Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Machine learning to predict myocardial injury and death after non-cardiac surgery

Myocardial injury due to ischaemia within 30 days of non-cardiac surgery is prognostically relevant. We aimed to determine the discrimination, calibration, accuracy, sensitivity and specificity of single-layer and multiple-layer neural networks for myocardial injury and death within 30 postoperative days. We analysed data from 24,589 participants in the Vascular Events in Non-cardiac Surgery Patients Cohort Evaluation study. Validation was performed on a randomly selected subset of the study population. Discrimination for myocardial injury by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.70 (0.69-0.72) vs. 0.71 (0.70-0.73) with variables available before surgical referral, p < 0.001; 0.73 (0.72-0.75) vs. 0.75 (0.74-0.76) with additional variables available on admission, but before surgery, p < 0.001; and 0.76 (0.75-0.77) vs. 0.77 (0.76-0.78) with the addition of subsequent variables, p < 0.001. Discrimination for death by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.71 (0.66-0.76) vs. 0.74 (0.71-0.77) with variables available before surgical referral, p = 0.04; 0.78 (0.73-0.82) vs. 0.83 (0.79-0.86) with additional variables available on admission but before surgery, p = 0.01; and 0.87 (0.83-0.89) vs. 0.87 (0.85-0.90) with the addition of subsequent variables, p = 0.52. The accuracy of the multiple-layer model for myocardial injury and death with all variables was 70% and 89%, respectively.

Automated electronic health record frailty assessment for older cardiac patients

Background

Frailty is an established risk factor for poorer outcomes in older hospitalised patients, but most measures require additional clinical review. Such formal frailty assessments are rarely undertaken in acute cardiac patients. However, routine electronic health records increasingly record health and functional deficits that together may represent the frailty phenotype.

Purpose

To report the outcomes of acute cardiac patients in relation to an automated frailty measurement, derived from routine electronic health records.

Methods

This retrospective observational cohort study included consecutive patients aged ≥70 years old who were managed under the specialist care of a consultant cardiologist between April 2016 and August 2020 in three acute hospitals across Edinburgh, Scotland. The Continuous Dynamic Evaluation of Frailty (CODE-f) score was derived from national Care Assurance Standards data that is mandated for older patient hospital care. This includes measures of cognition, functional dependence, nutrition, falls risk, continence, skin health and mobility. A total of 31 data points were included in an unweighted frailty index with scores ranging between 0 (no markers present) and 1 (all present). No CODE-f score was generated if insufficient data was completed (&gt;33% missing). The primary outcome was mortality at 1 year after hospital admission. Secondary outcomes were length of first (index) hospital stay and the number of days spent alive and out of hospital in the year after index admission (“home time”). In a nested cohort study of 318 consecutive patients at one hospital site, the Clinical Frailty Scale (CFS) was determined from manual electronic case note review for comparison with CODE-f scores.

Results

A total of 2,406 patients were included (mean age 79±6 years, 60% male). The CODE-f could be generated in 2,158 (90%) patients, with a mean score of 0.20±0.21. The primary outcome occurred in 352 (15%) patients. Those in the highest scoring CODE-f quartile (&gt;0.35) had greater than 3-fold increased risk of death at 1 year compared to patients in the lowest quartile (&lt;0.07), after adjustment for age and sex (27% versus 9%, adjusted odds ratio 3.44, 95% confidence intervals [CI] 2.47 to 4.82, p&lt;0.001). Increasing median length of index hospital stay was observed at CODE-f scores above 0.3 (Figure A). In the highest CODE-f quartile, nearly one third of patients experienced less than 9 months home time in the following year, compared to fewer than 1 in 10 in the lowest two quartiles (Figure B). In the nested cohort study, CODE-f scores were well correlated with the CFS (r=0.50, 95% CI 0.41 to 0.58, p&lt;0.001).

Conclusion

An automated electronic health record measure can identify frail older adults at risk of poorer recovery and death after acute cardiac illness. This could inform complex treatment decisions and future care planning for this patient group.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Chief Scientist Office

Exploring adherence to an early rule-out pathway for myocardial infarction in the emergency department using mixed-methods

Background

Incorporating a high-sensitivity cardiac troponin assay into a care pathway for the assessment of suspected acute coronary syndrome has enabled myocardial infarction to be ruled out earlier.

Purpose

Using mixed methods, we explored adherence to an early rule-out pathway in the HiSTORIC (High-Sensitivity Cardiac Troponin on Presentation to Rule Out Myocardial Infarction) randomised controlled trial.

Methods

In 16,972 consecutive patients we evaluated clinician adherence to an early rule-out pathway for the assessment of suspected acute coronary syndrome. Adherence was defined in patients with presentation cardiac troponin I concentrations &lt;5ng/L and symptom onset &gt;2 hours from presentation without serial troponin testing (type 1 adherence); presentation troponin &lt;5ng/L and symptom onset ≤2 hours from presentation with serial testing (type 2 adherence); or presentation troponin between 5ng/L and sex-specific 99th centile with serial testing (type 3 adherence). Semi-structured interviews were conducted with 23 clinicians to aid interpretation of the quantitative analysis. Qualitative data were coded and organized into themes.

Results

In patients with troponin &lt;5ng/L presenting &gt;2hr from symptom onset, adherence was achieved in 81% of patients. In patients presenting ≤2hr from symptom onset, 35% of patients had a second troponin test. In patients with an initial troponin concentration between 5ng/L and the 99th centile, 65% of patients had a second troponin test. Compared to patients managed by clinicians who were adherent to the pathway, patients with troponin over-testing (type 1 non-adherence) were more likely to be older (mean age 52±16 years versus 58±14, P&lt;0.001) and have a history of coronary disease (11% versus 27%, P&lt;0.001). In contrast, patients with under testing (type 2 non-adherence) tended to be younger (mean age 49±16 versus 63±15, P&lt;0.001), female (50% versus 37%, P&lt;0.001) and have lower presentation troponin levels (median concentration 1.0ng/L IQR 1.0 to 2.0, versus 5.0ng/L IQR 2.0–10.0) compared to those in whom testing was performed according to pathway recommendations. Semi-structured interview data revealed how pathway adherence was influenced by five main themes: guideline characteristics, patient characteristics, the healthcare practitioner, the healthcare system and scientific evidence. Clear visual pathway layout was fundamental in achieving optimal adherence. Strong clinical suspicion of acute coronary syndrome promoted repeat troponin testing and deviation from the pathway was felt to be justifiable by more senior clinicians.

