Usefulness of peak troponin-T to predict infarct size and long-term outcome in patients with first acute myocardial infarction after primary percutaneous coronary intervention

Comparative Cardioprotective Effectiveness: NOACs vs. Nattokinase-Bridging Basic Research to Clinical Findings

The use of non-vitamin K antagonist oral anticoagulants (NOACs) has brought a significant progress in the management of cardiovascular diseases, considered clinically superior to vitamin K antagonists (VKAs) particularly in the prevention and treatment of thromboembolic events. In addition, numerous advantages such as fixed dosing, lack of laboratory monitoring, and fewer food and drug-to-drug interactions make the use of NOACs superior to VKAs. While NOACs are synthetic drugs prescribed for specific conditions, nattokinase (NK) is a natural enzyme derived from food that has potential health benefits. Various experimental and clinical studies reported the positive effects of NK on the circulatory system, including the thinning of blood and the dissolution of blood clots. This enzyme showed not only fibrinolytic activity due to its ability to degrade fibrin, but also an affinity as a substrate for plasmin. Recent studies have shown that NK has additional cardioprotective effects, such as antihypertensive and anti-atherosclerotic effects. In this narrative review, we presented the cardioprotective properties of two different approaches that go beyond anticoagulation: NOACs and NK. By combining evidence from basic research with clinical findings, we aim to elucidate the comparative cardioprotective efficacy of these interventions and highlight their respective roles in modern cardiovascular care.

Impact of baseline ECG characteristics on changes in cardiac biomarkers and echocardiographic metrices after acute myocardial infarction treated with Empagliflozin

The EMMY trial was a multicentre, investigator-initiated, placebo-controlled, double-blind trial, which enrolled 476 patients immediately following AMI and the first study demonstrating a significant reduction in NT-proBNP-levels as well as significant improvements in cardiac structure and function in patients after acute myocardial infarction treated with empagliflozin vs. placebo. However, hardly any data are available investigating the prognostic role of baseline electrocardiogram metrics in SGLT2-inhibitor-treated patients. This post-hoc analysis investigated the association of baseline ECG metrics collected in one centre of the trial (181 patients) with changes in structural and functional cardiac parameters as well as cardiac biomarkers in response to Empagliflozin treatment. A total of 181 patients (146 men; mean age 58 ± 14 years) were included. Median PQ-interval was 156 (IQR 144-174) milliseconds (ms), QRS width 92 (84-98) ms, QTc interval 453 (428-478) ms, Q-wave duration 45 (40-60) ms, Q-wave amplitude 0.40 (0.30-0.70) millivolt (mV), and heart rate was 71 (64-85) bpm. For functional cardiac parameters (LVEF and E/e') of the entire cohort, a greater decrease of E/e' from baseline to week 26 was observed in shorter QRS width (P = 0.005).Structural cardiac endpoints were only found to have a significant positive correlation between LVEDD and Q wave duration (P = 0.037). Higher heart rate was significantly correlated with better response in LVEF (P = 0.001), E/e' (P = 0.021), and NT-proBNP (P = 0.005). Empagliflozin-treatment showed no interaction with the results. Baseline ECG characteristics post AMI are neither predictive for beneficial NTproBNP effects of Empagliflozin post AMI, nor for functional or structural changes within 26 weeks post AMI.

Cardiac Troponin, Kidney Function, Heart Failure and Mortality After Myocardial Infarction in Patients With and Without Kidney Impairment

Cardiac troponins (cTn) are routinely measured for the diagnosis and prognosis of myocardial infarction (MI). The relation between troponin levels, estimated glomerular filtration rate (eGFR), postinfarction heart failure (HF), and mortality is unclear in patients with kidney impairment. This is a retrospective, cross-sectional study of patients presenting to the Emergency Department at a single tertiary center. Participants presenting with confirmed type I MI from January 1, 2019, to December 31, 2021, were analyzed from the Myocardial Ischemia National Audit Project database. Main outcomes were acute HF, measured using Killip class, and inpatient mortality. Peak cardiac troponin T (cTnT) level was a secondary outcome. Data on 2,815 patients (67±14 years, 28% female) were analyzed. Ordinal logistic regression analysis was used to test for predictors of increasing Killip class. Binary logistic regression was used to test for predictors of inpatient mortality. Analysis of a sub-sample matched for age and diabetes mellitus status showed increased mortality in patients with eGFR <60 ml/min/1.73 m2 (12.2% vs 4.4%, p <0.001). Multivariate predictors of acute HF included log-transformed peak cTnT, eGFR, body mass index (BMI), and diabetes mellitus status. Multivariate predictors of inpatient mortality included log-transformed peak cTnT, eGFR, age, BMI, and Killip class 3/4. On multivariate analysis, eGFR, ST-elevation MI diagnosis, BMI, male gender, diabetes mellitus status, and hypertension were all predictive of peak cTnT after MI. In conclusion, peak cTnT level and eGFR at presentation after MI are independent predictors of acute HF severity and death in patients with and without kidney impairment.

High-Sensitivity Cardiac Troponin for Risk Assessment in Patients With Chronic Coronary Artery Disease

BACKGROUND

Cardiac troponin is used for risk stratification of patients with acute coronary syndromes; however, the role of testing in other settings remains unclear.

OBJECTIVES

The aim of this study was to evaluate whether cardiac troponin testing could enhance risk stratification in patients with chronic coronary artery disease independent of disease severity and conventional risk measures.

METHODS

In a prospective cohort of consecutive patients with symptoms suggestive of stable angina attending for outpatient coronary angiography, high-sensitivity cardiac troponin I was measured before angiography, and clinicians were blinded to the results. The primary outcome was myocardial infarction or cardiovascular death during follow-up.

RESULTS

In 4,240 patients (age 66 years [IQR: 59-73 years], 33% female), coronary artery disease was identified in 3,888 (92%) who had 255 (6%) primary outcome events during a median follow-up of 2.4 years (IQR: 1.3-3.6 years). In patients with coronary artery disease, troponin concentrations were 2-fold higher in those with an event compared with those without (6.7 ng/L [IQR: 3.2-14.2 ng/L] vs 3.3 ng/L [IQR: 1.7-6.6 ng/L]; P < 0.001). Troponin concentrations were associated with the primary outcome after adjusting for cardiovascular risk factors and coronary artery disease severity (adjusted HR: 2.3; 95% CI: 1.7-3.0, log10 troponin; P < 0.001). A troponin concentration >10 ng/L identified patients with a 50% increase in the risk of myocardial infarction or cardiovascular death.

CONCLUSIONS

In patients with chronic coronary artery disease, cardiac troponin predicts risk of myocardial infarction or cardiovascular death independent of cardiovascular risk factors and disease severity. Further studies are required to evaluate whether routine testing could inform the selection of high-risk patients for treatment intensification. (Myocardial Injury in Patients Referred for Coronary Angiography [MICA]; ISRCTN15620297).

Triage body temperature and its influence on patients with acute myocardial infarction

BACKGROUND

Fever can occur after acute myocardial infarction (MI). The influence of body temperature (BT) after hospital arrival on patients with acute MI has rarely been investigated.

METHODS

Patients who were diagnosed with acute MI in the emergency department (ED) of a tertiary teaching hospital between 1 January 2020 and 31 December 2020 were enrolled. Based on the tympanic temperature obtained at the ED triage, patients were categorized into normothermic (35.5°C-37.5°C), hypothermic (< 35.5°C), or hyperthermic (> 37.5°C) groups. The primary outcome was in-hospital cardiac arrest (IHCA), while the secondary outcomes were adverse events. Statistical significance was set at p < 0.05.

