Chest Pain Guidelines Research Articles

Management Considerations for Acute Coronary Syndromes in Chronic Kidney Disease.

Propensity of patients with chronic kidney disease (CKD) to adverse outcomes of acute coronary syndromes (ACS) derives, in part, from imperfection in management. Dearth of data resulting from underrepresentation of patients with CKD in ACS trials and underuse of evidence-based testing and therapy compound biological risks inherent to CKD. We sought in this narrative review to critically appraise contemporary evidence and offer suggested approaches to practicing clinicians for the optimization of ACS management in patients with CKD. Updated multisociety chest pain guidelines emphasize the diversity of clinical presentations of ACS, pertinent to recognition of ACS in patients with CKD. Evolving tools to predict and prevent acute kidney injury complicating invasive management of ACS serve to support improved access to and safety of percutaneous coronary intervention (PCI) in CKD patients, who remain at elevated risk. Growth in use of radial access, advances in PCI quality, incorporation of intravascular imaging, and new options and insights in pharmacotherapy contribute to an evolving calculus of ischemic and bleeding risk in ACS with bearing on management in CKD patients. Key opportunities to improve outcomes of ACS for patients with CKD center on avoiding underuse of beneficial medical and invasive therapies; enhancing safety of therapies by leveraging evidence-based strategies to prevent acute kidney injury; and devoting specific effort to investigation of ACS management in the context of CKD.

Artificial Intelligence Applications in Cardiovascular Magnetic Resonance Imaging: Are We on the Path to Avoiding the Administration of Contrast Media?

In recent years, cardiovascular imaging examinations have experienced exponential growth due to technological innovation, and this trend is consistent with the most recent chest pain guidelines. Contrast media have a crucial role in cardiovascular magnetic resonance (CMR) imaging, allowing for more precise characterization of different cardiovascular diseases. However, contrast media have contraindications and side effects that limit their clinical application in determinant patients. The application of artificial intelligence (AI)-based techniques to CMR imaging has led to the development of non-contrast models. These AI models utilize non-contrast imaging data, either independently or in combination with clinical and demographic data, as input to generate diagnostic or prognostic algorithms. In this review, we provide an overview of the main concepts pertaining to AI, review the existing literature on non-contrast AI models in CMR, and finally, discuss the strengths and limitations of these AI models and their possible future development.

Use of the HEAR Score for 30-Day Risk-Stratification in Emergency Department Patients

BackgroundThe 2021 American College of Cardiology/American Heart Association chest pain guidelines recommend risk scores such as HEAR (History, Electrocardiogram, Age, Risk factors) for short-term risk stratification, yet limited data exist integrating them with high-sensitivity cardiac troponin T (hs-cTnT). MethodsRetrospective, multicenter (n = 2), observational, US cohort study of consecutive emergency department patients without ST-elevation myocardial infarction who had at least one hs-cTnT (limit of quantitation [LoQ] <6 ng/L, and sex-specific 99th percentiles of 10 ng/L for women and 15 ng/L for men) measurement on clinical indications in whom HEAR scores (0-8) were calculated. The composite major adverse cardiovascular event (MACE) outcome was 30-day prognosis. ResultsAmong 1979 emergency department patients undergoing hs-cTnT measurement, 1045 (53%) were low risk (0-3), 914 (46%) intermediate risk (4-6), and 20 (1%) high risk (7-8) based on HEAR scores. HEAR scores were not associated with increased risk of 30-day MACE in adjusted analyses. Patients with quantifiable hs-cTnT (LoQ-99th) had an increased risk for 30-day MACE (3.4%) irrespective of HEAR scores. Those with serial hs-cTnT <99th percentile remained at low risk (range 0%-1.2%) across all HEAR score strata. Higher scores were not associated with long-term (2-year) events. ConclusionsHEAR scores are of limited value in those with baseline hs-cTnT <LoQ or hs-cTnT >99th percentile to define short-term prognosis. In those with baseline quantifiable hs-cTnT within the reference range (<99th percentile), a higher risk (>1%) for 30-day MACE exists even in those with low HEAR scores. With serial hs-cTnT measurements, HEAR scores overestimate risk when hs-cTnT remains <99th percentile.

Impact on stable chest pain pathways of CT fractional flow reserve

ObjectivesTo evaluate the impact of introducing CT fractional flow reserve (FFRCT) on stable chest pain pathways, concordance with National Institute for Health and Care Excellence (NICE) chest pain guidelines, resource...

