CK-MB), albumin (Alb), and cystatin C (CysC) in patients with chronic heart failure (HF), 93 patients diagnosed with chronic HF in our hospital from March 2019 to January 2020 are retrospectively analyzed and included in the HF group. Another 100 healthy subjects who come to our hospital for general physical examination are selected as the control group. Echocardiography is used to detect the cardiac parameters of each group. The experimental results show that echocardiography parameters combined with CK-MB, Alb, and CysC have high application value in diagnosis and evaluation of patients with chronic HF, which can provide theoretical basis for improving the prognosis of patients with chronic HF through real-time monitoring of the above indicators.

[COMPARISON OF LEVELS OF MYOCARDIAL INJURY MARKERS AND THE STATE OF THE OXYGEN BUDGET IN PATIENTS WITH MITRAL INSUFFICIENCY DURING SURGICAL CORRECTION, DEPENDING ON THE METHOD OF CARDIOPROTECTION].

The aim of our study was to compare the levels of myocardial damage markers and the state of the oxygen budget in patients with mitral valve insufficiency during its surgical correction, depending on the method of cardioprotection. We examined 85 patients with mitral valve insufficiency who underwent mitral valve replacement (MVR) surgery and anesthetic management according to the traditional method, the difference was only in the method of cardioprotection. In the I group (n=40) crystalloid cardioplegia (Bernsteinder's solution) was used, in the II group (n=45) - electrical fibrillation of the heart and intermittent clamping of the aorta. The level of markers of myocardial damage (MMD), indicators of the oxygen budget, and lactate were recorded in the patients. The method of cardioprotection of the heart did not affect the state of the myocardium, although such an indicator as the ratio of CPK MB/CPK was still lower in II group. In addition, in patients of this group, the state of the myocardium had a lesser effect on hemodynamic parameters. The oxygen budget was most influenced by the need for hemodilution, but indicators such as ΔSO2, ΔpO2, ΔCO2, EO2 and lactate levels indicate a more adequate supply of oxygen to tissues against the background of myocardial protection using electrical fibrillation of the heart and intermittent clamping of the aorta. Both methods of cardioprotection approximately equally affect the circulatory system, however, cardioprotection using electrical fibrillation of the heart and intermittent clamping of the aorta is more preferable.

Routine Postoperative Cardiac Testing is Unnecessary after Carotid Endarterectomy.

BACKGROUND: Routine laboratory testing to rule out myocardial infarction (MI) after carotid endarterectomy (CEA) is common in many centers. Its use in this patient population has not been thoroughly investigated. We hypothesize that routine testing for MI in post-CEA patients is of low yield and not cost-effective. METHODS: A retrospective review of 291 consecutive CEAs from February 2011 to July 2015 was performed. Two patients were excluded: one for postoperative noncardiac death and one for preoperative MI. Patient demographics, medications, medical history, type of anesthesia, and postoperative laboratory results were reviewed. All patients had troponin-I and creatine kinase-MB levels taken postoperatively. A patient was judged to have an MI if troponin-I was greater than or equal to 0.6 ng/mL or CK-MB is >6.3 ng/mL. The incidence of postoperative MI was recorded, and a cost analysis was performed. RESULTS: The mean age was 70.2 years (range: 42-92). Of all, 59.5% were male, and 92.4% had a history of hypertension. Preoperatively, 57.4% were on beta-blocker therapy, 86.5% on aspirin, and 52.2% on both. Most (80.6%) were on preoperative statin therapy, 26.9% had a prior history of MI (37.2% within 5 years of surgery), and 56.4% of patients had a prior coronary intervention (27.6% percutaneous, 28.7% coronary artery bypass grafting, and 11% both). All patients received general anesthesia. The mean procedure time was 121.5 min (range: 62-258). The mean postoperative length of stay was 2.6 days. Eight patients (2.7%) were judged to have acute MI, one of which was symptomatic. Three of the 8 (38%) had a prior history of MI. In asymptomatic patients, the peak level of troponin-I ranges from 0.52 to 3.64 ng/mL and that of CK-MB from 11.8 to 24 ng/mL. The symptomatic patient had chest pain and bradycardia. The patient had a peak troponin-I level of 1.59 ng/mL, with a CK-MB level of 11.5 ng/mL. All patients were treated medically. The cost per troponin-I and CK-MB is $27.78 and $31.44, respectively, in our institution. We estimate that eliminating routine postoperative troponin-I and CK-MB testing in patients who underwent CEA would have saved an estimated $51,343 over the course of treatment of the studied population. CONCLUSIONS: Routine postoperative cardiac laboratory testing in asymptomatic patients after CEA increases the hospital cost. The low overall rate of postoperative MI suggests that cardiac testing is best reserved for symptomatic patients or those with clinical suspicion for MI.

