scholarly journals Cardiac Troponin And Defining Myocardial Infarction

2021 ◽  
Author(s):  
Thomas E Kaier ◽  
Bashir Alaour ◽  
Michael Marber

Abstract The 4th Universal Definition of Myocardial Infarction has stimulated considerable debate since its publication in 2018. The intention was to define the types of myocardial injury through the lens of their underpinning pathophysiology. In this review we discuss how the 4th Universal Definition of Myocardial Infarction defines infarction and injury and the necessary pragmatic adjustments that appear in clinical guidelines to maximise triage of real-world patients.

2020 ◽  
Vol 13 (Suppl_1) ◽  
Author(s):  
Sandeep Jain ◽  
Andrew Hammes ◽  
Eric Rudofker ◽  
Karen Ream ◽  
Andrew E Levy

In the United States, the positive predictive value (PPV) of cardiac troponin for type 1 myocardial infarction is substantially lower than in Europe (15% vs. 50%). Further, even with publication of the 4 th Universal Definition of Myocardial Infarction, recent studies have shown that inaccurate classification of myocardial injury is common among clinicians in the United States. These findings are at least partly attributable to clinicians’ knowledge and attitudes about cardiac troponin testing; a survey of these parameters has never been conducted. Clinicians at the University of Colorado completed a brief 8-question multiple-choice survey related to troponin use, definitions of myocardial infarction and clinical assessment of elevated troponin levels. The survey was distributed via secure email and administered electronically using the Qualtrics™ platform. Responses were anonymous, completion was estimated to take 3 minutes and a lottery award system was used as an incentive for participation. Respondents included trainees, advanced practice providers and attending physicians from internal medicine, emergency medicine and medical subspecialties. We plan to obtain a total of 300 responses with descriptive findings of preliminary results included below. The survey was completed by 114 clinicians: 37 interns (32%), 45 residents (39%), 9 advanced practice providers (8%), 11 fellows (10%), and 12 attending physicians (11%). Regarding indications for troponin testing, 93% (106/114) indicated that they “usually” or “always” check troponin levels in patients with chest pain. More interestingly, 46% (52/112) reported checking troponin on “undifferentiated patients” at least half the time. For troponin interpretation, 97% (110/114) of participants identified that troponin levels alone cannot rule in or rule out coronary artery disease. In contrast, only 36% (41/114) and 55% (63/114), respectively, identified the NPV and PPV of a contemporary troponin assay for type 1 MI. Further, only 50% (57/114) of respondents identified that the likelihood of type 1 MI increases as troponin levels increase. Three brief clinical vignettes revealed that, while 78% (89/114) and 74% (45/61) of participants, respectively, identified type 1 MI and type 2 MI presentations, only 40% (21/53) of respondents correctly identified a vignette for non-ischemic myocardial injury. Concordant with this finding, 54% (61/114) of clinicians correctly identified the 4 th Universal Definition of Myocardial Infarction. These preliminary findings highlight important facets of clinician attitudes and knowledge about troponin testing that help explain the poor PPV for troponin and diagnostic misclassification observed among U.S. clinicians. These results could help guide curricular and clinical decision support interventions designed to improve the use and interpretation of cardiac troponin testing.


Circulation ◽  
2020 ◽  
Vol 141 (3) ◽  
pp. 161-171 ◽  
Author(s):  
Andrew R. Chapman ◽  
Philip D. Adamson ◽  
Anoop S.V. Shah ◽  
Atul Anand ◽  
Fiona E. Strachan ◽  
...  

Background: The introduction of more sensitive cardiac troponin assays has led to increased recognition of myocardial injury in acute illnesses other than acute coronary syndrome. The Universal Definition of Myocardial Infarction recommends high-sensitivity cardiac troponin testing and classification of patients with myocardial injury based on pathogenesis, but the clinical implications of implementing this guideline are not well understood. Methods: In a stepped-wedge cluster randomized, controlled trial, we implemented a high-sensitivity cardiac troponin assay and the recommendations of the Universal Definition in 48 282 consecutive patients with suspected acute coronary syndrome. In a prespecified secondary analysis, we compared the primary outcome of myocardial infarction or cardiovascular death and secondary outcome of noncardiovascular death at 1 year across diagnostic categories. Results: Implementation increased the diagnosis of type 1 myocardial infarction by 11% (510/4471), type 2 myocardial infarction by 22% (205/916), and acute and chronic myocardial injury by 36% (443/1233) and 43% (389/898), respectively. Compared with those without myocardial injury, the rate of the primary outcome was highest in those with type 1 myocardial infarction (cause-specific hazard ratio [HR] 5.64 [95% CI, 5.12–6.22]), but was similar across diagnostic categories, whereas noncardiovascular deaths were highest in those with acute myocardial injury (cause specific HR 2.65 [95% CI, 2.33–3.01]). Despite modest increases in antiplatelet therapy and coronary revascularization after implementation in patients with type 1 myocardial infarction, the primary outcome was unchanged (cause specific HR 1.00 [95% CI, 0.82–1.21]). Increased recognition of type 2 myocardial infarction and myocardial injury did not lead to changes in investigation, treatment or outcomes. Conclusions: Implementation of high-sensitivity cardiac troponin assays and the recommendations of the Universal Definition of Myocardial Infarction identified patients at high-risk of cardiovascular and noncardiovascular events but was not associated with consistent increases in treatment or improved outcomes. Trials of secondary prevention are urgently required to determine whether this risk is modifiable in patients without type 1 myocardial infarction. Clinical Trial Registration: https://www.clinicaltrials.gov . Unique identifier: NCT01852123.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Yader Sandoval ◽  
Stephen W Smith ◽  
Karen M Schulz ◽  
MaryAnn M Murakami ◽  
Fred S Apple

