Elevations of cardiac troponin I are associated with increased short-term mortality in noncardiac critically ill emergency department patients

Wright, R. Scott; Williams, Brent A.; Cramner, Hilarie; Gallahue, Fiona E.; Willmore, Theodore; Lewis, Larry M.; Ladenson, Jack H.; Jaffe, Allan S.

doi:10.1016/s0002-9149(02)02570-5

Cited by 60 publications

(35 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In critically ill patients, such elevations have profound prognostic importance. 150,151 Elevations can be due to occult coronary artery or toxic substances such as tumour necrosis factor and heat-shock protein, as occurs in sepsis. 93 Elevations can also be due to either acute or more chronic processes (Box 3).…”

Section: Other Clinical Situations In Which Troponin Levels May Be Elmentioning

confidence: 99%

Troponin: the biomarker of choice for the detection of cardiac injury

Babuin¹

2005

Canadian Medical Association Journal

539

390

View full text Add to dashboard Cite

T roponin is the biomarker of choice for the detection of cardiac injury. To use it properly, one must understand how sensitive the specific assay being used is for detecting cardiac injury, the fact that elevated troponin levels are highly specific for cardiac injury and some critical issues related to the basic science of the protein and its measurement. In this article, we review the biology of troponin, characteristics of assays that measure serum troponin levels and how to apply these measurements to patients who present with possible cardiovascular disease. We also discuss other clinical situations in which troponin levels may be elevated. The biology of troponinThe 3-unit troponin complex (troponin I, T and C) along with tropomyosin is located on the actin filament and is essential for the calcium-mediated regulation of skeletal and cardiac muscle contraction. 1 There are tissue-specific isoforms of troponin I, T and C. 2,3 Because the cardiac isoform of troponin C is shared by slow-twitch skeletal muscles, troponin C does not have cardiac specificity and thus is not used in assays for the diagnosis of cardiac injury. 4 There is one cardiac troponin I (cTnI) isoform in myocardial tissue. 5 This isoform has a post-translational tail of 32 amino acids on the N-terminus. 6,7 This sequence and the 42% and 45% dissimilarity with sequences of the other isoforms 8 have made possible the generation of highly specific monoclonal antibodies without cross-reactivity with other noncardiac forms. 9 Three genes control cardiac troponin T (cTnT). 10 These genes and alternative mRNA splicing produce a series of isoforms 10,11 with variable sequences close to the regions of the N-terminus and C-terminus. 10,12 Human cardiac muscle contains 4 troponin T isoforms, but only one is characteristic of the normal adult heart. 13,14 Highly specific antibodies have been made to the N-terminus-specific sequence of this cTnT isoform. 15 The skeletal isoforms present in the fetal heart are replaced by cTnI and cTnT late during fetal development. 16,17 cTnI is not expressed in skeletal muscle or other tissues during development 17 or in response to degenerative or regenerative muscle disease processes. 18 Thus, it is unlikely to be reexpressed in damaged tissues. The situation is more complex for cTnT. Re-expression of fetal forms occurs in cardiac tissue 12 and in diseased skeletal muscle. 19 With the firstgeneration cTnT assay, this problem was compounded by a nonspecific tag antibody that cross-reacted with troponin T in skeletal muscle. 20 Once this antibody was replaced by one with high specificity, false-positive elevations from skeletal muscle were eliminated. 15 Studies using immunohistochemistry and polymerase chain reaction have confirmed that these fetal isoforms are not detected by the assay used today. 21,22 Thus, the assay used to measure cTnT levels has cardiac specificity equivalent to that of assays for cTnI. Characteristics of troponin assaysMost troponin is found in the 3-unit complex (troponin I, T and C) of the c...

show abstract

Section: Other Clinical Situations In Which Troponin Levels May Be Elmentioning

confidence: 99%

Troponin: the biomarker of choice for the detection of cardiac injury

Babuin¹

2005

Canadian Medical Association Journal

539

390

View full text Add to dashboard Cite

show abstract

“…Furthermore, we also show that our chip-based fabrication methodology is highly reproducible in which biosensors fabricated six months apart (batch-to-batch variation) produced nearly identical sensitivity. Owing to the enormous importance of cTnT in human health where >10 ng/L level is considered to be high risk for Myocardial Infarction (MCI), [26][27][28][29][30][31][32][33][34][35] we expect that our simple, cost-effective, and ultrasensitive assay in real human biofluids will be capable of detecting the potentially minute change in cTnT concentrations in symptom-free (chest, back, or jaw pain, and stable coronary artery disease) and poorly differentiated cases and allow interpretation to prevent heart attack by early diagnosis, thereby greatly improving patient survival. 36 Finally, our determination of the most influential nanoscale structural parameters and our methodology to control surface functionalization and immobilization of receptors will provide experimental benchmarks for the fabrication of ultrasensitive biosensors to quantitatively study a variety of important protein-protein interactions.…”

