***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 
    ***DOCUMENTATION*** 
    ***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 Chest pain frequently prompts emergency medical services ( EMS ) call-outs . Early management of acute coronary syndrome ( ACS ) cases is crucial , but there is still controversy over the relevance of pain severity as a diagnostic criterion . STUDY OBJECTIVE The aim of this study was to determine whether there is a relationship between the severity of chest pain at the time of out-of-hospital emergency care and diagnosis of acute myocardial infa rct ion ( AMI ) . METHODS This was a subsidiary analysis of prehospital data  collated prospect ively by EMS in a large suburb . It concerned patients with chest pain taken to hospital by a mobile intensive care unit .  Pain was rated on EMS arrival using a visual analog , numeric or verbal rating scale and classified on severe or not severe according to the pain score . A diagnosis of AMI was confirmed or ruled out on the basis of 2 plasma troponin measurements and /or coronary angiography results . RESULTS Among the cohort of 2,279 patients included , 234 were suitable for analysis , of which 109 ( 47 % ) were diagnosed with AMI . The rate of severe pain on EMS arrival was not significantly different between AMI patients and no myocardial infa rct ion patients ( 49 % [ 95 % CI 40 to 58 ] and 43 % [ 34 to 52 ] , respectively ; P = 0.3 ; odds ratio 1.3 [ 0.8 - 2.3 ] after adjustment for age and gender ) . CONCLUSION In our out-of-hospital emergency setting , the severity of chest pain was not a useful diagnostic criterion for AMI Background Acute chest pain is a frequently occurring symptom in patients with medical emergencies and imposes potentially life threatening situations outside hospitals . Little is known about the epidemiology of patients with acute chest pain in a primary care setting in Norway , and we aim ed to obtain more representative data on such patients using data from emergency medical communication centres ( EMCCs ) . Methods Data were collected prospect ively during three months in 2007 from three EMCCs , covering 816 000 inhabitants . The EMCCs gathered information on every situation that was triaged as a red response ( defined as an " acute " response , with the highest priority ) , according to the Norwegian Index of Medical Emergencies . Records from ambulances and primary care doctors were subsequently collected . International Classification of Primary Care - 2 symptom codes and The National Committee on Aeronautics ( NACA ) System scores were assigned retrospectively . Only chest pain patients were included in the study . Results 5 180 patients were involved in red response situations , of which 21 % had chest pain . Estimated rate was 5.4 chest pain cases per 1000 inhabitants per year . NACA-scores indicated that 26 % of the patients were in a life-threatening medical situation . Median prehospital response time was 13 minutes ; an ambulance reached the patient in less than 10 minutes in 30 % of the cases . Seventy-six per cent of the patients with chest pain were admitted to a hospital for further investigation , 14 % received final treatment at a casualty clinic , while 10 % had no further investigation by a doctor ( " left at the scene " ) . Conclusions The majority of patients with acute chest pain were admitted to a hospital for further investigation , but only a quarter of the patients were assessed prehospitally to have a severe illness . This sheds light on the challenges for the EMCCs in deciding the appropriate level of response in patients with acute chest pain . Overtriage is to some extent both expected and desirable to intercept all patients in need of immediate help , but it is also well known that overtriage is re source dem and ing . Further research is needed to eluci date the challenges in the diagnosis and management of chest pain outside hospitals Objectives To evaluate whether a computer-based decision support system could be useful for the emergency medical system when identifying patients with acute myocardial infa rct ion ( AMI ) or life-threatening conditions and thereby improve the allocation of life support level . Methods Patients in the Municipality of Göteborg who dialled the dispatch centre due to chest pain during a period of 3 months . To analyse the relationship between patient characteristics ( according to a case record form used during an interview ) and the response variables ( AMI or life-threatening condition ) , multivariate logistic regression was used . For each patient , the probability of AMI/life-threatening condition was estimated by the model . We used these probabilities retrospectively to allocate advanced life support or basic life support . This model allocation was then compared with the true allocation made by the dispatchers . Results The sensitivity , that is , the percentage of AMI patients allocated to advanced life support , was 85.7 % in relation to the true allocation made by the dispatchers . The corresponding sensitivity regarding allocation made by the model was 92.4 % ( P=0.17 ) . The specificity was also slightly higher for the model allocation than the dispatcher allocation . Among the 15 patients with AMI who were allocated to basic life support by the dispatchers , nine died ( eight during and one after hospitalization ) . Among the eight patients with AMI allocated to basic life support by the model , only one patient died ( in hospital ) ( P=0.02 ) . Conclusion A computer-based decision support system including a prevalence function could be a valuable tool for allocating the level of life support . The case record form , however , used for the interview can be refined and a model based on a larger sample and confirmed in a prospect i ve study is recommended Background The number of requests to  