Non-ischaemic ECG Research Articles

Evaluating the integration of CTCA as part of an accelerated diagnostic pathway for patients presenting to the Emergency Department with acute chest pain: a two-year review

Abstract Introduction Chest pain accounts for 8.8% of all presentations to an Hospital Emergency Department. In line with ESC guidelines (2019), an adapted HEART pathway, utilising CT Coronary Angiogram (CTCA) is delivered by our Emergency Cardiology Advanced Nurse Practitioners (ANP) and Clinical Nurse Specialists (CNS) as part of an ambulatory chest pain pathway. It is our first line diagnostic test for patients with a non-ischaemic 12-lead ECG and normal cardiac biomarkers, with a low-to-intermediate HEART score. Responsibility for the referral of patients onto the pathway is shared with the Cardiology Registrars. This is a collaborative interdisciplinary pathway between Emergency Medicine, Cardiology, and Radiology. Purpose To evaluate the effectiveness and safety of CTCA as part of an Accelerated Diagnostic Pathway (ADP), for evaluation of chest pain of possible cardiac origin in low-to-intermediate risk chest pain patients. Methods We examined the CTCA and safety outcomes of patients presenting between Jan 1st 2022 – Dec 31st 2023 who were risk stratified as low-to-intermediate risk for coronary artery disease, based on Heart score, 12-lead ECG and biomarker testing, using the electronic patient records. Institutional ethics was in place. Results Between January 1st and December 31st 2022, 290 patients were referred for CTCA, with a total of 268 CTCAs completed. The number of patients referred on the ADP increased by 53.4% in 2023 with 445 being referred for CTCA, 416 of which have been completed, with 12 pending completion. 38% of patients were found to have evidence of coronary artery disease (CAD). Coronary artery disease causing at least 50% stenosis was identified in 11% of patients. 4.5% of these patients required revascularisation, 17 of whom underwent Percutaneous Coronary Intervention (PCI) with a further 13 being referred for Coronary Artery Bypass Grafting. A positive family history was the most dominant risk factor associated with significant CAD. An equivalent number of males to females were referred for CTCA, however, men were more than 7 times more likely to have severe disease. (12% vs 88%). All patients referred for CTCA via the chest pain pathway were followed up by the Emergency Cardiology ANP/CNS in a virtual clinic, delivering risk factor modification advice and preventative therapies, when indicated. There was no evidence of any major adverse cardiovascular events within a 30-day period for this patient cohort. Conclusion The integration of CTCA into an adapted HEART pathway has resulted a safe and timely discharge for patients presenting to ED with acute chest pain, of possible cardiac origin. CTCA offers excellent early detection of coronary artery disease in this patient cohort with normal ECGs and cardiac biomarkers, but with a history of chest pain suggestive of CAD.

A Single High-Sensitivity Cardiac Troponin T Strategy for Ruling Out Myocardial Infarction.

Ruling out acute myocardial infarction (AMI) in the emergency department (ED) is challenging. Studies have shown that a high-sensitivity cardiac troponin T (hs-cTnT) <5 ng/L or <6 ng/L at presentation (0 h) can be used to rule out AMI. The objective of this study was to identify whether an even higher hs-cTnT threshold can be used for a safe rule out of AMI in the ED. The derivation cohort consisted of 24,973 ED patients with a primary complaint of chest pain. In this cohort, we identified the highest concentration of 0 h hs-cTnT that corresponded to a negative predictive value (NPV) of ≥99.5% for the primary endpoint of AMI/all-cause death within 30 days and the secondary endpoint of all-cause death within one year. The results were validated in two cohorts consisting of 132,021 and 1167 ED chest pain patients. The 0 h hs-cTnT threshold corresponding to a NPV of ≥99.5% for the primary endpoint was <9 ng/L (NPV: 99.6% and 95% CI: 99.5-99.7). This cutoff provided a sensitivity of 96.2% (95% CI: 95.2-97.1) and identified 59.7% of the patients as low risk compared to 35.8% and 43.9% with a 0 h hs-cTnT <5 ng/L and <6 ng/L, respectively. The results were similar in the validation cohorts and seemed to perform even better in patients where the 0 h hs-cTnT was measured >3 h after symptom onset and in those with a nonischemic ECG and nonhigh risk history. A 0 h hs-cTnT cutoff of <9 ng/L safely rules out AMI/death within 30 days in a majority of chest pain patients and is a more effective strategy than the currently recommended <5 ng/L and <6 ng/L cutoffs. This trial is registered with NCT03421873.