Section: Introductionmentioning

confidence: 99%

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

Liyanage

Sangha

Sardar

2017

Analyst

View full text Add to dashboard Cite

Acute myocardial infarction (heart attack) is the fifth leading cause of death in the United States (Dariush et al. Circulation 2015, 131, e29-e322). This highlights the needs for early, rapid, and sensitive detection of its occurrence and severity through assaying cardiac biomarkers in human fluids. Herein we report chip-based fabrication of the first label-free, nanoplasmonic biosensor to assay cardiac Troponin T (cTnT) in human biofluids (plasma, serum, and urine) with high specificity. The sensing mechanism is based on the adsorption model that measures the localized surface plasmon resonance (LSPR) wavelength shift of anti-cTnT functionalized gold triangular nanoprisms (Au TNPs) induced by change of their local dielectric environment upon binding of cTnT. We demonstrate that controlled manipulation of sensing volume and decay length of Au TNPs together with the appropriate surface functionalization and immobilization of anti-cTnT onto TNPs allows us to achieve a limit of detection (LOD) of our cTnT assay at attomolar concentration (~15 aM) in human plasma. This LOD is at least 50 fold more sensitive than that of other label-free techniques. Furthermore, we demonstrate excellent sensitivity of our sensors in human serum and urine. Importantly, the strategy of our chip-based fabrication is extremely reproducible. We believe our powerful analytical tool for detection of cTnT directly in human biofluids using this highly reproducible, label-free LSPR sensor will have great potential for early diagnosis of heart attack and thus increase patients' survival rate.

show abstract

“…Increased cardiac troponin I or T levels have been demonstrated to be associated with increased mortality in patients with acute coronary syndromes [1, 2], acute pulmonary embolism [3, 4], heart failure [5, 6], end-stage renal disease [7, 8] and noncardiac critically ill emergency department patients [9]. Increased cardiac troponin I levels were found in 11 of 15 patients (73%) with infective endocarditis (IE) [10].…”

Section: Introductionmentioning

confidence: 99%

Patients with Infective Endocarditis and Increased Cardiac Troponin I Levels Have a Higher Incidence of In-Hospital Mortality and Valve Replacement than Those with Normal Cardiac Troponin I Levels

Tsenovoy¹,

Aronow²,

Joseph³

et al. 2008

Cardiology

View full text Add to dashboard Cite

Objectives: To investigate the association of increased cardiac troponin I levels with in-hospital mortality and valve replacement in patients with infective endocarditis (IE). Methods: The 62 patients included 36 men and 26 women, with a mean age of 60 ± 9 years, with IE diagnosed by the Duke criteria. All 62 patients had blood drawn for measurement of cardiac troponin I levels. A cardiac troponin I level >0.4 ng/ml was considered increased. All 62 patients underwent transesophageal echocardiography. Student’s t tests were used to analyze continuous variables. χ² tests were used to analyze dichotomous variables. Results: Transesophageal echocardiography diagnosed valvular vegetations in 56 of the 62 patients (90%). Cardiac troponin I levels were increased in 35 of the 62 patients (57%). In-hospital mortality or valve replacement occurred in 18 of 35 patients (51%) with increased cardiac troponin I levels versus 4 of 27 patients (15%) with normal cardiac troponin I levels (p < 0.005). Conclusions: Patients with IE and increased cardiac troponin I levels have a higher incidence of in-hospital mortality or valve replacement than those with normal cardiac troponin I levels.

show abstract

Elevations of cardiac troponin I are associated with increased short-term mortality in noncardiac critically ill emergency department patients

Cited by 60 publications

References 20 publications

Troponin: the biomarker of choice for the detection of cardiac injury

Troponin: the biomarker of choice for the detection of cardiac injury

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

Patients with Infective Endocarditis and Increased Cardiac Troponin I Levels Have a Higher Incidence of In-Hospital Mortality and Valve Replacement than Those with Normal Cardiac Troponin I Levels

Contact Info

Product

Resources

About