Association of Troponin-I Level on Admission with 6-month Clinical Consequences in Acute Coronary Syndrome Patients: A Preventive Approach in Patient Care (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.
Journal of the American College of Cardiology, 2013
The study objective was to validate a new high-sensitivity troponin I (hs-TnI) assay in a clinical protocol for assessing patients who present to the emergency department with chest pain. Background Protocols using sensitive troponin assays can accelerate the rule out of acute myocardial infarction in patients with low-risk (suspected) acute coronary syndrome (ACS). Methods This study evaluated 2 prospective cohorts of patients in the emergency department with ACS in an accelerated diagnostic pathway integrating 0-and 2-h hs-TnI results, Thrombolysis In Myocardial Infarction (TIMI) risk scores, and electrocardiography. Strategies to identify low-risk patients incorporated TIMI risk scores ¼ 0 or 1. The primary endpoint was a major adverse cardiac event (MACE) within 30 days. Results In the primary cohort, 1,635 patients were recruited and had 30-day follow-up. A total of 247 patients (15.1%) had a MACE. The finding of no ischemic electrocardiogram and hs-TnI 26.2 ng/l with the TIMI ¼ 0 and TIMI 1 pathways, respectively, classified 19.6% (n ¼ 320) and 41.5% (n ¼ 678) of these patients as low risk; 0% (n ¼ 0) and 0.8% (n ¼ 2) had a MACE, respectively. In the secondary cohort, 909 patients were recruited. A total of 156 patients (17.2%) had a MACE. The TIMI ¼ 0 and TIMI 1 pathways classified 25.3% (n ¼ 230) and 38.6% (n ¼ 351), respectively, of these patients as low risk; 0% (n ¼ 0) and 0.8% (n ¼ 1) had a MACE, respectively. Sensitivity, specificity, and negative predictive value for TIMI ¼ 0 in the primary cohort were 100% (95% confidence interval [CI]: 98.5% to 100%), 23.1% (95% CI: 20.9% to 25.3%), and 100% (95% CI: 98.8% to 100%), respectively. Sensitivity, specificity, and negative predictive value for TIMI 1 in the primary cohort were 99.2 (95% CI: 97.1 to 99.8), 48.7 (95% CI: 46.1 to 51.3), and 99.7 (95% CI: 98.9 to 99.9), respectively. Sensitivity, specificity, and negative value for TIMI 1 in the secondary cohort were 99.4% (95% CI: 96.5 to 100), 46.5% (95% CI: 42.9 to 50.1), and 99.7% (95% CI: 98.4 to 100), respectively. Conclusions An early-discharge strategy using an hs-TnI assay and TIMI score 1 had similar safety as previously reported, with the potential to decrease the observation periods and admissions for approximately 40% of patients with suspected ACS. (Advantageous Predictors of Acute Coronary Syndromes Evaluation [APACE] Study, NCT00470587; A 2hr Accelerated Diagnostic Protocol to Assess patients with chest Pain symptoms using contemporary Troponins as the only biomarker [ADAPT]: a prospective observational validation study, ACTRN12611001069943) (
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.
Medical Principles and Practice, 2002
Objective: To evaluate the role of serum troponin I (TnI) estimations in the early risk stratification of patients with acute coronary syndromes (ACS) subsequently diagnosed as acute myocardial infarction (AMI) or unstable angina (UA). Subjects and Methods: Blood samples were collected from 86 patients admitted to the Coronary Care Unit of the Mubarak Al-Kabeer Hospital, Kuwait, with a diagnosis of ACS on admission (TnI-1) and after 8 h (TnI-2) and 16 h (TnI-3). Blood was also collected from 38 age-matched healthy controls for comparison. Serum TnI was measured by paramagnetic particle chemiluminescent immunoassay. Results: Serum TnI of ! 0.05 ng/ ml, corresponding to the 99th percentile, was established for healthy subjects. Patients diagnosed as UA had a 99th percentile TnI-1 value of about 0.30 ng/ml. The best specificity and sensitivity for ACS was obtained for TnI-2; indeed, TnI-2 1 0.3 ng/ml gave a 1 80% certainty of diagnosis of AMI. Also, TnI-2 ! 0.3 ng/ml in ACS patients was approximately 80% sensitive for the diagnosis of UA but relatively nonspecific (approximately 40%). Specificity for TnI-2 for the diagnosis of UA improved to about 90% by narrowing the diagnostic range to 0.05-0.3 ng/ ml. TnI values in UA increased by ! 100% at 8 h, while in AMI, this increase was up to 1,000%. Conclusion: In the evaluation of ACS, admission and 8-hour serum TnI !0.05 ng/ml is probably not cardiac in origin; serum TnI 10.3 ng/ml on admission and increasing rapidly by 8 h is likely AMI, and serum TnI 1 0.05 and ! 0.3 ng/ml on admission with a mild increase by 8 h is likely due to UA.
