External validation of the emergency department assessment of chest pain score accelerated diagnostic pathway (EDACS-ADP).

OBJECTIVE: The emergency department assessment of chest pain score accelerated diagnostic pathway (EDACS-ADP) facilitates low-risk ED chest pain patients early to outpatient investigation. We aimed to validate this rule in a North American population. METHODS: We performed a retrospective validation of the EDACS-ADP using 763 chest pain patients who presented to St Paul's Hospital, Vancouver, Canada, between June 2000 and January 2003. Patients were classified as low risk if they had an EDACS <16, no new ischaemia on ECG and non-elevated serial 0-hour and 2-hour cardiac troponin concentrations. The primary outcome was the number of patients who had a predetermined major adverse cardiac event (MACE) at 30 days after presentation. RESULTS: Of the 763 patients, 317 (41.6%) were classified as low risk by the EDACS-ADP. The sensitivity, specificity, negative predictive value and positive predictive value of the EDACS-ADP for 30-day MACE were 100% (95% CI 94.2% to 100%), 46.4% (95% CI 42.6% to 50.2%), 100% (95% CI 98.5% to 100.0%) and 17.5% (95% CI 14.1% to 21.3%), respectively. CONCLUSIONS: This study validated the EDACS-ADP in a novel context and supports its safe use in a North American population. It confirms that EDACS-ADP can facilitate progression to early outpatient investigation in up to 40% of ED chest pain patients within 2 hours.

Cost and outcomes of assessing patients with chest pain in an Australian emergency department.

OBJECTIVES: We sought to characterise the demographics, length of admission, final diagnoses, long-term outcome and costs associated with the population who presented to an Australian emergency department (ED) with symptoms of possible acute coronary syndrome (ACS). DESIGN, SETTING AND PARTICIPANTS: Prospectively collected data on ED patients presenting with suspected ACS between November 2008 and February 2011 was used, including data on presentation and at 30 days after presentation. Information on patient disposition, length of stay and costs incurred was extracted from hospital administration records. MAIN OUTCOME MEASURES: Primary outcomes were mean and median cost and length of hospital stay. Secondary outcomes were diagnosis of ACS, other cardiovascular conditions or non-cardiovascular conditions within 30 days of presentation. RESULTS: An ACS was diagnosed in 103 (11.1%) of the 926 patients recruited. 193 patients (20.8%) were diagnosed with other cardiovascular-related conditions and 622 patients (67.2%) had non-cardiac-related chest pain. ACS events occurred in 0 and 11 (1.9%) of the low-risk and intermediate-risk groups, respectively. Ninety-two (28.0%) of the 329 high-risk patients had an ACS event. Patients with a proven ACS, high-grade atrioventricular block, pulmonary embolism and other respiratory conditions had the longest length of stay. The mean cost was highest in the ACS group ($13 509; 95% CI, $11 794-$15 223) followed by other cardiovascular conditions ($7283; 95% CI, $6152-$8415) and non-cardiovascular conditions ($3331; 95% CI, $2976-$3685). CONCLUSIONS: Most ED patients with symptoms of possible ACS do not have a cardiac cause for their presentation. The current guideline-based process of assessment is lengthy, costly and consumes significant resources. Investigation of strategies to shorten this process or reduce the need for objective cardiac testing in patients at intermediate risk according to the National Heart Foundation and Cardiac Society of Australia and New Zealand guideline is required.

Should fee-for-service be for all guideline-advocated acute coronary syndrome (ACS) care? Observations from the Snapshot ACS study.

OBJECTIVE: The aim of the present study was to explore the association of health insurance status on the provision of guideline-advocated acute coronary syndrome (ACS) care in Australia. METHODS: Consecutive hospitalisations of suspected ACS from 14 to 27 May 2012 enrolled in the Snapshot study of Australian and New Zealand patients were evaluated. Descriptive and logistic regression analysis was performed to evaluate the association of patient risk and insurance status with the receipt of care. RESULTS: In all, 3391 patients with suspected ACS from 247 hospitals (23 private) were enrolled in the present study. One-third of patients declared private insurance coverage; of these, 27.9% (304/1088) presented to private facilities. Compared with public patients, privately insured patients were more likely to undergo in-patient echocardiography and receive early angiography; furthermore, in those with a discharge diagnosis of ACS, there was a higher rate of revascularisation (P < 0.001). Each of these attracts potential fee-for-service. In contrast, proportionately fewer privately insured ACS patients were discharged on selected guideline therapies and were referred to a secondary prevention program (P = 0.056), neither of which directly attracts a fee. Typically, as GRACE (the Global Registry of Acute Coronary Events) risk score rose, so did the level of ACS care; however, propensity-adjusted analyses showed lower in-hospital adverse events among the insured group (odds ratio 0.68; 95% confidence interval 0.52-0.88; P = 0.004). CONCLUSION: Fee-for-service reimbursement may explain differences in the provision of selected guideline-advocated components of ACS care between privately insured and public patients.

