Troponin elevation: is it ischemia?

2020 ◽  
pp. 7-11
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Cardiac Troponin ◽  
Stress Test ◽  
Obstructive Coronary Artery Disease ◽  
Plasma Concentrations ◽  
High Sensitivity ◽  
Hemodynamic Overload ◽  
Artery Disease ◽  
Transient Elevation

Cardiac troponin is the preferred biomarker for myocardial infarction, thanks to its sensitivity and absolute specificity for the heart. The availability of high-sensitivity assays (hs-cTnT and hs-cTnI), capable of measuring with excellent analytical precision very low levels of circulating troponin, raised the issue of whether transient ischemia is a sufficient stimulus for troponin release. For this purpose, in a series of patients submitted to a stress test (exercise ECG/echo test; dipyridamole echo test; dobutamine echo test), we measured plasma levels of hs-cTnT at baseline and 6 hours after the end of the test. Plasma concentrations of hs-cTnT significantly increased in the vast majority of patients after the test. Significant elevations were documented in response to each stressor, regardless of the test result, after both positive and negative tests. Moreover, troponin significantly increased in response to the stress, both in patients with and in patients without obstructive coronary artery disease. Despite a good sensitivity (80% and 89%), troponin showed a very low specificity (32% and 47%) for stress-induced ischemia and coronary artery disease, respectively. Myocardial release of troponin is a multifactorial process, mediated not only by cardiomyocyte necrosis, but also through several different mechanisms such as myocardial ischemia, increase in cardiac work, and hemodynamic overload. Transient elevation of high sensitivity cardiac troponin is not a useful tool for detecting spontaneous or stress-induced ischemia. L

scholarly journals Derivation and External Validation of a High‐Sensitivity Cardiac Troponin–Based Proteomic Model to Predict the Presence of Obstructive Coronary Artery Disease

2020 ◽  
Vol 9 (16) ◽  
Author(s):  
Cian P. McCarthy ◽  
Johannes T. Neumann ◽  
Sam A. Michelhaugh ◽  
Nasrien E. Ibrahim ◽  
Hanna K. Gaggin ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Predictive Value ◽  
Cardiac Troponin ◽  
Coronary Stenosis ◽  
Characteristic Curve ◽  
Obstructive Coronary Artery Disease ◽  
External Validation ◽  
High Sensitivity ◽  
Artery Disease

Background Current noninvasive modalities to diagnose coronary artery disease (CAD) have several limitations. We sought to derive and externally validate a hs‐cTn (high‐sensitivity cardiac troponin)–based proteomic model to diagnose obstructive coronary artery disease. Methods and Results In a derivation cohort of 636 patients referred for coronary angiography, predictors of ≥70% coronary stenosis were identified from 6 clinical variables and 109 biomarkers. The final model was first internally validated on a separate cohort (n=275) and then externally validated on a cohort of 241 patients presenting to the ED with suspected acute myocardial infarction where ≥50% coronary stenosis was considered significant. The resulting model consisted of 3 clinical variables (male sex, age, and previous percutaneous coronary intervention) and 3 biomarkers (hs‐cTnI [high‐sensitivity cardiac troponin I], adiponectin, and kidney injury molecule‐1). In the internal validation cohort, the model yielded an area under the receiver operating characteristic curve of 0.85 for coronary stenosis ≥70% ( P <0.001). At the optimal cutoff, we observed 80% sensitivity, 71% specificity, a positive predictive value of 83%, and negative predictive value of 66% for ≥70% stenosis. Partitioning the score result into 5 levels resulted in a positive predictive value of 97% and a negative predictive value of 89% at the highest and lowest levels, respectively. In the external validation cohort, the score performed similarly well. Notably, in patients who had myocardial infarction neither ruled in nor ruled out via hs‐cTnI testing (“indeterminate zone,” n=65), the score had an area under the receiver operating characteristic curve of 0.88 ( P <0.001). Conclusions A model including hs‐cTnI can predict the presence of obstructive coronary artery disease with high accuracy including in those with indeterminate hs‐cTnI concentrations.

scholarly journals High sensitivity cardiac troponins: Can they help in diagnosing myocardial ischaemia?