HEART Score Recalibration Using Higher Sensitivity Troponin T

We examined the diagnostic performance of a recalibrated History, Electrocardiogram, Age, Risk factors, Troponin (HEART), and Thrombolysis in Myocardial Infarction (TIMI) score in patients with suspected acute cardiac syndrome (ACS). Recalibration of troponin thresholds was performed, including shifting from the 99th percentile to the limit of detection (LOD) or to the limit of quantification (LOQ) We compared the discharge potential and safety of the recalibrated composite scores using a single presentation high-sensitivity cardiac troponin (hs-cTn) T to the conventional scores and with a LOD/LOQ troponin strategy alone. We undertook a 2-center prospective cohort study in the United Kingdom (UK) (2018) (Clinicaltrials.gov NCT03619733) to specifically assess recalibrated risk scores (shifting the troponin subset scoring from 99th percentile to LOD [UK]) and combined the results of this with secondary analyses of 2 prospective cohort studies in the UK (2011) and the United States (2018, using LOQ rather than LOD). The primary outcome was major adverse cardiovascular events (MACE), defined as adjudicated type 1 myocardial infarction (MI), urgent coronary revascularization, and all-cause death, at 30 days. We evaluated the original scores using hs-cTn below the 99th percentile and recalibrated scores using hs-cTn <LOD/LOQ and compared these composite scores with a single hs-cTnT less than LOD/LOQ combined with a nonischemic ECG. For each discharge strategy, an assessment of clinical effectiveness was also made, defined as the proportion of patients eligible for discharge from the emergency department without the need for further inpatient testing. We studied 3,752 patients (3,003 in the UK and 749 in the United States). Median age was 58 years, and 48% were female. At 30 days, 330/3,752 (8.8%) experienced MACE. The sensitivities of the original HEART less or equal to 3 and recalibrated HEART less or equal to 3 scores for rule-out were 96.1% (95% confidence interval [CI], 93.4 to 97.9) and 98.6% (95% CI, 96.5 to 99.5) respectively; the original TIMI less or equal to 1 and recalibrated TIMI less or equal to 1 scores' sensitivities were 79.7% (95% CI, 74.9 to 83.9) and 96.1% (95% CI, 93.4 to 97.9) respectively; and nonischemic ECG with hs-cTn T below the 99th percentile and hs-cTn T less than LOD/LOQ was 79.7% (95%CI, 0.749 to 0.839) and 99.1% (95% CI, 0.974 to 0.998), respectively. Recalibrated HEART less or equal to 3 was projected to discharge 14% more patients than hs-cTn T less than LOD/LOQ. The improved sensitivity ofrule-out for recalibrated HEART less than or equal to 3 came at the cost of reduced specificity (50.8% versus 53.8% for recalibrated HEART and conventional HEART respectively). This study indicates that recalibrated HEART score of less or equal to 3 is a feasible and safe early discharge strategy using a single presentation hs-cTnT. This finding should be further tested using competitor hs-cTn assays in independent prospective cohorts before implementation.