The Use and Efficacy of FFR-CT: Real-World Multicenter Audit of Clinical Data With Cost Analysis

BackgroundFractional flow reserve–computed tomography (FFR-CT) is endorsed by UK and U.S. chest pain guidelines, but its clinical effectiveness and cost benefit in real-world practice are unknown. ObjectivesThe purpose of this study was to audit the use of FFR-CT in clinical practice against England’s National Institute for Health and Care Excellence guidance and assess its diagnostic accuracy and cost. MethodsA multicenter audit was undertaken covering the 3 years when FFR-CT was centrally funded in England. For coronary computed tomographic angiograms (CCTAs) submitted for FFR-CT analysis, centers provided data on symptoms, CCTA and FFR-CT findings, and subsequent management. Audit standards included using FFR-CT only in patients with stable chest pain and equivocal stenosis (50%-69%). Diagnostic accuracy was evaluated against invasive FFR, when performed. Follow-up for nonfatal myocardial infarction and all-cause mortality was undertaken. The cost of an FFR-CT strategy was compared to alternative stress imaging pathways using cost analysis modeling. ResultsA total of 2,298 CCTAs from 12 centers underwent FFR-CT analysis. Stable chest pain was the main symptom in 77%, and 40% had equivocal stenosis. Positive and negative predictive values of FFR-CT were 49% and 76%, respectively. A total of 46 events (2%) occurred over a mean follow-up period of 17 months; FFR-CT (cutoff: 0.80) was not predictive. The FFR-CT strategy costs £2,102 per patient compared with an average of £1,411 for stress imaging. ConclusionsIn clinical practice, the National Institute for Health and Care Excellence criteria for using FFR-CT were met in three-fourths of patients for symptoms and 40% for stenosis. FFR-CT had a low positive predictive value, making its use potentially more expensive than conventional stress imaging strategies.

Abstract 11021: Chest Symptoms and Subsequent Risk of Incident Cardiovascular Disease: The Atherosclerosis Risk in Communities (ARIC) Study

Introduction: The 2021 AHA/ACC Chest Pain Guideline classifies the likelihood of ischemia according to chest symptom characteristics. However, the associations of various chest symptoms with long-term risk of different cardiovascular disease (CVD) have not been fully investigated. Aim: To quantify the associations of chest pain and dyspnea with incident major CVD. Methods: In 13,200 ARIC participants (mean age 54 [SD 6] years, 56% female, 25% Blacks) without prior CVD at visit 1 (1987-89), we categorized chest pain into definite angina, possible angina, non-anginal chest pain, and no chest pain based on the WHO Rose questionnaire, and dyspnea into grade 0, 1, 2, and 3-4 based on the Medical Research Council scale. CVD outcomes included myocardial infarction (MI), heart failure (HF), atrial fibrillation (AF), and ischemic stroke (median follow-up, 26-28 years). We estimated 30-year cumulative incidence accounting for competing risk of deaths and ran multivariable Cox models. Results: Definite angina and possible angina were robustly associated with incident MI (Table), with adjusted HR 1.83 (95%CI 1.51-2.22) and 1.64 (1.26-2.13), respectively. These two chest pain types were also related to HF, AF, and ischemic stroke, although possible angina did not reach statistical significance for stroke. Even non-anginal chest pain was associated with MI, HF, and AF. Dyspnea showed graded association with all CVD outcomes, but particularly with MI and HF (bottom half of Table). For example, grade 3-4 and 2 showed HR of 2.13 (1.71-2.65) and 1.41 (1.13-1.76), respectively, for MI. When chest pain and dyspnea were modeled simultaneously, their associations were independent. Conclusions: In persons without prior CVD, chest pain and dyspnea were independently associated with different CVD events over 30 years. Our findings suggest broad prognostic implications of chest pain beyond coronary disease and emphasize the importance of recognizing dyspnea for CVD risk management.