RESULTS

There were 440 enrollees; significant differences were found among the normothermic (n = 369, 83.9%), hypothermic (n = 27, 6.1%), and hyperthermic (n = 44, 10.0%) groups in the triage respiratory rate (median [IQR]) (20.0 [4.0] cycles/min versus 20.0 [4.0] versus 20.0 [7.5], p = 0.009), triage heart rate (88.0 [29.0] beats/min versus 82.0 [28.0] versus 102.5 [30.5], p < 0.001), presence of ST-elevation MI (42.0% versus 66.7% versus 31.8%, p = 0.014), need for cardiac catheterization (87.3% versus 85.2% versus 72.7%, p = 0.034), initial troponin T level (165.9 [565.2] ng/L versus 49.1 [202.0] versus 318.8 [2002.0], p = 0.002), peak troponin T level (343.8 [1405.9] ng/L versus 218.7 [2318.2] versus 832.0 [2640.8], p = 0.003), length of ICU stay (2.0 [3.0] days versus 3.0 [8.0] versus 3.0 [9.5], p = 0.006), length of hospital stay (4.0 [4.5] days versus 6.0 [15.0] versus 10.5 [10.8], p < 0.001), and infection during hospitalization (19.8% versus 29.6% versus 63.6%, p < 0.001) but not in IHCA (7.6% versus 14.8% versus 11.4%, p = 0.323) or any adverse events (50.9% versus 48.1% versus 63.6%, p = 0.258). Multivariable analysis showed no significant association of triage BT with IHCA or any major complication.

CONCLUSION

Triage BT did not show a significant association with IHCA or adverse events in patients with acute MI. However, triage BT could be associated with different clinical presentations and should warrant further investigation.

Clinically Acquired High Sensitivity Cardiac Troponin T is a Poor Predictor of Reduced Left Ventricular Ejection Fraction After ST Elevation Myocardial Infarction: A National Cohort Study-ANZACS-QI 65

OBJECTIVE

Cardiac troponins (cTn) have been used historically to estimate infarct size in ST elevation myocardial infarction (STEMI). Within a resource constrained health care environment, cTn could therefore be used for prioritisation of patients for cardiac imaging, in particular echocardiography. We aimed to determine how useful routinely collected cTn would be in predicting significant left ventricular (LV) impairment.

METHODS

All patients in the All New Zealand Acute Coronary Syndrome Quality Improvement (ANZACS-QI) registry with their first episode of STEMI between January 2013 and November 2018, who had high sensitivity troponin T measured, were included. We excluded patients with no left ventricular ejection fraction (LVEF) assessment, known LV dysfunction, or prior myocardial infarction.

RESULTS

In total, 3,698 patients were included in the analysis. A higher mean hsTnT (admission and peak) was seen in patients with more severely impaired LV function but there was significant overlap in the range of hsTnT between the different LVEF categories. Cardiac troponins demonstrated poor discriminative ability to either predict or exclude significant LV impairment (LVEF <40%). At an optimal cutpoint of 3,405 ng/L, peak hsTnT had a sensitivity of 56.5% (95% confidence interval [CI] 42-62%), a specificity of 65.3% (95% CI 62-79%) and an area under the receiver operating curve of 0.62 (95% CI 0.60-0.64).

CONCLUSION

This is the largest study comparing clinically measured troponin levels and LV function in patients presenting with STEMI. A definite, but weak, association was seen between peak troponin and the degree of LV dysfunction, with significant overlap in troponin levels between levels of myocardial dysfunction. Routinely acquired troponin is not suitable for clinical use as a method of prioritising patients for cardiac imaging.

Cluster analysis of extracellular matrix biomarkers predicts the development of impaired systolic function within 1 year of acute myocardial infarction

The clinical utility of combining extracellular matrix (ECM) biomarkers to predict the development of impaired systolic function following acute myocardial infarction (AMI) remains largely undetermined. A combination of ELISA and multiplexing assays were performed to measure matrix metalloproteinase (MMP)-2, MMP-3, MMP-8, MMP-9, periostin, N-terminal type I procollagen (PINP) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in plasma samples from 120 AMI patients. All patients had an echocardiogram within 1 year of AMI, and were divided into impaired (n = 37, LVEF < 50%) and preserved (n = 83, LVEF ≥ 50%) systolic function groups. Exploratory factor analysis was performed on log-transformed biomarkers using principle axis analysis with Oblimin rotation. Cluster analysis was performed on log-transformed and normalised biomarkers using Ward’s method of minimum variance and the squared Euclidean distance metric. Upon univariate analysis, current smoking, prescription of ACE inhibitors at discharge, peak hsTnT > 610 ng/L (median), MMP-8 levels, Factor 1 scores and Cluster One assignment were predictive of impaired systolic function. Upon multivariate analysis, Cluster One assignment (odds ratio [95% CI], 2.74 [1.04–7.23], p = 0.04) remained an independent predictor of systolic dysfunction in combination with clinical variables. These observations support the usefulness of combining ECM biomarkers using cluster analysis for predicting the development of impaired systolic function in AMI patients.

Short-term exposure to traffic-related air pollution and STEMI events: Insights into STEMI onset and related cardiac impairment

AIMS

Evidence on the impacts of traffic-related air pollution (TRAP) on ST-segment elevation myocardial infarction (STEMI) events is limited. We aimed to assess the acute effects of TRAP exposure on the clinical onset of STEMI and related cardiac impairments.

METHODS AND RESULTS

We recruited patients who were admitted for STEMI and underwent primary percutaneous coronary intervention at Peking University Third Hospital between 2014 and 2020. Indicators relevant to cardiac impairments were measured. Concomitantly, hourly concentrations of traffic pollutants were monitored throughout the study period, including fine particulate matter, black carbon (BC), particles in size ranges of 5-560 nm, oxides of nitrogen (NO_X), nitrogen dioxide, and carbon monoxide. The mean (SD) age of participants was 62.4 (12.5) years. Daily average (range) concentrations of ambient BC and NO_X were 3.9 (0.1-25.0) μg/m³ and 90.8 (16.6-371.7) μg/m³. Significant increases in STEMI risks of 5.9% (95% CI: 0.1, 12.0) to 21.9% (95% CI: 6.0, 40.2) were associated with interquartile range increases in exposure to TRAP within a few hours. These changes were accompanied by significant elevations in cardiac troponin T levels of 6.9% (95% CI: 0.2, 14.1) to 41.7% (95% CI: 21.2, 65.6), as well as reductions in left ventricular ejection fraction of 1.5% (95% CI: 0.1, 2.9) to 3.7% (95% CI: 0.8, 6.4). Furthermore, the associations were attenuated in participants living in areas with higher residential greenness levels.

CONCLUSIONS

Our findings extend current understanding that short-term exposure to higher levels of traffic pollution was associated with increased STEMI risks and exacerbated cardiac impairments, and provide evidence on traffic pollution control priority for protecting vulnerable populations who are at greater risks of cardiovascular events.

COVID-19-Associated Myocarditis: An Evolving Concern in Cardiology and Beyond

Simple Summary

Coronavirus disease-2019 (COVID-19) affects many organs in the body, including the heart. One complication of particular concern is inflammation of the heart muscle, called myocarditis. This paper presents updated research data on COVID-19-associated myocarditis. Specifically, we review the incidence, potential mechanisms, blood and imaging tests that can be used to detect the disease. We emphasize that, in contrast with early reports, recent data suggest that myocarditis in the setting of COVID-19 is relatively uncommon, yet infected individuals are at a substantially increased risk for poor outcomes. It is important to continue research in this area.

Abstract

The direct and indirect adverse effects of SARS-CoV-2 infection on the cardiovascular system, including myocarditis, are of paramount importance. These not only affect the disease course but also determine clinical outcomes and recovery. In this review, the authors aimed at providing an update on the incidence of Coronavirus disease-2019 (COVID-19)-associated myocarditis. Our knowledge and experience relevant to this area continues to evolve rapidly since the beginning of the pandemic. It is crucial for the scientific and medical community to stay abreast of current information. Contrasting early reports, recent data suggest that the overall incidence of SARS-CoV-2-associated myocarditis is relatively low, yet infected individuals are at a substantially increased risk. Therefore, understanding the pathophysiology and diagnostic evaluation, including the use of serum biomarkers and imaging modalities, remain important. This review aims to summarize the most recent data in these areas as they relate to COVID-19-associated myocarditis. Given its increasing relevance, a brief update is included on the proposed mechanisms of myocarditis in COVID-19 vaccine recipients.