Technical challenges and innovative solutions for bedside alarms

The guidelines advocate, in patients with chest pain, comparison of the acute ECG with a previously made, non-ischemic ECG that serves as a reference, to corroborate the working diagnosis of acute coronary syndrome (ACS). Our approach of this serial comparison is to compute the differences between the ST vectors at the J point and 60 ms thereafter (∆ST(J + 0), ∆ST(J + 60)) and between the ventricular gradient (VG) vectors (∆VG). In the current study, we investigate if reference ECGs remain valid in time.We studied 6 elective non-ischemic ECGs (ECG0, ECG1, …, ECG5), 5 years apart, in 88 patients. Within each patient, serial comparisons were done 1) between all successive ECGs, and 2) between each of ECG1, ECG2, …, ECG5 and ECG0, computing, in addition to ∆ST(J + 0), ∆ST(J + 60) and ∆VG, the difference in heart rates, ∆HR. Additionally, relevant clinical events and the diagnoses associated with each ECG were collected. Linear regression was used to assess trends in ∆ST(J + 0), ∆ST(J + 60) and ∆VG; multiple linear regression was used to assess the influence of the clinical events and diagnoses on ∆ST(J + 0), ∆ST(J + 60) and ∆VG.There were no trends in the differences between successive ECGs. Positive trends were seen with increasing time lapses between ECGs: ∆ST(J + 0), ∆ST(J + 60) and ∆VG increased per year by 0.65 μV, 1.45 μV and 3.69 mV∙ms, respectively. Extrapolation to a time lapse of 0 yielded 50.92 μV, 36.63 μV and 20.91 mV∙ms for the short-term reproducibility of ∆ST(J + 0), ∆ST(J + 60) and ∆VG, respectively. Multiple linear regression revealed that clinical variables could explain only 10%, 17% and 13% of the variability in ∆ST(J + 0), ∆ST(J + 60) and ∆VG, respectively.With a view on ischemia detection thresholds in the order of magnitude of 58 μV for ∆ST and 26 mV·ms for ∆VG, our study suggests that it is important to have a recent ECG available for the detection of myocardial ischemia, as an “aged” ECG may have lost its validity as a reference.

Prospective RandOmised Trial of Emergency Cardiac Computerised Tomography (PROTECCT)

ObjectiveMany patients presenting with suspected acute coronary syndrome (ACS) have high-sensitivity cardiac troponin (hs-cTn) concentrations between rule-in and rule-out thresholds and hence need serial testing, which is time consuming. The...

High sensitivity troponin - Six hours is the magic number

BackgroundHigh sensitivity troponin assays have become widespread for emergency department evaluation of acute chest pain. We assessed if a high sensitivity troponin under the 99th percentile upper reference limit drawn at 6 h or greater from symptom onset could safely rule out acute coronary syndrome in patients who did not meet the rapid rule-out strategy. MethodsWe conducted a multicenter retrospective study examining emergency department patients with chest pain who did not meet rapid-rule out criteria and were admitted for further evaluation. Among these admitted patients, we assessed the rate of clinically relevant adverse cardiac events (death, cardiac or respiratory arrest, STEMI, or life-threatening arrhythmia) and NSTEMI in patients with high sensitivity troponin less than the 99th percentile value obtained after at least 6 h of chest pain. ResultsOut of 1187 patients admitted, we found 30 clinically relevant adverse cardiac events, all of which occurred in patients admitted for another compelling reason or ischemic ECG. 36 patients had an NSTEMI, of which 33 were identified with high sensitivity troponin greater than 99th percentile upper reference limit within 6 h of chest pain onset. This left 0 clinically relevant adverse cardiac events and 3 NSTEMI among the 429 patients with high sensitivity troponin less than the 99th percentile at 6 h and nonischemic ECG and no other compelling reason for admission. ConclusionThis study assessed patients with chest pain with high sensitivity troponin values between 3 ng/L and the 99th percentile upper reference limit after 6 h of chest pain and found that they have a low rate of clinically relevant adverse cardiac events and NSTEMI.

Rapid Exclusion of Acute Myocardial Injury and Infarction With a Single High-Sensitivity Cardiac Troponin T in the Emergency Department: A Multicenter United States Evaluation.