Introduction: High-sensitivity cardiac troponin (hs-cTn) assays have not yet been FDA cleared for clinical use in the United States (US). Pending expected approval of hs-cTn assays, which will use gender-specific cutoffs (GSC), it is relevant to recognize the causes of cTn increases using hs-cTnI assays in a US population. Our purpose was to describe the frequency of distinct etiologies of hs-cTnI assay increases using GSC. Methods: Retrospective study of 310 patients with serial hs-cTnI (Abbott ARCHITECT, 99th percentiles: F:16 ng/L; M:34 ng/L) measurements. Patients with an increased hs-cTnI were adjudicated into categories according to the 3rd Universal Definition of MI. Categories included, A: primary myocardial ischemia (i.e. plaque rupture); B: injury secondary to supply/demand imbalance; C: injury not related to myocardial ischemia (i.e. cardiac contusion, ablation, shock, surgery); D: multifactorial or indeterminate myocardial injury (i.e. heart failure, critically ill, pulmonary HTN, sepsis, stroke, renal failure, pulmonary embolism); E: Unknown. Results: 127 (41%) had an increased hs-cTnI above the GSC 99th percentile, whereas 183 (59%) had a normal hs-cTnI. The most common causes of hs-cTnI increases were: a) multifactorial or indeterminate injury - 43% among all patients and 52% in males, and b) supply/demand imbalance - 39% in women (Table). Injury related to primary myocardial ischemia was present in 10% (n=13). Females had more injury related to supply/demand ischemia than males (39% vs. 18%, p=0.01), whereas males had more multifactorial or indeterminate injury (52% vs. 33%, p=0.05). Conclusions: Most increased hs-cTnI values were explained by non-plaque rupture conditions. Males tended to have hs-cTnI increases due to multifactorial/indeterminate causes, whereas in women supply/demand imbalance was the most common etiology. Investigations are needed to better understand if etiologies of myocardial injury have gender differences.


2019 ◽  
Vol 65 (3) ◽  
pp. 484-489 ◽  
Author(s):  
Atul Anand ◽  
Anoop S V Shah ◽  
Agim Beshiri ◽  
Allan S Jaffe ◽  
Nicholas L Mills

Abstract BACKGROUND The universal definition of myocardial infarction (UDMI) standardizes the approach to the diagnosis and management of myocardial infarction. High-sensitivity cardiac troponin testing is recommended because these assays have improved precision at low concentrations, but concerns over specificity may have limited their implementation. METHODS We undertook a global survey of 1902 medical centers in 23 countries evenly distributed across 5 continents to assess adoption of key recommendations from the UDMI. Respondents involved in the diagnosis and management of patients with suspected acute coronary syndrome completed a structured telephone questionnaire detailing the primary biomarker, diagnostic thresholds, and clinical pathways used to identify myocardial infarction. RESULTS Cardiac troponin was the primary diagnostic biomarker at 96% of surveyed sites. Only 41% of centers had adopted high-sensitivity assays, with wide variation from 7% in North America to 60% in Europe. Sites using high-sensitivity troponin more frequently used serial sampling pathways (91% vs 78%) and the 99th percentile diagnostic threshold (74% vs 66%) than sites using previous-generation assays. Furthermore, high-sensitivity institutions more often used earlier serial sampling (≤3 h) and accelerated diagnostic pathways. Fewer than 1 in 5 high-sensitivity sites had adopted sex-specific thresholds (18%). CONCLUSIONS There has been global progress toward the recommendations of the UDMI, particularly in the use of the 99th percentile diagnostic threshold and serial sampling. However, high-sensitivity assays are still used by a minority of sites, and sex-specific thresholds by even fewer. Additional efforts are required to improve risk stratification and diagnosis of patients with myocardial infarction.