Revisiting myocardial necrosis biomarkers: assessment of the effect of conditioning therapies on infarct size by kinetic modelling.

Infarct size is a major predictor of subsequent cardiovascular events following ST-segment elevation myocardial infarction (STEMI) and is frequently used in clinical trials focused on cardioprotection. Approximately assessed through serial blood sampling, it can be accurately measured by imaging techniques, e.g. cardiac magnetic resonance imaging, which is the actual gold standard for infarct size determination but with limited availability in daily practice. We developed a mathematical biomarker kinetic model based on pharmacokinetic compartment models to easily and accurately estimate infarct size using individual data from five clinical trials evaluating the impact of conditioning therapies in STEMI between 2005 and 2013. Serial blood sampling was available in all studies with data regarding creatine kinase (CK), CK specific of cardiomyocytes (CK-MB) and cardiac troponin I. Our model allowed an accurate estimation of biomarker release as a surrogate marker of infarct size and a powerful assessment of conditioning treatments. This biomarker kinetic modelling approach identified CK-MB as the most accurate biomarker in determining infarct size and supports the development of limited sampling strategies that estimate total biomarker amount released with a lower number of samples. It will certainly be a useful add-on to future studies in the field of STEMI and cardioprotection.

Characterization of a functional recombinant human creatine kinase-MB isoenzyme prepared by tandem affinity purification from Escherichia coli.

Creatine kinase isoform CK-MB has been widely applied as a biomarker of myocardial injury. While a variety of methods have been used to measure CK-MB activity or mass in clinical laboratories, a CK-MB standard is needed to eliminate between-method bias. Because the in vitro expression of human creatine kinase generates three isoenzymes, CK-MM, CK-MB, and CK-BB, it is important to establish an effective method to purify the isoform CK-MB from the mixture. In this study, we aimed at using tandem affinity purification (TAP) to purify recombinant CK-MB protein and evaluate its value in clinical laboratories. After the optimized sequence coding CK-M and CK-B were synthesized, they were combined with TAP tags (6His and SBP) and inserted into a pRSFDuet vector; then, the constructed 6His-CK-M-SBP-CK-B-pRSF plasmid was transformed into Escherichia coli BL21 (DE3) for expression. After TAP, we obtained purified CK-MB protein. We also did recovery testing using the engineered CK-MB and standard CK-MB (Randox) at different concentrations, and the results suggested that the engineered CK-MB could be used as the reference material. Moreover, the stability study of recombinant CK-MB showed high stability during long-term storage at -80 °C. In conclusion, the TAP-purified recombinant CK-MB protein may be a much better and cheaper standard or reference material for clinical laboratories.

Plaque Characterization to Inform the Prediction and Prevention of Periprocedural Myocardial Infarction During Percutaneous Coronary Intervention: The CANARY Trial (Coronary Assessment by Near-infrared of Atherosclerotic Rupture-prone Yellow).

