Admission cTnT Research Articles

Diurnal variation in admission troponin concentrations in patients with chest pain in the emergency department

BackgroundRecent studies have suggested that there may be large diurnal variation in cardiac troponin T (cTnT) concentrations measured with a high sensitive assay. ObjectiveTo investigate if clinically relevant diurnal variation in cTnT concentrations is present in patients with chest pain in the emergency department (ED). MethodsWe included all patients with chest pain, but no myocardial infarction (MI), and no other acute condition that may affect troponin concentrations in the ED at Karolinska University Hospital, Stockholm, Sweden, 2011–2014. Time periods for blood sampling were: 00.00–03.59 am, 04.00–07.59 am, 08.00–11.59 am, 00.00–03.59 pm, 04.00–07.59 pm, and 08.00–11.59 pm. Negative binomial regression models were used to calculate least-square means of admission cTnT concentrations with 95% confidence intervals (CIs). ResultsA total of 19,460 patients were included with a mean age of 54 ± 16 years. Patients who arrived during the night were younger, but other characteristics were similar among the time periods. The greatest mean admission cTnT concentrations for men (9.0 ng/l, 95% CI, 8.7–9.3), and women (8.0 ng/l, 95% CI, 7.8–8.2) were found at 08.00–11.59 am. After adjustment for age and estimated glomerular filtration rate, no significant diurnal variation in admission cTnT concentrations was observed. ConclusionsIn a cohort of unselected patients with chest pain, and no acute condition affecting troponin admission concentrations, we found no evidence of clinically relevant diurnal variation in admission cTnT concentrations. There is no need to take the time point when blood is drawn into account in the assessment of admission cTnT concentrations in the ED.

Heart-type fatty acid-binding protein detects more patients with non-ST segment elevation myocardial infarction compared to troponin-T

Abstract Objective To assess the value of using heart-type fatty acid-binding protein (H-FABP) as a marker of acute myocardial infarction (AMI) in patients presenting with non-ST segment elevation ACS (NSTE-ACS) in comparison with troponin-T (cTnT). Methods 122 consecutive patients presented with ischemic-type chest pain within the first 4 h of symptom onset with NSTE-ACS. Blood samples were obtained on arrival for H-FABP and cTnT. Patients with cTnT negative test on admission had a repeat analysis 6 h later. Patients with both H-FABP negative and admission cTnT positive had repeat analysis of H-FABP 6 h later. Results On admission, H-FABP was positive in 84 patients (68.9%) versus 36 patients (29.5%) with cTnT (p = 0.032). On repeat analysis after 6 h, total number of cTnT positive patients was 94 (77%) and cTnT negative was 28 (23%). All cTnT negative patients had negative H-FABP. Of cTnT positive patients, 84 (89.4%) had positive H-FABP test while the remaining 10 (10.6%) had “false” negative results. Using the final results of cTnT positive as gold standard, early assessment of cTnT within 4 h of chest pain had sensitivity of 38.3% and specificity of 100% while H-FABP had sensitivity of 89.4% and specificity of 100%. Conclusions For patients presenting with suspected ACS within 4 h of onset of symptoms, H-FABP detects a significantly larger number of patients with NSTEMI compared to troponin-T.

Prediction of long-term outcome by measurement of serum concentration of cardiac troponins in critically ill dogs with systemic inflammation.

BackgroundMyocardial injury, detected by cardiac troponin I and T (cTnI and cTnT), has been associated with long‐term death in the noncardiac human intensive care unit (ICU).HypothesisPresence of myocardial injury predicts 1‐year case fatality in critically ill dogs with systemic inflammation.AnimalsThirty‐eight dogs with evidence of systemic inflammation and no primary cardiac disease.MethodsProspective cohort study. In dogs admitted to the ICU with evidence of systemic inflammation, blood samples were obtained at ICU admission for measurement of cTnI and cTnT, and cTnI was measured once daily during ICU hospitalization. Receiver operating characteristic (ROC) curves were used to examine prognostic capacity of admission cTnI, admission cTnT, and peak cTnI concentrations.ResultsOne‐year case fatality rate was 47% (18/38 dogs). Admission cTnI concentrations were (median [range]) 0.48 [0.004–141.50] ng/mL, and peak cTnI concentrations were 1.21 [0.021–141.50] ng/mL. Admission cTnT concentrations were 15 [<13–3744] ng/L. For each marker, non‐survivors had significantly higher concentrations than survivors (P = .0082–.038). ROC analyses revealed areas under curves [95% CI] of 0.707 [0.537–0.843] for peak cTnI and 0.739 [0.571–0.867] for admission cTnT, respectively. At the optimal cut‐off, concentrations were 1.17 ng/mL (peak cTnI) and 23 ng/L (admission cTnT), sensitivities were 72% and 72%, and specificities were 70% and 80%, respectively.Conclusions and Clinical ImportanceWhile peak cTnI and admission cTnT are significantly related to 1‐year case fatality in critically ill dogs with systemic inflammation, low sensitivities and specificities prevent their prediction of long‐term outcome in individual patients. Troponins might play a role in identification of dogs at long‐term risk of death.