There are good data to support using a single high-sensitivity cardiac troponin T (hs-cTnT) below the limit of detection of 5 ng/L to exclude acute myocardial infarction. Per the US Food and Drug Administration, hs-cTnT can only report to the limit of quantitation of 6 ng/L, a threshold for which there are limited data. Our goal was to determine whether a single hs-cTnT below the limit of quantitation of 6 ng/L is a safe strategy to identify patients at low risk for acute myocardial injury and infarction. The efficacy (proportion identified as low risk based on baseline hs-cTnT<6 ng/L) of identifying low-risk patients was examined in a multicenter (n=22 sites) US cohort study of emergency department patients undergoing at least 1 hs-cTnT (CV Data Mart Biomarker cohort). We then determined the performance of a single hs-cTnT<6 ng/L (biomarker alone) to exclude acute myocardial injury (subsequent hs-cTnT >99th percentile in those with an initial hs-cTnT<6 ng/L). The clinically intended rule-out strategy combining a nonischemic ECG with a baseline hs-cTnT<6 ng/L was subsequently tested in an adjudicated cohort in which the diagnostic performance for ruling out acute myocardial infarction and safety (myocardial infarction or death at 30 days) were evaluated. A total of 85 610 patients were evaluated in the CV Data Mart Biomarker cohort, among which 24 646 (29%) had a baseline hs-cTnT<6 ng/L. Women were more likely than men to have hs-cTnT<6 ng/L (38% versus 20%, P<0.0001). Among 11 962 patients with baseline hs-cTnT<6 ng/L and serial measurements, only 1.2% developed acute myocardial injury, resulting in a negative predictive value of 98.8% (95% CI, 98.6-99.0) and sensitivity of 99.6% (95% CI, 99.5-99.6). In the adjudicated cohort, a nonischemic ECG with hs-cTnT<6 ng/L identified 33% of patients (610/1849) as low risk and resulted in a negative predictive value and sensitivity of 100% and a 30-day rate of 0.2% for myocardial infarction or death. A single hs-cTnT below the limit of quantitation of 6 ng/L is a safe and rapid method to identify a substantial number of patients at very low risk for acute myocardial injury and infarction.

Monocyte chemoattractant protein-1 is not predictive of cardiac events in patients with non-low-risk chest pain

BackgroundPrior studies suggest monocyte chemoattractant protein-1 (MCP-1) may be useful for risk stratifying ED patients with chest pain. We hypothesise that MCP-1 will be predictive of 90-day major adverse cardiovascular...

Modified HEART score, utilising a single high-sensitive troponin sample, allows early, safe discharge of suspected acute coronary syndrome: a prospective multicentre cohort study of 3016 patients

Abstract Background Combining HSTnT (high sensitive troponin T) values at low levels with composite risk scores may improve early safe, discharge in suspected acute coronary syndromes (ACS). We tested this hypothesis by a prospective study of 3016 consecutive patients with suspected ACS in 2 large hospitals. Methods Consecutive chest pain (CP) presentations with HSTnT sampled and ECG undertaken at presentation were prospectively defined in 2 time periods (2011-12, n=1642 [derivation] 2018, n=1376 [validation]). The HstnT input was modified: dichotomous HSTnT input was lowered to &amp;lt;5 (limit of detection, LOD) or ≥5ng/l (mod TIMI and GRACE), HEART score was re-calibrated (&amp;lt;5 = 0 [LOD], ≥5–14 = 1, &amp;gt;14 = 2 [99th percentile]). All biomarker positive CP index and re-admissions to any regional hospital (catchment population 2.6 million) were independently adjudicated for MI by 2 experienced physicians. Primary outcome was MACE (adjudicated type 1 MI, unplanned coronary revascularisation and all cause death) at 6 weeks. Results In the 2 cohorts demographic factors were similar: median age 59 and 56, male 52% and 52%, previous MI 20% and 14% for 2011-12 and 2018 respectively. At 6 weeks 180 (11%) and 75 (5.4%) suffered type 1 MI and 211 (12.9%) and 92 (6.7%) patients suffered MACE in the 2011-12 and 2018 cohorts respectively. Only Mod HEART ≤3 and undetectable HSTnT, with a nonischaemic ECG, achieved prespecified NPV of &amp;gt;99.5% in both derivation and validation cohorts (table). However Modified HEART ≤3 score could discharge approximately 12% more patients as compared to undetectable HSTnT strategy. Conclusion Modified HEART score ≤3, with the use of a single HSTnT, appears the optimum early discharge strategy for suspected ACS Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Liverpool university Hospitals, North-West Educational Cardiac Group