Abstract 14283: Influence of the HEAR Score for 30-day Risk-Stratification in Emergency Department Patients Evaluated With High-Sensitivity Cardiac Troponin T

Background: The 2021 ACC/AHA chest pain guidelines recommend risk scores such as HEAR (History, Electrocardiogram, Age, Risk Factors) for short term risk-stratification yet limited data exists integrating them with high-sensitivity cardiac troponin T (hs-cTnT). Methods: Retrospective, multicenter (n=2), observational, U.S. cohort study of consecutive ED patients without ST-elevation myocardial infarction (MI) who had at least one hs-cTnT (limit of quantitation, LoQ, &lt;6 ng/L, and sex-specific 99 th percentiles of 10 ng/L for women and 15 ng/L for men) measurement on clinical indication in whom HEAR scores (0-8) were calculated. The composite major adverse cardiovascular (MACE) outcome was 30-day MI and death. Results: Among 1,979 ED patients undergoing hs-cTnT measurement, 1045 (53%) were classified as low-risk (0-3), 914 (46%) as intermediate-risk (4-6), and 20 (1%) as high-risk (7-8) based on HEAR scores. HEAR scores were not associated with an increased risk of 30-day MACE after adjusted analyses. Outcomes according to risk-strata based on HEAR scores and baseline hs-cTnT are shown in Table 1. Patients with quantifiable hs-cTnT (LoQ-99 th ) had an increased risk for 30-day MACE (3.4%) despite being estimated to be low-risk (0-3) per HEAR scores. Conversely, those with serial hs-cTnT&lt;99 th percentile remained at low-risk (range 0% to 1.2%) for 30-day MACE across HEAR score strata. Conclusions: HEAR scores are of limited value in those with baseline hs-cTnT&lt;LoQ or hs-cTnT&gt;99 th percentile where hs-cTnT identifies very low and high-risk patients irrespective of HEAR scores. In those with baseline quantifiable hs-cTnT within the reference range (&lt;99 th percentile), a higher risk (&gt;1%) for 30-day MACE exists even in those with low HEAR scores. With serial hs-cTnT measurements, HEAR scores overestimate risk when hs-cTnT remains &lt;99 th percentile.

Selección de lo mejor del año 2022 en imagen cardiaca

This review article aims to summarize the role of cardiac imaging regarding the most relevant technical and knowledge advances published within the last year. Although diagnosis and detection of cardiac involvement due to coronavirus disease maintain a prominent place, other interesting hot topics have been raised. Among the most relevant, it is noteworthy to highlight the prognostic utility of different parameters obtained by advanced imaging techniques in the field of valvular heart disease, cardiovascular prevention or cardio-oncology, the prominent role of imaging in the first diagnostic step of the new Chest Pain guidelines or the exponential growth of percutaneous structural interventionism, where further knowledge is demanded in terms of patient selection, procedure timing or predictors of success. Finally, artificial intelligence is a promising tool already in our hands, we hope that diagnostic precision and interpretation time will improve thanks to these technological advances.

Implications of the North American 2021 Chest Pain guidelines in the diagnostic approach to patients with stable chest pain and low pretest probability of obstructive coronary artery disease

Abstract Background The North American 2021 Chest Pain Guidelines recommend not testing stable patients with low pretest likelihood of obstructive coronary artery disease (CAD), defined as pretest probability &amp;lt;15% using contemporary models (Class I recommendation). In selected cases among this subset of patients, coronary artery calcium (CAC) score is considered a “reasonable first-line test” (Class IIa). Despite some supporting evidence, the clinical implications of a widespread adoption of these recommendations remain unclear. The purpose of this study was to assess the results of three different testing strategies for patients with pretest probability &amp;lt;15%: A) defer testing; B) perform CAC score and withhold further testing if = 0, and proceed to coronary CT angiography (CCTA) if &amp;gt;0; C) perform CCTA in all. Methods We conducted a two-center cross-sectional study assessing symptomatic patients with suspected CAD who underwent CAC score and CCTA. Patients with known CAD, suspected acute coronary syndrome, or symptoms other than chest pain or dyspnea were excluded. Pretest probability of obstructive CAD was calculated based on age, sex and symptom typicality. Obstructive CAD was defined as any luminal stenosis ≥50% on CCTA. Results A total of 2259 patients were screened, of which 1385 (61.3%) had pretest probability &amp;lt;15% and were included in the analysis (mean age 57±11 years, 79% women). Symptom characteristics were: 48% non-anginal chest pain, 26% atypical angina, 21% dyspnea, and 5% typical chest pain. Overall, the prevalence of obstructive CAD was 10.3% (n=142). In the 786 patients (56.6%) with a CAC score of 0, 8.5% (n=67) had some degree of CAD [1.9% (n=15) obstructive, and 6.6% (n=52) nonobstructive]. Among those with CAC &amp;gt;0 (n=599), 21.2% (n=127) had obstructive CAD. The results that would be reached with each of the 3 diagnostic strategies are presented in Figure 1. The number of patients needed to scan with strategy B (CAC as gatekeeper) vs. A (no testing) to identify one patient with obstructive CAD was 11, whereas the number needed to scan with strategy C (CCTA for all) vs. strategy B was 91. Conclusions Not testing patients with suspected CAD and pretest likelihood &amp;lt;15% would lead to missing obstructive CAD in 1 out of 10 patients. Using CAC as a gatekeeper in this subgroup would decrease the use of CCTA by more than 50%, at the cost of missing obstructive CAD in 1 out of 100 patients. These findings may be used to inform decisions on testing, which will ultimately depend on how much diagnostic uncertainty and missed diagnoses patients and their physicians are willing to accept. Funding Acknowledgement Type of funding sources: None.