Point-of-care test of heart-type fatty acid-binding protein for the diagnosis of early acute myocardial infarction

To investigate the efficacies of point-of-care test of heart-type fatty-acid binding protein (H-FABP) and its combinations with the conventional biomarkers in the diagnosis of early acute myocardial infarction (AMI). 227 patients suspected of AMI were consecutively recruited in two centers. Biomarkers including H-FABP, myoglobin (MYO), creatine kinase-myocardial band (CK-MB) and cardiac troponin T (cTnT) were determined simultaneously at admission. AMI was defined according to the universal definition of myocardial infarction. Chi-Square test was adopted for the analysis. In patients presenting within 12 h of symptom onset, the sensitivity of H-FABP[93.0% (95% CI: 86.6%-96.9%)] was significantly higher than that of initial CK-MB [67.5% (95% CI: 58.1%-76.0%), P<0.0001], cTnT [69.3% (95%CI: 60.0%-77.6%), P<0.0001] and MYO [68.6% (95% CI: 54.1%-80.9%), P<0.05]. The negative predictive value of H-FABP [92.8% (95%CI: 86.3%-96.8%)] was significantly higher than that of initial CK-MB [74.7% (95% CI: 66.8%-81.5%), P<0.001] and cTnT [75.9% (95% CI: 68.1%-82.6%), P<0.001]. The sensitivity of H-FABP+cTnT combination [94.7% (95% CI: 88.9%-98.0%)] was significantly higher than that of admission cTnT [69.3% (95% CI: 60.0%-77.6%), P<0.0001], CK-MB+cTnT [75.4% (95% CI: 66.5%-83.0%), P<0.0001] and MYO+CK-MB+cTnT [74.5% (95% CI: 60.4%-85.7%), P<0.05]. The negative predictive value of H-FABP+cTnT [94.5% (95% CI: 88.4%-98.0%] was significantly higher than that of initial cTnT [75.9% (95% CI: 68.1%-82.6%), P<0.001] and CK-MB+cTnT [79.1% (95% CI: 71.2%-85.6%), P<0.001]. Subgroup analysis showed that the superiorities of both the sensitivities and the negative predictive values of H-FABP and H-FABP+cTnT combination occurred only in patients who presented within 6 h of the symptom onset. Point-of-care test of H-FABP can be used as a valuable biomarker to detect or exclude an early-stage AMI. Combining H-FABP and cTnT provides the best performance for early AMI diagnosis.

Elevated admission cardiac troponin T is associated with microvascular dysfunction in acute myocardial infarction treated with emergency angioplasty

We speculated that elevated admission cardiac troponin T (cTnT) could predict worse microvascular function in patients with ST-elevation myocardial infarction who are managed with emergency percutaneous coronary intervention. In 27 patients with ST-elevation myocardial infarction, we obtained admission cTnT, angiography at the time of intervention, and cardiovascular magnetic resonance after 3 days. Elevated admission cTnT was associated with a higher corrected Thrombolysis In Myocardial Infarction frame count (P = 0.04) and with a trend toward worse myocardial blush grade at the end of the procedure (P = 0.069), indicating a higher degree of microvascular obstruction. This was confirmed by its correlation with the size of perfusion defect seen at first-pass cardiovascular magnetic resonance (rho = 0.42, P = 0.028). In contrast, admission cTnT did not correlate with the amount of muscle necrosis as seen by delayed-enhancement cardiovascular magnetic resonance (rho = 0.12, P = 0.55). Elevated admission cTnT predicts worse microvascular function in ST-elevation myocardial infarction patients managed with emergency percutaneous coronary intervention. Measuring admission cTnT might provide the interventionalist with useful information for selecting additional therapies that benefit coronary microcirculation.