Conclusion

This analysis revealed successful implementation of the early rule-out pathway with interview data aiding interpretation of trial data. Younger patients with lower troponin concentrations were less likely to receive pathway recommended serial troponin testing. Clinical judgement is one of the main reasons for discontinuation of pathway recommendations.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Socioeconomic deprivation: an important largely unrecognized risk factor in primary prevention of cardiovascular disease

Background

Socioeconomic deprivation is associated with higher cardiovascular morbidity and mortality. Whether deprivation status should be incorporated in more cardiovascular risk estimation scores remains unclear.

Purpose

This study evaluates how socioeconomic deprivation status affects the performance of three primary prevention cardiovascular risk scores.

Methods

The Generation Scotland Scottish Family Health Study was used to evaluate the performance of three cardiovascular risk scores with (ASSIGN) and without (SCORE2, PCE) socioeconomic deprivation as a covariate in the risk prediction model. Deprivation was defined by Scottish Index of Multiple Deprivation score. The predicted 10-year risk was evaluated against the observed event rate for the cardiovascular outcome of each risk score. The comparison was made across three groups defined by the deprivation index score consisting of group 1 defined as most deprived, group 3 defined as least deprived and group 2 which consisted of individuals in the middle deprivation categories.

Results

The study population consisted of 15,506 individuals (60.0% female, median age of 51). Across the population 1,808 (12%) individuals were assigned to group 1 (most deprived), 8,119 (55%) to group 2, and 4,708 (32%) to group 3 (least deprived). Risk scores based on models that did not include deprivation status significantly under predicted risk in the most deprived (6.4% observed versus 4.6% predicted for SCORE2 and 6.7% observed versus 4.7% predicted for PCE, p&lt;0.001 for both). Both risk scores also significantly overpredicted the risk in the least deprived group (4.0% observed versus 4.7% predicted for SCORE2, p=0.007 and 4.2% observed versus 4.9% predicted for PCE, p=0.028). In contrast, no significant difference was demonstrated in the observed versus predicted risk when using the ASSIGN risk score, which included socioeconomic deprivation status in the risk model.

Conclusions

Socioeconomic status is a largely unrecognized risk factor in primary prevention of cardiovascular disease. Risk scores that exclude socioeconomic deprivation as a covariate under- and overestimate the risk in the most and least deprived individuals, respectively. This study highlights the importance of incorporating socioeconomic deprivation status in risk estimation systems to ultimately reduce inequalities in health care provision for cardiovascular disease.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The British Heart Foundation.Health Data Research UK which receives its funding from HDR UK Ltd (HDR-5012) funded by the UK Medical Research Council, Engineering and Physical Sciences Research Council, Economic and Social Research Council, Department of Health and Social Care (England), Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Health and Social Care Research and Development Division (Welsh Government), Public Health Agency (Northern Ireland), British Heart Foundation and the Wellcome Trust.

Machine learning to optimise use of cardiac troponin in the diagnosis of acute myocardial infarction

Background

Guidelines recommend fixed cardiac troponin thresholds for the assessment of patients with suspected acute coronary syndrome, however, performance varies in important patient groups as concentrations are influenced by age, sex and comorbidities. This limitation can be addressed using machine learning algorithms.

Methods

Machine learning algorithms were developed that integrate cardiac troponin concentrations at presentation or on serial testing with age, sex and clinical features in 10,038 consecutive emergency patients with suspected acute coronary syndrome. The primary outcome was an adjudicated diagnosis of type 1, type 4b or type 4c myocardial infarction. The best performing algorithm was selected for the CoDE-ACS (Collaboration for the Diagnosis and Evaluation of Acute Coronary Syndrome) decision-support tool, and performance was externally validated in 3,035 patients pooled from three prospective studies.

Findings

CoDE-ACS had excellent discrimination and calibration using cardiac troponin at presentation (area under curve [AUC] 0.959, 95% confidence interval 0.948–0.971, Brier score 0.040), in the pooled external validation cohort. At presentation, the rule-out score identified 62.1% (1,885/3,035) of all patients as low-probability of myocardial infarction with a 99.5% (99.1–99.7%) negative predictive value and 97.0% (96.3–97.6%) sensitivity. The rule-in score identified 8.3% (252/3,035) of patients as high-probability with an 83.7% (82.4–85.0%) positive predictive value and 98.5% (98.0–98.9%) specificity. Performance of the rule-out and rule-in scores was consistent across patient subgroups (Figure 1 and Figure 2). CoDE-ACS incorporating a second cardiac troponin measurement also had excellent discrimination and calibration (AUC 0.971 [0.962–0.980], Brier score 0.039) and refined the individualised probabilities in the 29.5% (898/3,035) of patients neither ruled-out or ruled-in at presentation to guide further investigation.

Conclusions

We developed and externally validated the CoDE-ACS decision-support tool using machine learning to aid in the diagnosis of myocardial infarction. CoDE-ACS had excellent diagnostic performance to rule-out and rule-in myocardial infarction at presentation, performed consistently across patient subgroups, and provided individualised probabilities to guide further care in those who require serial troponin measurements.

Conclusions

We developed and externally validated the CoDE-ACS decision-support tool using machine learning to aid in the diagnosis of myocardial infarction. CoDE-ACS had excellent diagnostic performance to rule-out and rule-in myocardial infarction at presentation, performed consistently across patient subgroups, and provided individualised probabilities to guide further care in those who require serial troponin measurements.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health ResearchBritish Heart Foundation

Outcomes following acute myocardial injury and type 2 myocardial infarction in patients with and without coronary artery disease

Background

Acute myocardial injury and type 2 myocardial infarction typically occur in the setting of a concurrent illness. Differentiating acute myocardial injury from type 2 myocardial infarction is challenging as it relies on the assessment of myocardial ischaemia. Indeed, some have questioned whether this distinction is important, as patients with both conditions are at increased risk of future cardiovascular events. Whether this risk is similar and the role of identifying those with coronary artery disease is uncertain.

Purpose

To determine whether future risk of cardiovascular events and death differs in patients with type 2 myocardial infarction and acute myocardial injury according to the presence or absence of prior coronary artery disease.