Annals of Translational Medicine, 2016
Background: Cardiac troponin (cTn) testing has reduced the likelihood of erroneous discharge of patients with acute coronary syndrome (ACS) from the emergency department (ED), but doubts remain about optimal clinical use. This study was planned for evaluating the predictive significance of cTn values between the limit of detection of the method and the 99th percentile in ED patients evaluated for suspected ACS. Methods: In this retrospective study all hospital records of patients admitted over a 6-month period to the ED and with at least one cTnI value comprised between the limit of detection (0.01 ng/mL) and the 99th percentile of the assay (0.05 ng/mL) were analyzed. Results: A total of 4,749 patients with cTnI value between 0.01-0.05 ng/mL were identified among 57,879 ED visits throughout the study period. Overall, 2,189 patients (46.1%) were discharged from the ED, 2,529 (53.25%) were admitted to the hospital and 31 (0.65%) died during ED stay. A total number of 289 patients out of 2,189 who were discharged (i.e., 13.2%) had additional ED visits within 30 days. Among these, 6 were diagnosed with ACS, representing 0.27% of patients discharged [negative predictive value (NPV) 0.997; 95% CI, 0.994-0.999] and 2.1% of those with second admission (NPV 0.979; 95% CI, 0.955-0.992). Only one of the 2,529 patients admitted to the hospital (i.e., 0.04%) developed an ACS during hospital stay. Conclusions: The results of our retrospective study suggest that the suitability of using a contemporary-sensitive cTnI immunoassay assay in the context of an appropriate protocol represents a safe and effective strategy for ruling in and ruling out ACS in patients presenting to the ED.
Cardiac troponin I measurement using the ACS:180 to predict four-year cardiac event rate
Annals of Clinical Biochemistry: International Journal of Laboratory Medicine, 2008
Background This study aimed at evaluating the ability of cardiac troponin I (cTnI) measurement on the ACS:180 for prognostic risk stratification. Sequential admissions to the coronary care unit of a busy district general hospital were studied. All patients were followed up for a maximum of 4.3 years and cardiac events, either cardiac death, readmission with acute myocardial infarction or admission with acute unstable angina were documented. Methods Blood samples were taken on admission and at 4 and 12 h. A serum aliquot was taken and stored frozen at −70oC. The frozen aliquots were subsequently analysed for cTnI by chemiluminescent immunoassay using an ACS:180. Patients were categorized into those with or without ST segment elevation on the presenting electrocardiogram. The optimized decision threshold for mortality and event prediction was then determined by log-rank analysis and by construction of Kaplan-Meier survival plots. Results A total of 289 patients (196 men) median age 65...
Patients with Acute Coronary Syndrome and Normal High-sensitivity Troponin
The American Journal of Medicine, 2011
BACKGROUND: Failure to identify patients with acute coronary syndrome (ACS) is a serious clinical problem. The incidence, characteristics, and outcome of ACS patients with normal high-sensitivity cardiac troponin T (hs-cTnT) levels at presentation are unknown. METHODS: In a prospective multicenter study, hs-cTnT was determined in a blinded fashion in 1181 consecutive patients presenting with acute chest pain to the emergency department. The final diagnosis of ACS was adjudicated by 2 independent cardiologists. Patients were followed for 12 months. RESULTS: ACS was the adjudicated diagnosis in 351 patients (30%), including 187 patients with acute myocardial infarction (AMI) and 164 patients with unstable angina (UA). At presentation, hs-cTnT was normal (Ͻ.014 ug/L) in 112 ACS patients (32%), including 11 patients (6%) with AMI and 101 patients (62%) with UA (P Ͻ.001). Multivariable analysis revealed previous statin treatment, younger age, preserved renal function, and the absence of ST deviation on the electrocardiogram as independently associated with normal hs-cTnT levels. Mortality rates in ACS patients with normal hs-cTnT level were 0.0% at 30 days, 0.0% at 90 days, and 2.0% (95% confidence interval, 0.5-7.9) at 360 days, which was significantly lower than in ACS patients with elevated hs-cTnT level at presentation (17.5% at 360 days, P Ͻ.001). Conversely, AMI rates at 360 days was higher in ACS patients with normal versus elevated hs-cTnT levels (P ϭ .004). CONCLUSION: Almost one third of ACS patients have normal hs-cTnT levels at presentation, mostly patients with UA. ACS patients with normal hs-cTnT have a very low mortality, but an increased rate of AMI during the subsequent 360 days.
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