OBJECTIVES: This study sought to determine whether pre-percutaneous coronary intervention (PCI) plaque characterization using near-infrared spectroscopy identifies lipid-rich plaques at risk of periprocedural myonecrosis and whether these events may be prevented by the use of a distal protection filter during PCI. BACKGROUND: Lipid-rich plaques may be prone to distal embolization and periprocedural myocardial infarction (MI) in patients undergoing PCI. METHODS: Patients undergoing stent implantation of a single native coronary lesion were enrolled in a multicenter, prospective trial. Near-infrared spectroscopy and intravascular ultrasound were performed at baseline, and lesions with a maximal lipid core burden index over any 4-mm length (maxLCBI4mm) ≥600 were randomized to PCI with versus without a distal protection filter. The primary endpoint was periprocedural MI, defined as troponin or a creatine kinase-myocardial band increase to 3 or more times the upper limit of normal. RESULTS: Eighty-five patients were enrolled at 9 U.S. sites. The median (interquartile range) maxLCBI4mm was 448.4 (274.8 to 654.4) pre-PCI and decreased to 156.0 (75.6 to 312.6) post-PCI (p < 0.0001). Periprocedural MI developed in 21 patients (24.7%). The maxLCBI4mm was higher in patients with versus without MI (481.5 [425.6 to 679.6] vs. 371.5 [228.9 to 611.6], p = 0.05). Among 31 randomized lesions with maxLCBI4mm ≥600, there was no difference in the rates of periprocedural MI with versus without the use of a distal protection filter (35.7% vs. 23.5%, respectively; relative risk: 1.52; 95% confidence interval: 0.50 to 4.60, p = 0.69). CONCLUSIONS: Plaque characterization by near-infrared spectroscopy identifies lipid-rich lesions with an increased likelihood of periprocedural MI after stent implantation, presumably due to distal embolization. However, in this pilot randomized trial, the use of a distal protection filter did not prevent myonecrosis after PCI of lipid-rich plaques.

[Evaluation of postoperative myocardial injury by heart-type fatty acid-binding protein in off-pump coronary artery bypass grafting surgery]. / Valoración del daño miocárdico mediante la medición de la heart-fatty acid-binding protein en cirugía de revascularización coronaria sin circulación extracorpórea. Estudio preliminar.

BACKGROUND AND GOAL OF STUDY: Postoperative myocardial infarction is a serious and frequent complication of cardiac surgery. Nonetheless, diagnosis in this context it is occasionally challenging. We sought to evaluate the kinetics and diagnostic accuracy of the new biomarker « heart-type fatty acid-binding protein ¼ (h-FABP) in the early detection of myocardial injury in patients undergoing off-pump coronary artery bypass grafting, compared with classical biomarkers. MATERIALS AND METHODS: A prospective study was conducted on 17 consecutive patients who underwent off-pump coronary artery bypass grafting during a 2 month period. Blood samples were drawn for measurement of myocardial ischemic injury biomarkers (h-FABP, troponin, creatine kinase [CK] and CK-MB), at baseline (T1), immediate post-coronary artery bypass grafting (T2), on ICU admission (T3), and after 4 (T4), 8 (T5), 24 (T6) and 48 h (T7). Perioperative ischemic complications, defined according to electrocardiographic, echocardiographic and hemodynamic criteria, were recorded. RESULTS: Earlier biomarkers peak plasma values occurred at T4 with troponin (2.9 ± 5.2 ng/mL), and at T5 with h-FABP (37.9 ± 55.5 ng/mL). Maximum values of CK and CK-MB occurred later, both in T6 (741 ± 779 and 37 ± 51 U/L, respectively). The optimized cut-off obtained for h-FABP was 19 ng/mL, providing a sensitivity and specificity of 77 and 75%, respectively, for diagnosis of perioperative ischemic injury, with an area under the ROC curve for h-FABP of 0.83 (95% CI 0.6-1.0) vs. 0.63 (95% CI 0.33-0.83) for troponin. This cut-off value for h-FABP is reached on average at T2 (mean value of h-FABP at T2: 18.9 ± 21.5 ng/mL). CONCLUSION: This is the first study evaluating the kinetics of h-FABP biomarker in perioperative off-pump coronary artery bypass grafting, and the cut-off value established could help to extend earlier detection of myocardial ischemia in this context.

