Remote myocardial fibrosis predicts adverse outcome in patients with myocardial infarction on clinical cardiac magnetic resonance imaging.

BACKGROUND: Heart failure (HF) most commonly occurs in patients who have had a myocardial infarction (MI), but factors other than MI size may be deterministic. Fibrosis of myocardium remote from the MI is associated with adverse remodelling. We aimed to i) Investigate the association between remote myocardial fibrosis, measured using cardiovascular magnetic resonance (CMR) extracellular volume (ECV), and HF and death following MI, ii) Identify predictors of remote myocardial fibrosis in patients with evidence of MI, and determine the relationship with infarct size. METHODS: Multicentre prospective cohort study of 1,199 consecutive patients undergoing CMR with evidence of MI on late gadolinium enhancement. Median follow-up 1,133 (895-1,442) days. Cox proportional hazards modelling was used to identify factors predictive of the primary outcome, a composite of first hospitalisation for HF (HHF) or all-cause mortality, post-CMR. Linear regression modelling was used to identify determinants of remote ECV. RESULTS: Remote myocardial fibrosis was a strong predictor of primary outcome (χ2: 15.6, HR: 1.07 per 1% increase in ECV, 95% CI: 1.04-1.11, p<0.001), and was separately predictive of both HHF and death. The strongest predictors of remote ECV were diabetes, sex, natriuretic peptides, and body mass index, but, despite extensive phenotyping, the adjusted model R2 was only 0.283. The relationship between infarct size and remote fibrosis was very weak. CONCLUSIONS: Myocardial fibrosis, measured using CMR ECV, is a strong predictor of HHF and death in patients with evidence of MI. The mechanisms underlying remote myocardial fibrosis formation post-MI remain poorly understood, but factors other than infarct size appear to be important.

The effect of 1.5 T cardiac magnetic resonance on human circulating leucocytes.

Aims: Investigators have proposed that cardiovascular magnetic resonance (CMR) should have restrictions similar to those of ionizing imaging techniques. We aimed to investigate the acute effect of 1.5 T CMR on leucocyte DNA integrity, cell counts, and function in vitro, and in a large cohort of patients in vivo. Methods and results: In vitro study: peripheral blood mononuclear cells (PBMCs) were isolated from healthy volunteers, and histone H2AX phosphorylation (γ-H2AX) expression, leucocyte counts, and functional parameters were quantified using flow cytometry under the following conditions: (i) immediately following PBMC isolation, (ii) after standing on the benchside as a temperature and time control, (iii) after a standard CMR scan. In vivo study: blood samples were taken from 64 consecutive consenting patients immediately before and after a standard clinical scan. Samples were analysed for γ-H2AX expression and leucocyte counts. CMR was not associated with a significant change in γ-H2AX expression in vitro or in vivo, although there were significant inter-patient variations. In vitro cell integrity and function did not change with CMR. There was a significant reduction in circulating T cells in vivo following CMR. Conclusion: 1.5 T CMR was not associated with DNA damage in vitro or in vivo. Histone H2AX phosphorylation expression varied markedly between individuals; therefore, small studies using γ-H2AX as a marker of DNA damage should be interpreted with caution. Cardiovascular magnetic resonance was not associated with loss of leucocyte viability or function in vitro. Cardiovascular magnetic resonance was associated with a statistically significant reduction in viable leucocytes in vivo.

Growth differentiation factor-15 in patients with or at risk of heart failure but before first hospitalisation.

OBJECTIVE: Identification of patients at risk of adverse outcome from heart failure (HF) at an early stage is a priority. Growth differentiation factor (GDF)-15 has emerged as a potentially useful biomarker. This study sought to identify determinants of circulating GDF-15 and evaluate its prognostic value, in patients at risk of HF or with HF but before first hospitalisation. METHODS: Prospective, longitudinal cohort study of 2166 consecutive patients in stage A-C HF undergoing cardiovascular magnetic resonance and measurement of GDF-15. Multivariable linear regression investigated determinants of GDF-15. Cox proportional hazards modelling, Net Reclassification Improvement and decision curve analysis examined its incremental prognostic value. Primary outcome was a composite of first hospitalisation for HF or all-cause mortality. Median follow-up was 1093 (939-1231) days. RESULTS: Major determinants of GDF-15 were age, diabetes and N-terminal pro-B-type natriuretic peptide, although despite extensive phenotyping, only around half of the variability of GDF-15 could be explained (R2 0.51). Log-transformed GDF-15 was the strongest predictor of outcome (HR 2.12, 95% CI 1.71 to 2.63) and resulted in a risk prediction model with higher predictive accuracy (continuous Net Reclassification Improvement 0.26; 95% CI 0.13 to 0.39) and with greater clinical net benefit across the entire range of threshold probabilities. CONCLUSION: In patients at risk of HF, or with HF but before first hospitalisation, GDF-15 provides unique information and is highly predictive of hospitalisation for HF or all-cause mortality, leading to more accurate risk stratification that can improve clinical decision making. TRIAL REGISTRATION NUMBER: NCT02326324.