Prognostic significance of Troponin I in patients undergoing primary percutaneous coronary intervention

This observational study investigates the prognostic significance of troponin I in patients undergoing primary percutaneous intervention (pPCI). Sequential cardiac biomarker sampling of the enrolled patients (n = 167) was performed on admission and at 6,12,24 and 48 h. Clinical characteristics, major adverse cardiac and cerebrovascular events (MACCE) (death, reinfarction, stroke and new or worsening heart failure) and left ventricular ejection fraction (LVEF) were noted on admission and 30 day follow-up. A 24-h troponin I level >60 ng/ml predicted MACCE (OR 4.06, p = 0.023; adjusted OR 5.09, p = 0.034) and less than 10% improvement in LVEF on follow-up (OR 2.49, p = 0.007). Thus, in patients undergoing pPCI, 24-h cardiac Troponin I is a good non-invasive surrogate to predict MACCE and improvement in LVEF.

A combined biomarker approach for characterising extracellular matrix profiles in acute myocardial infarction

Extracellular matrix (ECM) biomarkers are useful for measuring underlying molecular activity associated with cardiac repair following acute myocardial infarction (AMI). The aim of this study was to conduct exploratory factor analysis (EFA) to examine the interrelationships between ECM biomarkers, and cluster analysis to identify if distinct ECM profiles could distinguish patient risk in AMI. Ten ECM biomarkers were measured from plasma in 140 AMI patients: MMP-2, -3, -8, -9, periostin, procollagen I N-Terminal propeptide, osteopontin, TGF-β1, TIMP-1 and -4. EFA grouped eight ECM biomarkers into a two-factor solution, which comprised three biomarkers in Factor 1 and five biomarkers in Factor 2. Notably, ECM biomarkers were not separated based on biological function. Cluster analysis grouped AMI patients into three distinct clusters. Cluster One (n = 54) had increased levels of MMP-8, MMP-9, and TGF-B1. Cluster Two (n = 43) had elevated levels of MMP-2, MMP-3, osteopontin, periostin and TIMP-1, and increased high-sensitivity troponin T and GRACE scores. Cluster Three (n = 43) had decreased levels of ECM biomarkers. Circulating ECM biomarkers demonstrated collinearity and entwined biological functions based on EFA analysis. Using cluster analysis, patients with similar clinical presentations could be separated into distinct ECM profiles that were associated with differential patient risk. Clinical significance remains to be determined.

Heart failure after myocardial infarction: incidence and predictors

Aims

The aim of the present paper was to provide an up‐to‐date view on epidemiology and risk factors of heart failure (HF) development after myocardial infarction.

Methods and results

Based on literature review, several clinical risk factors and biochemical, genetic, and imaging biomarkers were identified to predict the risk of HF development after myocardial infarction.

Conclusions

Heart failure is still a frequent complication of myocardial infarction. Timely identification of subjects at risk for HF development using a multimodality approach, and early initiation of guideline‐directed HF therapy in these patients, can decrease the HF burden.

Whole blood transcriptome profile at hospital admission discriminates between patients with ST-segment elevation and non-ST-segment elevation acute myocardial infarction

Whether ST-segment (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) should be regarded as distinct pathophysiological entities is a matter of debate. We tested the hypothesis that peripheral blood gene-expression profiles at presentation distinguish STEMI from NSTEMI. We performed a case-control study collecting whole-blood from 60 STEMI and 58 NSTEMI (defined according to the third universal definition of MI) consecutive patients on hospital admission. We used RNA-sequencing for the discovery phase, comparing 15 STEMI vs. 15 NSTEMI patients, matched for age, sex, and cardiovascular risk factors, and quantitative PCR in the remaining unmatched patients for validating top-significant genes. Gene-level differential expression analysis identified significant differences in the expression of 323 genes: 153 genes withstood correction for admission cardiac troponin I (cTnI), differentiating the two conditions independently of myocardial necrosis extent. Functional annotation analysis uncovered divergent modulation in leukocyte and platelet activation, cell migration, and mitochondrial respiratory processes. Linear regression analysis revealed gene expression patterns on admission predicting infarct size, as indexed by cTnI peak (R² = 0.58–0.75). Our results unveil distinctive pathological traits for these two MI subtypes and provide insights into the early assessment of injury extent. This could translate into RNA-based disease-specific biomarkers for precision diagnosis and risk stratification.

Impact of comorbidities on peak troponin levels and mortality in acute myocardial infarction

OBJECTIVES

To characterise peak cardiac troponin levels, in patients presenting with acute myocardial infarction (AMI), according to their comorbid condition and determine the influence of peak cardiac troponin (cTn) levels on mortality.

METHODS

We included patients with the first admission for AMI in the UK. We used linear regression to estimate the association between eight common comorbidities (diabetes mellitus, previous angina, peripheral arterial disease, previous myocardial infarction (MI), chronic kidney disease (CKD), cerebrovascular disease, chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD)) and peak cTn. Peak cTn levels were adjusted for age, sex, smoking status and comorbidities. Logistic regression and restricted cubic spline models were employed to investigate the association between peak cTn and 180-day mortality for each comorbidity.

RESULTS

330 367 patients with ST elevation myocardial infarction and non-ST elevation myocardial infarction were identified. Adjusted peak cTn levels were significantly higher in patients with CKD (adjusted % difference in peak cTnT for CKD=42%, 95% CI 13.1 to 78.4) and significantly lower for patients with COPD, previous angina, previous MI and CHF when compared with patients without the respective comorbidities (reference group) (cTnI; COPD=-21.7%, 95% CI -29.1 to -13.4; previous angina=-24.2%, 95% CI -29.6 to -8.3; previous MI=-13.5%, 95% CI -20.6 to -5.9; CHF=-28%, 95% CI -37.2 to -17.6). Risk of 180-day mortality in most of the comorbidities did not change substantially after adjusting for peak cTn. In general, cTnI had a stronger association with mortality than cTnT.

CONCLUSIONS

In this nationwide analysis of patients presenting with AMI, comorbidities substantially influenced systemic concentrations of peak cTn. Comorbid illness is a significant predictor of mortality regardless of peak cTn levels and should be taken into consideration while interpreting cTn both as a diagnostic and prognostic biomarker.

Increased Plasma Cardiac Troponin I in Live-Stranded Cetaceans: Correlation with Pathological Findings of Acute Cardiac Injury

Capture myopathy (CM), is a syndrome that occurs as the result of the stress during and after capture, handling, restraint, and transport of wild animals. Although CM has been described for many species of cetaceans, characterization of the acute cardiac injury - an important component of this syndrome - are still scarce. In this study, we firstly estimated a normal range for cardiac troponin I (cTnI) on cetaceans. Here, through biochemical analysis (especially of cTnI) and histopathological, histochemical, and immunohistochemical correlations with decreased troponin immunolabelling, we studied the cardiac injury in live-stranded cetaceans. Nine cetaceans which stranded alive on the Canary Islands (January 2016 - June 2019) were included in this study. Sampled individuals presented elevated values of plasma cTnI, which were correlated to histopathological lesions comprised of vascular changes and acute degenerative lesions. Immunohistochemically, injured cardiomyocytes showed a decreased intrafibrillar troponin immunoreaction. This is the first attempt to establish a normal baseline range for cTnI in cetaceans, and the first study comparing plasma biomarkers values with histopathological and immunohistochemical findings. This approach allowed us to demonstrate the degree of cardiac damage as a result of injury, consistent with ischemia-reperfusion lesions. The knowledge gained here could improve decision-making procedures during stressful situations, mainly in live-strandings, handling, and rehabilitation, thereby reducing the mortality of cetaceans.

Myocardial Blood Flow Quantified by Low-Dose Dynamic CT Myocardial Perfusion Imaging Is Associated with Peak Troponin Level and Impaired Left Ventricle Function in Patients with ST-Elevated Myocardial Infarction

Objective

To investigate the association of myocardial blood flow (MBF) quantified by dynamic computed tomography (CT) myocardial perfusion imaging (MPI) with troponin level and left ventricle (LV) function in patients with ST-segment elevated myocardial infarction (STEMI).

Materials and Methods

Thirty-five STEMI patients who successfully had undergone reperfusion treatment within 1 week of their infarction were consecutively enrolled. All patients were referred for dynamic CT-MPI. Serial high-sensitivity troponin T (hs-TnT) levels and left ventricular ejection fraction (LVEF) measured by echocardiography were recorded. Twenty-six patients with 427 segments were included for analysis. Various quantitative parameters derived from dynamic CT-MPI were analyzed to determine if there was a correlation between hs-TnT levels and LVEF on admission and again at the 6-month mark.