Methods

We conducted a secondary analysis of a multi-centre randomised controlled trial of 48,282 consecutive patients with suspected acute coronary syndrome. Patients with an adjudicated index diagnosis of acute myocardial injury and type 2 myocardial infarction were stratified according to whether they were known previously to have coronary artery disease defined as prior coronary revascularisation, myocardial infarction, or angina. Cardiovascular death or myocardial infarction adjusted for the competing risk of non-cardiovascular death and all-cause death at one year was compared.

Results

In 9,115 patients with elevated cardiac troponin concentrations, 1,676 (18%) and 1,121 (12%) had acute myocardial injury and type 2 myocardial infarction, respectively. Patients with either condition known to have coronary artery disease were older (mean [standard deviation] age 78 [11] versus 73 [16] years) and more likely to be female (55% versus 45%) than those with no prior history. Coronary artery disease was previously identified in 40% (454/1,121) and 30% (509/1,167) of those with type 2 myocardial infarction and acute myocardial injury, respectively. Cardiovascular death or myocardial infarction at one year was more common in patients known to have coronary artery disease than those without for both acute myocardial injury (23% [115/509]) versus 14% [158/1,167]; P&lt;0.001) and type 2 myocardial infarction (20% [91/454] versus 10% [69/667]; log-rank P&lt;0.001) (Figure 1). Similarly all-cause death at one year was higher in patients with known coronary artery disease for both acute myocardial injury (31% [357/1,167] versus 18% [123/667]; P&lt;0.001) and type 2 myocardial infarction (40% [115/509] versus 30% [135/454]; P&lt;0.001) (Figure 2).

Conclusion

Coronary artery disease is recognised in around one third of patients with acute myocardial injury and type 2 myocardial infarction and is associated with higher rates of cardiovascular events and all-cause death. Risk doubled in those with coronary artery disease and was similar whether the index diagnosis was myocardial injury or infarction, suggesting that coronary investigation and secondary prevention may have a role in both conditions.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The University of Edinburgh and British Heart Foundation

Implementation of high-sensitivity cardiac troponin and risk of myocardial infarction or death at 5 years: a stepped-wedge cluster-randomised controlled trial

Background

Implementation of a high-sensitivity cardiac troponin I assay with the sex-specific 99th centile as the diagnostic threshold identifies more patients with myocardial injury and infarction, but whether this impacts on long-term clinical outcomes is unknown.

Purpose

In a prespecified analysis of a stepped-wedge cluster-randomised controlled trial performed across ten hospitals in Scotland, we evaluated the impact of implementing a high-sensitivity cardiac troponin I assay on outcomes at 5 years in consecutive patients with suspected acute coronary syndrome.

Methods

Throughout the trial, all 48,282 patients had cardiac troponin I concentrations measured using both a contemporary (standard care) and high-sensitivity (implementation) assay. During standard care, results from the high-sensitivity assay were concealed and the contemporary assay was used to guide care. Hospitals were randomly allocated to early (n=5) or late (n=5) implementation of the high-sensitivity assay using the sex-specific 99th centile to guide care and results from the contemporary assay were concealed. Patients reclassified by the high-sensitivity assay were defined as those with cardiac troponin concentrations above the sex-specific 99th centile but below the contemporary assay diagnostic threshold. Subsequent myocardial infarction or all-cause death at 5 years was compared before and after implementation using an adjusted Cox proportional hazards model in those reclassified by the high-sensitivity assay and stratified by index diagnosis.

Results

Overall, 10,360 patients had cardiac troponin concentrations greater than the sex-specific 99th centile of whom 1,771 (17%) were reclassified by the high-sensitivity assay. Compared to those identified as having elevated cardiac troponin by the contemporary assay, patients reclassified by the high-sensitivity assay were more likely to have non-ischemic myocardial injury (54% versus 28%) and less likely to have type 1 myocardial infarction (33% versus 59%; P&lt;0.001 for both). In those reclassified, the 5-year incidence of subsequent myocardial infarction or all-cause death was 63% (456/720) before and 54% (567/1051) after implementation of the high-sensitivity assay (adjusted hazard ratio [aHR] 0.75 [95% CI 0.57–0.98]) (Figure 1). Following implementation, subsequent myocardial infarction or all-cause death at 5 years was reduced in patients with non-ischemic myocardial injury (aHR 0.66 [0.51–0.86]) but not type 1 or type 2 myocardial infarction (aHR 0.90 [0.78–1.03] and 0.81 [0.55–1.20], respectively).

Conclusions

In patients with suspected acute coronary syndrome, implementation of a high-sensitivity cardiac troponin assay was associated with a lower risk of subsequent myocardial infarction or death at 5 years. Improvements in outcome were greater in those with a diagnosis of non-ischemic myocardial injury rather than infarction.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Impact of patient selection on performance of an early rule-out pathway for myocardial infarction: from research to the real world

Background

Early rule-out pathways for myocardial infarction using high-sensitivity cardiac troponin are widely recommended in the assessment of patients with suspected acute coronary syndrome. Although developed in selected patients participating in research studies, these pathways are applied more widely in clinical practice where the diagnostic performance and effectiveness of these pathways may differ.

Purpose

To evaluate the performance of an early rule-out pathway for myocardial infarction using high-sensitivity cardiac troponin in selected and consecutive unselected patients with suspected acute coronary syndrome.

Methods

Presentation and serial high-sensitivity cardiac troponin I concentrations were measured in two cohorts of patients with suspected acute coronary syndrome presenting to the Emergency Departments across three acute care hospitals in Scotland. In the unselected cohort, electronic health record data were collected on consecutive patients in whom the usual care clinician measured cardiac troponin for suspected acute coronary syndrome. In the selected cohort, patients with suspected acute coronary syndrome were approached between 8am and 8pm by research staff and written informed consent obtained. In both cohorts, the performance of the High-STEACS early rule-out pathway was evaluated for an adjudicated diagnosis of myocardial infarction (type 1, type 4b or type 4c) during the index hospital admission.

Results

The unselected and selected patient cohorts comprised of 1,242 (median age 60 [interquartile range 47–75] years, 46% women) and 1,695 (median age 61 [52–73] years, 40% women) patients respectively. Myocardial infarction was diagnosed in 6% (74/1,242) and 14% (232/1,695) of patients in the unselected and selected patient cohorts respectively. More patients had myocardial infarction ruled-out in the unselected (74% [828/1,112] versus 66% [1,102/1,678]; P&lt;0.001), with similar negative predictive value (99.9% [95% CI 99.7%-100%] versus 99.7% [95% CI 99.4%-99.0%) and sensitivity (99.3% [95% CI 97.4%-100%] versus 98.9% [95% CI 97.6%-99.9%]; Figure 1). In the selected cohort, more patients had intermediate troponin concentrations requiring serial testing (36% versus 29%) or had myocardial infarction diagnosed (34% versus 26%; P&lt;0.001 for both). In contrast, the positive predictive value for myocardial infarction was lower in unselected patients (26.1% [95% CI 21.2%-31.4%] versus 39.9% [95% CI 35.9%-44.0%]).