Predicting hospitalisation for heart failure and death in patients with, or at risk of, heart failure before first hospitalisation: a retrospective model development and external validation study.

BACKGROUND: Identifying people who are at risk of being admitted to hospital (hospitalised) for heart failure and death, and particularly those who have not previously been hospitalised for heart failure, is a priority. We aimed to develop and externally validate a prognostic model involving contemporary deep phenotyping that can be used to generate individual risk estimates of hospitalisation for heart failure or all-cause mortality in patients with, or at risk of, heart failure, but who have not previously been hospitalised for heart failure. METHODS: Between June 1, 2016, and May 31, 2018, 3019 consecutive adult patients (aged ≥16 years) undergoing cardiac magnetic resonance (CMR) at Manchester University National Health Service Foundation Trust, Manchester, UK, were prospectively recruited into a model development cohort. Candidate predictor variables were selected according to clinical practice and literature review. Cox proportional hazards modelling was used to develop a prognostic model. The final model was validated in an external cohort of 1242 consecutive adult patients undergoing CMR at the University of Pittsburgh Medical Center Cardiovascular Magnetic Resonance Center, Pittsburgh, PA, USA, between June 1, 2010, and March 25, 2016. Exclusion criteria for both cohorts included previous hospitalisation for heart failure. Our study outcome was a composite of first hospitalisation for heart failure or all-cause mortality after CMR. Model performance was evaluated in both cohorts by discrimination (Harrell's C-index) and calibration (assessed graphically). FINDINGS: Median follow-up durations were 1118 days (IQR 950-1324) for the development cohort and 2117 days (1685-2446) for the validation cohort. The composite outcome occurred in 225 (7·5%) of 3019 patients in the development cohort and in 219 (17·6%) of 1242 patients in the validation cohort. The final, externally validated, parsimonious, multivariable model comprised the predictors: age, diabetes, chronic obstructive pulmonary disease, N-terminal pro-B-type natriuretic peptide, and the CMR variables, global longitudinal strain, myocardial infarction, and myocardial extracellular volume. The median optimism-adjusted C-index for the externally validated model across 20 imputed model development datasets was 0·805 (95% CI 0·793-0·829) in the development cohort and 0·793 (0·766-0·820) in the external validation cohort. Model calibration was excellent across the full risk profile. A risk calculator that provides an estimated risk of hospitalisation for heart failure or all-cause mortality at 3 years after CMR for individual patients was generated. INTERPRETATION: We developed and externally validated a risk prediction model that provides accurate, individualised estimates of the risk of hospitalisation for heart failure and all-cause mortality in patients with, or at risk of, heart failure, before first hospitalisation. It could be used to direct intensified therapy and closer follow-up to those at increased risk. FUNDING: The UK National Institute for Health Research, Guerbet Laboratories, and Roche Diagnostics International.

Acute and Chronic Cardiopulmonary Effects of High Dose Interleukin-2 Therapy: An Observational Magnetic Resonance Imaging Study.

High dose interleukin-2 (IL-2) is known to be associated with cardiopulmonary toxicity. The goal of this study was to evaluate the effects of high dose IL-2 therapy on cardiopulmonary structure and function. Combined cardiopulmonary magnetic resonance imaging (MRI) was performed in 7 patients in the acute period following IL-2 therapy and repeated in 4 patients in the chronic period. Comparison was made to 10 healthy volunteers. IL-2 therapy was associated with myocardial and pulmonary capillary leak, tissue oedema and cardiomyocyte injury, which resulted in acute significant left ventricular (LV) dilatation, a reduction in LV ejection fraction (EF), an increase in LV mass and a prolongation of QT interval. The acute effects occurred irrespective of symptoms. In the chronic period many of the effects resolved, but LV hypertrophy ensued, driven by focal replacement and diffuse interstitial myocardial fibrosis and increased cardiomyocyte mass. In conclusion, IL-2 therapy is ubiquitously associated with acute cardiopulmonary inflammation, irrespective of symptoms, which leads to acute LV dilatation and dysfunction, increased LV mass and QT interval prolongation. Most of these effects are reversible but IL-2 therapy is associated with chronic LV hypertrophy, driven by interstitial myocardial fibrosis and increased cardiomyocyte mass. The findings have important implications for the monitoring and long term impact of newer immunotherapies. Future studies are needed to improve risk stratification and develop cardiopulmonary-protective strategies.