Results

The mean radiation dose for dynamic CT-MPI was 3.2 ± 1.1 mSv. Infarcted territories had significantly lower MBF (30.5 ± 7.4 mL/min/100 mL versus 73.4 ± 8.1 mL/min/100 mL, p < 0.001) and myocardial blood volume (MBV) (2.8 ± 0.9 mL/100 mL versus 4.2 ± 1.1 mL/100 mL, p = 0.044) compared with those of reference territories. MBF showed the best correlation with the level of peak hs-TnT (r = −0.682, p < 0.001), and MBV showed a moderate correlation with the level of peak hs-TnT (r = −0.437, p = 0.026); however, the other parameters did not show any significant correlation with hs-TnT levels. As for the association with LV function, only MBF was significantly correlated with LVEF at the time of admission (r = 0.469, p = 0.016) and at 6 months (r = 0.585, p = 0.001).

Conclusion

MBF quantified by dynamic CT-MPI is significantly inversely correlated with the level of peak hs-TnT. In addition, patients with lower MBF tended to have impaired LV function at the time of their admission and at 6 months.

Impact of Type 2 Myocardial Infarction (MI) on Hospital-Level MI Outcomes: Implications for Quality and Public Reporting

BACKGROUND

The International Classification of Diseases (ICD) coding system does not recognize type 2 myocardial infarction (MI) as a separate entity; therefore, patients with type 2 MI continue to be categorized under the general umbrella of non-ST-segment-elevation myocardial infarction (NSTEMI). We aim to evaluate the impact of type 2 MI on hospital-level NSTEMI metrics and discuss the implications for quality and public reporting.

METHODS AND RESULTS

We conducted a single-center retrospective analysis of 1318 patients discharged with a diagnosis of NSTEMI between July 2013 and October 2014. The Third Universal Definition was used to define type 1 and type 2 MI. Weighted Kaplan-Meier curves were used to analyze risk of mortality and readmission. Overall, 1039 patients met NSTEMI criteria per the Third Universal Definition; of those, 264 (25.4%) had type 2 MI. Patients with type 2 MI were older, were more likely to have chronic kidney disease, and had lower peak troponin levels. Compared with type 1 MI patients, those with type 2 MI had higher inpatient mortality (17.4% versus 4.7%, P<0.0001) and were more likely to die from noncardiovascular causes (71.7% versus 25.0%, P<0.0001). Despite weighting for patient characteristics and discharge medications, patients with type 2 MI had higher mortality at both 30 days (risk ratio: 3.63; 95% confidence interval, 1.67-7.88) and 1 year (risk ratio: 1.98; 95% confidence interval, 1.44-2.73) after discharge. Type 2 MI was also associated with a lower 30-day cardiovascular-related readmission (risk ratio: 0.49; 95% confidence interval, 0.12-2.06).

CONCLUSIONS

NSTEMI metrics are significantly affected by type 2 MI patients. Type 2 MI patients have distinct etiologies, are managed differently, and have higher mortality compared with patients with type 1 MI. Moving forward, it may be appropriate to exclude type 2 MI data from NSTEMI quality metrics.

Predictors of decreased left ventricular function subsequent to follow-up echocardiography after percutaneous coronary intervention following acute ST-elevation myocardial infarction

The preferred treatment for patients with ST elevation myocardial infarction (STEMI) is primary percutaneous coronary intervention (PCI). However, not all patients improve or maintain heart function following primary PCI, and certain patients may experience decreased heart function. The present study investigated factors associated with left ventricular (LV) dysfunction, and improvement or deterioration of LV ejection fraction (LVEF) at follow-up echocardiography following successful primary PCI. The clinical outcomes following primary PCI were also investigated. The present study assessed 4,044 patients who underwent primary PCI following a diagnosis of STEMI between January 2008 and March 2012. A total of 1,736 patients who underwent echocardiography between 30 days and 1 year after STEMI and PCI, and who had completed clinical follow-up, were included in the present study. A total of 243 patients (14.0%) demonstrated LV dysfunction at follow-up echocardiography. Multivariate analysis revealed that LV dysfunction (≤40%) at index STEMI, LVEF at index admission, renal insufficiency (creatinine ≥1.4 mg/dl), peak creatine kinase (CK) and peak CK MB isoenzyme (CKMB) were independent predictors of LV dysfunction at follow-up. Independent predictors for the deterioration of LVEF at follow-up were dyslipidemia, LVEF at index admission, LVEF ≤40% at index admission, peak CK and peak troponin-I. Furthermore, being male, having no history of coronary artery disease, pre-thrombolysis in myocardial infarction (TIMI) flow, LVEF at index admission, LVEF ≤40% at index admission, peak CKMB and peak troponin I were independent predictors of LVEF improvement at follow-up. One-year major adverse cardiac events were significantly increased in the LV dysfunction group compared with patients who did not exhibit LV dysfunction according to Cox regression analysis (13.6 vs. 20.4%; P=0.017). Therefore, the present study may provide valuable prognostic information for clinicians to advise patients who experience LV dysfunction despite having undergone successful primary PCI. Additional management is required in patients with these high-risk features following STEMI.

High-sensitivity cardiac troponin I and risk of heart failure in patients with suspected acute coronary syndrome: a cohort study

Aims

Heart failure may occur following acute myocardial infarction, but with the use of high-sensitivity cardiac troponin assays we increasingly diagnose patients with minor myocardial injury. Whether troponin concentrations remain a useful predictor of heart failure in patients with acute coronary syndrome is uncertain.

Methods and results

We identified all consecutive patients (n = 4748) with suspected acute coronary syndrome (61 ± 16 years, 57% male) presenting to three secondary and tertiary care hospitals. Cox-regression models were used to evaluate the association between high-sensitivity cardiac troponin I concentration and subsequent heart failure hospitalization. C-statistics were estimated to evaluate the predictive value of troponin for heart failure hospitalization. Over 2071 years of follow-up there were 83 heart failure hospitalizations. Patients with troponin concentrations above the upper reference limit (URL) were more likely to be hospitalized with heart failure than patients below the URL (118/1000 vs. 17/1000 person years, adjusted hazard ratio: 7.0). Among patients with troponin concentrations

Conclusion

Cardiac troponin is an excellent predictor of heart failure hospitalization in patients with suspected acute coronary syndrome. The strongest associations were observed in patients with troponin concentrations in the normal reference range, in whom high-sensitivity cardiac troponin assays identify those at increased risk of heart failure who may benefit from further investigation and treatment.

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Key Words

• Acute coronary syndrome
• Heart failure
• High-sensitivity cardiac troponin

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MESH Headings

• Acute Coronary Syndrome/blood
• Acute Coronary Syndrome/complications
• Acute Coronary Syndrome/diagnosis
• Aged
• Biomarkers/blood
• Female
• Heart Failure/blood
• Heart Failure/etiology
• Humans
• Male
• Middle Aged
• Predictive Value of Tests
• Prognosis
• Risk Factors
• Troponin I/blood

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Grants

• 201492/Z/16/Z Wellcome Trust
• FS/16/75/32533 British Heart Foundation
• SP/12/10/29922 British Heart Foundation
• SP/12/10/29922 British Heart Foundation
• HICG/1/40 Chief Scientist Office
• FS/16/14/32023 British Heart Foundation
• PG/15/51/31596 British Heart Foundation

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Affiliation(s)

Dominik Stelzle BHF Centre for Cardiovascular Science, University of Edinburgh, 49 Little Fracne Cresc, Edinburgh EH16 4SB, UK
Anoop S V Shah BHF Centre for Cardiovascular Science, University of Edinburgh, 49 Little Fracne Cresc, Edinburgh EH16 4SB, UK
Atul Anand BHF Centre for Cardiovascular Science, University of Edinburgh, 49 Little Fracne Cresc, Edinburgh EH16 4SB, UK
Fiona E Strachan BHF Centre for Cardiovascular Science, University of Edinburgh, 49 Little Fracne Cresc, Edinburgh EH16 4SB, UK
Andrew R Chapman BHF Centre for Cardiovascular Science, University of Edinburgh, 49 Little Fracne Cresc, Edinburgh EH16 4SB, UK
Martin A Denvir BHF Centre for Cardiovascular Science, University of Edinburgh, 49 Little Fracne Cresc, Edinburgh EH16 4SB, UK
Nicholas L Mills BHF Centre for Cardiovascular Science, University of Edinburgh, 49 Little Fracne Cresc, Edinburgh EH16 4SB, UK
David A McAllister The Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK The Usher Institute of Population Health and Informatics, University of Edinburgh, Edinburgh, UK

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High Sensitivity Troponins Discriminate Different Morphologies of Coronary Artery Plaques Being Assessed by Coronary Computed Tomography Angiography

BACKGROUND

This study evaluates the association between high sensitivity troponin I (hsTnI) and T (hsTnT) and the morphology of coronary artery plaques detected by coronary computed tomography angiography (CCTA) in patients with suspected coronary artery disease (CAD).