271EMF Advancing Emergency Department Chest Pain Risk Stratification With Monocyte Chemoattractant Protein-1 and High-Sensitivity Troponin

The History, Electrocardiogram, Age, Risk factor, and Troponin Pathway (HEART Pathway) risk stratifies 50-55% of emergency department (ED) chest pain patients as non-low-risk and recommends that they receive observation and stress testing. The objective of this study was to determine if two novel biomarkers, MCP-1 and hs-cTnT, alone or in combination, can achieve ≥ 99% sensitivity and negative predictive value for 90-day MACE among non-low-risk HEART Pathway patients. A case-control study was nested within a multicenter, prospective study (STOP-CP). ED patients ≥ 21 years old who presented to the ED with symptoms concerning for acute coronary syndrome who had a HEAR score ≥ 4 or known coronary artery disease (CAD), a non-ischemic ECG, and non-elevated contemporary troponins at 0- and 3-hours were eligible for inclusion. Cases (N=40) were patients with 90-day MACE events (all-cause mortality, myocardial infarction, or revascularization). Controls (N=179) were patients without MACE who were selected based on frequency matching using age, sex, race, and numeric HEAR score or the presence of known CAD. Receiver operator curves were used to assess biomarker performance at various cut-points. Sensitivity and specificity were calculated. The prevalence of MACE in non-low-risk patients in the STOP-CP study was 6.5% (40/618). This was used for determining negative predictive value (NPV) and positive predictive value (PPV). Among the 40 cases and 179 controls, there was no significant difference in age (p=0.90), sex (p=1.00), race (p=0.91), or HEAR score/presence of CAD (p=0.89). An MCP-1 cut-point of 194 pg/mL resulted in 50.0% (95% CI 33.8-66.2%) sensitivity and 93.1% (95% CI 90.5-95.0%) NPV for 90-day MACE. A MCP-1 measure of 238 pg/mL had a 30.0% (95% CI 16.6-46.5%) sensitivity and 93.5% (95% CI 92.0-94.7%) NPV. A hs-cTnT result of 11 ng/L was 60.0% (95% CI 43.3-75.1) sensitive with a NPV of 95.7% (95% CI 93.8-97.1). At a hs-cTnT cut-point of 19 ng/L, sensitivity was 30.0% (95% CI 16.6-46.5%) with a 94.5% (95% CI 93.3-95.5%) NPV. These data suggest that MCP-1 is not a useful biomarker for risk-stratifying ED patients with non-low-risk chest pain. Hs-cTnT may be a useful biomarker for enabling additional patients to be classified as low-risk and discharged without lengthy evaluations.

Short-term prognosis of unstable angina in the era of high-sensitivity cardiac troponin: insights for early rule-out strategies.

It is unclear if strategies to rule-out myocardial infarction (MI) based on a single high-sensitivity troponin T (hsTnT) measurement at the emergency department (ED) presentation may also exclude unstable angina. We measured hsTnT ex-post on the admission frozen blood sample of 644 subjects with Braunwald IIIB CK-MB-negative unstable angina. This analysis included the 240 patients with hsTnT value ≤99th percentile reference limit (UA). We evaluated the clinical outcome of UA patients and the applicability of two rule-out strategies based on the combination of a non-ischemic ECG with (1) a single hsTnT value below the Limit-of-Detection (LoD), (2) a TIMI risk score ≤1. UA patients with hsTnT ≤99th percentile reference limit had a favorable 30-day outcome [0.8% MI, 0% cardiovascular death (CVD)], but the rate of CVD/MI at 180-day was 4.7%. Sensitivities for UA were 94.6% according to the 'TIMI ≤1-strategy' and 75.4% according to 'hsTnT-below-LoD-strategy', accounting for 5.4 and 24.6% missed diagnoses, respectively. A prognostic risk stratification to guide appropriate outpatient assessment in potential discharged unrecognized UA patients was developed: a risk score based on the combination of age >60 years and C-reactive protein >4.5 mg/L effectively stratified the 180-day CVD/MI occurrence: 0, 2.5 and 12.7% for score 0, 1 and 2 (log-rank = 0.001, C-statistic = 0.776). Single measurement hsTnT strategies, successfully tested to rule-out MI, may allow safe ED discharge of patients with a suspected acute coronary syndrome: even if UA may not be excluded, its short-term prognosis is favorable. UA patients with a C-reactive protein >4.5 mg/L and older than 60 years have a substantial medium-term cardiovascular risk and may benefit from a timely outpatient diagnostic assessment.