2018 ◽  
Author(s):  
Atul Anand ◽  
Anoop SV Shah ◽  
Agim Beshiri ◽  
Allan S Jaffe ◽  
Nicholas L Mills

AbstractImportanceThe third Universal Definition of Myocardial Infarction aimed to standardize the approach to the diagnosis and management of myocardial infarction. High-sensitivity cardiac troponin testing was recommended, as these assays have improved precision at low concentrations, but concerns over specificity may have limited implementation.ObjectiveTo determine the global adoption of high-sensitivity cardiac troponin assays and key recommendations from the Universal Definition.Design, Setting and ParticipantsGlobal survey of 1,902 medical centers across 23 countries evenly distributed across all five continents. Included respondents were involved in the diagnosis and management of patients with suspected acute coronary syndrome at their institutions.Main Outcomes and MeasuresStructured questionnaire detailing the primary biomarker used for myocardial infarction, diagnostic thresholds and critical elements of clinical pathways for comparison to the third Universal Definition recommendations.ResultsCardiac troponin was the primary diagnostic biomarker for myocardial infarction at 96% of all sites surveyed. Only 41% of centers had adopted high-sensitivity cardiac troponin assays, with wide variation from 7% in North America to 60% in Europe. Sites using high-sensitivity assays more frequently employed serial sampling pathways (91% vs. 78%) and the 99th percentile diagnostic threshold (74% vs. 66%) when compared to sites using the previous generation of troponin assays. Furthermore, sites using high-sensitivity assays more often used earlier serial sampling (≤3 hours) and accelerated diagnostic pathways. However, fewer than 1 in 5 sites using high-sensitivity assays had adopted sex-specific thresholds (18%).Conclusions and RelevanceProgress has been made in adopting the recommendations of the Universal Definition of Myocardial Infarction, particularly in the use of the 99th percentile diagnostic threshold and serial sampling. However, high-sensitivity assays are used in a minority of sites and sex-specific thresholds in even fewer. These findings highlight regions where additional efforts are required to improve the risk stratification and diagnosis of patients with myocardial infarction.


2012 ◽  
Vol 58 (1) ◽  
pp. 274-283 ◽  
Author(s):  
Jacobus P J Ungerer ◽  
Louise Marquart ◽  
Peter K O'Rourke ◽  
Urs Wilgen ◽  
Carel J Pretorius

Abstract BACKGROUND Data to standardize and harmonize the differences between cardiac troponin assays are needed to support their universal status in diagnosis of myocardial infarction. We characterized the variation between methods, the comparability of the 99th-percentile cutoff thresholds, and the occurrence of outliers in 4 cardiac troponin assays. METHODS Cardiac troponin was measured in duplicate in 2358 patient samples on 4 platforms: Abbott Architect i2000SR, Beckman Coulter Access2, Roche Cobas e601, and Siemens ADVIA Centaur XP. RESULTS The observed total variances between the 3 cardiac troponin I (cTnI) methods and between the cTnI and cardiac troponin T (cTnT) methods were larger than expected from the analytical imprecision (3.0%–3.7%). The between-method variations of 26% between cTnI assays and 127% between cTnI and cTnT assays were the dominant contributors to total variances. The misclassification of results according to the 99th percentile was 3%–4% between cTnI assays and 15%–17% between cTnI and cTnT. The Roche cTnT assay identified 49% more samples as positive than the Abbott cTnI. Outliers between methods were detected in 1 patient (0.06%) with Abbott, 8 (0.45%) with Beckman Coulter, 10 (0.56%) with Roche, and 3 (0.17%) with Siemens. CONCLUSIONS The universal definition of myocardial infarction should not depend on the choice of analyte or analyzer, and the between- and within-method differences described here need to be considered in the application of cardiac troponin in this respect. The variation between methods that cannot be explained by analytical imprecision and the discordant classification of results according to the respective 99th percentiles should be addressed.


2019 ◽  
Vol 14 (9) ◽  
Author(s):  
Christopher J King ◽  
Andrew E Levy ◽  
Jeffrey C Trost

In this clinical practice update, we aim to review the updated definition of Type 2 MI (T2MI) and nonischemic myocardial injury (NIMI), since these are the two predominant diagnoses among patients with elevated troponin in the absence of T1MI. We also provide a clinical framework for clinicians to think through elevated serum cardiac troponin levels and identify opportunities for quality improvement around this critical issue.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248289
Author(s):  
Anthony (Ming-yu) Chuang ◽  
Mau T. Nguyen ◽  
Ehsan Khan ◽  
Dylan Jones ◽  
Matthew Horsfall ◽  
...  