METHODS

Patients undergoing CCTA were prospectively enrolled. CCTA was indicated by a low to intermediate pretest probability for CAD during routine clinical care. Within 24 hours of CCTA examination, peripheral blood samples were taken to measure hsTnI, hsTnT, and N-terminal probrain natriuretic peptide (NT-proBNP).

RESULTS

A total of 99 patients were enrolled with 43% without CAD, 9% with noncalcified plaques, 28% with calcified plaques, and 19% with mixed type plaque lesions. Both hsTnI and hsTnT levels were able to discriminate significantly between the groups, especially in the presence of mixed coronary plaques (AUC range: 0.741-0.752; p = 0.0001). In multivariate logistic regression models, hsTnT, but not hsTnI, was still significantly associated with mixed coronary plaque morphology (odds ratio = 8.968; 95% CI 1.999-40.241; p = 0.004).

CONCLUSIONS

Both hsTnI and hsTnT are able to discriminate between different coronary artery plaques morphologies, whereas hsTnT was significantly associated with mixed coronary plaques in patients with suspected CAD. This trial is registered with NCT03074253.

Achieving biosensing at attomolar concentrations of cardiac troponin T in human biofluids by developing a label-free nanoplasmonic analytical assay

A nanoplasmonic-based highly reproducible and ultrasensitive analytical sensor was fabricated to quantify cardiac troponin T at attomolar concentration with high selectivity.

Non-contrast cardiac CT immediately after percutaneous coronary intervention: does it predict the risk of left ventricular remodeling in patients with ST-elevation myocardial infarction?

To assess the clinical utility of non-contrast cardiac CT (CCT) immediately after successful percutaneous coronary intervention (PCI) for predicting the risk of left ventricle (LV) remodeling in the management of patients with acute myocardial infarction (AMI), 35 patients with AMI underwent non-contrast CCT immediately after PCI. Volume and transmural extent of myocardial delayed enhancement (DE) were assessed on non-contrast CCT. Serial echocardiography and serologic biomarkers were evaluated at baseline and at 2 and 12 months after AMI. Based on an increase in left ventricular end-diastolic volume (LVEDV) ≥20 % at 2 months, patients were classified into two groups: LV remodeling (group 1, n = 14) and no LV remodeling (group 2, n = 21). Clinical characteristics, imaging parameters, and serologic biomarkers were compared between the two groups. Higher incidence of hypertension, longer time to reperfusion, and higher Killip classification at admission were observed for group 1 than for group 2, but these differences were not statistically significant (P > 0.05). Greater volume and transmural extent of DE on non-contrast CCT and poorer resolution of ST-segment elevation on ECG were observed in group 1 compared to group 2, but these results were not statistically significant (P > 0.05). Measurement of biochemical markers showed that probrain natriuretic peptide (proBNP), initial high sensitivity C reactive protein (hs-CRP), and maximum troponin T level were significantly higher in group 1 than in group 2 (P < 0.05) at 2 months. Based on the trend of greater volume and transmural extent of DE in group 1 compared to group 2, non-contrast CCT immediately after PCI, in combination with serologic biomarkers (proBNP, hs-CRP, and troponin T) might be useful for managing patients with AMI.

Cardiac troponin elevation pattern in patients undergoing a primary percutaneous coronary intervention for ST-segment elevation myocardial infarction: characterization and relationship with cardiovascular events during hospitalization

HYPOTHESIS

We aimed to describe the kinetics and associated prognostic implications of the cardiac troponin release curve after a primary percutaneous coronary intervention (PPCI) in patients presenting with ST-segment elevation myocardial infarction (STEMI).

PATIENTS AND METHODS

We prospectively determined, in a prespecified timely manner, serial cardiac troponin I levels and obtained clinical, ECG, and echocardiographic data from 175 consecutive patients hospitalized with STEMI who underwent PPCI. The median peak troponin levels and time until troponin peaking were determined.

RESULTS

The troponin elevation curve following PPCI was single peaked, with a median value measuring 715 times the upper normal limit and a median peaking time of 8 h. Later-peaking troponin levels were associated with a TIMI flow grade of 0/1 at the initiation of angiography and with lack of at least 70% regression in the ST-elevation on the first post-PPCI ECG. Higher peak values were similarly associated with these two parameters as well as with a lower blush score and with distal embolization during PPCI. Both higher peak values and later peaking of troponin were associated independently with higher occurrence of the combined adverse cardiovascular event outcomes consisting of death, congestive heart failure, and recurrent infarction.

CONCLUSION

The cardiac troponin elevation curve following PPCI for STEMI shows a single peak and is affected by the adequacy of myocardial reperfusion. This method can serve as a simple surrogate for risk stratification of patients with STEMI who undergo PPCI.

Prognostic value of plasma biomarkers in patients with acute coronary syndrome: a review of advances in the past decade

Acute coronary syndrome (ACS), especially myocardial infarction, commonly known as a heart attack, is a serious life-threatening cardiovascular disease. Despite dramatic therapeutic advances, there have still been more than 20% patients with ACS suffering recurrent adverse cardiovascular events 3 years after disease onset. Therefore, the aim to prevent cardiac death caused by the heart attack remains challenging. Plasma biomarkers, originally developed to complement clinical assessment and electrocardiographic examination for the diagnosis of ACS, have been reported to play important prognostic roles in predicting adverse outcomes. These biomarkers mirror different pathophysiological mechanisms in association with ACS. In this review, we focus on advances of prognostic biomarkers in the past decade for short- and long-term risk assessment and management of patients with ACS.

Prognostic value of high sensitivity troponin T after ST-segment elevation myocardial infarction in the era of cardiac magnetic resonance imaging

Aims

To determine if high sensitivity troponin T (hs-TnT) measurements performed during the 'plateau phase' of troponin release (≥48 h) following ST-segment elevation myocardial infarction (STEMI) can predict major adverse cardiovascular endpoints (MACE), and to evaluate its prognostic value compared with cardiac magnetic resonance imaging (CMRI) parameters.

Methods and results

We prospectively recruited 201 first presentation STEMI patients. Serial hs-TnT levels were measured at admission, peak (highest), 24, 48 and 72 h. CMRI and transthoracic echocardiography were performed (4 days median) post-STEMI, evaluating infarct scar characteristics and left ventricular ejection fraction (LVEF). Associations were determined between hs-TnT levels and CMRI parameters early after STEMI with MACE (comprising mortality, re-infarction, new or worsening of heart failure, cerebrovascular accident, and sustained ventricular arrhythmias) at medium-term follow-up. After 602 days (median), 33 (17%) patients had MACE. Upper tertile hs-TnT levels at 48 and 72 h were associated with MACE (Kaplan-Meier P = 0.002 and P = 0.012, respectively). Multivariate Cox analyses, incorporating diabetes, CMRI scar size, LVEF and hs-TnT levels (applied at a single hs-TnT time point) showed that 48 and 72 h hs-TnT levels were independent predictors for MACE (HR = 1.20, P = 0.002, and HR = 1.21, P = 0.035 respectively).

Conclusion

Measurement of hs-TnT in the plateau phase after STEMI is an inexpensive method of prognostic risk assessment.