Limit of detection of troponin discharge strategy versus usual care: randomised controlled trial

IntroductionThe clinical effectiveness of a ‘rule-out’ acute coronary syndrome (ACS) strategy for emergency department patients with chest pain, incorporating a single undetectable high-sensitivity cardiac troponin (hs-cTn) taken at presentation, together...

Noninvasive Cardiac Testing vs Clinical Evaluation Alone in Acute Chest Pain

The incremental benefit of noninvasive testing in addition to clinical evaluation (history, physical examination, an electrocardiogram [ECG], and biomarker assessment) vs clinical evaluation alone for patients who present to the emergency department (ED) with acute chest pain is unknown. To examine differences in outcomes with clinical evaluation and noninvasive testing (coronary computed tomographic angiography [CCTA] or stress testing) vs clinical evaluation alone. This study was a retrospective analysis of data from the randomized multicenter Rule Out Myocardial Ischemia/Infarction by Computer Assisted Tomography (ROMICAT-II) trial. Data for 1000 patients who presented with chest pain to the EDs at 9 hospitals in the United States were evaluated. Clinical evaluation plus noninvasive testing (CCTA or stress test) vs clinical evaluation alone. Primary outcome was length of stay (LOS). Secondary outcomes included hospital admission, direct ED discharge, downstream testing, rates of invasive coronary angiography, revascularization, major adverse cardiac events (MACE), repeated ED visit or hospitalization for recurrent chest pain at 28 days, and cost. Safety end points were missed acute coronary syndrome (ACS) and cumulative radiation exposure during the index visit and follow-up period. Of the 1000 patients randomized, 118 patients (12%) (mean [SD] age, 53.2 [7.8]; 49 [42%] were female) did not undergo noninvasive testing, whereas 882 (88%) (mean [SD] age, 54.4 [8.14] years; 419 [48%] were female) received CCTA or stress testing. There was no difference in baseline characteristics or clinical presentation between groups. Patients who underwent clinical evaluation alone experienced a shorter LOS (20.3 vs 27.9 hours; P < .001), lower rates of diagnostic testing (P < .001) and angiography (2% vs 11%; P < .001), lower median costs ($2261.50 vs $2584.30; P = .009), and less cumulative radiation exposure (0 vs 9.9 mSv; P < .001) during the 28-day study period. Lack of testing was associated with a lower rate of diagnosis of ACS (0% vs 9%; P < .001) and less coronary angiography and percutaneous coronary intervention (PCI) during the index visit (0% vs 10%; P < .001, and 0% vs 4%; P = .02, respectively). There was no difference in rates of PCI (2% vs 5%; P = .15), coronary artery bypass surgery (0% vs 1%; P = .61), return ED visits (5.8% vs 2.8%; P = .08), or MACE (2% vs 1%; P = .24) in the 28-day follow-up period. In patients presenting to the ED with acute chest pain, negative biomarkers, and a nonischemic ECG result, noninvasive testing with CCTA or stress testing leads to longer LOS, more downstream testing, more radiation exposure, and greater cost without an improvement in clinical outcomes. clinicaltrials.gov Identifier: NCT01084239.

Review: A single hs-cTnT with a cutpoint < limit of detection plus a nonischemic ECG can rule out acute MI.