Clinical and financial impact of removing creatine kinase-MB from the routine testing menu in the emergency setting.

CONTEXT: Cardiac troponins T and I have replaced creatine kinase-MB (CK-MB) as the criterion standard for diagnosing myocardial injury. However, many laboratories still routinely perform a high volume of CK-MB testing in conjunction with troponin. PURPOSE: The purpose of this study is to study the clinical and financial impact of removing CK-MB from the routine emergency department (ED) test menu at a large academic medical center. METHODS: Creatine kinase-MB was removed from ED ordering templates and laboratory requisitions (ie, intervention), although the test could still be manually ordered. Data for creatine kinase (CK), CK-MB, and troponin T (TnT) specimens ordered during a 12-month period (6 months preintervention and 6 months postintervention) (n = 14571) was downloaded from our laboratory information system. All specimens with (1) normal TnT (ie, <0.01 ng/mL), (2) elevated CK-MB (ie, >6.6 ng/mL), and (3) elevated CK-MB index (ie, >5) were considered discrepant and independently reviewed by 2 ED clinicians for the presence of an acute coronary syndrome and for documentation of final diagnosis. Creatine kinase, CK-MB, and TnT ED volumes preintervention and postintervention were analyzed to assess laboratory cost savings. RESULTS: Of the 6444 cases included in the analysis, only 17 were discrepant. Of all 17 cases, no patients were diagnosed with acute coronary syndrome. After removing CK-MB from the templates and requisitions, CK-MB and CK volumes decreased by 80% and 76%, respectively, translating to annual reagent cost savings of approximately $47000. CONCLUSIONS: Creatine kinase-MB can be removed from the routine ED test menu without adversely affecting patient care. In addition, substantial cost savings can be achieved by reducing unnecessary CK-MB testing and associated CK orders.

Cardiac biomarker measurement after elective percutaneous coronary interventions in older patients: insights from the National Cardiovascular Data Registry.

BACKGROUND: Guidelines recommend consideration of cardiac biomarker measurement after elective percutaneous coronary intervention (PCI), especially with complex cases or complicated procedures. However, the long-term prognostic implications of biomarker measurement after elective PCI have not been well characterized in older patients. METHODS: We examined 157,825 Medicare patients undergoing elective PCI in the United States from 2004 to 2008 at 711 hospitals in the CathPCI Registry. Clinical characteristics and 1-year mortality risk were studied, stratified by creatine kinase-muscle band measurement. RESULTS: Overall, 26% of patients on elective PCI had postprocedure biomarkers measured. These patients had more complex coronary anatomy and procedures but had similar rates of PCI success and inhospital mortality when compared with patients without biomarker measurement. The treating hospital was a significant factor associated with the likelihood of postprocedure biomarker surveillance. Hospitals that measured creatine kinase-muscle band in ≥ 90% of patients on elective PCI had lower associated 1-year mortality rates (adjusted hazard ratio 0.84, 95% CI 0.75-0.94) compared with hospitals that measured in < 10% of patients. CONCLUSIONS: Among older patients undergoing elective PCI, postprocedure cardiac biomarker measurement occurred infrequently and was concentrated at certain hospitals. Hospitals that routinely measured post-PCI biomarkers were associated with lower long-term mortality compared with hospitals without routine measurement.

Coronary microemboli effects in preexisting acute infarcts in a swine model: cardiac MR imaging indices, injury biomarkers, and histopathologic assessment.