Cardiac troponin I for prediction of clinical outcomes and cardiac function through 3-month follow-up after primary percutaneous coronary intervention for ST-segment elevation myocardial infarction

BACKGROUND

Circulating levels of cardiac troponin I (cTnI) after ST-segment elevation myocardial infarction (STEMI) are associated with infarct size and chronic left ventricular dysfunction, but the relation to clinical end points and biochemical measures of global cardiac function remains less well defined.

METHODS

One thousand sixty-six patients receiving primary percutaneous coronary intervention (PCI) in the PROTECTION AMI trial were studied in a post hoc analysis. Cardiac troponin I was measured at several time points during the index hospitalization, and patients were followed up for 3 months before reassessment including N-terminal pro-B-type natriuretic peptide (NT-proBNP) and left ventricular ejection fraction (LVEF) measurements.

RESULTS

The median (quartile 1-3) cTnI levels were 0.4 (0.1-0.4) μg/L at admission, 33.1 (12.8-72.1) μg/L after 16 to 24 hours, and 9.1 (3.9-17.5) μg/L after 70 to 80 hours. In adjusted models, all post-PCI single points, peak, and area under curve were found to be independently associated with clinical events, NT-proBNP >118 pmol/L, or LVEF <40% (P for all <.001). When cTnI was added to a baseline risk model for prediction of clinical events, the C statistic improved from 0.779 to 0.846 (16-24 hours) and 0.859 (70-80 hours). Quantified by integrated discrimination improvement, the addition of cTnI significantly augmented prediction ability (relative integrated discrimination improvement 44%-154%; P for all ≤.001). Consistent improvements in discrimination of NT-proBNP >118 pmol/L and LVEF <40% were observed.

CONCLUSIONS

Cardiac troponin I measured after primary PCI for STEMI is independently associated with clinical outcomes and cardiac function through 3-month follow-up. These results suggest that cTnI levels are a useful risk stratification tool in STEMI patients.

Prognostic significance of elevated troponin in non-cardiac hospitalized patients: a systematic review and meta-analysis

Cardiac biomarker troponin can be elevated in patients without a primary cardiac diagnosis and may have prognostic value. We conducted a systematic review to estimate the prevalence and prognostic significance of elevated troponin levels in patients admitted to hospital without a primary cardiac diagnosis. Literature search was done using MEDLINE (1946 to November 2012), EMBASE (1974 to Week 45, 2012), and Cochrane Central Register of Controlled Trials (November 2012). Two independent investigators reviewed full-text studies for final inclusion. We included studies of patients admitted without a primary cardiac diagnosis. Eligible studies compared adverse outcomes in patients with normal versus elevated troponin levels. Twenty-seven studies were included in the meta-analysis. Elevated troponin was associated with increased in-hospital and 30-day mortality (25 studies, 7255 patients, OR 3.88, 95% CI 2.90-5.19, P < 0.0001). Elevated troponin was also associated with increased risk of long-term mortality at 6 months (9 studies, 5368 patients, OR 4.21, 95% CI 1.84-9.64, P < 0.00001). Troponin is an independent predictor of short-term mortality with a pooled adjusted OR of 2.36, 95% CI 1.47-3.76, P < 0.0003. In conclusion, elevated troponin in non-cardiac patients is independently associated with increased mortality.

Macrophage migration inhibitory factor for the early prediction of infarct size

BACKGROUND

Early diagnosis and knowledge of infarct size is critical for the management of acute myocardial infarction (MI). We evaluated whether early elevated plasma level of macrophage migration inhibitory factor (MIF) is useful for these purposes in patients with ST-elevation MI (STEMI).

METHODS AND RESULTS

We first studied MIF level in plasma and the myocardium in mice and determined infarct size. MI for 15 or 60 minutes resulted in 2.5-fold increase over control values in plasma MIF levels while MIF content in the ischemic myocardium reduced by 50% and plasma MIF levels correlated with myocardium-at-risk and infarct size at both time-points (P < 0.01). In patients with STEMI, we obtained admission plasma samples and measured MIF, conventional troponins (TnI, TnT), high sensitive TnI (hsTnI), creatine kinase (CK), CK-MB, and myoglobin. Infarct size was assessed by cardiac magnetic resonance (CMR) imaging. Patients with chronic stable angina and healthy volunteers were studied as controls. Of 374 STEMI patients, 68% had elevated admission MIF levels above the highest value in healthy controls (> 41.6 ng/mL), a proportion similar to hsTnI (75%) and TnI (50%), but greater than other biomarkers studied (20% to 31%, all P < 0.05 versus MIF). Only admission MIF levels correlated with CMR-derived infarct size, ventricular volumes and ejection fraction (n = 42, r = 0.46 to 0.77, all P < 0.01) at 3 day and 3 months post-MI.

CONCLUSION

Plasma MIF levels are elevated in a high proportion of STEMI patients at the first obtainable sample and these levels are predictive of final infarct size and the extent of cardiac remodeling.

Use of high-sensitivity troponin assays predicts mortality in patients with normal conventional troponin assays on admission-insights from a meta-analysis

BACKGROUND

Use of high-sensitivity troponin (hs-Tn) assays can detect small levels of myocardial damage previously undetectable with conventional troponin (c-Tn) assays. However, prognostic utility of these hs-Tn assays in prediction of mortality remains unclear in the presence of nonelevated c-Tn levels on admission. A systematic review and meta-analysis was performed to assess mortality risk of patients with hs-Tn elevations in the setting of normal c-Tn levels.

HYPOTHESIS

Patients with hs-Tn elevations with normal c-Tn levels on admission blood samples, drawn to rule out acute coronary syndrome (ACS), have a higher mortality risk than those without hs-Tn or c-Tn elevations.

METHODS

A search was made of the PubMed, CENTRAL, EMBASE, CINAHL, EBSCO, and Web of Science databases. Studies evaluating patients with suspected ACS that reported mortality rates for those with elevated hs-Tn levels but normal c-Tn levels on admission were included. A random-effects model was used to pool event rates, and data were reported in odds ratios (95% confidence interval).

RESULTS

Four studies (N = 2033, mean age 64-75 years, 49%-70% male) revealed that nearly 32% of suspected ACS patients with normal c-Tn levels on admission had elevated hs-Tn levels. Elevated hs-Tn levels conferred a significantly higher risk of all-cause mortality vs normal hs-Tn levels (odds ratio: 4.35, 95% confidence interval: 2.81-6.73, P < 0.01), with negligible heterogeneity (I(2) = 0%).

CONCLUSIONS

Elevation of hs-Tn levels predicted a higher risk of mortality in patients with suspected ACS and may aid in the early identification of higher-risk patients in this setting. Future studies are needed to investigate further optimal management strategies.

Cardiac troponins I and T: molecular markers for early diagnosis, prognosis, and accurate triaging of patients with acute myocardial infarction

Acute myocardial infarction (AMI) is the leading cause of death worldwide, with early diagnosis still being difficult. Promising new cardiac biomarkers such as troponins and creatine kinase (CK) isoforms are being studied and integrated into clinical practice for early diagnosis of AMI. The cardiac-specific troponins I and T (cTnI and cTnT) have good sensitivity and specificity as indicators of myocardial necrosis and are superior to CK and its MB isoenzyme (CK-MB) in this regard. Besides being potential biologic markers, cardiac troponins also provide significant prognostic information. The introduction of novel high-sensitivity troponin assays has enabled more sensitive and timely diagnosis or exclusion of acute coronary syndromes. This review summarizes the available information on the potential of troponins and other cardiac markers in early diagnosis and prognosis of AMI, and provides perspectives on future diagnostic approaches to AMI.