Novel biomarkers in early diagnosis of acute myocardial infarction compared with cardiac troponin T

To evaluate the role of novel biomarkers in early detection of acute myocardial infarction (MI) in patients admitted with acute chest pain. A prospective study of 664 patients presenting to two coronary care units with chest pain was conducted over 3 years from 2003. Patients were assessed on admission: clinical characteristics, ECG (electrocardiogram), renal function, cardiac troponin T (cTnT), heart fatty acid binding protein (H-FABP), glycogen phosphorylase-BB, NT-pro-brain natriuretic peptide, D-dimer, hsCRP (high sensitivity C-reactive protein), myeloperoxidase, matrix metalloproteinase-9, pregnancy associated plasma protein-A, soluble CD40 ligand. A > or = 12 h cTnT sample was also obtained. MI was defined as cTnT > or = 0.03 microg/L. In patients presenting <4 h of symptom onset, sensitivity of H-FABP for MI was significantly higher than admission cTnT (73 vs. 55%; P = 0.043). Specificity of H-FABP was 71%. None of the other biomarkers challenged cTnT. Combined use of H-FABP and cTnT (either one elevated initially) significantly improved the sensitivities of H-FABP or cTnT (85%; P < or = 0.004). This combined approach also improved the negative predictive value, negative likelihood ratio, and the risk ratio. Assessment of H-FABP within the first 4 h of symptoms is superior to cTnT for detection of MI, and is a useful additional biomarker for patients with acute chest pain.

Predictors of elevated cardiac troponin T on admission in ST-segment elevation myocardial infarction

In patients with ST-segment elevation acute myocardial infarction (STEMI), elevated cardiac troponin T (cTnT) on admission is associated with poorer outcomes despite early reperfusion. Presentation delay is thought to be the most important factor for the elevation of cTnT on admission. We evaluated presentation delay and other potential predictors of elevated cTnT on admission in patients treated with primary percutaneous coronary interventions (PCI) for STEMI. CTnT was measured upon arrival in the PCI centre in 444 patients with acute STEMI. An elevated cTnT was defined as > 0.05 microg/L. The mean age was 61.7 years and patients were admitted at a median of 155 min after symptom onset. Almost 50% had an elevated cTnT on admission. Patients with a positive cTnT on admission were less likely to have successful primary PCI (87 versus 93%, P=0.048) and had significantly higher rates of one-year mortality (4.9 versus 1.3%, P=0.031). There was a significant association between presentation delay and the prevalence of elevated admission cTnT, but even patients with early presentation (<120 min after symptom onset) still had a high prevalence of elevated cTnT (33%). After multivariate analysis, apart from presentation delay, anterior MI location and higher age were independent predictors of elevated cTnT on admission. In patients with STEMI, the prevalence of elevated cTnT on admission is high, even in patients with early presentation. Independent predictors of elevated cTnT on admission are presentation delay, increasing age and anterior MI location.

Risk stratification of chest pain patients by point-of-care cardiac troponin T and myoglobin measured in the emergency department

A prospective multicenter study including 1410 chest pain patients with suspected acute coronary syndromes was carried out to examine the predictive value of biological cardiac markers for adverse events measured by a point-of-care system. Admission cardiac troponin T (cTnT) and myoglobin were measured in parallel on a point-of-care system in the emergency department and – together with CK-MB mass – on lab analyzers. In a one-year follow-up, cardiac and non-cardiac death, acute myocardial infarction, unstable angina pectoris and need for revascularization were registered. Median time between onset of symptoms and admission was 285 min; 172 patients (12.2%) had no event during follow-up. If the cTnT, measured either by the point-of-care system or a conventional lab analyzer, was > 0.05 μg/L, then the chance of a cardiac event during the follow-up period was doubled (18% vs. 9%). Serial cTnT measurement did not add any further value to the predictive power of the admission cTnT. Myoglobin and CK-MB mass identified increasing risk with increasing concentration quartiles; cardiac event rates were 2.8- to 4.4-fold higher between the quartiles with the lowest and those with the highest analyte concentration, respectively. There was no difference in non-cardiac death rates between any concentration quartiles. In conclusion, the prediction of clinical events by cardiac troponin T and myoglobin measured with a point-of-care analyzer in the emergency department was as good as that of the same cardiac markers and CK-MB mass measured on lab analyzers.