2017 ◽  
Vol 7 (6) ◽  
pp. 544-552 ◽  
Author(s):  
Enrico Orsini ◽  
Paolo Caravelli ◽  
Frank Lloyd Dini ◽  
Mario Marzilli
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Myocardial Ischaemia ◽  
Cardiac Troponin ◽  
Stress Test ◽  
Significant Proportion ◽  
High Sensitivity ◽  
Left Ventricular ◽  
Artery Disease ◽  
Test Result

Background: Cardiac troponin is the most sensitive marker of myocardial injury, but controversy still exists about its role in detecting ischaemia. Methods: To investigate the role of troponin as a marker of stress-induced ischaemia, circulating high sensitivity cardiac troponin T (hs-cTnT) was measured and compared with the MB fraction of creatine kinase (CK-MB) in 125 patients undergoing a stress test (53 electrocardiogram/echo exercise, 42 echo dipyridamole and 30 echo dobutamine tests). Results: Plasma concentrations of hs-cTnT increased after the tests in 90/125 patients, while an increase of CK-MB was seen in 31/125 patients ( p<0.0001). Overall, hs-cTnT significantly increased from 17.5±16.9 ng/l to 25.5±27.9 ng/l ( p<0.0001), without significant changes of CK-MB. Significant increments in hs-cTnT were documented after exercise test (from 15.9±11.9 ng/l to 19.5±13.6 ng/l, p<0.0001) and dobutamine test (from 20.6±20.8 ng/l to 37.8±31.1 ng/l, p=0.0006), in absence of changes in CK-MB according to each stressor. Among the 125 tests, 84 were diagnosed as negative and 41 as positive for myocardial ischaemia. Significant increments in hs-cTnT were detected after both negative (from 18.6±19.2 ng/l to 27.1±32.1 ng/l, p=0.0018) and positive test (from 15.2±10.8 ng/l to 22.3±16.2 ng/l, p=0.0005), without significant changes of CK-MB according to the test result. Despite a positive correlation between stress-induced increase of hs-cTnT and obstructive coronary artery disease, the release of troponin was observed also in a significant proportion of patients without coronary stenoses. Left ventricular hypertrophy markedly enhanced myocardial release of troponin. Conclusions: Circulating troponin increases in most patients undergoing a stress test, irrespective of the test result and of coronary artery disease. Plasma release of troponin depends on multiple pathogenetic mechanisms, making the biomarker a not reliable tool in detecting transient ischaemia.

P3645Prognosis in relation to high-sensitivity C-reactive protein levels in patients with non-obstructive coronary artery disease

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
H W Zhang ◽  
Y X Cao ◽  
J L Jin ◽  
Y L Guo ◽  
Y Gao ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Obstructive Coronary Artery Disease ◽  
High Sensitivity ◽  
C Reactive Protein ◽  
Development Fund ◽  
Reactive Protein ◽  
Increased Risk ◽  
Hs Crp ◽  
Artery Disease