Peak and fixed-time high-sensitive troponin for prediction of infarct size, impaired left ventricular function, and adverse outcomes in patients with first ST-segment elevation myocardial infarction receiving percutaneous coronary intervention

The clinical use of advanced imaging modalities for early determination of infarct size and prognosis is limited. As a specific indicator of myocardial necrosis, cardiac troponin T (cTnT) can be used as a surrogate measure for this purpose. The present study sought to investigate the use of peak and serial 6-hour fixed-time high-sensitive (hs) cTnT for estimation of infarct size, left ventricular (LV) function, and prognosis in consecutive patients with ST-segment elevation myocardial infarction. The infarct size was expressed as the 48-hour cumulative creatine kinase release. LV function at 3 months was assessed using the echocardiographic wall motion score index and LV ejection fraction using radionuclide ventriculography. Adverse outcomes, comprising all-cause death, implantable cardioverter-defibrillator implantation, or hospitalization for heart failure, were recorded at 1 year of follow-up. In 188 patients, the peak and all fixed-time values correlated significantly with the 48-hour cumulative creatine kinase release, wall motion score index, and LV ejection fraction. The hs-cTnT value at 24 hours demonstrated the greatest correlation (r = 0.86, r = 0.47, and r = -0.59, respectively; p <0.001 for all). In the multivariate regression models adjusted for the clinical parameters, almost all were independently associated with the 48-hour cumulative creatine kinase release, wall motion score index, and LV ejection fraction, with the hs-cTnT value at 24 hours having the largest effect. Moreover, all cTnT values independently predicted adverse outcomes, again, with the hs-cTnT value at 24 hours showing the largest influence (hazard ratio 3.77, 95% confidence interval 2.12 to 6.73, p <0.001). In conclusion, not only peak, but all fixed-time hs-cTnT values were associated with infarct size, LV function at 3 months, and adverse outcomes 1 year after ST-segment elevation myocardial infarction. The value 24 hours after the onset of symptoms had the closest associations with all outcomes. Therefore, serial sampling for a peak value might be redundant.

Multi-marker network in ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention: when and what to measure

BACKGROUND

Data on the correlations between biomarkers to suggest cost-effective multi-marker (MM) panels predictive for ST-elevation myocardial infarction (STEMI) patients are lacking. We sought to explore the relationship between cardiac troponin I (cTnI), C-reactive protein (CRP), B-type natriuretic peptide (BNP), and chromogranin A (CgA) accounting for biomarkers' profiles detected within 48h from successful primary percutaneous coronary intervention (PPCI).

METHODS

In 73 STEMI patients cTnI, CRP, BNP, and CgA were measured before PPCI and 6, 24, and 48h later. STATIS methods generalizing Principal Component Analysis on three-way data sets were employed to extract information about: 1) similarities between patients, 2) contribution of each time of sampling and 3) correlations between biomarkers' profiles.

RESULTS

STEMI patients who underwent successful PPCI emerged to have a homogeneous profile tailored on biomarkers' evaluation within 48h. Their measurements at 24h contributed the most variability and information both to patients' and to biomarkers' profiles. BNP and cTnI were highly correlated and explained the 40.1% of the total variance, whereas CgA resulted independent and explained the 26.3% of the total variance.

CONCLUSIONS

Markers' measurements at 24h after PPCI contributed most information to the definition of patients' profile. BNP and cTnI resulted interchangeable in a MM panel for reporting about the extent of necrosis.

Myopericarditis in children: elevated troponin I level does not predict outcome

Myopericarditis is primarily a pericarditic syndrome with some degree of myocardial involvement, as evident by elevated cardiac enzymes. Differentiating myopericarditis from acute coronary syndromes can be challenging and may require coronary angiography or perfusion studies. Data on myopericarditis and its outcome for children are scarce. This study delineates the demography, clinical presentation, and outcomes of myopericarditis for children and evaluates the prognostic value of elevated troponin I. The authors retrospectively reviewed 880 patients younger than 18 years of age who were admitted with diagnoses of chest pain, myocarditis, or pericarditis between 2000 and 2010 at their institution. Myopericarditis was defined as a clinical presentation of pericarditis in the presence of elevated levels of cardiac enzymes. Medical records were reviewed to abstract the demographic data, clinical presentation, evaluation, treatment, and follow-up outcomes. A total of 12 patients (1.4%) with myopericarditis were identified. All the patients were male, 8 (67%) of whom were Caucasian, and their median age was 16 years (range, 11-17 years). Two of the patients (17%) had recently used illicit drugs, and two (17%) had recently smoked cigarettes. At presentation, symptoms included chest pain in 12 patients (100%, 12/12), upper respiratory symptoms in 3 patients (25%, 3/12), and shortness of breath in 3 patients (25%, 3/12). No cardiac murmur or gallop was noted in any patient. Electrocardiographic (ECG) changes included diffuse ST-T changes (5 patients), localized ST-T changes (6 patients), and no ST-T changes (1 patient). All the patients had elevated levels of cardiac enzymes, with a median Troponin I level of 21.4 ng/ml (range, 5.0-134.4 ng/ml) and a median CK-MB level of 50.2 ng/ml (range, 7-135 ng/ml). Echocardiography showed normal left ventricular systolic function in all the patients (median ejection fraction, 61%; range, 56-69%). None had pericardial effusion during the first echocardiographic evaluation. Coronary angiography showed normal coronary arteries in all nine subjects for whom it was performed. Treatment of myopericarditis consisted of ibuprofen, acetaminophen, and/or aspirin. During a median follow-up period of 2 months (range, 2 weeks to 3 years), all the patients were asymptomatic with echocardiography showing normal left ventricular size and function. Myopericarditis was exclusively seen in male adolescents. Despite markedly elevated levels of cardiac enzymes, the clinical evolution of myopericarditis seems benign without any myocardial dysfunction. The inflammatory involvement of the myocardium appears to be self-limited without short-term, overt sequelae. An elevated troponin I level in myopericarditis, unlike acute coronary syndromes, does not seem to carry an adverse prognosis. Further studies are needed to evaluate the long-term prognosis for such patients.

Biomarker panel of cardiac and skeletal muscle troponins, fatty acid binding protein 3 and myosin light chain 3 for the accurate diagnosis of cardiotoxicity and musculoskeletal toxicity in rats

Cardiotoxicity and musculoskeletal toxicity can be life-threatening, and thus have strong impact on both the development and marketing of drugs. Because the conventional biomarkers such as aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and creatine kinase (CK) have low detection power, there has been increasing interest in developing biomarkers with higher detection power. The current study examined the usefulness of several promising biomarkers, cardiac and skeletal muscle troponins (cTnI, cTnT and sTnI), fatty acid binding protein 3 (FABP3) and myosin light chain 3 (MYL3), and compared the obtained data to AST, LDH and CK in rat models treated with various myotoxic and non-myotoxic compounds (isoproterenol, metaproterenol, doxorubicin, mitoxantrone, allylamine, cyclosporine A, cyclophosphamide, aminoglutethimide, acetaminophen, methapyrilene, allylalcohol and α-naphthylisothiocyanate). These promising biomarkers were found to be superior to the conventional biomarkers, as they had a specific and abundant distribution within the heart and/or skeletal muscles; exhibited a positive correlation between the amplitude of increases and the degree of pathological alterations; had higher diagnostic accuracy for detecting pathological alterations; and had the additive effect of improving the diagnostic accuracy of conventional biomarkers. However, these promising biomarkers have several drawbacks including a rapid clearance, the fact that they are affected by renal dysfunction, and different reactivity to the mode of action of individual myotoxicants. In conclusion, the promising biomarkers cTnI, cTnT, FABP3, MYL3, and sTnI demonstrated sensitivity and specificity for cardiac and skeletal myotoxicity that was superior to those of conventional biomarkers, while we should pay attention to the drawbacks of these biomarkers when used in toxicity studies.

The prognostic value of plasma fibrinogen concentrations of patients with ST-elevation myocardial infarction and treated by primary percutaneous coronary intervention: a cautionary message

BACKGROUND

Fibrinogen elevation is associated with a worse prognosis in patients with acute coronary syndrome (ACS). The aim of the present study was to assess the prognostic value of increased fibrinogen concentrations in ST-elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention (PCI).

METHODS

A total of 428 STEMI patients treated with primary PCI were retrospectively selected (median age: 62 years; 82.5% males) from a continuous case series of 832 ACS patients. Plasma fibrinogen concentrations were measured before PCI and after 24, 48, and 72 hours. In the 4-year follow-up, one major adverse cardiovascular event (MACE) occurred in 111 patients (40%): 17 re-STEMI (7%), 64 re-PCI (22%), 22 cardiac deaths (7%), and eight non ST-elevated acute coronary syndromes (NSTEACS, 4%).