Noncardiac Esophageal Chest Pain -A Comprehensive Review

Abstract Background and aim. Noncardiac chest pain (NCCP) is a medical condition described as acute, recurrent, or chronic chest pain, that is difficult to distinguish from ischemic heart pain, when the cardiac source has been excluded. Noncardiac chest pain represents a challenging clinical situation in gastroenterology practice, requiring sometimes a high amount of clinical investigation for a specific diagnostic. In some cases, the etiology is represented by esophageal diseases. This review aims to present the updated knowledge of the esophageal origin of NCCP. Methods. A search was performed in the main databases containing medical publications. The following search terms were used: noncardiac chest pain, esophageal chest pain (ECP), pathophysiology, noncardiac chest pain etiology, gastroesophageal reflux disease (GERD), motility esophagus disorders, functional chest pain. Observational studies were included. Studies that described only cardiac chest pain were excluded. Results. Noncardiac chest pain requires precise recognition of signs, symptoms and diagnostic testing in clinical practice. Due to financial constraints on subsequent care, an accurate algorithm based on clinical noncardiac chest pain guidelines should be followed. Esophageal chest pain represents a challenging diagnosis. Conclusions. Noncardiac chest pain is a prevalent and alarming symptom. Esophageal chest pain etiology should be considered once a cardiac source has been excluded.

509 Cardiovascular Computed Tomography And FFRCTIn The United States Medicare Population From 2013-2020

Introduction: Over the past decade, through numerous technical advances and clinical studies, cardiovascular computed tomography (CCT) has gained increasing acceptance; recently evidenced by receiving multiple class 1, level A recommendations in the 2021 AHA/ACC Chest Pain Guidelines. We aimed to evaluate recent CCT practice and practitioner trends in the US Medicare population with the motivation of guiding practice, training, and advocacy.

456 Analyzing Reporting Language And Communication Patterns Following Coronary CT Angiography (CCTA)

Introduction: The anatomic and physiologic information provided by coronary CT angiography (CCTA) represents a paradigmatic shift in the noninvasive evaluation of chest pain with utilization only bolstered further following the release of the 2021 AHA Chest Pain Guidelines. This shift is not only an adjustment for providers, but also for patients who have now been granted real time access to their medical records in the age of the almost one-year-old Cures act. This study therefore aims to review CCTA reports as well as how these results are conveyed to patients to help identify potentials gaps and miscommunications which could negatively impact long term medical care.

491 Implications Of The North American 2021 Chest Pain Guidelines In The Diagnostic Approach To Patients With Stable Chest Pain And Low Pretest Probability Of Obstructive Coronary Artery Disease

Introduction: The North American 2021 Chest Pain Guidelines recommend not testing stable patients with low pretest likelihood of obstructive coronary artery disease (CAD), defined as pretest probability (PTP) < 15% using contemporary models (Class I recommendation). In selected cases among this subset of patients, coronary artery calcium (CAC) score is considered a “reasonable first-line test” (Class IIa). Despite some supporting evidence, the clinical implications of a widespread adoption of these recommendations remain unclear.

Recent Advances in Coronary Computed Tomography Angiogram: The Ultimate Tool for Coronary Artery Disease.

