***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: BACKGROUND The rapid and reliable diagnosis of acute myocardial infa rct ion is a major unmet clinical need . METHODS We conducted a multicenter study to examine the diagnostic accuracy of new , sensitive cardiac troponin assays performed on blood sample s obtained in the emergency department from 718 consecutive patients who presented with symptoms suggestive of acute myocardial infa rct ion . Cardiac troponin levels were determined in a blinded fashion with the use of four sensitive assays ( Abbott-Architect Troponin I , Roche High-Sensitive Troponin T , Roche Troponin I , and Siemens Troponin I Ultra ) and a st and ard assay ( Roche Troponin T ) . The final diagnosis was adjudicated by two independent cardiologists . RESULTS Acute myocardial infa rct ion was the adjudicated final diagnosis in 123 patients ( 17 % ) . The diagnostic accuracy of measurements obtained at presentation , as quantified by the area under the receiver-operating-characteristic curve ( AUC ) , was significantly higher with the four sensitive cardiac troponin assays than with the st and ard assay ( AUC for Abbott-Architect Troponin I , 0.96 ; 95 % confidence interval [ CI ] , 0.94 to 0.98 ; for Roche High-Sensitive Troponin T , 0.96 ; 95 % CI , 0.94 to 0.98 ; for Roche Troponin I , 0.95 ; 95 % CI , 0.92 to 0.97 ; and for Siemens Troponin I Ultra , 0.96 ; 95 % CI , 0.94 to 0.98 ; vs. AUC for the st and ard assay , 0.90 ; 95 % CI , 0.86 to 0.94 ) . Among patients who presented within 3 hours after the onset of chest pain , the AUCs were 0.93 ( 95 % CI , 0.88 to 0.99 ) , 0.92 ( 95 % CI , 0.87 to 0.97 ) , 0.92 ( 95 % CI , 0.86 to 0.99 ) , and 0.94 ( 95 % CI , 0.90 to 0.98 ) for the sensitive assays , respectively , and 0.76 ( 95 % CI , 0.64 to 0.88 ) for the st and ard assay . We did not assess the effect of the sensitive troponin assays on clinical management . CONCLUSIONS The diagnostic performance of sensitive cardiac troponin assays is excellent , and these assays can substantially improve the early diagnosis of acute myocardial infa rct ion , particularly in patients with a recent onset of chest pain . ( Clinical Trials.gov number , NCT00470587 . BACKGROUND High-sensitivity troponin ( HS-TnT ) combined with copeptin have been proposed to expedite the diagnostic exclusion of acute myocardial infa rct ion . The Global Registry of Acute Coronary Events ( GRACE ) has been vali date d and recommended by the European Society of Cardiology as a prognostic score in the management of acute coronary syndrome ( ACS ) without ST-segment elevation ( non-ST+ ) on the electrocardiogram . Our study examined whether a low GRACE score ( < 108 ) combined with negative HS-TnT ( < 14 ng/L ) and copeptin ( < 14 pmol/L ) reliably exclude the diagnosis of non-ST+ ACS , including non-ST-segment elevation myocardial infa rct ion and unstable angina . METHODS This observational , prospect i ve study included patients presenting with chest pain lasting < 6 hours , consistent with non-ST+ ACS .  Blood was collected early for measurements of copeptin and HS-TnT. The negative predictive value of combined copeptin , HS-TnT , and GRACE score was calculated in the diagnosis of non-ST+ ACS . The thresholds of positivity were 14 ng/L for HS-TnT , 14 pmol/L for copeptin and 108 for the GRACE score . RESULTS Among 247 patients retained in the analysis , the diagnosis of ACS was made in 50 ( 20.4 % ) , including 39 non-ST-segment elevation myocardial infa rct ion and 11 unstable angina . The negative predictive value of combined HS-TnT , copeptin and GRACE score was 99 % . CONCLUSION A negative copeptin associated with a negative HS-TnT in a patient presenting with a low GRACE score expedited the diagnostic exclusion of non-ST+ ACS Background — The role of the vasopressin system after acute myocardial infa rct ion is unclear . Copeptin , the C-terminal part of the vasopressin prohormone , is secreted stoichiometrically with vasopressin . We compared the prognostic value of copeptin and an established marker , N-terminal pro-B-type natriuretic peptide ( NTproBNP ) , after acute myocardial infa rct ion . Methods and Results — In this prospect i ve single-hospital study , we recruited 980 consecutive post – acute myocardial infa rct ion patients ( 718 men , median [ range ] age 66 [ 24 to 95 ] years ) , with follow-up over 342 ( range 0 to 764 ) days .  Plasma copeptin was highest on admission ( n=132 , P<0.001 , day 1 versus days 2 to 5 ) and reached a plateau at days 3 to 5 . In the 980 patients  , copeptin ( measured at days 3 to 5 ) was elevated in patients who died ( n=101 ) or were readmitted with heart failure ( n=49 ) compared with survivors ( median [ range ] 18.5 [ 0.6 to 441.0 ] versus 6.5 [ 0.3 to 267.0 ] pmol/L , P<0.0005 ) . With logistic regression analysis , copeptin ( odds ratio , 4.14 , P<0.0005 ) and NTproBNP ( odds ratio , 2.26 , P<0.003 ) were significant independent predictors of death or heart failure at 60 days . The area under the receiver operating characteristic curves for copeptin ( 0.75 ) and NTproBNP ( 0.76 ) were similar . The logistic model with both markers yielded a larger area under the curve ( 0.84 ) than for NTproBNP ( P<0.013 ) or copeptin ( P<0.003 ) alone , respectively . Cox modeling predicted death or heart failure with both biomarkers ( log copeptin [ hazard ratio , 2.33 ] , log NTproBNP [ hazard ratio , 2.70 ] ) . In patients stratified by NTproBNP ( above the median of ≈900 pmol/L ) , copeptin above the median ( ≈7 pmol/L ) was associated with poorer outcome ( P<0.0005 ) . Findings were similar