Conclusion

The prevalence of myocardial infarction is lower in patients with suspected acute coronary syndrome evaluated in routine practice compared to those selected to participate in a research study. Whilst more patients have myocardial infarction accurately ruled out, the positive-predictive value in those ruled in is lower resulting in more hospital admissions with elevated cardiac troponin due to other conditions.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): British Heart FoundationMedical Research Council

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Coronary artery disease and cardiovascular outcomes in patients with type 2 myocardial infarction

Purpose

To evaluate the role of coronary disease in predicting adverse cardiovascular events in patients with type 2 myocardial infarction.

Background

Type 2 myocardial infarction occurs due to imbalance in myocardial oxygen supply or demand without atherothrombosis. There is currently no consensus on how patients with type 2 myocardial infarction should be investigated or treated. Although non-cardiovascular mortality is common in this population, the incidence of future cardiovascular events is similar to those with myocardial infarction due to plaque rupture. Observational data suggest patients with type 2 myocardial infarction and underlying coronary artery disease may be at higher risk of cardiovascular events, but to date, most findings have been observed in selected rather than consecutive patient cohorts.

Methods

We conducted a secondary analysis of a multi-centre randomised controlled trial of 48,282 consecutive patients attending hospital with suspected acute coronary syndrome. In 9,115 patients, high-sensitivity cardiac troponin concentrations were &gt;99th centile, and the diagnosis was adjudicated in line with the Fourth Universal Definition. Patients with type 2 myocardial infarction were stratified by the presence of previous coronary artery disease and evaluated for a primary outcome of cardiovascular death or Type 1 or 4b myocardial infarction at one year. Competing risk cox regression models were used to evaluate predictors of the primary outcome selected a priori on the basis of clinical importance, with adjustment for the competing risk of non-cardiovascular death.

Results

The diagnosis of type 1 and type 2 myocardial infarction was made in 55% (4,981) and 12% (1,121) of patients, respectively. Compared to patients without a previous diagnosis of coronary artery disease, those with coronary disease were older (78 vs 71) and more likely to be female (54% vs 46%). The incidence of future cardiovascular death or myocardial infarction was highest in patients with type 2 myocardial infarction and previous coronary disease (20%, 91/454), compared to those with type 2 myocardial infarction without known coronary disease (10%, 69/667, P&lt;0.001), and was similar to patients with type 1 myocardial infarction (17%, 863/4981, Figure 1). After adjusting for cardiovascular risk factors, the presence of known coronary disease remained an important predictor for future cardiovascular death or myocardial infarction (adjusted Hazard Ratio 1.45, 95% confidence interval 1.03 to 2.03; Figure 2).

Conclusion

Coronary artery disease is an independent predictor of cardiovascular outcomes in patients with type 2 myocardial infarction. Further research is required to evaluate whether systematic investigation for coronary artery disease and targeted secondary prevention could improve outcomes in patients with type 2 myocardial infarction.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Figure 1Figure 2

The impact of age on the diagnosis of type 1 myocardial infarction using high-sensitivity cardiac troponin

Background

Cardiac troponin concentrations are influenced by age and comorbidities with values above the 99th centile diagnostic threshold more common in older patients without myocardial infarction. Despite this, rule-in thresholds for myocardial infarction are applied universally regardless of age or comorbidities.

Purpose

We sought to evaluate how age and cardiovascular comorbidities influence the diagnostic performance of high-sensitivity cardiac troponin I for myocardial infarction.

Methods

In a secondary analysis of a multi-centre randomised controlled trial, we identified 45,991 consecutive patients with suspected acute coronary syndrome without ST-segment elevation myocardial infarction. The diagnostic performance of high-sensitivity cardiac troponin I measured at presentation for type 1 myocardial infarction was evaluated for the sex-specific 99th centile and thresholds three and five times this value in patients stratified by age (under 50 years, between 50 and 75 years, and over 75 years). The effect of comorbidities on diagnostic accuracy was evaluated using regression modelling.

Results

Of the 45,991 patients, 8,187 (18%) had myocardial injury of which 7,677 (94%) had a presentation troponin above the sex-specific 99th centile. Mean age of those with myocardial injury was 74 years (range 18–108). The positive predictive value (PPV) of the 99th centile was 54.6% (95% confidence interval [CI] 50.6–58.8%), 58.8% (56.9–60.6%) and 36.6% (35.1–38.2%) in patients under 50 years, between 50 and 75 years, and over 75 years, respectively. Rule-in thresholds three and five-times the 99th centile gave a higher PPV in all age groups with a PPV of 45.5% (43.1–47.8%) and 50.4% (47.6–53.2%), respectively in those aged over 75 years (Table 1). Regardless of threshold, specificity and PPV was lowest in patients over 75 years and decreased with advancing age (Figure 1). Across all age groups, the presence of heart failure resulted in the greatest decrease in PPV (36.9% [34.6–39.2%] versus 50.6% [49.3–51.8%]). Adjusting for cardiovascular comorbidities resulted in modest change in the discrimination of cardiac troponin for myocardial infarction (area under curve 0.89 vs 0.90) and did not prevent a decline in diagnostic accuracy in older patients.

Conclusion

The specificity and PPV of high-sensitivity cardiac troponin I for myocardial infarction decreases with advancing age. Cardiovascular comorbidities impact the PPV of troponin, but do not explain the decline in diagnostic accuracy with age. Clinicians should be aware of these important differences in performance by age of the diagnostic and rule-in thresholds for myocardial infarction when interpreting troponin results in older patients.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University of Edinburgh Figure 1

Trajectories of high-sensitivity cardiac troponin I in the two decades before cardiovascular death in Whitehall II

Background

High-sensitivity cardiac troponin may be a promising biomarker that could be used for personalised cardiovascular risk prediction and monitoring in the general population. Temporal changes in high-sensitivity cardiac troponin before cardiovascular death are largely unexplored.