Cardiac involvement in cystic fibrosis evaluated using cardiopulmonary magnetic resonance.

Cystic fibrosis (CF) transmembrane conductance regulator is expressed in myocardium, but cardiac involvement in CF remains poorly understood. The recent development of a combined cardiopulmonary magnetic resonance imaging technology allows for a simultaneous interrogation of cardiac and pulmonary structure and function. The aim of this study was to investigate myocardial manifestations in adults with CF, both in a stable state and during an acute respiratory exacerbation, and to investigate the relationship between cardiac and pulmonary disease. Healthy adult volunteers (n = 12) and adults with CF (n = 10) were studied using a multiparametric cardiopulmonary magnetic resonance protocol. CF patients were scanned during an acute respiratory exacerbation and re-scanned when stable. Stable CF was associated with left ventricular dilatation and hypertrophy (LVH; left ventricular mass: CF 59 ± 9 g/m2 vs. control 50 ± 8 g/m2; p = 0.028). LVH was predominantly driven by extracellular myocardial matrix expansion (extracellular matrix mass: CF 27.5 ± 3.4 g vs. control 23.6 ± 5.2 g; p = 0.006; extracellular volume [ECV]: CF 27.6 [24.7-29.8]% vs. control 24.8 [22.9-26.0]%; p = 0.030). Acute CF was associated with an acute reduction in left ventricular function (ejection fraction: acute 57 ± 3% vs. stable 61 ± 5%; p = 0.025) and there was a suggestion of myocardial oedema. Myocardial oedema severity was strongly associated with the severity of airflow limitation (r = - 0.726, p = 0.017). Multiparametric cardiopulmonary magnetic resonance technology allows for a simultaneous interrogation of cardiac and pulmonary structure and function. Stable CF is associated with adverse myocardial remodelling, including left ventricular systolic dilatation and hypertrophy, driven by myocardial fibrosis. CF exacerbation is associated with acute myocardial contractile dysfunction. There is also a suggestion of myocardial oedema in the acute period which is related to pulmonary disease severity.

The Diagnostic and Prognostic Utility of Contemporary Cardiac Magnetic Resonance in Suspected Acute Myocarditis.

Cardiovascular magnetic resonance (CMR) is used to investigate suspected acute myocarditis, however most supporting data is retrospective and few studies have included parametric mapping. We aimed to investigate the utility of contemporary multiparametric CMR in a large prospective cohort of patients with suspected acute myocarditis, the impact of real-world variations in practice, the relationship between clinical characteristics and CMR findings and factors predicting outcome. 540 consecutive patients we recruited. The 113 patients diagnosed with myocarditis on CMR performed within 40 days of presentation were followed-up for 674 (504-915) days. 39 patients underwent follow-up CMR at 189 (166-209) days. CMR provided a positive diagnosis in 72% of patients, including myocarditis (40%) and myocardial infarction (11%). In multivariable analysis, male sex and shorter presentation-to-scan interval were associated with a diagnosis of myocarditis. Presentation with heart failure (HF) was associated with lower left ventricular ejection fraction (LVEF), higher LGE burden and higher extracellular volume fraction. Lower baseline LVEF predicted follow-up LV dysfunction. Multiparametric CMR has a high diagnostic yield in suspected acute myocarditis. CMR should be performed early and include parametric mapping. Patients presenting with HF and reduced LVEF require closer follow-up while those with normal CMR may not require it.

Impact on service provision for non-invasive cardiac imaging following NICE recommendations: an observational study.