for death and heart failure as individual end points . Conclusions — The vasopressin system is activated after acute myocardial infa rct ion . Copeptin may predict adverse outcome , especially in those with an elevated NTproBNP ( more than ≈900 pmol/L ) Aims To test the utility of a single copeptin determination at presentation to the emergency department ( ED ) as a short-term prognosis marker in patients with non-ST-elevation acute coronary syndrome ( NSTEACS ) . To compare the results with those achieved with conventional troponin . Methods A multicentric , prospect i ve , observational , longitudinal , cohort study involving 15 Spanish EDs . Inclusion : consecutive patients with chest pain ( < 12 h ) finally diagnosed of NSTEACS . Measurements :  copeptin and troponin at arrival . Cut-off point for  copeptin  : 25.9 pmol/l . Follow-up : within 2 months after ED attendance to identify 30-day adverse events . Discriminatory capacity of copeptin and troponin was compared by receiver operating characteristic ( ROC ) curves . Results We included 377 patients with NSTEACS . Adverse events : 11 ( 2.9 % ) patients died , 27 ( 7.2 % ) had an adverse coronary event , 14 ( 3.7 % ) had a stroke , and 48 ( 12.7 % ) a composite endpoint . The initial copeptine value was over 25.9 pmol/l in 114 patients , and they presented a higher mortality rate ( OR : 4.2 , ( 95 % CI 1.2 to 14.8 ) ; p=0.03 ) . This association disappeared after adjusting by clinical variables or troponin level . No significant differences were found for the remaining endpoints . The area under the curve of the ROC curve of 30-day mortality was 0.73 ( 95 % CI 0.58 to 0.87 ) for copeptin , and 0.80 ( 95 % CI 0.73 to 0.87 ) for troponin . Conclusions In patients with NSTEACS , determination of copeptin at presentation to the ED is associated with risk of death during the subsequent month . This association , however , disappears after adjusting by baseline features or troponin level , so copeptin does not add complementary prognostic information over that provided by troponin Abstract Background : Identifying older patients with non-ST- elevation myocardial infa rct ion ( NSTEMI ) within the very large proportion with elevated high-sensitive cardiac troponin T ( hs-cTnT ) is a diagnostic challenge because they often present without clear symptoms or electrocardiographic features of acute coronary syndrome to the emergency department ( ED ) . We prospect ively investigated the diagnostic and prognostic performance of copeptin ultra-sensitive ( copeptin-us ) and hs-cTnT compared to hs-cTnT alone for NSTEMI at prespecified cut-offs in unselected older patients . Methods : We consecutively enrolled 306 non-surgical patients ≥70 years presenting to the ED . In addition to clinical examination , copeptin-us and hs-cTnT  were measured at admission . Two cardiologists independently adjudicated the final diagnosis of NSTEMI after review ing all available data . All patients were followed up for cardiovascular-related death within the following 12 months . Results : NSTEMI was diagnosed in 38 ( 12 % ) patients ( age 81±6 years ) . The combination of copeptin-us ≥14 pmol/L and hs-cTnT ≥0.014 µg/L compared to hs-cTnT ≥0.014 µg/L alone had a positive predictive value of 21 % vs. 19 % to rule in NSTEMI . The combination of copeptin-us < 14 pmol/L and hs-cTnT < 0.014 µg/L compared to hs-cTnT < 0.014 µg/L alone had a negative predictive value of 100 % vs. 99 % to rule out NSTEMI . Hs-cTnT ≥0.014 µg/L alone was significantly associated with outcome . When copeptin-us ≥14 pmol/L was added , the net reclassification improvement for outcome was not significant ( p=0.809 ) . Conclusions : In unselected older patients presenting to the ED , the additional use of copeptin-us at predefined cut-offs may help to reliably rule out NSTEMI but may not help to increase predicted risk for outcome compared to hs-cTnT alone Background The combination of the new high sensitivity troponin T ( hsTnT ) assays and copeptin , a biomarker of endogenous stress , has been suggested to have the potential of early rule-out of acute coronary syndrome ( ACS ) . The aim of this study was to examine the ability of this combination to rule out ACS in patients presenting with chest pain and to compare the diagnostic performance to hsTnT alone . Method In this prospect i ve observational study , patients with chest pain admitted for observation were consecutively included . Patients presenting with ST elevation were excluded .  Copeptin and hsTnT  were analyzed at admission and hsTnT was thereafter determined approximately every 3rd hour as long as clinical ly indicated . The follow-up period was 60 days . A combined primary endpoint of ACS , non-elective percutanous coronary intervention , non-elective coronary artery bypass surgery and death of all causes was used . Results 478 patients were included . 107 ( 22 % ) patients were diagnosed with ACS during hospital stay . 70 ( 14 % ) had non-ST-segment elevation myocardial infa rct ion ( NSTEMI ) and 37 ( 8 % ) had unstable angina pectoris (UAP).The combination of hsTnT > 14 ng/L or copeptin ≥14 pmol/L at admission identified ACS with a higher sensitivity than hsTnT alone : 0.83 ( 95 % confidence interval ( CI ) : 0.74 - 0.89 ) versus 0.69 ( 95 % CI : 0.59 - 0.77 ) , p < 0.001 . Negative predict 
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Conclusions Adding copeptin to cTn improved the sensitivity and negative predictive value for the diagnosis of NSTEMI compared to cTn alone .
Thus , adding copeptin to cTn might help to screen NSTEMI early upon admission to the ED