Purpose

Using the longitudinal Whitehall II cohort, we evaluated whether three serial high-sensitivity cardiac troponin I measurements over 15 years improved prediction of cardiovascular death when compared to a single time point at baseline.

Methods

Whitehall II is an ongoing longitudinal observation cohort study of 10,308 civil servants, and we included participants who had at least one cardiac troponin measurement and outcome data available. We constructed time trajectories to evaluate the temporal pattern of cardiac troponin I in those who died from cardiovascular disease as compared to those who did not. Cox regression and joint models were used to investigate the association of cardiac troponin I in relation to cardiovascular death using single time point (at baseline) and repeated measurements (at baseline, 10 and 15 years), respectively. The discriminative ability was assessed by the concordance index.

Results

In total, we included 7,293 individuals (mean age of 58 years [SD 7] at baseline, 29.4% women). Of these, 5,818 (79.8%) and 4,045 (55.5%) individuals had a second and third cardiac troponin I concentration measured, respectively. Cardiovascular death occurred in 281 (3.9%) individuals during a median follow-up of 21.4 [IQR, 15.8 to 21.8] years. In the 21-year trajectories of cardiac troponin I, we observed higher baseline concentrations in those who died due to cardiovascular disease as compared to those who did not (median 5 [IQR, 2 to 9] ng/L versus 3 [IQR, 2 to 5] ng/L respectively, Figure). Cardiac troponin I was an independent predictor of cardiovascular death, and the hazard ratio (HR) derived from the joint model that included serial cardiac troponin measurements was higher than the HR derived from the single time point model (single time point model: adjusted HR 1.53, 95% Confidence Interval [CI] 1.37 to 1.70 per naturally log transformed unit of cardiac troponin I, versus repeated measurements model: adjusted HR 1.79, 95% CI 1.58 to 2.02). The discriminative ability of the cardiac troponin model improved when using repeated measurements (concordance index of unadjusted cardiac troponin models, single time point: 0.668 versus repeated measurements: 0.724).

Conclusions

Our study shows that cardiac troponin I trajectories were persistently higher among individuals who died from cardiovascular disease. Cardiac troponin I is a strong independent predictor of cardiovascular death, and incorporating repeated measurements of cardiac troponin improves cardiovascular risk prediction in the general population.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Cardiac troponin I measurements and analysis were supported by were supported by Siemens Healthineers. The study was supported by Health Data Research UK which receives its funding from HDR UK Ltd (HDR-5012) funded by the UK Medical Research Council, Engineering and Physical Sciences Research Council, Economic and Social Research Council, Department of Health and Social Care (England), Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Health and Social Care Research and Development Division (Welsh Government), Public Health Agency (Northern Ireland), British Heart Foundation and the Wellcome Trust. NLM is supported by the British Heart Foundation through a Senior Clinical Research Fellowship (FS/16/14/32023), Programme Grant (RG/20/10/34966) and a Research Excellence Award (RE/18/5/34216). The funders had no role in the study and the decision to submit this work to be considered for publication.

Mechanisms of myocardial injury and clinical outcomes in patients hospitalised with suspected COVID-19

Background

Myocardial injury is associated with adverse outcomes in patients with COVID-19. However, the prognostic role of myocardial injury in COVID-19 compared to other acute illnesses and the underlying mechanisms of injury are poorly understood.

Methods

In a prospective, multi-centre, cohort study conducted in secondary and tertiary care hospitals in Scotland, all consecutive patients with suspected COVID-19 underwent cardiac troponin (ARCHITECTSTAT high-sensitive troponin I (hs-cTnI) assay; Abbott Laboratories) testing in plasma that was surplus to clinical requirements. The results were not reported unless required by the attending clinician. We evaluated the prevalence of myocardial injury, mechanisms and outcomes in all patients. In those with any hs-cTnI concentration above the sex-specific 99th centile the diagnosis was adjudicated according to the 4th Universal Definition of Myocardial Infarction. The primary outcome of all-cause mortality was compared in those with and without myocardial injury and COVID-19 by cox regression adjusted for age, sex, renal function and co-morbidities.

Results

A total of 2,916 (median age 69 [interquartile range, IQR 54–79] years, 53% women) consecutive patients with suspected COVID-19 were followed up for 228 [IQR 203–249] days. Myocardial injury occurred in 26% (750/2,916) with a median troponin concentration of 66 [35–178] ng/L; the prevalence was 41% (46/112) and 25% (704/2,804) in those with and without COVID-19, respectively. The most common mechanism was acute non-ischaemic myocardial injury occurring in 80% (37/46) and 71% (502/704) of patients with and without COVID-19, respectively. Type 1 myocardial infarction (2% and 4%), type 2 myocardial infarction (7% and 14%) and chronic myocardial injury (11% and 11%) were less common and only one patient had confirmed myocarditis. In patients with myocardial injury mortality was increased compared to those without (P&lt;0.001 log rank), whether they had COVID-19 (54% [25/46] versus 26% [17/66]) or not (35% [248/704] versus 14% [294/2100]). Myocardial injury was an independent predictor of death in all patients (adjusted hazard ratio [aHR] 2.04, 95% confidence interval [CI] 1.71 to 2.43), but this excess risk was not higher in patients with COVID-19 (aHR 1.58, 95% CI 0.75 to 3.15) compared to those without the condition (aHR 2.01, 95% CI 1.81 to 2.49).

Conclusion

Myocardial injury is common in hospitalised patients with suspected COVID-19 whether or not COVID-19 was the cause of their presentation. The majority of patients had acute non-ischaemic myocardial injury rather than a defined cardiac condition. Despite this the presence of myocardial injury was an independent predictor of death in all hospitalised patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): British Heart Foundation Kaplan-Meier curve for all-cause death

Troponin to risk stratify patients with suspected acute coronary syndrome for computed tomography coronary angiography

Background

Patients with suspected acute coronary syndrome in whom myocardial infarction has been ruled-out are at risk of future adverse cardiac events. However, the optimal approach to risk stratify and investigate these patients is uncertain.

Methods

We performed a prospective cohort study of 250 patients presenting to the Emergency Department with suspected acute coronary syndrome and troponin concentrations below the sex-specific 99th centile (16 ng/L for women and 34 ng/L for men). Patients were recruited in a 2:1 fashion stratified by peak high-sensitivity cardiac troponin I concentration above and below the early rule-out threshold of 5 ng/L (167 patients with intermediate troponin concentrations between 5 ng/L and the sex-specific 99th centile threshold and 83 patients with troponin concentrations &lt;5 ng/L). All patients underwent computed tomography coronary angiography after they were discharged from hospital.