PURPOSE: To use cardiac magnetic resonance (MR) imaging indices, injury biomarkers, and microscopy for quantifying the effects of defined microemboli volume and sizes on viability, left ventricular (LV) function, and perfusion in preexisting acute myocardial infarcts in a swine model. MATERIALS AND METHODS: Institutional approval was obtained to perform x-ray fluoroscopy and 90-minute left anterior descending coronary artery occlusion-reperfusion (single ischemic insult) in 16 pigs and coronary embolization in eight of the 16 pigs (32 mm(3), 40-120 µm microemboli) (double ischemic insults). Another eight pigs served as controls. Cardiac MR imaging results (viability, function, and perfusion), injury biomarkers (creatine-kinase-MB and troponin I), and histopathologic evaluations were quantified. Analysis of variance was performed, and a P value less than .02 was considered to indicate a significant difference. RESULTS: Delayed contrast material-enhanced MR imaging allowed simultaneous visualization of hyperenhanced large infarcts, hypoenhanced microvascular obstruction (MVO) zones, and moderately enhanced patchy microinfarcts in border zones, which represent different degrees of contraction and perfusion in the respective regions, in pigs subjected to double ischemic insults. The increase in myocardial damage was smaller in pigs with double insults (15.7% ± 1.1% of total LV mass) than in those with a single insult (12.4% ± 1.2%, P < .02), but the reduction in LV ejection fraction was disproportional (32% ± 0.6% and 38% ± 1%, P < .02, respectively). Delayed contrast-enhanced imaging can allow quantification of the MVO zone but can result in underestimation of the extent of myocardial damage compared with microscopy in animals subjected to double insults (18.2 ± 1.6, P < .02). A significant increase in cardiac injury biomarkers was observed at 18-24 hours in both cohorts. The additional effect of microemboli on troponin I was demonstrated at 68-72 hours (3.2 ng/mL ± 0.85 [3.20 µg/L ± 0.85] vs 1.34 ng/mL ± 0.43 [1.34 µg/L ± 0.43], P < .02). CONCLUSION: MR imaging has the potential to allow visualization of acute myocardial infarcts, MVO zones, and patchy microinfarcts simultaneously. The accentuated LV dysfunction caused by double ischemic insults was linked to expansion of the MVO zone, perfusion deficits, and myocardial damage.

Randomised Assessment of Treatment using Panel Assay of Cardiac markers--Contemporary Biomarker Evaluation (RATPAC CBE).

OBJECTIVES: To test the diagnostic accuracy for detecting an acute myocardial infarction (AMI) using highly sensitive troponin assays and a range of new cardiac biomarkers of plaque destabilisation, myocardial ischaemia and necrosis; to test the prognostic accuracy for detecting adverse cardiac events using highly sensitive troponin assays and this range of new cardiac biomarkers; and to estimate the cost-effectiveness of using highly sensitive troponin assays or this range of new cardiac biomarkers instead of an admission and 10- to 12-hour troponin measurement. DESIGN: Substudy of the point-of-care arm of the RATPAC (Randomised Assessment of Treatment using Panel Assay of Cardiac markers) trial. SETTING: The emergency departments of six hospitals. PARTICIPANTS: Prospective admissions with chest pain and a non-diagnostic electrocardiogram randomised to point-of-care assessment or conventional management. INTERVENTIONS: Blood samples taken on admission and 90 minutes from admission for measurement of cardiac markers [cardiac troponin I (cTnI), myoglobin and creatine kinase MB isoenzyme (CK-MB)] by point-of-care testing. An additional blood sample was taken at admission and 90 minutes from admission for analysis of high-sensitivity cTnI (two methods) and cardiac troponin T (cTnT), myoglobin, heart-type fatty acid-binding protein (H-FABP), copeptin and B-type natriuretic peptide (NTproBNP). MAIN OUTCOME MEASURES: 1. Diagnostic accuracy compared with the universal definition of myocardial infarction utilising laboratory measurements of cardiac troponin performed at the participating sites together with measurements performed in a core laboratory. 2. Ability of biomarker measurements to predict major adverse cardiac events (death, non-fatal AMI, emergency revascularisation or hospitalisation for myocardial ischaemia) at 3 months' follow-up. 3. Comparison of incremental cost per quality-adjusted life-year (QALY) of different biomarker measurement strategies for the diagnosis of myocardial infarction. RESULTS: Samples were available from 850 out of 1132 patients enrolled in the study. Measurement of admission myoglobin [area under the curve (AUC) 0.76] and CK-MB (AUC 0.84) was diagnostically inferior and did not add to the diagnostic efficiency of cTnI (AUC 0.90-0.94) or cTnT (AUC 0.92) measurement on admission. Simultaneous measurement of H-FABP and cTnT or cTnI did improve admission diagnostic sensitivity to 0.78-0.92, but only to the same level as that achieved with troponin measured on admission and at 90 minutes from admission (0.78-0.95). Copeptin (AUC 0.62) and NTproBNP (AUC 0.85) measured on admission were not useful as diagnostic markers. As a prognostic marker, troponin measured on admission using a high-sensitivity assay (AUC 0.73-0.83) was equivalent to NTproBNP measurement (AUC 0.77) on admission, but superior to copeptin measurement (AUC 0.58). From modelling, 10-hour troponin measurement is likely to be cost-effective compared with rapid rule-out strategies only if a £30,000 per QALY threshold is used and patients can be discharged as soon as a negative result is available. CONCLUSIONS: The measurement of high-sensitivity cardiac troponin is the best single marker in patients presenting with chest pain. Additional measurements of myoglobin or CK-MB are not clinically effective or cost-effective. The optimal timing for measurement of cardiac troponin remains to be defined. Copeptin measurement is not recommended. H-FABP requires further investigation before it can be recommended for simultaneous measurement with high-sensitivity troponin in patients with acute chest pain. TRIAL REGISTRATION: ISRCTN37823923. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 15. See the HTA programme website for further project information.