The emerging technologies in multidetector computed tomography scanners gave the ability to image coronary arteries in a single heartbeat, at a higher quality, and low radiation dose. Furthermore, incorporating artificial intelligence and machine learning into image processing and interpretation have extended the use for coronary computed tomography angiogram (CCTA) and its applications. In this review, we will explore the recent evidence and advances supporting CCTA to become the ultimate tool for coronary artery disease. Results from the EVINCI, ISCHEMIA, SCOT-HEART, and PROMISE showed that CCTA is better in patients' risk stratification and in detecting subclinical atherosclerosis, resulting in earlier interventions and lesser events. Additionally, CCTA gave us a closer look on atherosclerotic disease by identifying different type of plaque and their clinical significance. Furthermore, FFRCT is a notable example of incorporating artificial intelligence into CCTA. This technology helped us to accurately and non-invasively identify flow limiting lesions, guiding revascularization. As a result of the recent evidence, CCTA have made its way into the chest pain guidelines all over the world. Moreover, CCTA have the potential to revolutionize our understanding and standards in screening, preventing, and managing heart disease.

ESC 2019 guidelines on chronic coronary syndromes: can calcium scoring improve the risk underestimation associated with the updated pre-test probability risk score?

Abstract Funding Acknowledgements Type of funding sources: None. Introduction The European Society of Cardiology (ESC) published an updated stable chest pain guideline in 2019. It recommends the use of an updated pre-test probability (PTP) risk score (RS) to assess the likelihood of coronary artery disease (CAD), to try and reduce the risk overestimation associated with previous risk scores. We sought to assess the performance of the 2019 PTPRS in a contemporary cohort of patients undergoing CT coronary angiography (CTCA). Furthermore, we focussed on patients with PTPRS &amp;lt;15%, and assessed the utility of CT calcium scores as a discriminator of risk. Methods 652 patients who were investigated with CTCA for stable chest pain between January 2017 and May 2018 were included in a retrospective analysis. CTCA reported CAD degree of stenosis as normal/minimal stenosis, mild (30-50%), moderate (50-70%), or severe (&amp;gt;70%). ESC 2019 pre-test probability risk scores were retrospectively calculated and compared. Results A total of 652 patients underwent CTCA between 01 January 2017 and 31 May 2018, of which 330 were male and 322 were female, with an average age of 55 years ±11 years. Using the ESC 2019 PTPRS there were no patients with PTPRS &amp;gt;85%. 2 patients had PTPRS 50-85%; one patient had moderate stenosis and one mild stenosis on CTCA. There were 267 patients with PTPRS 15-50%; 23 (9%) patients had severe CTCA stenosis, 37 (14%) a moderate stenosis, and 34 (13%) a mild stenosis. A further 379 patients had PTPRS &amp;lt;15%; 11 (3%) had severe stenosis and 20 (5%) moderate stenosis. A further 27 (7%) patients had mild CTCA stenosis. A total of 357 of 379 patients with PTPRS &amp;lt;15% based on ESC 2019 had a CT calcium score. 236 patients were found to have a calcium score of zero, and 121 patients had a score greater than zero, with a range between 1 and 930. Of patients with zero calcium score, only 1 (0.4%) patient had severe stenosis, 2 (0.8%) moderate stenoses and 6 (2.5%) mild stenosis. In contrast, in patients with positive calcium scores, 10 (8%) had severe stenosis, 18 (15%) moderate stenosis, and 22 (18%) mild stenosis. Conclusions The ESC 2019 PTPRS classified this as an overall low risk cohort. The downward risk modification of PTPRS has led to a large number of patients being classified as low risk with PTPRS &amp;lt;15%. No or deferred investigation is recommended by the ESC in this cohort. However, the use of CT calcium scores in patients with PTPRS &amp;lt;15%, detected the majority of patients with any degree of CAD. CT calcium scores are a simple and low cost risk modifier, and may help identify patients who may benefit from primary prevention as per SCOT-Heart. Patients with calcium score greater than zero could be investigated with CTCA.

National Trends in Coronary Artery Disease Imagingassociations with Health Care Outcomes and Costs