Background The Fourth Universal Definition of Myocardial Infarction (MI) differentiates MI from myocardial injury. We characterised the temporal course of cardiac and non-cardiac outcomes associated with MI, acute and chronic myocardial injury. Methods We included all patients presenting to public emergency departments in South Australia between June 2011–Sept 2019. Episodes of care (EOCs) were classified into 5 groups based on high-sensitivity troponin-T (hs-cTnT) and diagnostic codes: 1) Acute MI [rise/fall in hs-cTnT and primary diagnosis of acute coronary syndrome], 2) Acute myocardial injury with coronary artery disease (CAD) [rise/fall in hs-cTnT and diagnosis of CAD], 3) Acute myocardial injury without CAD [rise/fall in hs-cTnT without diagnosis of CAD], 4) Chronic myocardial injury [elevated hs-cTnT without rise/fall], and 5) No myocardial injury. Multivariable flexible parametric models were used to characterize the temporal hazard of death, MI, heart failure (HF), and ventricular arrhythmia. Results 372,310 EOCs (218,878 individuals) were included: acute MI (19,052 [5.12%]), acute myocardial injury with CAD (6,928 [1.86%]), acute myocardial injury without CAD (32,231 [8.66%]), chronic myocardial injury (55,056 [14.79%]), and no myocardial injury (259,043 [69.58%]). We observed an early hazard of MI and HF after acute MI and acute myocardial injury with CAD. In contrast, subsequent MI risk was lower and more constant in patients with acute injury without CAD or chronic injury. All patterns of myocardial injury were associated with significantly higher risk of all-cause mortality and ventricular arrhythmia. Conclusions Different patterns of myocardial injury were associated with divergent profiles of subsequent cardiac and non-cardiac risk. The therapeutic approach and modifiability of such excess risks require further research.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A R Chapman ◽  
P D Adamson ◽  
A Anand ◽  
A S V Shah ◽  
K K Lee ◽  
...  

Abstract Background The Universal Definition of Myocardial Infarction recommends the 99th centile diagnostic threshold using a high-sensitivity cardiac troponin (hs-cTn) assay and the classification of patients by the etiology of myocardial injury. Whether implementation of this definition improves risk stratification, treatment or outcomes is unknown. Methods In a stepped-wedge cluster randomized controlled trial, we implemented a high-sensitivity troponin assay and the recommendations of the Universal Definition in 48,282 consecutive patients with suspected acute coronary syndrome across ten hospitals. In a pre-specified secondary analysis, we compared the primary outcome of myocardial infarction or cardiovascular death, and secondary outcome of non-cardiovascular death at one year across diagnostic categories as per the Fourth Universal Definition. We applied competing risks methodology in all analyses, using a cumulative incidence function and determining the cause-specific hazard ratio (csHR) for competing outcomes. Results Cardiac troponin concentrations were elevated in 21.5% (10,360/48,282) of all trial participants. Implementation increased the diagnosis of type 1 myocardial infarction by 11% (510/4,471), type 2 myocardial infarction by 22% (205/916), acute myocardial injury by 36% (443/1,233) and chronic myocardial injury by 43% (389/898). The risk and rate of the primary outcome was highest in those with type 1 myocardial infarction, whereas the risk and rate of non-cardiovascular death was highest in those with acute myocardial injury (Table, Figure). Despite increases in anti-platelet therapy and coronary revascularization after implementation, the primary outcome was unchanged in patients with type 1 myocardial infarction (csHR 1.00, 95% CI 0.82 to 1.21), or in any other category. Adjusted csHR for competing outcomes Myocardial infarction or cardiovascular death Non-cardiovascular death Adjusted csHR (95% CI) Adjusted csHR (95% CI) Type 1 myocardial infarction 5.64 (5.12 to 6.22) 0.83 (0.72 to 0.96) Type 2 myocardial infarction 3.50 (2.94 to 4.15) 1.72 (1.44 to 2.06) Acute myocardial injury 4.38 (3.80 to 5.05) 2.65 (2.33 to 3.00) Chronic myocardial injury 3.88 (3.31 to 4.55) 2.06 (1.77 to 2.40) Cox regression models adjusted for age, sex, diabetes, ischaemic heart disease, season, days since trial onset and site of recruitment (as a random effect). Cumulative incidence and number at risk Conclusions Implementation of the recommendations of the Universal Definition identified patients with different risks of future cardiovascular and non-cardiovascular events, but did not improve outcomes. Greater understanding of the underlying mechanisms and effective strategies for the investigation and treatment of patients with myocardial injury and infarction are required if we are to improve outcomes. Acknowledgement/Funding British Heart Foundation


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