Abstract Background It has been reported that coronary artery disease (CAD) is characterized by inflammation and non-obstructive CAD (NOCAD) increases the risk of cardiovascular events (CVEs) compared with ones with normal or near-normal coronary arteries (NNCA), even is similar to obstructive CAD (OCAD). We hypothesized that elevated high-sensitivity C-reactive protein (hs-CRP) may be linked to CVEs in those patients with NOCAD. Purpose To investigate the predictive role of hs-CRP in patients with NOCAD. Methods Of 7,746 consecutive patients with angina-like chest pain admissions, 4,662 eligible patients were enrolled who received coronary artery angiography (CAG) and followed up for the CVEs comprising all-cause mortality, myocardial infarction, stroke and late revascularization. According to the results of CAG, the patients were classified as NNCA group (<20% stenosis, n=698, 15.0%), NOCAD group (20–49% stenosis, n=639, 14.3%), and OCAD group (≥50% stenosis, n=3325, 70.7%). They were further subdivided into 3 groups according to baseline hs-CRP levels (<1, 1–3 and >3 mg/L). Proportional hazards models were used to assess the risk of CVEs in all patients enrolled. Results A total of 338 patients (7.3%) experienced CVEs during an average of 13403 person-years follow-up. Patients with NOCAD and OCAD had higher rates of CVEs compared to those with NNCA (p<0.05, respectively). In Cox's models after adjustment of confounders, the risk of CVEs elevated with the increasing degrees of CAD with hazard ratio of 2.01 [95% confidence interval (95% CI): 1.07–3.79, p=0.03] for patients with NOCAD and 2.81 (95% CI: 1.60–4.93, p<0.001) for patients with OCAD compared with the NNCA group. Moreover, elevated hs-CRP levels were associated with the severity of coronary lesions and an elevated increased risk of CVEs in patients with NOCAD and OCAD compared those with NNCA (p<0.05, respectively). Conclusions Patients with NOCAD had indeed worse outcomes and hs-CRP levels were positively in relation to the CVEs in those with NOCAD, which may help to the risk assessment in ones with NOCAD. Acknowledgement/Funding This study was partly supported by Capital Health Development Fund (201614035) and CAMS Innovation Fund for Medical Sciences (2016-I2M-1-011) awarded

scholarly journals Occult obstructive coronary artery disease is associated with prolonged cardiac troponin elevation following strenuous exercise

2019 ◽  
Vol 27 (11) ◽  
pp. 1212-1221 ◽  
Author(s):  
Øyunn Kleiven ◽  
Torbjørn Omland ◽  
Øyvind Skadberg ◽  
Tor H Melberg ◽  
Magnus F Bjørkavoll-Bergseth ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Computed Tomography Angiography ◽  
Cardiac Troponin ◽  
Coronary Computed Tomography Angiography ◽  
Obstructive Coronary Artery Disease ◽  
Strenuous Exercise ◽  
Coronary Computed Tomography ◽  
Artery Disease

Background Sudden cardiac death among middle-aged recreational athletes is predominantly due to myocardial ischaemia. This study examined whether measuring cardiac troponin I and T (cTnI and cTnT) after strenuous exercise could identify occult obstructive coronary artery disease. Design Prospective observational study. Methods Subjects were recruited from 1002 asymptomatic recreational cyclists completing a 91-km mountain bike race (North Sea Race Endurance Exercise Study). No subject had known cardiovascular disease or took cardiovascular medication. Blood samples were collected within 24 h before and 3 h and 24 h after the race. Coronary computed tomography angiography was performed in 80 participants with the highest post-exercise cTnI and in 40 reference subjects with moderately elevated cTnI values. Results Study subjects ( N = 120) were 45 (36–52) years old and 74% were male. There were similar demographics in the High-cTnI group and the Reference group. The cTn concentrations were highest at 3 h post-race: cTnI, 224 (125–304) ng/L; cTnT, 89 (55–124) ng/L. Nine subjects had obstructive coronary artery disease on coronary computed tomography angiography, eight of whom were High-cTnI responders. Two subjects had myocardial bridging, both High-cTnI responders. Troponin concentrations at 24 h post-race were higher in subjects with obstructive coronary artery disease than in the rest of the cohort ( n = 109): cTnI, 151 (72–233) ng/L vs. 24 (19–82) ng/L, p = 0.005; cTnT, 39 (25–55) ng/L vs. 20 (14–31) ng/L, p = 0.002. The areas under the receiver operating characteristic curves for predicting obstructive coronary artery disease were 0.79, p = 0.005 (cTnI) and 0.82, p = 0.002 (cTnT). Conclusion In subjects with occult obstructive coronary artery disease there was a prolonged elevation of cTn following strenuous exercise.

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