Results

Overall, 37.6% (94/250) of patients had normal coronary arteries whilst 36.0% (90/250) and 26.4% (66/250) had non-obstructive and obstructive coronary artery disease, respectively. Patients with intermediate troponin concentrations were more likely to have coronary artery disease than those with troponin concentrations &lt;5 ng/L (71.9% [120/167] versus 43.4% [36/83]; odds ratio 3.33 [95% confidence interval 1.92–5.78]). This association persisted irrespective of whether patients had anginal symptoms. Conversely, there was no difference in the prevalence of coronary artery disease between those with and without anginal symptoms (63.2% [67/106] and versus 61.8% [89/144]; odds ratio 0.92 [0.48–1.76]). The majority of patients found to have coronary artery disease did not have a prior diagnosis and were not on optimal preventative medical therapy prior to undergoing computed tomography coronary angiography (50.8% [61/120] and 61.0% [22/36], versus 61.7% [74/120] and 69.4% [25/36] in patients with intermediate versus low troponin concentrations, respectively).

Conclusions

In patients with suspected acute coronary syndrome who have myocardial infarction ruled out, those with intermediate cardiac troponin concentrations are three-times more likely to have coronary artery disease than those with low troponin concentrations. Conversely anginal symptoms did not discriminate between those with and without coronary artery disease. Further studies are required to determine if targeting computed tomography coronary angiography to those with intermediate cardiac troponin concentrations can improve the use of preventative medical therapies and clinical outcomes.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The British Heart Foundation Odds ratio of coronary artery diseaseCumulative proportion with CAD

Association of coronary artery calcium score groups with qualitative and quantitatively assessed adverse plaque

Introduction

Coronary artery calcification is a marker of cardiovascular risk, but its association with qualitatively and quantitatively assessed plaque subtypes on coronary computed tomography (CT) angiography (CCTA) is unknown.

Methods

In this post-hoc analysis, CT images and clinical outcomes were assessed in SCOT-HEART trial participants. Agatston coronary artery calcium score (CACS) was measured on non-contrast CT and was stratified as zero (0 Agatston units, AU), minimal (1 to 9AU), low (10 to 99AU), moderate (100 to 399AU), high (400 to 999AU) and very high (≥1000AU). Adverse plaques were investigated with qualitative (visual categorisation of positive remodelling, low-attenuation plaque, spotty calcification, napkin ring sign) and quantitative (calcified, non-calcified, low-attenuation and total plaque burden) methods.

Results

Images of 1769 patients were assessed (mean age 58±9 years, 56% male, median Agatston score 21 [interquartile range 0 to 230] AU). Of these 36% had a zero, 9% minimal, 20% low, 17% moderate, 10% high and 8% very high CACS. Amongst patients with a zero CACS, 14% had nonobstructive disease, 2% had obstructive disease, 2% had visually assessed adverse plaques and 13% had quantitative low-attenuation plaque (LAP) burden &gt;4% (Figure 1). Non-calcified and low-attenuation plaque burden increased between patients with zero, minimal and low CACS (p&lt;0.001), but there was no difference between those with medium, high and very high CACS. Over a median follow-up of 4.8 [4.1 to 5.7] years, fatal or non-fatal myocardial infarction occurred in 41 patients, 10% of whom had zero CACS. CACS ≥1000AU (Hazard ratio (HR) 4.55 [1.20 to 17.3], p=0.026) and low-attenuation plaque burden (HR 1.74 [1.19 to 2.54], p=0.004) were the only predictors of myocardial infarction, independent of obstructive disease and cardiovascular risk score. Figure 2 shows example CCTA images in a patient with zero CACS, non-calcified plaque (red), low attenuation plaque (orange) burden &gt;4% and obstructive disease in the left anterior descending coronary artery.

Conclusions

In patients with stable chest pain, a zero CACS is associated with a good prognosis, but 1 in 6 have coronary artery disease, including the presence of adverse plaques.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): British Heart Foundation, National Institute of Health/National Heart, Lung, and Blood Institute

Predictors of UK healthcare worker burnout during the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic is putting health professionals under increasing pressure. This population is already acknowledged to be at risk of burnout.

AIM

We aim to provide a 'snapshot' of the levels of burnout, anxiety, depression and distress among healthcare workers during the COVID-19 pandemic.

METHODS

We distributed an online survey via social media in June 2020 open to any UK healthcare worker. The primary outcome measure was symptoms of burnout measured using the Copenhagen Burnout Inventory. Secondary outcomes of depression, anxiety, distress and subjective measures of stress were also recorded. Multivariate logistic regression analysis was performed to identify factors associated with burnout, depression, anxiety and distress.

RESULTS

A total of 539 persons responded to the survey; 90% female and 53% nurses. Participants with moderate-to-severe burnout were younger (49% vs. 33% under 40 years, P = 0.004), more likely to have pre-existing comorbidities (21% vs. 12%, P = 0.031), twice as likely to have been redeployed from their usual role (22% vs. 11%; P = 0.042), or to work in an area dedicated to COVID-19 patients (50% vs. 32%, P < 0.001) and were almost 4 times more likely to have previous depression (24% vs. 7%; P = 0.012).

CONCLUSION

Independent predictors of burnout were being younger, redeployment, exposure to patients with COVID-19, being female and a history of depression. Evaluation of existing psychological support interventions is required with targeted approaches to ensure support is available to those most at risk.

Dynamic Changes in High-Sensitivity Cardiac Troponin I in Response to Anthracycline-Based Chemotherapy

AIMS

Treatment advances have improved cancer-related outcomes and shifted interest towards minimising long-term iatrogenic complications, particularly chemotherapy-related cardiotoxicity. High-sensitivity cardiac troponin I (hs-cTnI) assays accurately quantify very low concentrations of plasma troponin and enable early detection of cardiomyocyte injury prior to the development of myocardial dysfunction. The profile of hs-cTnI in response to anthracycline-based treatment has not previously been described.

MATERIALS AND METHODS

This was a multicentre prospective observational cohort study. Female patients with newly diagnosed invasive breast cancer scheduled to receive anthracycline-based (epirubicin) chemotherapy were recruited. Blood sampling was carried out before and 24 h after each cycle. Hs-cTnI concentrations were measured using the Abbott ARCHITECT_STAT assay.