Source Citation Pickering JW, Than MP, Cullen L, et al. Rapid rule-out of acute myocardial infarction with a single high-sensitivity cardiac troponin T measurement below the limit of detection: a c...

Characteristics and occurrence of type 2 myocardial infarction in emergency department patients: a prospective study

ObjectiveTo identify differences in prevalence, demographics, clinical features and outcomes for type 1 myocardial infarction (T1MI) and type 2 myocardial infarction (T2MI) in a cohort of patients presenting to the...

Out-of-hours exercise treadmill testing reduces length of hospital stay for chest pain admissions.

The objective was to examine the impact of out-of-hours exercise treadmill tests (ETTs) on length of hospital stay (LOS) for patients admitted to a chest pain assessment unit with symptoms suggestive of acute coronary syndrome. Prospective observational study with 30-day follow-up of low-to-intermediate-risk chest pain patients undergoing out-of-hours ETT. Eligible patients had a nonischemic ECG, normal 6-12-h ST-segment monitoring, a negative 12-h troponin T assay, and no contraindications to exercise. Observed LOS was compared to expected LOS in the absence of out-of-hours ETT, using Wilcoxon rank-sum test. Estimated bed day savings and major adverse events at 30 days after discharge were examined. Four hundred and twenty-two patients with a mean age of 52 years (SD 13 years, 25-83 years) were evaluated. Fifty-two per cent (n = 221) were men; 66% (n = 279) had one or less cardiovascular risk factors; and 79% (n = 334) of the patients presented on a Friday or Saturday. ETT was performed on a weekend day in 86% (n = 363) of the patients, facilitating same-day discharges in 71% (n = 300). The median LOS (interquartile range) was 1 day (1, 2 days) for patients assessed with out-of-hours ETT. The expected median LOS (IQR) was 3 days (2, 4 days) (P < 0.05) in the absence of out-of-hours ETT. Each out-of-hours ETT was estimated to save a mean (SD, range) of 1.6 (0.6, 1-4) bed days. Thirty-day mortality and readmission rates were 0 and 0.2% (1 of 422), respectively. The availability of out-of-hours ETT facilitates safe early discharge and reduced LOS for low-to-moderate-risk patients admitted with symptoms of acute coronary syndrome.

Diagnostic Accuracy of High-Sensitivity Cardiac Troponin T at Presentation Combined With History and ECG for Ruling Out Major Adverse Cardiac Events

We evaluate the diagnostic accuracy of a high-sensitivity cardiac troponin T (hs-cTnT) level less than 5ng/L or less than or equal to 14 ng/L at emergency department (ED) presentation, combined with the emergency physician's assessment of history and ECG, for ruling out major adverse cardiac events within 30 days. This prospective observational study enrolled consecutive ED chest pain patients. Emergency physicians' assessments of patient history and ECG were collected. The primary outcome was 30-day major adverse cardiac events, defined as acute myocardial infarction, unstable angina, cardiogenic shock, ventricular arrhythmia, atrioventricular block, cardiac arrest, or death of cardiac or unknown cause. A total of 1,138 patients were included in the final analysis. The combination of hs-cTnT less than 5 ng/L, anonischemic ECG result, and a nonhigh risk history was present for 29.2% of all patients and had a sensitivity of 99.2% (95% confidence interval [CI] 95.6% to 100%), negative predictive value (NPV) of 99.7% (95% CI 98.3% to 100%), and anegative likelihood ratio of 0.02 (95% CI 0 to 0.17) for 30-day major adverse cardiac events. The same combination withhs-cTnT less than or equal to 14 ng/L was present in 66.7% of the patients and had a sensitivity of 92% (95% CI 85.8% to 96.1%), NPV of 98.7% (95% CI 97.6% to 99.4%), and negative likelihood ratio of 0.11 (95% CI 0.06 to 0.20). A single hs-cTnT result of less than 5 ng/L at ED presentation when combined with a nonischemic ECG result and a nonhigh risk history identified 29% of chest pain patients at a very low risk of 30-day major adverse cardiac events. A similar strategy with hs-cTnT less than or equal to 14 ng/L was associated with a higher miss rate.