Performance of risk stratification for acute coronary syndrome with two-hour sensitive troponin assay results.

BACKGROUND: Risk stratification processes for patients with possible acute coronary syndrome (ACS) recommend the use of serial sensitive troponin testing over at least 6h. Troponin assays vary in their analytical performance. Utility in accurate risk stratification at 2h post-presentation is unknown. METHODS: A diagnostic accuracy study of patients presenting to the emergency department (ED) with symptoms of ACS was performed. Troponin was measured at 0, 2 and 6h post-presentation. Acute myocardial infarction (AMI) was adjudicated by cardiologists and incorporated the 0 and 6h troponin values measured by a sensitive troponin assay. Results were described using standard measures of test accuracy. RESULTS: Of the 685 patients, 51 (7.4%) had 30-day AMI or cardiac death, and 76 (11.1%) had secondary outcomes (all cause death, ACS and revascularisation procedures). There was no significant difference in the diagnostic accuracy of early versus late biomarker strategies when used with the current risk stratification processes. Incorporation of a significant delta did not improve the stratification at 2h post-presentation. CONCLUSIONS: Accelerated risk stratification of patients with ACS symptoms may occur at 2h post-presentation using troponin results measured by a sensitive assay. Incorporation of such a strategy could support improvements in patient flow within EDs.

Comparison of early biomarker strategies with the Heart Foundation of Australia/Cardiac Society of Australia and New Zealand guidelines for risk stratification of emergency department patients with chest pain.

OBJECTIVES: To compare cardiac risk stratification using a 0 and 2 h point-of-care (POC) cardiac troponin (cTn), 0 and 2 h POC multi-biomarkers against the 0 and 6 h laboratory cTn reference standard. METHODS: A prospective observational study of ED patients presenting with chest pain was performed. Patients were risk stratified and treated as per the Heart Foundation of Australia/Cardiac Society of Australia and New Zealand (HF-A/CS-ANZ) guidelines using the 0 and 6 h laboratory cTn (T6). Patients were further stratified using a 0 and 2 h POC cTn (T2) plus 0 and 2 h POC multi-biomarkers (cTn, creatine kinase-MB, myoglobin) (M2). The T6, T2 and M2 strategies were compared using the 30-day major adverse cardiac events as the primary outcome. RESULTS: Seven hundred and four patients (median age 54 years, male 62.1%) were enrolled. Using the T6 reference standard, 2%, 61% and 37% were stratified as low, intermediate and high risk, respectively. The 30-day event rates were 0%, 3.5% and 28.6%, respectively. The T2 strategy stratified 1.5%, 57% and 41% as low, intermediate and high risk, respectively, with 30-day event rates of 0%, 4.2% and 24.8%, respectively. The M2 strategy resulted in significantly different risk distribution with 1%, 40% and 59% stratified as low, intermediate and high risk, respectively, with 30-day event rates of 0%, 3.9% and 18.8%, respectively. CONCLUSION: Using a 2 h POC cTn-only biomarker strategy with the HF-A/CS-ANZ guidelines accurately identified a population at intermediate risk of 30-day events in whom further objective testing might be accelerated, allowing subsequent early discharge of the majority of this cohort. Within 2 h of presentation a high risk population could be identified in whom early management, including admission, was required.

Cardiac MRI assessment of left and right ventricular parameters in healthy Australian normal volunteers.

Cardiac magnetic resonance imaging (MRI) is being utilised increasingly for the purposes of cardiovascular imaging. Limited data suggest a high degree of reproducibility for parameters such as left ventricular (LV) ejection fraction (EF), mass, end-diastolic and end-systolic volumes (EDV and ESV). We sought to investigate reproducibility and establish means for these parameters in a selected normal non-Aboriginal Australian population, using cardiac MRI. Sixty normal volunteers underwent cardiac MRI investigation using a 1.5 T MRI system. Steady state free precession imaging was performed with short axis cine images through the left ventricle obtained. All images were acquired with cardiac gating. Two independent observers then analysed the data set. Data were collected for assessment of left ventricular EF, EDV, ESV, mass and right ventricular volumes. Data are presented as mean+/-S.D. Total imaging time was approximately 15 min. All patients were able to complete the full protocol. Left ventricular parameters: EF 58.5+/-8.0%, LV mass 114.2+/-40.6g, EDV 117.3+/-33.4 mls and ESV 50.0+/-22.2 mls. Right ventricular parameters: EF 45.6+/-11.6%, EDV 163.5+/-52.2 mls and ESV 89.5+/-34.3 mls. Intraclass correlation coefficients for LV: EF 0.84, LV mass 0.84, EDV 0.85 and ESV 0.89. Cardiac MRI provides high quality information about cardiac function with a high level of reproducibility. Cardiac MRI parameters in a normal non-Aboriginal Australian population are provided.