Admission troponin T, advanced age and male gender identify patients with improved myocardial tissue perfusion after abciximab administration for ST-segment elevation myocardial infarction

The aim was to investigate the effect of abciximab on microvascular perfusion in different subgroups of patients undergoing direct PCI for acute STEMI. We enrolled 145 consecutive patients with TIMI grade 3 flow after direct PCI for acute STEMI. The GPIIb/IIIa inhibitor abciximab was administered in 57 patients (39.3%). Myocardial perfusion was the primary outcome measure and was assessed by analysis of cardiac troponin T wash-out. Treatment effects on myocardial perfusion and clinical outcome were tested for predefined subgroups including patients with an admission cTnT > or = 0.1 microg/L, diabetes mellitus, male gender, age > 70 years, and time from symptom onset to reperfusion > 6 hours. A significant improvement of cTnT wash-out was seen in patients with an admission cTnT > or = 0.1 microg/L, in males and in older patients. Improved tissue level reperfusion did not translate into a significant reduction of cardiac mortality or the incidence of the combined endpoint consisting of cardiac death, nonfatal reinfarction and need for target vessel revascularisation during 30 day- and long-term follow-up (mean 274 days). In conclusion, adjunctive administration of abciximab improves myocardial perfusion in patients with normal epicardial flow after direct PCI, particularly in patients with an cTnT > or = 0.1 microg/L on admission, age over 70 years and male gender.

Prognostic significance of admission cardiac troponin T in patients treated successfully with direct percutaneous interventions for acute ST-segment elevation myocardial infarction.

Cardiac troponin T (cTnT) elevations at admission indicate a high-risk subgroup of patients with acute ST-segment elevation myocardial infarction, possibly due to a higher failure rate of reperfusion therapies. We sought to determine the predictive role of admission cTnT in patients with ST-segment elevation myocardial infarction undergoing successful direct percutaneous coronary intervention. A total of 218 consecutive patients with ST-segment elevation myocardial infarction were enrolled. Patients were stratified according to admission cTnT and infarct location. They were followed prospectively for short-term and long-term outcomes. RESULTS A positive cTnT (47.7%) was associated with higher mortality rates at 30 days (14.4% vs. 3.5%, p = .003) and 12 months (17.3% vs. 4.4%, p =.007). cTnT allowed discrimination of patients at high and low risk for cardiac death at 30 days and 12 months among anterior (19.2% vs. 7.9%, p = .19, and 25% vs. 13.2%, p = .22, respectively) and, more impressively, among nonanterior acute myocardial infarction (9.6% vs. 1.3%, p = .04, and 11.5% vs. 1.3%, p = .017, respectively). In multivariate analysis, older age, anterior infarct location, and depressed left ventricular function were the most potent independent predictors of future risk. Among clinical variables available at admission, cTnT indicated independently a higher risk of cardiac death (odds ratio, 3.1 [1.07-9.01], p =.038). This increased risk associated with a positive cTnT was almost independent of time delays from onset of symptoms to admission (3.8 vs. 2.3 hrs in cTnT-positive vs. cTnT-negative patients, p <.001). Admission cTnT is a strong predictor of future cardiac risk in patients with ST-segment elevation myocardial infarction, despite successful restoration of Thrombolysis in Myocardial Infarction grade 3 coronary flow by direct percutaneous coronary intervention.

Risk stratification and therapeutic decision making in patients with acute coronary syndrome--the role of cardiac troponin T.

Patients with chest pain represent an inhomogeneous group with greatly varying severity of coronary artery disease and cardiac risk. The proper selection of different treatment strategies in these patients requires reliable risk assessment. Patients with definitive myocardial infarction: in patients with ST-segment elevation on ECG, a positive troponin T (cTnT) on admission identifies a group of patients having a threefold higher mortality rate than patients with a negative cTnT test. The differences in risk based on cTnT are found for patients treated with thrombolytic as well as mechanical recanalization therapy. These differences in mortality based on admission cTnT may be explained by more severe coronary artery disease, worse left ventricular function, and less efficient microvascular reperfusion in the cTnT-positive patients. Patients with rest angina: in patients with angina at rest, a positive cTnT value on admission identifies a subgroup having a threefold higher cardiac event rate than cTnT-negative patients. The cTnT-positive patients seem to benefit from treatment with low molecular weight heparin and fibrinogen receptor antagonists, while cTnT-negative patients do not. The differences in risk and response to therapy may be due to more severe coronary artery disease, more critical coronary artery stenoses, and a higher rate of intracoronary thrombus formation in the cTnT-positive versus negative patients. Low risk chest pain patients: in low risk chest pain patients, (i.e. no rest angina, no ECG-changes) cTnT-positive patients on admission have a twofold higher cardiac event rate than cTnT-negative patients. The proper treatment strategy for the low risk cTnT-positive patients remains to be determined. Troponin T versus troponin 1: many of the findings on cTnT also relate to troponin I. However, there is a high interassay variability of troponin I assays, which has to be taken into consideration.