Accelerated Diagnostic Protocol Driven Chest Pain Units: An Effective But Underutilised Potential

Background: This study aimed to review the impact of several changes in August 2012, to the management of patients presenting with acute undifferentiated chest pain, with a possible diagnosis of acute coronary syndrome. Methods: This was a retrospective, observational, single centre study in Christchurch Hospital, New Zealand. Results from April 2011 and April 2014 were compared following these changes:1.Switching from conventional cardiac troponin I to high sensitivity cardiac troponin I (hs-cTnI)2.An accelerated diagnostic protocol (ADP) - low risk patients (modified TIMI = 0, negative serial hs-cTnI at 0h and 2h, non-ischaemic ECG) discharged with outpatient stress testing within 72 hours3.A Chest Pain Unit (CPU) managing low to intermediate risk (modified TIMI = 0–3) patients. End points were discharge within 6 hours/median length of stay (MLOS) in those with non-cardiac chest pain (NCCP) and 1 year death/acute myocardial infarction Results: There were 108 of 300 (36.0%) chest pain admissions in April 2011 diagnosed with NCCP, MLOS 23.43 hours, 20 (18.5%) discharged within 6 hours, 1 year adverse event rate 10 (9.3%). There were 137 of 341 (40.2%) admissions in April 2014 diagnosed with NCCP, MLOS 20.45 hours, 13 (9.5%) discharged within 6 hours. 11 of those with NCCP were CPU patients with MLOS of 6.58 hours. 1 year adverse event rate was 3 (2.2%). MLOS was effectively reduced by one third for CPU patients. Conclusion: ADP driven CPUs are safe alternative was to manage acute patients presenting with undifferentiated chest pain. MLOS was effectively reduced by one third for CPU patients. However, the true cost-effective benefits remain unclear due to underutilisation.

Beyond triage: the diagnostic accuracy of emergency department nursing staff risk assessment in patients with suspected acute coronary syndromes

ObjectivesTo establish the accuracy of emergency department (ED) nursing staff risk assessment using an established chest pain risk score alone and when incorporated with presentation high-sensitivity troponin testing as part...

Diagnostic values of chest pain history, ECG, troponin and clinical gestalt in patients with chest pain and potential acute coronary syndrome assessed in the emergency department.

In the assessment of chest pain patients with suspected acute coronary syndrome (ACS) in the emergency department (ED), physicians rely on global diagnostic impressions (‘gestalt’). The aim of this study was to determine the diagnostic value of the ED physician’s overall assessment of ACS likelihood, and the values of the main diagnostic modalities underlying this assessment, namely the chest pain history, the ECG and the initial troponin result. 1,151 consecutive ED chest pain patients were prospectively included. The ED physician’s interpretation of the chest pain history, the ECG, and the global likelihood of ACS were recorded on special forms. The discharge diagnoses were retrieved from the medical records. A chart review was carried out to determine whether patients with a non-ACS diagnosis at the index visit had ACS or suffered cardiac death within 30 days. The gestalt was better than its components both at ruling in (“Obvious ACS”, LR 29) and at ruling out (“No Suspicion of ACS”, LR 0.01) ACS. In the “Strong suspicion of ACS” group, 60% of the patients did not have ACS. A positive TnT (LR 24.9) and an ischemic ECG (LR 8.3) were strong predictors of ACS and seemed superior to pain history for ruling in ACS. In patients with a normal TnT and non-ischemic ECG, chest pain history typical of AMI was not a significant predictor of AMI (LR 1.9) while pain history typical of unstable angina (UA) was a moderate predictor of UA (LR 4.7). Clinical gestalt was better than its components both at ruling in and at ruling out ACS, but overestimated the likelihood of ACS when cases were assessed as strong suspicion of ACS. Among the components of the gestalt, TnT and ECG were superior to the chest pain history for ruling in ACS, while pain history was superior for ruling out ACS.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-015-0992-9) contains supplementary material, which is available to authorized users.