pre-hospital emergency medical services ( PEMS ) has increased in Europe over the last 20 years , but epidemiology of PEMS interventions has little be investigated . The aim of this analysis was to describe time trends of  PEMS  activity in a region of western Switzerl and . Methods Use of data routinely and prospect ively collected for  PEMS intervention in the Canton of Vaud , Switzerl and , from 2001 to 2010 . This Swiss Canton comprises approximately 10 % of the whole Swiss population . Results We observed a 40 % increase in the number of requests to PEMS between 2001 and 2010 . The overall rate of requests was 35/1000 inhabitants for ambulance services and 10/1000 for medical interventions ( SMUR ) , with the highest rate among people aged ≥ 80 . Most frequent reasons for the intervention were related to medical problems , predominantly unconsciousness , chest pain respiratory distress , or cardiac arrest , whereas severe trauma interventions decreased over time . Overall , 89 % were alive after 48 h. The survival rate after 48 h increased regularly for cardiac arrest or myocardial infa rct ion . Conclusion Routine prospect i ve data collection of prehospital emergency interventions and monitoring of activity was feasible over time . The results we found add to the underst and ing of determinants of PEMS use and need to be considered to plan use of emergency health services in the near future . More comprehensive analysis of the quality of services and patient safety supported by indicators are also required , which might help to develop prehospital emergency services and new processes of care Abstract Objective . Retrospective research has shown that 19 % of 12-lead prehospital electrocardiograms ( prehospital ECGs ) had clinical ly significant abnormalities that were not captured on the initial emergency department ( ED ) ECG and had the potential to change medical management . The purpose of this study was to prospect ively determine how many prehospital ECGs had clinical ly significant abnormalities not present on the initial ED ECG and determine how many prehospital ECGs changed physician management . Methods . We conducted a 3-month , prospect i ve cohort study of patients who had a 12-lead prehospital ECG completed by EMS prior to arriving at one of two tertiary care EDs . STEMI bypass patients were excluded . Physicians review ed the prehospital ECG to determine whether there were any clinical ly significant abnormalities present on the prehospital ECG not captured on the initial ED ECG . Physicians recorded if and how the prehospital ECG changed their management . Results . A total of 281 patients were enrolled . Thirty-five ( 12.5 % ; 95 % CI : 9.1 % , 16.8 % ) prehospital ECGs showed changes that were not captured on the initial ED ECG ( 11 ST depression , 5 T-wave inversion [ TWI ] , 2 ST depression and TWI , 12 arrhythmia , 2 arrhythmia with ST depression , 2 ST elevation , 1 unknown ) . Fifty-two ( 18.5 % ; 95 % CI : 14.4 % , 23.5 % ) prehospital ECGs influenced physician management . There were 30 ( 10.7 % ) instances where physicians were willing to refer the patient to an inpatient service based on information captured on the prehospital ECG , regardless if the initial ED ECG was normal . Conclusions . Prehospital ECGs show clinical ly significant abnormalities that are not always captured on the initial ED ECG . Prehospital ECGs have the potential to change the management of patients in the ED AIMS To evaluate the diagnostic performance of a portable semi-quantitative whole blood immunoassay measuring soluble human fatty acid-binding protein [ H-FABP ] ( CardioDetect ) for the pre-hospital detection of myocardial infa rct ion ( MI ) . METHODS AND RESULTS We enrolled prospect ively 108 consecutive patients with acute ischemic type chest pain in whom the first medical care was delivered by a mobile intensive care unit ( MICU ) .  CTnI , myoglobin , CK-MB and CardioDetect were first assessed in the MICU before hospital admission using point-of-care assays and then cTnI was serially measured during the hospital stay . MI was defined as a positive cTnI in any sample over the first 24 h. The vast majority of the patients ( 77/108 ) were admitted <3 h of symptoms onset . Pre-hospital cTnI sample was normal in 96 patients ( 88.9 % ) of whom 43 had subsequent cTnI elevation . A positive H-FABP using the CardioDetect assay had a significantly better sensitivity than cTnI , myoglobin and CK-MB ( 87.3 % vs 21.8 % , 64.2 % and 41.5 % , respectively ) to identify MI . The significant better sensitivity of the CardioDetect assay was also observed among patients who presented <3 h of symptom onset . The specificity of the CardioDetect assay was significantly better than that of myoglobin , irrespective of the time delay from symptom onset to measurement . In patients with normal pre-hospital cTnI and no ST-elevation ( n=63 ) , assessment based only on a positive H-FABP had 83.3 % sensitivity , 93.3 % specificity for the diagnosis of an evolving MI . CONCLUSION Early assessment of H-FABP in patients presenting with chest pain improves the diagnosis of on 
    Output:
    
These studies provided strong evidence for an increased risk of an acute LTC with increasing age , male gender , elevated heart rate , low systolic blood pressure and ST elevation or ST depression on a 12-lead ECG .
The evidence was inconclusive regarding dyspnoea , cold sweat/paleness , nausea/vomiting , history of chronic heart failure , smoking , Right Bundle Branch Block or T-inversions on the ECG .
CONCLUSIONS Factors reflecting age , gender , myocardial ischemia and a compromised cardiovascular system predicted an increased risk of an acute life-threatening condition in the prehospital setting in cases of acute chest pain .
These factors may form the basis for prehospital risk stratification in acute chest pain