Comparison of early biomarker strategies with the Heart Foundation of Australia/Cardiac Society of Australia and New Zealand guidelines for risk stratification of emergency department patients with chest pain.

OBJECTIVES: To compare cardiac risk stratification using a 0 and 2 h point-of-care (POC) cardiac troponin (cTn), 0 and 2 h POC multi-biomarkers against the 0 and 6 h laboratory cTn reference standard. METHODS: A prospective observational study of ED patients presenting with chest pain was performed. Patients were risk stratified and treated as per the Heart Foundation of Australia/Cardiac Society of Australia and New Zealand (HF-A/CS-ANZ) guidelines using the 0 and 6 h laboratory cTn (T6). Patients were further stratified using a 0 and 2 h POC cTn (T2) plus 0 and 2 h POC multi-biomarkers (cTn, creatine kinase-MB, myoglobin) (M2). The T6, T2 and M2 strategies were compared using the 30-day major adverse cardiac events as the primary outcome. RESULTS: Seven hundred and four patients (median age 54 years, male 62.1%) were enrolled. Using the T6 reference standard, 2%, 61% and 37% were stratified as low, intermediate and high risk, respectively. The 30-day event rates were 0%, 3.5% and 28.6%, respectively. The T2 strategy stratified 1.5%, 57% and 41% as low, intermediate and high risk, respectively, with 30-day event rates of 0%, 4.2% and 24.8%, respectively. The M2 strategy resulted in significantly different risk distribution with 1%, 40% and 59% stratified as low, intermediate and high risk, respectively, with 30-day event rates of 0%, 3.9% and 18.8%, respectively. CONCLUSION: Using a 2 h POC cTn-only biomarker strategy with the HF-A/CS-ANZ guidelines accurately identified a population at intermediate risk of 30-day events in whom further objective testing might be accelerated, allowing subsequent early discharge of the majority of this cohort. Within 2 h of presentation a high risk population could be identified in whom early management, including admission, was required.

Assessment of the ST segment deviation area as a potential physiological marker of the acute myocardial infarction.