Background: We sought to determine the impact of temporal trends and the 2016 updated National Institute for Health and Care Excellence chest pain guidelines (CG95) on imaging investigations and outcomes for coronary artery disease. Methods: Investigations for coronary artery disease from 2012-2018 were extracted from the English national database of imaging procedures and linked to national hospital admission and mortality registries. Growth rates were calculated, adjusted for population size, and linked with trends in cardiovascular hospital admissions and mortality compared across tertiles of imaging growth. The impact of CG95 was assessed using an interrupted time-series analysis. Findings: From 2012-2018, 1,909,314 investigations for coronary artery disease were performed, with an annualised per capita growth rate of 4·8%. At a national level, CG95 was associated with a rise in coronary computed tomography angiography (CTA) (exp(β) 1·10 [95% confidence interval 1·03 to 1·18], p=0·006), with no change in myocardial perfusion imaging and a potential modest fall in invasive coronary angiography (exp(β) 0·997 [0·993 to 1·00], p=0·06). At a regional level, greater CTA growth was associated with reduced hospitalisations for myocardial infarction (-0·7 [-0·8 to 1·7] admissions/100,000 population/year) whereas lower growth was associated with increased hospitalisations for myocardial infarction (1·8 [0·9 to 2·7] admissions/100,000 population/year). Cardiovascular and coronary artery disease deaths fell by -2·95 [-3·11 to -2·72] and -1·66 [-1·79 to -1·51] deaths/100,000/year respectively (p<0·0001 for both). Coronary artery disease deaths fell more in regions with the highest CTA growth compared to those with the lowest growth (-3·29 [-3·60 to -2·95] versus -2·32 [-2·82 to -2·10] deaths/100,000/year). Interpretation: Imaging investigations for coronary artery disease are increasing, with the greatest growth seen in coronary CTA following CG95. Greater regional increases in coronary CTA were associated with fewer hospitalisations for myocardial infarction and a more rapid fall in coronary artery disease mortality. Funding: JRWM is supported by the NIHR Cambridge Biomedical Research Centre. JHFR is part-supported by the NIHR Cambridge Biomedical Research Centre, the British Heart Foundation, HEFCE, the EPSRC and the Wellcome Trust. DEN is supported by the British Heart Foundation (CH/09/002, RG/16/10/32375, RE/18/5/34216) and is the recipient of a Wellcome Trust Senior Investigator Award (WT103782AIA). MCW (FS/ICRF/20/26002) is supported by the British Heart Foundation. Declaration of Interest: JRWM, MCW, GR and DEN were investigators in the SCOT-HEART trial.

ESC 2019 guidelines on chronic coronary syndromes: could calcium scoring improve detection of coronary artery disease in patients with low risk score. Findings from a retrospective cohort of patients in a district general hospital.

BackgroundThe European Society of Cardiology (ESC) published an updated stable chest pain guideline in 2019, recommending the use of an updated pre-test probability (PTP) risk score (RS) to assess the likelihood of coronary artery disease (CAD). We sought to compare the 2019 and 2013 PTPRS in a contemporary cohort of patients.Methods612 patients who were investigated with computed tomography coronary angiography (CTCA) for stable chest pain were included in a retrospective analysis.ResultsThere were 255 patients with 2019 PTPRS 15–50% with a 9% yield of severe CAD on CTCA, compared with 402 patients and a 4% yield using the 2013 PTPRS (p = 0.01). 355 patients had a 2019 PTPRS of <15%, with 3% found to have severe CAD, compared with 67 patients and none with severe CAD using the 2013 PTPRS (p = 0.14). 336 of patients with 2019 PTPRS of <15% had a calcium score as part of the CTCA. 223 of these had a zero calcium score and only one had severe CAD. In comparison, 113 patients had a positive calcium score, and 10 (9%) had severe CAD (p < 0.001).DiscussionThe ESC 2019 PTPRS classifies more patients as at lower risk of CAD and hence reduces the risk overestimation associated with the 2013 PTPRS. However, in patients with a 2019 PTPRS of <15%, who would not be investigated, the use of the calcium score detected the majority of patients with significant CAD, who may benefit from secondary prevention and an associated mortality benefit as per the SCOT-Heart trial.

P1589 Yield of invasive coronary angiography following the UK NICE 2016 guideline expansion of CT coronary angiography