RESULTS

We recruited 78 women with a median (interquartile range) age of 52 (49-61) years. The median baseline troponin concentration was 1 (1-4) ng/l and the median cumulative epirubicin dose was 394 (300-405) mg/m². Following an initial 33% fall 24 h after anthracycline dosing (P < 0.001), hs-cTnI concentrations increased by a median of 50% (P < 0.001) with each successive treatment cycle. In total, 45 patients had troponin measured immediately before the sixth treatment cycle, 21 (46.6%) of whom had hs-cTnI concentrations ≥16 ng/l, indicating myocardial injury. Plasma hs-cTnI concentrations before the second treatment cycle were a strong predictor of subsequent myocardial injury.

CONCLUSIONS

Cardiotoxicity arising from anthracycline therapy is detectable in the earliest stages of breast cancer treatment and is cumulative with each treatment cycle. This injury is most reliably determined from blood sampling carried out before rather than after each treatment cycle.

P1695Incidence and outcomes of unstable angina compared to non-ST elevation myocardial infarction

Objective

Assess the incidence and compare characteristics and outcome of unstable angina (UA) and Non-ST-Elevation myocardial infarction (NSTEMI)

Design

Two independent prospective multicenter diagnostic studies (Advantageous Predictors of Acute Coronary Syndromes Evaluation (APACE) and High-Sensitivity Troponin in the Evaluation of Patients With Acute Coronary Syndrome (High-STEACS)) enrolling patients with acute chest discomfort presenting to the emergency department. Central adjudication of the final diagnosis was done by two independent cardiologists using all clinical information including serial measurements of high-sensitivity cardiac troponin (hs-cTn). All-cause death and future non-fatal MI were assessed at 30-days and 1-year.

Results

8992 patients were enrolled at 11 centres. UA was adjudicated in 366/4122 (8.9%) and 137/4870 (2.8%) patients in APACE and High-STEACS, respectively, and NSTEMI in 622 (15.1%) and 651 (13.4%). Coronary artery disease was pre-existing in 73% and 76% of patients with unstable angina. At 30-days, all-cause mortality in UA was substantially lower as compared to NSTEMI (0.5% versus 3.7%, p=0.002 in APACE, 0.7% versus 7.4%, p=0.004 in High-STEACS). Similarly, at 1-year in UA all-cause mortality was 3.3% [95% CI 1.2–5.3] vs 10.4% [7.9–12.9] in APACE, and 5.1% [0.7–9.5] vs 22.9% [19.3–26.4] in High-STEACS, and similar to non-cardiac chest pain (NCCP). In contrast, future non-fatal MI in APACE was comparable in UA and NSTEMI (11.2%, [7.8–14.6] and 7.9%, [5.7–10.2]), and higher than in NCCP (0.6%, [0.2–1.0]).

1-year survival free from future AMI

Conclusions

The incidence and the mortality of UA is substantially lower than that of NSTEMI, while the rate of future non-fatal MI is similar.

Acknowledgement/Funding

Swiss National Science Foundation, Swiss Heart Foundation, Cardiovascular Research Foundation Basel, British Heart Foundation Project Grants, Butler S

247Safety and efficacy of high-sensitivity cardiac troponin for risk stratification in patients with suspected acute coronary syndrome

Background

Guidelines acknowledge the emerging role of high-sensitivity cardiac troponin (hs-cTn) assays for the risk stratification and rapid rule-out of myocardial infarction, but multiple approaches have been described. We previously demonstrated the utility of a single hs-cTnI concentration <5 ng/L at presentation to risk stratify patients with suspected acute coronary syndrome (ACS).

Purpose

To assess the safety and efficacy of a hs-cTnI concentration <5 ng/L at presentation in consecutive patients included in the High-STEACS (High-SensitivityTroponin in the Evaluation of patients with Acute Coronary Syndrome) randomised controlled trial.

Methods

The High-STEACS trial was a stepped wedge cluster randomised controlled trial in ten hospitals across Scotland that included 48,282 patients in whom high-sensitivity cardiac troponin was requested by the attending clinician for evaluation of suspected ACS. Patients with ST-segment elevation myocardial infarction (STEMI) were excluded. We evaluated the negative predictive value (NPV) and sensitivity of a presentation hs-cTnI <5 ng/L for a composite outcome of type 1 myocardial infarction, or subsequent type 1 myocardial infarction or cardiac death at 30 days. To assess safety, we report the one-year risk of type 1 myocardial infarction or cardiac death. To assess efficacy, we report the proportion of patients with cardiac troponin <5 ng/L at presentation.

Results

We included 47,101 consecutive patients in the analysis (mean 61±17 years old, 47% female). Of these patients, 27,500 (58%) had a cardiac troponin <5 ng/L at presentation. Overall, 4,313/47,101 (9%) patients had a composite outcome at 30 days, but the event rate was only 0.4% in those with troponin <5 ng/L (98/27,500). The NPV for the composite outcome in those <5 ng/L was 99.7% (95% confidence intervals [CI] 99.6–99.7) and the sensitivity was 98.0% (95% CI 97.6–98.4). In those without evidence of myocardial injury at presentation (hs-cTnI <99thcentile), type 1 myocardial infarction or cardiac death at one year occurred in 197 (0.7%) patients with cardiac troponin <5 ng/L, compared to 647 (5.5%) of those ≥5 ng/L. The NPV was unchanged across all age groups, although efficacy fell as fewer older patients had hs-cTnI concentrations below the risk stratification threshold (see Figure).

Conclusion

A hs-cTnI concentration <5 ng/L at presentation identifies the majority of patients with suspected ACS as low-risk of early or late cardiac events. Although the proportion identified as low risk is reduced in older populations, the safety of this risk stratification approach is maintained across patients of all ages.

Acknowledgement/Funding

British Heart Foundation

P5013Trends in hospitalised cardiac arrest outcomes over 25 years in Scotland

Introduction

Cardiac arrest is a major healthcare burden; survival has historically been poor. Contemporary therapies have been associated with improvements in out-of-hospital cardiac arrest survival in other healthcare systems.

Purpose

To determine temporal trends and predictors of 30-day and overall survival in patients with cardiac arrest who survive to hospital admission in Scotland.