The purpose of this article is to present the assessment of the ST segment deviation area as a feature estimated from electrocardiographic signals to improve the current quantitative measures, which have low correlation with standard measures, such as biomarkers. In total 20 subjects were involved in the study. They were classified into two distinct groups (anterior and inferior) related to the localization of the acute myocardial infarction (AMI). The area of the ST segment was calculated by using customized software developed in Matlab®. From the analysis of this parameter it may be possible to correlate the ST deviation area with the necrosis risk area on myocardial tissue. The correlation between the ST area estimates were compared with Aldrich score, which uses the height of the J point instead of the area. It was calculated the correlation between the ST area, the Aldrich score and biomarkers of myocardial injury in patients. A Spearman correlation coefficient of 0.58 was estimated when comparing Aldrich score and the biomarkers for inferior AMI. The coefficient was 0.99 when correlating the biomarkers to the ST area. Therefore, this feature is a potential physiological marker of inferior AMI. The possibility of estimating the necrosis extent by means of electrocardiographic analysis allows for the reduction of cost and time since there may be no requirement for additional laboratorial exams, consequently improving the treatment efficacy and the prognosis of patients affected by acute myocardial infarction.

Interhospital variation in the RATPAC trial (Randomised Assessment of Treatment using Panel Assay of Cardiac markers).

BACKGROUND: The RATPAC trial showed that using a point-of-care panel of CK-MB(mass), myoglobin and troponin at baseline and 90 min increased the proportion of patients successfully discharged home, leading to reduced median length of initial hospital stay. However, it did not change mean hospital stay and may have increased mean costs per patient. The aim of this study was to explore variation in outcome and costs between participating hospitals. METHODS: RATPAC was a pragmatic multicentre randomised controlled trial (N=2243) and economic analysis comparing diagnostic assessment using the panel to standard care for patients with acute chest pain due to suspected myocardial infarction at six hospitals. The difference in the proportion of patients successfully discharged (primary outcome) and mean costs per patient between the participating hospitals was compared. RESULTS: Point-of-care assessment led to a higher proportion of successful discharges in four hospitals, a lower proportion in one and was equivocal in another. The OR (95% CI) for the primary outcome varied from 0.12 (0.01 to 1.03) to 11.07 (6.23 to 19.66) with significant heterogeneity between the centres (p<0.001). The mean cost per patient for the intervention group ranged from being £214.49 less than the control group (-132.56 to 657.10) to £646.57 more expensive (73.12 to 1612.71), with weak evidence of heterogeneity between the centres (p=0.0803). CONCLUSION: The effect of point-of-care panel assessment on successful discharge and costs per patient varied markedly between hospitals and may depend on local protocols, staff practices and available facilities.

Detection of multiple cardiac markers with an integrated acoustic platform for cardiovascular risk assessment.

This work describes the application of a newly emerged biosensing configuration incorporating a Surface Acoustic Wave device integrated with a multi-channel microfluidic module for the rapid and efficient analysis of cardiac markers. The examined cardiac markers of creatine kinase MB (CK-MB), cardiac reactive protein (CRP), D-dimer and pregnancy-associated plasma protein A (PAPP-A), comprise a group of both established and emerging heart disease proteins, that has never been probed before with any kind of biochip-related platform. The four markers were successfully detected; kinetics and affinity studies on their interactions with the surface immobilized antibodies are also presented. A concentration detection limit of less than 1 nM was achieved, with a dynamic range of more than two orders of magnitude, covering some of the pathological and healthy areas of interest. Mixtures of biomarkers applied to the device surface were used to prove the specificity of each binding event and investigate the microsystem's performance in the presence of complex fluids, towards future utilization with real samples. The simplicity and multiplexing ability of the integrated platform render the system ideal as a potential diagnostic tool for cardiovascular risk assessment, where simultaneous analysis of various protein markers is required.

Assessment of echo-attenuated plaque by optical coherence tomography and its impact on post-procedural creatine kinase-myocardial band elevation in elective stent implantation.