Abstract The UK National Institute of Health and Care Excellence (NICE) updated chest pain guidelines in 2016 and recommended CT coronary angiography (CTCA) as the first line investigation for all patients presenting with new stable chest pain and the removal of the pre-test probability risk scoring. There is a concern that using CTCA in populations with higher likelihood of coronary artery disease (CAD), can lead to higher rates of downstream testing with invasive coronary angiography (ICA). We implemented the NICE 2016 guideline and audited the downstream testing after CTCA. We also evaluated the performance of the ESC risk score (ESC RS). Methods We undertook a retrospective search of the radiology database from January 2017 to June 2018. CTCA reported CAD degree of stenosis as normal/minimal stenosis, mild (30-50%), moderate (50-70%), or severe (&amp;gt;70%). Results In total 652 patients underwent CTCA (mean age 55 yrs; 330 male). 92 patients were found to have moderate or severe stenosis. 69 of them were referred directly to ICA, with 63 undergoing ICA and confirming severe CAD in 40 patients, a yield of 63%. 18 patients with moderate stenosis were referred for stress echo (SE) with one positive result. In total 35 patients went on to be revascularised. 62 patients were found to have mild stenosis. The majority of patients (n = 462) had normal/minimal stenosis. There were 36 inconclusive studies. The ESC RS was calculated retrospectively with the following results: 70 patients had an ESC RS &amp;lt;15% and 2 (3%) were found to have moderate stenosis. 427 patients had an ESC RS 15-50%; 17 (4%) had severe stenosis and 32 (8%) moderate stenosis. 149 patients had an ESC RS 50-85%; 17 (11%) were found to have severe stenosis and 23 (15%) moderate stenosis. Lastly 2 patients had an ESC RS &amp;gt;85% and one had moderate stenosis. Conclusions Our results demonstrate that CTCA is an effective first line test for most patients with new stable chest pain as the majority were found to have normal/minimal disease. In the patients that went on to have ICA, CTCA had a relatively high yield of detecting severe CAD (63%). This was achieved with some use of SE as a gatekeeper to ICA, particularly in patients with moderate CTCA stenosis. SE should be used more after CTCA in patients with moderate stenosis, as a gatekeeper to ICA. The ESC RS was predictive of significant CAD but overestimated the likelihood of CAD. Abstract P1589 Figure. Severe CTCA stenosis of the LAD

P1487 Anomalous right coronary artery from mid left anterior descending artery

Abstract 55-year-old male with history of transient ischaemic attack, excised gastro-intestinal stromal tumour, and osteoarthritis presented to rapid access chest pain clinic with history of atypical chest pain. There were no resting electrocardiographic changes. In accordance with NICE stable chest pain guidelines, a CT coronary angiogram was requested to further assess for any underlying coronary artery disease. This showed normal origin of left main stem (LMS) from left coronary sinus of aorta, however there was an anomalous origin of the right coronary artery (RCA) as a branch from the mid portion of left anterior descending artery (LAD). This was deemed to be an incidental finding with a benign course and not the cause of his symptoms. Coronary anomalies have a reported incidence of 1.3% at invasive coronary angiography (1), and a reported incidence of 0.014-0.066% of single coronary artery (2). Anomalous RCA usually courses from the LMS and courses between the aorta and pulmonary artery. We present an extremely rare variant of single coronary artery arising from the mid LAD without any associated congenital or structural abnormality, on CT coronary angiography (the gold standard for demonstrating coronary anatomy). This is rarely reported in the literature and is a benign coronary anomaly. Abstract P1487 Figure.

An Audit of Paramedic Administration of Oxygen Therapy to Patients with Suspected Acute Coronary Syndrome

Introduction In the past, high flow oxygen was routinely administered to patients with suspected acute myocardial infarction. Recent evidence has suggested there is no benefit from hyperoxaemia, and in these patients it might result in adverse outcomes. The Australian and New Zealand Council of Resuscitation (ANZCOR) guideline previously recommended routine oxygen therapy, but a recent change has occurred. The ANZCOR current guideline recommends selective use of oxygen therapy in patients with suspected acute myocardial infarction, to achieve oxygen saturations ≥94% and &lt;98%. Because the change occurred recently, the South Australian paramedic adherence rate to the ANZCOR guideline was unknown. Therefore, the aim of this study was to determine the South Australian paramedic adherence rate to the ANZCOR oxygen use in acute coronary syndrome recommendations. Methods A retrospective audit of patient case notes was conducted, for patients with chest pain presenting via ambulance to a tertiary hospital emergency department, during a 3-month period. Paramedic administration of oxygen therapy was then compared against the ANZCOR recommendations. Results Paramedics treated a total of 111/139 (79.9%, CI 72.4–85.7%) in line with the ANZCOR guideline and the treatment of 28/139 (20.1%, CI 14.3–27.6%) fell outside of the recommendations. Conclusion Although the results demonstrated a degree of compliance, this could be improved through clinical education, a review of the local chest pain guidelines, an introduction of a drug protocol for oxygen therapy and future research investigating the reasons for non-compliance to the best practice guidelines.