Troponin I in Patients without Chest Pain (original) (raw)
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Journal of the American College of Cardiology, 2004
We compared outcomes in patients with non-ST-segment elevation acute coronary syndromes (ACS) according to the degree of cardiac troponin I (cTnI) elevation. BACKGROUND Controlled trials of high-risk patients have found that troponin elevations identify an even higher risk subset. It is unclear whether outcomes are similar among a lower risk, heterogeneous patient group. Also, few studies have reported outcomes other than myocardial infarction (MI) or death, based on the peak troponin value. METHODS Consecutively, admitted patients without ST-segment elevation on the initial electrocardiogram underwent serial marker sampling using creatine kinase (CK), CK-MB fraction, and cTnI. Patients were grouped according to peak cTnI: negative ϭ no detectable cTnI; low ϭ peak greater than the lower limit of detectability but less than the optimal diagnostic value; intermediate ϭ peak greater than or equal to the optimal diagnostic value but less than the manufacturer's suggested upper reference limit (URL); and high ϭ peak greater than or equal to the URL. Thirty-day outcomes included cardiac death, MI based on CK-MB, revascularization, significant disease, and a reversible defect on stress testing. Six-month mortality was also determined. Negative evaluations for ischemia included nonsignificant disease, no reversible stress defect, and negative rest perfusion imaging. RESULTS Of the 4,123 patients admitted, 893 (22%) had detectable cTnI values. Cardiac events and positive test results at 30 days and 6-month mortality increased significantly with increasing cTnI values. Negative evaluations for ischemia were significantly and inversely related to peak cTnI values. Although adverse events were significantly more common in patients with a low cTnI value than in those with negative cTnI, negative evaluations for ischemia were frequent. CONCLUSIONS Increased cTnI values are associated with worse outcomes. Although low cTnI values are associated with adverse events, they do not have the same implication as higher cTnI values, and nonischemic evaluations are frequent.
Clinical Biochemistry, 2000
The controversy whether there is a clinically significant difference between troponin T (cTnT) and troponin I (cTnI) in regard to predictive value and cardiac specificity is still ongoing. Methods: We evaluated enzyme-linked immunosorbent assay systems for cTnI and cTnT in patients with acute coronary syndromes and multiple control groups to define threshold values for risk stratification and compare their predictive value. Results: In 312 patients with noncardiac chest pain, cTnI levels were below the detection limit of 0.2 g/L and cTnT levels were 0.011 [0.010 -0.013] g/L. In patients with end-stage renal failure (n ϭ 26) and acute (n ϭ 38) or chronic (n ϭ 16) skeletal muscle damage, median concentrations were 0.20 [0.20 -0.35], below the detection limit, and 0.20 [0.20 -0.25] for cTnI, and 0.04 [0.01-0.10], 0.011 [0.005-0.025], and 0.032 [0.009 -0.054] g/L for cTnT. In patients with acute coronary syndromes (n ϭ 1130), maximized prognostic value for 30-day outcome (death, infarction) was observed at a threshold level of 1.0 g/L for cTnI (29.0% positive) and at 0.06 g/L for cTnT (35.0% positive). Significant differences in the area-under-the-curve values were observed between cTnI and cTnT (0.685 vs. 0.802; p ϭ 0.005). For both markers, the area-under-thecurve values did not increase with the second (within 24 h after enrollment) or third (48 h) blood draw. CTnI showed a less strong association with 30-day outcome than cTnT. When cTnI was put in a logistic multiple-regression model first, cTnT did add significant information. Conclusion: By using the defined threshold values and the employed test systems, single testing for cTnI and cTnT within 12 h after symptom onset was appropriate for risk stratification. Despite the lower cardiac specificity for cTnT, it appears to have a stronger association with the patients' outcome, whereas, as previously shown, the ability to identify patients who benefit from treatment with a GP IIb/IIIa receptor antagonist is similar.