BACKGROUND: Chest pain or discomfort due to angina can have a potentially poor prognosis, emphasising the importance of prompt and accurate diagnosis. The National Institute for Health and Clinical Excellence (NICE) published 'Chest pain of recent onset' guidelines in March 2010. These guidelines appraise the role of newer non-invasive modalities in cardiac imaging in the prompt and cost-effective diagnosis of coronary artery disease. OBJECTIVE: To study the service requirement for non-invasive cardiac imaging in patients with stable chest pain using current NICE guidance. DESIGN: Single-centre, 6-month (January 2010 to June 2010) observational study. SETTING: Rapid access chest pain clinics in a large university teaching hospital providing secondary care cardiology services. METHODS: Clinic letters were used to ascertain the type of chest pain and cardiovascular risk factors. The resting 12-lead ECG was examined for any ischaemic changes. Patients were then retrospectively allocated to an assessment pathway based on NICE guidance for the evaluation of stable chest pain. Pretest likelihood of coronary artery disease was calculated using Pryor et al's table as published by NICE. Depending on the calculated pretest probability, their NICE-suggested investigation was determined. This included no further investigations, cardiac CT, functional imaging or invasive angiography. RESULTS: 500 patients were seen in rapid access chest pain clinics, 65 of which did not meet the referral criteria of having chest pain. On the basis of previous practice, 52% of patients were likely to have an exercise tolerance test. According to current NICE guidance as applied to our cohort of patients, 128 (30%) would have required functional imaging, 119 (27%) no further investigation, 95 (22%) cardiac CT, and 93 (21%) invasive angiography. CONCLUSION: Functional imaging and then cardiac CT are the main investigations required in the assessment of patients with stable chest pain.

Myocardial involvement in eosinophilic granulomatosis with polyangiitis evaluated with cardiopulmonary magnetic resonance.

Patients with eosinophilic granulomatosis with polyangiitis (EGPA) most commonly die from cardiac causes, however, cardiac involvement remains poorly characterised and the relationship between cardiac and pulmonary disease is not known. This study aimed to characterise myocardial and pulmonary manifestations of EGPA, and their relationship. Prospective comprehensive cardiopulmonary investigation, including a novel combined cardiopulmonary magnetic resonance imaging (MRI) technology, was performed in 13 patients with stable EGPA. Comparison was made with 11 prospectively recruited matched healthy volunteers. Stable EGPA was associated with focal replacement and diffuse interstitial myocardial fibrosis (myocardial extracellular volume 26.9% vs. 24.7%; p = 0.034), which drove a borderline increase in left ventricular mass (56  ±  9 g/m2 vs. 49  ±  8 g/m2; p = 0.065). Corrected QT interval was significantly prolonged and was associated with the severity of myocardial fibrosis (r = 0.582, p = 0.037). Stable EGPA was not associated with increased myocardial capillary permeability or myocardial oedema. Pulmonary tissue perfusion and capillary permeability were normal and there was no evidence of pulmonary tissue oedema or fibrosis. Forced expiratory volume in one second showed a strong inverse relationship with myocardial fibrosis (r = -0.783, p = 0.038). In this exploratory study, stable EGPA was associated with focal replacement and diffuse interstitial myocardial fibrosis, but no evidence of myocardial or pulmonary inflammation or pulmonary fibrosis. Myocardial fibrosis was strongly associated with airway obstruction and abnormal cardiac repolarisation. Further investigation is required to determine the mechanisms underlying the association between heart and lung disease in EGPA and whether an immediate immunosuppressive strategy could prevent myocardial fibrosis formation.

Substrate for the Myocardial Inflammation-Heart Failure Hypothesis Identified Using Novel USPIO Methodology.

OBJECTIVES: The purpose of this study was to identify where ultrasmall superparamagnetic particles of iron oxide (USPIO) locate to in myocardium, develop a methodology that differentiates active macrophage uptake of USPIO from passive tissue distribution; and investigate myocardial inflammation in cardiovascular diseases. BACKGROUND: Myocardial inflammation is hypothesized to be a key pathophysiological mechanism of heart failure (HF), but human evidence is limited, partly because evaluation is challenging. USPIO-magnetic resonance imaging (MRI) potentially allows specific identification of myocardial inflammation but it remains unclear what the USPIO-MRI signal represents. METHODS: Histological validation was performed using a murine acute myocardial infarction (MI) model. A multiparametric, multi-time-point MRI methodology was developed, which was applied in patients with acute MI (n = 12), chronic ischemic cardiomyopathy (n = 7), myocarditis (n = 6), dilated cardiomyopathy (n = 5), and chronic sarcoidosis (n = 5). RESULTS: USPIO were identified in myocardial macrophages and myocardial interstitium. R1 time-course reflected passive interstitial distribution whereas multi-time-point R2* was also sensitive to active macrophage uptake. R2*/R1 ratio provided a quantitative measurement of myocardial macrophage infiltration. R2* behavior and R2*/R1 ratio were higher in infarcted (p = 0.001) and remote (p = 0.033) myocardium in acute MI and in chronic ischemic cardiomyopathy (infarct: p = 0.008; remote p = 0.010), and were borderline higher in DCM (p = 0.096), in comparison to healthy controls, but were no different in myocarditis or sarcoidosis. An R2*/R1 threshold of 25 had a sensitivity and specificity of 90% and 83%, respectively, for detecting active USPIO uptake. CONCLUSIONS: USPIO are phagocytized by cardiac macrophages but are also passively present in myocardial interstitium. A multiparametric multi-time-point MRI methodology specifically identifies active myocardial macrophage infiltration. Persistent active macrophage infiltration is present in infarcted and remote myocardium in chronic ischemic cardiomyopathy, providing a substrate for HF.

