A rapid troponin I assay is not optimal for determination of troponin status and prediction of subsequent cardiac events at suspicion of unstable coronary syndromes (original) (raw)
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Acute Coronary Syndrome vs Nonspecific Troponin ElevationClinical Predictors and Survival Analysis
Archives of Internal Medicine, 2007
Although troponin is considered a specific marker for the diagnosis of acute coronary syndrome (ACS), recent studies have shown troponin elevation in a variety of nonischemic conditions. Our aim was to determine the predictors for the diagnosis of ACS in the presence of an abnormal troponin level. All patients with abnormal troponin T levels were analyzed. Demographic and clinical data were collected and death was recorded. The study group was divided into 2 subgroups: ACS vs nonthrombotic troponin elevation. A multivariate logistic regression analysis was performed to define variables that predict the diagnosis of ACS. The positive predictive value (PPV) for ACS diagnosis was calculated, and a survival analysis was performed. During the study period, 615 patients had elevated troponin T levels. Only 326 patients (53%) received a main diagnosis of ACS, while 254 (41%) had nonthrombotic troponin elevation; for 35 patients (6%), the diagnosis was not conclusive. Positive predictors for the diagnosis of ACS were age between 40 and 70 years, history of hypertension or ischemic heart disease, normal renal function, and a troponin T level higher than 1.0 ng/mL. The overall PPV of troponin T for ACS diagnosis was only 56% (95% CI, 52%-60%). The PPV of troponin T level higher than 1.0 ng/mL in the presence of normal renal function was 90% but was as low as 27% for values of 0.1 to 1.0 ng/mL for elderly patients with renal failure. In-hospital and long-term survival rates were significantly better (P<.001) for patients with ACS. Nonspecific troponin elevation is a common finding among hospitalized patients and correlates with worse prognosis. The diagnosis of myocardial infarction should still mostly be based on the clinical presentation. The predictors and algorithm suggested in this study might increase the diagnostic accuracy of ACS and direct the appropriate treatment.
Acute Coronary Syndrome vs Nonspecific Troponin Elevation
Archives of Internal Medicine, 2007
Background: Although troponin is considered a specific marker for the diagnosis of acute coronary syndrome (ACS), recent studies have shown troponin elevation in a variety of nonischemic conditions. Our aim was to determine the predictors for the diagnosis of ACS in the presence of an abnormal troponin level. Methods: All patients with abnormal troponin T levels were analyzed. Demographic and clinical data were collected and death was recorded. The study group was divided into 2 subgroups: ACS vs nonthrombotic troponin elevation. A multivariate logistic regression analysis was performed to define variables that predict the diagnosis of ACS. The positive predictive value (PPV) for ACS diagnosis was calculated, and a survival analysis was performed. Results: During the study period, 615 patients had elevated troponin T levels. Only 326 patients (53%) received a main diagnosis of ACS, while 254 (41%) had nonthrombotic troponin elevation; for 35 patients (6%), the diagnosis was not conclusive. Positive predictors for the
Scandinavian Journal of Clinical & Laboratory Investigation, 2000
van Domburg RT, Cobbaert C, MuÈ ller-Bardorff M, Kampmann M, Kimman GP, Rauscher T, Schoolmann S, Zerback R, Katus HA, Simoons ML. Timedependent diagnostic performance of a rapid troponin T version 2 bedside test in patients with acute coronary syndromes. Scand J Clin Lab Invest 2000; 60: 665± 676.
JAMA, 2011
Context Although troponin assays have become increasingly more sensitive, it is unclear whether further reductions in the threshold of detection for plasma troponin concentrations will improve clinical outcomes in patients with suspected acute coronary syndrome (ACS). Objective To determine whether lowering the diagnostic threshold for myocardial infarction (MI) with a sensitive troponin assay could improve clinical outcomes. Design, Setting, and Patients All consecutive patients admitted with suspected ACS to the Royal Infirmary of Edinburgh, Edinburgh, Scotland, before (n=1038; February 1-July 31, 2008, during the validation phase) and after (n=1054; February 1-July 31, 2009, during the implementation phase) lowering the threshold of detection for myocardial necrosis from 0.20 to 0.05 ng/mL with a sensitive troponin I assay were stratified into 3 groups (Ͻ0.05 ng/mL, 0.05-0.19 ng/mL, and Ն0.20 ng/mL). During the validation phase, only concentrations above the original diagnostic threshold of 0.20 ng/mL were reported to clinicians. Main Outcome Measure Event-free survival (recurrent MI and death) at 1 year in patients grouped by plasma troponin concentrations. Results Plasma troponin concentrations were less than 0.05 ng/mL in 1340 patients (64%), 0.05 to 0.19 ng/mL in 170 patients (8%), and 0.20 ng/mL or more in 582 patients (28%). During the validation phase, 39% of patients with plasma troponin concentrations of 0.05 to 0.19 ng/mL were dead or had recurrent MI at 1 year compared with 7% and 24% of those patients with troponin concentrations of less than 0.05 ng/mL (PϽ.001) or 0.20 ng/ mL or more (P=.007), respectively. During the implementation phase, lowering the diagnostic threshold to 0.05 ng/mL was associated with a lower risk of death and recurrent MI (from 39% to 21%) in patients with troponin concentrations of 0.05 to 0.19 ng/mL (odds ratio, 0.42; 95% confidence interval, 0.24-0.84; P=.01). Conclusions In patients with suspected ACS, implementation of a sensitive troponin assay increased the diagnosis of MI and identified patients at high risk of recurrent MI and death. Lowering the diagnostic threshold of plasma troponin was associated with major reductions in morbidity and mortality.
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...
The Medical journal of Malaysia, 2005
Acute coronary syndrome (ACS) patients with positive troponin T (TnT) test are at higher risk for death and myocardial reinfarction. They would significantly benefit from early aggressive pharmacologic and invasive therapy. However, TnT test is not widely available. This retrospective study of 173 patients with ACS showed: that prolonged or repetitive episodes of angina at rest in the previous 24 hours (p = 0.01) and evidence of myocardial ischaemia on ECG (p < 0.001) were associated with positive TnT tests (> or = 0.1 ng/mL). The two variables in combination showed 100% positive predictive value, facilitating early identification and streamlining of therapy.
Troponin elevation in coronary vs. non-coronary disease
European Heart Journal, 2010
Acute myocardial infarction is defined as myocardial cell death due to prolonged myocardial ischaemia. Cardiac troponins (cTn) are the most sensitive and specific biochemical markers of myocardial injury and with the new high-sensitivity troponin methods very minor damages on the heart muscle can be detected. However, elevated cTn levels indicate cardiac injury, but do not define the cause of the injury. Thus, cTn elevations are common in many disease states and do not necessarily indicate the presence of a thrombotic acute coronary syndrome (ACS). In the clinical work it may be difficult to interpret dynamic changes of troponin in conditions such as stroke, pulmonary embolism, sepsis, acute perimyocarditis, Tako-tsubo, acute heart failure, and tachycardia. There are no guidelines to treat patients with elevated cTn levels and no coronary disease. The current strategy of treatment of patients with elevated troponin and non-acute coronary syndrome involves treating the underlying causes. The aim of this paper is to review data from studies of non-ACS patients with acutely elevated troponin who in clinical practice may be difficult to discriminate from ACS patients.