Journal of the American College of Cardiology, 2012
The purpose of this study was to determine whether a new accelerated diagnostic protocol (ADP) for possible cardiac chest pain could identify low-risk patients suitable for early discharge (with follow-up shortly after discharge). Background Patients presenting with possible acute coronary syndrome (ACS), who have a low short-term risk of adverse cardiac events may be suitable for early discharge and shorter hospital stays. Methods This prospective observational study tested an ADP that included pre-test probability scoring by the Thrombolysis In Myocardial Infarction (TIMI) score, electrocardiography, and 0 ϩ 2 h values of laboratory troponin I as the sole biomarker. Patients presenting with chest pain due to suspected ACS were included. The primary endpoint was major adverse cardiac event (MACE) within 30 days. Results Of 1,975 patients, 302 (15.3%) had a MACE. The ADP classified 392 patients (20%) as low risk. One (0.25%) of these patients had a MACE, giving the ADP a sensitivity of 99.7% (95% confidence interval [CI]: 98.1% to 99.9%), negative predictive value of 99.7% (95% CI: 98.6% to 100.0%), specificity of 23.4% (95% CI: 21.4% to 25.4%), and positive predictive value of 19.0% (95% CI: 17.2% to 21.0%). Many ADP negative patients had further investigations (74.1%), and therapeutic (18.3%) or procedural (2.0%) interventions during the initial hospital attendance and/or 30-day follow-up. Conclusions Using the ADP, a large group of patients was successfully identified as at low short-term risk of a MACE and therefore suitable for rapid discharge from the emergency department with early follow-up. This approach could decrease the observation period required for some patients with chest pain. (An observational study of the diagnostic utility of an accelerated diagnostic protocol using contemporary central laboratory cardiac troponin in the assessment of patients presenting to two Australasian hospitals with chest pain of possible cardiac origin; ACTRN12611001069943) (
The American Journal of Emergency Medicine, 2001
Patients who have low-risk clinical features and negative cardiac troponin levels may be suitable for early discharge after a brief period of observation Jn the emergency department (ED). Little is known about the prevalence and severity of coronary artery disease in such patients, although this has implications for follow-up. Subjects included 570 patients who were at -<7% risk of acute myocardial infarction (AMI), remained clinically stable (defined as the absence of new ischemic changes on their electrocardiograph, signs or symptoms of heart failure, the development of a cardiac arrhythmia or hypotension requiring either inotropes or volume repletion) and had cardiac troponin I (cTnl) levels <0.2 #g1-1 during the initial 12 hours of hospitalization. Clinical features were documented and those undergoing stress tests and/or coronary angiograms had these graded by 2 independent observers. Overall, 190 (33.3%) of this population, who might be considered suitable for early discharge, had objective evidence of coronary artery disease. Patients with chest pain who are at low risk of AMI, remain clinically stable and have negative cTnl over the initial 12 hours of observation are a heterogeneous population, some of who have threatening coronary disease. This does not preclude early discharge from the ED but emphasizes the need for careful assessment and follow-up. (Am J Emerg Med 2001;19: 118-121.
The American Journal of Medicine, 2011
Background-Cardiac troponin levels help risk-stratify patients presenting with an acute coronary syndrome (ACS). Although they may be elevated in patients presenting with Non-ACS conditions, specific diagnoses and long-term outcomes within that cohort are unclear. Methods and Results-Using the Veterans Affairs (VA) centralized databases, we identified all hospitalized patients in 2006 who had a troponin assay obtained during their initial reference hospitalization. Based on ICD-9 diagnostic codes, primary diagnoses were categorized as either ACS or Non-ACS conditions. Of a total of 21,668 patients with an elevated troponin level who were discharged from the hospital, 12,400 (57.2%) had a Non-ACS condition. Among that cohort, the most common diagnostic category involved the cardiovascular system and congestive heart failure (N=1661) and chronic coronary artery disease (N=1648) accounted for the major classifications. At one-year following hospital discharge, mortality in patients with a Non-ACS condition was 22.8% and was higher than the ACS cohort (Odds Ratio=1.39; 95%CI: 1.30-1.49). Despite the high prevalence of cardiovascular diseases in patients with a Non-ACS diagnosis, utilization of cardiac imaging within 90 days of hospitalization was low compared with ACS patients (Odds Ratio=0.25; 95%CI: 0.23-0.27).
CJEM, 2004
ABSTRACTObjective:To determine the ability of troponin I (TnI) measurement to predict the likelihood of a serious cardiac outcome over the subsequent 72 hours in patients presenting to the emergency department (ED) with symptoms suggestive of an acute coronary syndrome.Methods:This prospective observational study enrolled consecutive patients presenting to 2 urban tertiary care hospital EDs over a 5-week period. Eligible patients included those for whom a TnI test was ordered within 24 hours of arrival and in whom no serious cardiac outcome occurred before the test result was available. Patients were followed for 72 hours and serious cardiac outcomes documented; these included cardiovascular death, myocardial infarction, congestive heart failure, serious arrhythmia and refractory pain. We calculated likelihood ratios (LRs) to describe the association of the TnI result with serious cardiac outcomes.Results:Of the 352 enrolled patients, 20 had a serious cardiac outcome within 72 hours...
PLOS ONE, 2018
Background Normal high sensitivity cardiac troponin (hs-cTn) assays rule out acute myocardial infarction (AMI) with great accuracy, but additional non-invasive testing is frequently ordered. This observational study evaluates whether clinical characteristics can contribute to risk stratification and could guide referral for additional testing. Methods 918 serial patients with acute chest pain and normal hs-cTnT levels were prospectively included. Major adverse cardiac events (MACE) and non-invasive test results were assessed during one-year follow-up. Patients were classified as low and high risk based on clinical characteristics. Results MACE occurred in 6.1% of patients and mainly comprised revascularizations (86%). A recent abnormal stress test, suspicious history, a positive family history and higher baseline hs-cTnT levels were independent predictors of MACE with odds ratios of 16.00 (95%
Revista española de cardiología, 2003
INTRODUCTION AND OBJECTIVES. To study the significance of chest pain in the clinical practice of a Spanish hospital and to evaluate the impact of routine troponin determination. In our institution, routine serial measurements of troponins I and T were made in the evaluation of chest pain in 2000. We compared the results obtained in 1999 for all patients who visited the emergency room for chest pain and the patients who were hospitalized. We recorded the diagnosis at discharge, duration of the hospital stay, and associated costs. In 2000, 1,820 patients with chest pain visited the emergency department, which was equivalent to 1.9% of visits and 7.5 cases per 1,000 people and year: 43% of these patients were hospitalized for suspected acute coronary syndrome as compared to 49% in 1999 (-12%; p > 0.001). Among the patients admitted, 28% were discharged with a diagnosis of non-ischemic chest pain. Troponin determinations were associated with a lower probability of admission due to un...