Mechanisms Underlying the Association of Chronic Obstructive Pulmonary Disease With Heart Failure.

OBJECTIVES: The purposes of this study were to determine why chronic obstructive pulmonary disease (COPD) is associated with heart failure (HF). Specific objectives included whether COPD is associated with myocardial fibrosis, whether myocardial fibrosis is associated with hospitalization for HF and death in COPD, and whether COPD and smoking are associated with myocardial inflammation. BACKGROUND: COPD is associated with HF independent of shared risk factors. The underlying pathophysiological mechanism is unknown. METHODS: A prospective, multicenter, longitudinal cohort study of 572 patients undergoing cardiac magnetic resonance (CMR), including 450 patients with COPD and 122 age- and sex-matched patients with a median: 726 days (interquartile range: 492 to 1,160 days) follow-up. Multivariate analysis was used to examine the relationship between COPD and myocardial fibrosis, measured using cardiac magnetic resonance (CMR). Cox regression analysis was used to examine the relationship between myocardial fibrosis and outcomes; the primary endpoint was composite of hospitalizations for HF or all-cause mortality; secondary endpoints included hospitalizations for HF and all-cause mortality. Fifteen patients with COPD, 15 current smokers, and 15 healthy volunteers underwent evaluation for myocardial inflammation, including ultrasmall superparamagnetic particles of iron oxide CMR. RESULTS: COPD was independently associated with myocardial fibrosis (p < 0.001). Myocardial fibrosis was independently associated with the primary outcome (hazard ratio [HR]: 1.14; 95% confidence interval [CI]: 1.08 to 1.20; p < 0.001), hospitalization for HF (HR: 1.25 [95% CI: 1.14 to 1.36]); p < 0.001), and all-cause mortality. Myocardial fibrosis was associated with outcome measurements more strongly than any other variable. Acute and stable COPD were associated with myocardial inflammation. CONCLUSIONS: The associations between COPD, myocardial inflammation and myocardial fibrosis, and the independent prognostic value of myocardial fibrosis elucidate a potential pathophysiological link between COPD and HF.

Association of Cardiovascular Disease With Respiratory Disease.

BACKGROUND: The relationship between respiratory diseases and individual cardiovascular diseases, and the impact of cardiovascular diseases on mortality in patients with respiratory disease, are unclear. OBJECTIVES: This study sought to determine the relationship between chronic obstructive pulmonary disease (COPD), asthma and interstitial lung disease (ILD), and individual cardiovascular diseases, and evaluate the impact of individual cardiovascular diseases on all-cause mortality in respiratory conditions. METHODS: The authors conducted a cohort study of all patients admitted to 7 National Health Service hospitals across the North West of England, between January 1, 2000, and March 31, 2013, with relevant respiratory diagnoses, with age-matched and sex-matched control groups. RESULTS: A total of 31,646 COPD, 60,424 asthma, and 1,662 ILD patients were included. Control groups comprised 158,230, 302,120, and 8,310 patients, respectively (total follow-up 2,968,182 patient-years). COPD was independently associated with ischemic heart disease (IHD), heart failure (HF), atrial fibrillation, and peripheral vascular disease, all of which were associated with all-cause mortality (e.g., odds ratio for the association of COPD with HF: 2.18 [95% confidence interval (CI): 2.08 to 2.26]; hazard ratio for the contribution of HF to mortality in COPD: 1.65 [95% CI: 1.61 to 1.68]). Asthma was independently associated with IHD, and multiple cardiovascular diseases contributed to mortality (e.g., HF hazard ratio: 1.81 [95% CI: 1.75 to 1.87]). ILD was independently associated with IHD and HF, both of which were associated with mortality. Patients with lung disease were less likely to receive coronary revascularization. CONCLUSIONS: Lung disease is independently associated with cardiovascular diseases, particularly IHD and HF, which contribute significantly to all-cause mortality. However, patients with lung disease are less likely to receive coronary revascularization.