OBJECTIVES: This study examined morphological characteristics of echo-attenuated plaques by optical coherence tomography (OCT) and evaluated their influence on creatine kinase-myocardial band (CK-MB) elevation after percutaneous coronary intervention (PCI) in patients with elective stent implantation. BACKGROUND: Recent intravascular ultrasound studies have described atherosclerotic plaques with echo attenuation (EA) without associated bright echoes that are correlated with no-reflow phenomenon after PCI. METHODS: We studied 135 native de novo culprit coronary lesions in 135 patients with normal pre-PCI CK-MB levels (28 with unstable angina; 107 with stable angina) who underwent intravascular ultrasound and OCT examinations before elective stent implantation. The lesions were divided into 2 groups based on the presence or absence of EA, and OCT findings were compared. We then determined predictors of post-PCI CK-MB elevation. RESULTS: EA was found in 47 (34.8%) lesions and was associated with the presence of OCT-derived thin-capped fibroatheroma, ruptured plaques, greater lipid content, intravascular ultrasound-derived large reference and plaque area, lesion eccentricity, and microcalcification. Elevated CK-MB levels were observed in 36 (26.7%) lesions, and significantly more frequently in lesions with EA than without. In multivariable analysis, EA (odds ratio [OR]: 3.49; 95% confidence interval [CI]: 1.53 to 7.93; p = 0.003) and OCT-derived ruptured plaque (OR: 2.92; 95% CI: 1.21 to 7.06; p = 0.017) were independent predictors of post-PCI CK-MB elevation. CONCLUSIONS: Atherosclerotic plaques with EA were associated with characteristics considered to be high risk or unstable. OCT examination showed an additive predictive value to the presence of EA for post-PCI CK-MB elevation.

Cost-effectiveness of point-of-care biomarker assessment for suspected myocardial infarction: the randomized assessment of treatment using panel Assay of cardiac markers (RATPAC) trial.

OBJECTIVES: Chest pain due to suspected myocardial infarction (MI) is responsible for many hospital admissions and consumes substantial health care resources. The Randomized Assessment of Treatment using Panel Assay of Cardiac markers (RATPAC) trial showed that diagnostic assessment using a point-of-care (POC) cardiac biomarker panel consisting of CK-MB, myoglobin, and troponin increased the proportion of patients successfully discharged after emergency department (ED) assessment. In this economic analysis, the authors aimed to determine whether POC biomarker panel assessment reduced health care costs and was likely to be cost-effective. METHODS: The RATPAC trial was a multicenter individual patient randomized controlled trial comparing diagnostic assessment using a POC biomarker panel (CK-MB, myoglobin, and troponin, measured at baseline and 90 minutes) to standard care without the POC panel in patients attending six EDs with acute chest pain due to suspected MI (n = 2,243). Individual patient resource use data were collected from all participants up to 3 months after hospital attendance using self-completed questionnaires at 1 and 3 months and case note review. ED staff and POC testing costs were estimated through a microcosting study of 246 participants. Resource use was valued using national unit costs. Health utility was measured using the EQ-5D self-completed questionnaire, mailed at 1 and 3 months. Quality-adjusted life-years (QALYs) were calculated by the trapezium rule using the EQ-5D tariff values at all follow-up points. Mean costs per patient were compared between the two treatment groups. Cost-effectiveness was estimated in terms of probability of dominance and incremental cost per QALY. RESULTS: Point-of-care panel assessment was associated with higher ED costs, coronary care costs, and cardiac intervention costs, but lower general inpatient costs. Mean costs per patient were £1217.14 (standard deviation [SD] ± 3164.93), or $1,987.14 (SD ±$4,939.25), with POC versus £1005.91 (SD ±£1907.55), or $1,568.64 (SD ±$2,975.78), with standard care (p = 0.056). Mean QALYs were 0.158 (SD ± 0.052) versus 0.161 (SD ± 0.056; p = 0.250). The probability of standard care being dominant (i.e., cheaper and more effective) was 0.888, while the probability of the POC panel being dominant was 0.004. These probabilities were not markedly altered by sensitivity analysis varying the costs of the POC panel and excluding intensive care costs. CONCLUSIONS: Point-of-care panel assessment does not reduce costs despite reducing admissions and may even increase costs. It is unlikely to be considered a cost-effective use of health care resources.