RESULTS

According to the reference change value, fibrinogen concentrations increased in 25% of patients at 24 h, 64% at 48 h and 19% at 72 h. Only fibrinogen concentrations at 48 h showed a mild association with overall MACEs (p = 0.036): the risk increased, starting from a concentration of 4 g/L. However a further multivariate model did not confirm any prognostic value. No association with specific MACEs emerged.

CONCLUSIONS

In contrast to NSTEACS patients, fibrinogen concentrations increased slightly in STEMI patients after primary PCI, however, they were not as prognostic as for MACEs.

Biomarkers in acute myocardial injury

Acute coronary syndrome (ACS) is a significant cause of morbidity and mortality worldwide. The proper diagnosis of ACS requires reliable and accurate biomarker assays to detect evidence of myocardial necrosis. Currently, troponin is the gold standard biomarker for myocardial injury and is used commonly in conjunction with creatine kinase-MB (CK-MB) and myoglobin to enable a more rapid diagnosis of ACS. A new generation of highly sensitive troponin assays with improved accuracy in the early detection of ACS is now available, but the correct interpretation of assay results will require a careful consideration of assay characteristics and the clinical setting prior to incorporation into routine practice. B-type natriuretic peptides, copeptin, ischemia-modified albumin, heart-type fatty-acid-binding protein, myeloperoxidase, C-reactive protein, choline, placental growth factor, and growth-differentiation factor-15 make up a promising group of other biomarkers that have shown the ability to improve prognosis and diagnosis of ACS compared with traditional markers.

Inside ST-elevation myocardial infarction by monitoring concentrations of cardiovascular risk biomarkers in blood

BACKGROUND

No information is available on the optimal sampling time to catch the highest increase for biomarkers whose elevation after ST-elevation myocardial infarction (STEMI) is prognostic for adverse events. This study aimed to investigate release kinetics and peak times of cardiac troponin I (cTnI), C-reactive protein (CRP), B-type natriuretic peptide (BNP), chromogranin A (CgA) and cystatin C (CyC) in STEMI patients undergoing primary percutaneous coronary intervention (PPCI).

METHODS

Blood concentrations of cTnI, CRP, BNP, CgA and CyC were measured before and 6 h, 24 h, and 48 h after PPCI in 84 STEMI patients. The averaged trajectory of marker kinetics was estimated by multivariable regression models adjusted for patient characteristics and orthogonal polynomials were used to describe related releases.

RESULTS

From the estimated kinetics cTnI peaked at 10 h from symptoms, BNP at 28 h and CRP within 30 h. CyC concentrations did not change, whereas CgA concentrations increased from 6 to 48 h after PPCI. The amount of BNP release was found to be affected by the interaction between gender and age: females<75 years had BNP concentrations fourfold higher than males.

CONCLUSIONS

According to different release kinetics a single blood sampling for measuring all biomarkers is not recommended.

Established and novel biomarkers in ST-elevation myocardial infarction

Cardiac biomarkers assist in the diagnosis of and risk stratification in acute coronary syndromes. In ST-elevation myocardial infarction (STEMI), rapid diagnosis and initiation of reperfusion via primary percutaneous coronary intervention or fibrinolysis is often based on the clinical history and presenting ECG, but measurement of biomarkers in the early and/or late phases of STEMI may allow the selection of patients who are at increased or decreased risk of subsequent complications. Although the measurement of only three biomarkers (troponin, natriuretic peptides and C-reactive protein) are currently included in practice guidelines, more than 20 other novel cardiac biomarkers have been proposed to provide improved risk stratification after a STEMI.

Significance of 99mTc-sestamibi myocardial scintigraphy after percutaneous coronary intervention in patients with acute myocardial infarction

Background

This study was designed to clarify the significance of washout rate (WR) determined from ^99mTc-sestamibi myocardial scintigraphic images and the levels of cardiac enzymes in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI).

Material/Methods

A total of 56 consecutive patients with AMI (mean age 65.8±8.5 years), who underwent PCI on admission, were included. Cardiac enzyme, the MB isoenzyme of creatinine kinase (CK-MB), was measured every 3 h after admission. Two weeks after the onset of AMI, ^99mTc-sestamibi myocardial scintigraphy was performed at early (30 min) and delayed (4 h) phases after tracer injection. The heart-to-mediastinum ratio (H/M) and WR were calculated from the planar images.

Results

PCI was performed at 9.4±6.0 h after the onset of AMI. In 26 patients the culprit lesion was located in the right coronary artery and in 24 patients it was located in the left anterior descending coronary artery. The peak CK-MB was 274.1±169.4 IU/L (13.5±3.9 h). The early and delayed H/Ms and WR of ^99mTc-sestamibi were 2.74±0.58, 3.00±0.70, and 58.8±10.0%, respectively. The delayed H/M was significantly correlated with the peak CK-MB (r=−0.37, p=0.005). The WR of ^99mTc-sestamibi was also significantly correlated with the peak CK-MB (r=−0.34, p=0.012).

Conclusions

These results suggest that the WR determined from ^99mTc-sestamibi myocardial scintigraphic images reflects the extent of myocardial damage in AMI patients.

Myocardial infarction after carotid stenting and endarterectomy: results from the carotid revascularization endarterectomy versus stenting trial

BACKGROUND

The Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) found a higher risk of stroke after carotid artery stenting and a higher risk of myocardial infarction (MI) after carotid endarterectomy.

METHODS AND RESULTS

Cardiac biomarkers and ECGs were performed before and 6 to 8 hours after either procedure and if there was clinical evidence of ischemia. In CREST, MI was defined as biomarker elevation plus either chest pain or ECG evidence of ischemia. An additional category of biomarker elevation with neither chest pain nor ECG abnormality was prespecified (biomarker+ only). Crude mortality and risk-adjusted mortality for MI and biomarker+ only were assessed during follow-up. Among 2502 patients, 14 MIs occurred in carotid artery stenting and 28 MIs in carotid endarterectomy (hazard ratio, 0.50; 95% confidence interval, 0.26 to 0.94; P=0.032) with a median biomarker ratio of 40 times the upper limit of normal. An additional 8 carotid artery stenting and 12 carotid endarterectomy patients had biomarker+ only (hazard ratio, 0.66; 95% confidence interval, 0.27 to 1.61; P=0.36), and their median biomarker ratio was 14 times the upper limit of normal. Compared with patients without biomarker elevation, mortality was higher over 4 years for those with MI (hazard ratio, 3.40; 95% confidence interval, 1.67 to 6.92) or biomarker+ only (hazard ratio, 3.57; 95% confidence interval, 1.46 to 8.68). After adjustment for baseline risk factors, both MI and biomarker+ only remained independently associated with increased mortality.

CONCLUSIONS

In patients randomized to carotid endarterectomy versus carotid artery stenting, both MI and biomarker+ only were more common with carotid endarterectomy. Although the levels of biomarker elevation were modest, both events were independently associated with increased future mortality and remain an important consideration in choosing the mode of carotid revascularization or medical therapy.

CLINICAL TRIAL REGISTRATION

URL: http://www.ClinicalTrials.gov. Unique identifier: NCT00004732.

The utility of troponin measurement to detect myocardial infarction: review of the current findings

Myocardial infarction (MI) is defined by the presence of myocardial necrosis in combination with clinical evidence of myocardial ischemia. Cardiac troponins are regulatory proteins within the myocardium that are released into the circulation when damage to the myocyte has occurred. Therefore, serum troponin is an exquisitely sensitive marker of myocardial injury and is necessary for establishing the diagnosis of MI. High-sensitivity troponin assays are improving the diagnostic accuracy and rapid detection of myocardial infarction. The early identification of MI is vital for the institution of anti-thrombotic therapy to limit myocardial damage and preserve cardiac function. Troponin has both diagnostic and prognostic significance in the setting of acute coronary syndrome (ACS). Increased troponin levels in the absence of ACS should prompt an evaluation for an alternative, non-thrombotic mechanism of troponin elevation and direct management at the underlying cause. This review describes the role of troponin in the evaluation of patients with suspected myocardial infarction.