Clinical applications of multi-parametric CMR in myocarditis and systemic inflammatory diseases.

Cardiac magnetic resonance (CMR) has changed the management of suspected viral myocarditis by providing a 'positive' diagnostic test and has lead to new insights into myocardial involvement in systemic inflammatory conditions. In this review we analyse the use of CMR tissue characterisation techniques across the available studies including T2 weighted imaging, early gadolinium enhancement, late gadolinium enhancement, Lake Louise Criteria, T2 mapping, T1 mapping and extracellular volume assessment. We also discuss the use of multiparametric CMR in acute cardiac transplant rejection and a variety of inflammatory conditions such as sarcoidosis, systemic lupus erythrematous, rheumatoid arthritis and systemic sclerosis.

Treatment of tachycardia: bradycardia syndrome in a patient with obstructive sleep apnoea.

Obstructive sleep apnoea (OSAS) affects 4% of men and 2% of women aged 30-65 years. It is diagnosed in the presence of excessive daytime sleepiness and an apnoea-hypopnoea index (AHI) of ≥5 on polysomnography. Rhythm disturbances are common in OSAS and continuous positive airway pressure (CPAP) has been shown to be beneficial. We present a case of a patient with obesity, atrial fibrillation with fast ventricular response, significant nocturnal pauses (3.9 s) and tachycardiomyopathy. A polysomnography confirmed severe OSAS (AHI=64.25). CPAP improved bradycardia and allowed for the introduction of ß-blockers. Subsequent Holter monitoring revealed better rate control with the longest pause of 2 s and the patient's left ventricular systolic function improved. CPAP prevented our patient from invasive treatment, allowed for rate control and improvement of tachycardiomyopathy. With such a high prevalence of OSAS, clinicians should be aware that CPAP may aid arrhythmia control.

Takotsubo cardiomyopathy case series: typical, atypical and recurrence.

Takotsubo cardiomyopathy (TCM) is characterised by a transient left ventricular (LV) dysfunction, ECG changes that can imitate acute myocardial infarction and positive cardiac biomarkers in the absence of obstructive coronary artery disease. The exact pathogenesis of TCM is unclear but emotional or physical stress is a common denominator. We present three cases encompassing a spectrum of the disease: A typical TCM with apical LV dyskinesis, an atypical TCM with mid-ventricular regions affected and a TCM recurrence. Our cases show that TCM symptoms vary between individuals and may vary in the same patient. All our patients reported acute emotional stress prior to the onset of symptoms, had LV systolic dysfunction, positive cardiac biomarkers and non-obstructed coronary arteries. In all cases, LV systolic dysfunction eventually improved. TCM may account for 0.7-2.5% of acute coronary syndromes. It is more prevalent in the female population and can reoccur. Treatment is mainly supportive.

Are we failing our trainees in providing opportunities to attain procedural confidence?

Practical procedures play a crucial role in clinical outcome. High proportions of Mersey trainees report a lack of procedural confidence despite the fact that the majority want to perform more procedures. Training has to be carefully analysed to address these shortcomings.

Oxygen therapy in patients with chest pain of acute onset: single centre audit experience.

INTRODUCTION: Although oxygen therapy has been commonly used in the treatment of acute coronary syndromes, evidence shows that oxygen administration is not always beneficial to patients with acute chest pain and in certain circumstances may, in fact, be harmful. Hence, several national and international organizations have issued guidelines restricting its use to hypoxic patients only. AIM: To audit and change the inappropriate practice of administering oxygen therapy indiscriminately to patients with acute chest pain. SETTING: Emergency department, coronary care unit and heart assessment centre in a large teaching hospital. METHODS: The authors identified 100 patients who presented with acute chest pain and collected data on oxygen prescription, administration and documentation from clinical notes and observation charts. RESULTS: Only 71% of patients in a hospital setting were correctly assessed for requiring oxygen therapy. After introducing local guidelines and a series of lectures, this rose to 94%. A third audit showed sustained change, with 96% of patients being appropriately assessed for needing oxygen therapy. DISCUSSION: The introduction of local guidelines and a series of lectures improved handling of oxygen in patients presenting with acute chest pain.