Methods

We conducted a consecutive individual patient linkage study using data from the Scottish Morbidity Records held by the Information Services Division, National Health Service Scotland. We identified all patients who had an index cardiac arrest hospitalisation from 1st January 1990 to 31st December 2014. The primary outcome was 30-day mortality. Generalised additive models were used to estimate temporal trends. Year of admission was the primary explanatory variable, adjusted for age, sex, comorbidities (stroke, myocardial infarction, heart failure), Scottish Index of Multiple Deprivation (SIMD, a national deprivation score), and angiography within 30 days of admission. Cox regression models were constructed for overall mortality, adjusting for the above variables.

Results

In total, 47,692 patients had an index hospitalisation with cardiac arrest in Scotland between 1990 and 2014. The mean age was 69±16 years; 45% (n=21,257) were female. Most patients (n=24,867, 52.4%) were in top two SIMD quintiles (greater deprivation). Incidence was lowest in 1990 (27 per 100,000 population), rising until 1998 (47 per 100,000) before declining (mean 30 per 100,000 for 2010–2014) (Figure 1A). Overall rates of angiography and PCI at 30 days were low (5.4% and 3.1% respectively), albeit higher in more recent years (14.1% and 9.6% respectively for 2010–2014).

Thirty-day mortality was high but decreased over time (73.7% from 1990–1994 to 63.1% from 2010–2014, p<0.001). This effect persisted after adjustment for covariates. The predicted 30-day mortality for a 69 year old patient was highest in 1990 (75%, 95% confidence interval [CI] 73–77%) and lowest in 2014 (66%, 95% CI 64–68%) (Figure 1B). Age, heart failure and greater deprivation were other independent predictors of 30-day mortality. In contrast, previous myocardial infarction and angiography within 30 days were predictors of reduced 30-day mortality. On Cox regression analysis, age (hazard ratio [HR] 1.15, 95% CI 1.14–1.16 per 10 years) and heart failure (HR 1.11, 95% CI 1.08–1.14) were independent predictors of overall mortality. Thirty-day angiography (HR 0.29, 95% CI 0.28–0.31) was the strongest independent predictor of survival, likely reflecting selection bias, in addition to year of admission, previous myocardial infarction and less deprivation.

Temporal trends in cardiac arrest

Conclusions

Hospital episodes with cardiac arrest in Scotland peaked in the late 1990s and have since fallen. Thirty-day mortality remains high, with an improvement over time that is independent of baseline patient characteristics.

P1578Outcomes in patients with renal impairment and myocardial injury or infarction identified by high-sensitivity cardiac troponin testing: a secondary analysis of the High-STEACS trial

Background

Patients with renal impairment are at increased risk of myocardial infarction (MI), but the interpretation of cardiac troponin is challenging in this setting. The use of high-sensitivity cardiac troponin (hs-cTn) assays increases the detection of myocardial injury, yet may contribute to uncertainty in the diagnosis of MI in those with renal impairment.

Purpose

To describe the diagnosis and outcomes of patients with myocardial injury or infarction identified using a hs-cTnI assay, stratified by renal function.

Methods

In a pre-specified secondary analysis of a stepped-wedge cluster-randomised controlled trial, we identified consecutive patients with a hs-cTnI concentration greater than the sex-specific 99th centile between June 2013 and March 2016. The diagnoses of type 1 or type 2 MI were adjudicated and classified according to the 4th Universal Definition of Myocardial Infarction. Renal impairment was defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73m2.The primary outcome of type 1 or type 4b MI or cardiovascular death was compared in patients with and without renal impairment at 1 year.

Results

A measure of renal function was available in 47,334 (98.0%) patients, of whom 7,933 (16.8%) had renal impairment (mean age 76±12 years; 54% female). Plasma hs-cTnI concentrations were >99th centile in 47.9% (3,800/7,933) of patients with renal impairment and 16.3% (6,439/39,401) of patients with normal renal function. In those with and without renal impairment, the adjudicated diagnosis was type 1 MI in 35.2% (1,336/3,800) and 55.8% (3,596/6,439) of patients, and type 2 MI in 12.6% (480/3,800) and 9.7% (626/6,439) of patients, respectively (P<0.001 for both). In patients with hs-cTnI concentrations >99th centile, the primary outcome occurred in 24.9% (945/3,800) of patients with renal impairment, compared to 12.1% (779/6,439) of patients with normal renal function (P<0.001). In patients with type 1 MI, the primary outcome occurred in 32.6% (436/1,336) of those with renal impairment and 11.7% (419/3,596) of those without (P<0.001). In patients with type 2 MI, the primary outcome occurred in 20.4% (98/480) and 9.9% (62/626) of patients with and without renal impairment, respectively (P<0.001).

Conclusion

Almost half of all patients with suspected acute coronary syndrome and renal impairment have hs-cTnI concentrations greater than the sex-specific 99th centile. Whilst only one in three had a diagnosis of type 1 MI, an elevated troponin concentration was associated with a poorer prognosis in those with concomitant renal impairment compared to those without, irrespective of the index diagnosis.

Acknowledgement/Funding

British Heart Foundation

P1731High-sensitivity troponin with sex-specific thresholds in suspected acute coronary syndrome

Background/Introduction

Major disparities between women and men in the diagnosis, management and outcome of acute coronary syndrome are well recognised. Whether sex-specific diagnostic thresholds for myocardial infarction will address these differences is uncertain.

Purpose

To evaluate the impact of implementing a high-sensitivity cardiac troponin I (hs-cTnI) assay with sex-specific diagnostic thresholds for myocardial infarction in women and men with suspected acute coronary syndrome.

Methods

In a stepped-wedge, cluster-randomized controlled trial across ten hospitals we evaluated the implementation of a hs-cTnI assay in 48,282 (47% women) consecutive patients with suspected acute coronary syndrome. During a validation phase the hs-cTnI assay results were suppressed and a contemporary cTnI assay with a single threshold was used to guide care. Myocardial injury was defined as any hs-cTnI concentration >99th centile of 16 ng/L in women and 34 ng/L in men. The primary outcome was myocardial infarction after the initial presentation or cardiovascular death at 1 year. In this prespecified analysis, we evaluated outcomes in men and women before and after implementation of the hs-cTnI assay.

Results

Use of the hs-cTnI assay with sex-specific thresholds increased myocardial injury in women by 42% (from 3,521 (16%) to 4,991 (22%)) and by 6% in men (from 5,068 (20%) to 5,369 (21%)). Whilst treatment increased in both sexes, women with myocardial injury remained less likely than men to undergo coronary revascularisation (15% versus34%), or to receive dual anti-platelet (26% versus43%), statin (16% versus26%) or other preventative therapies (P<0.001 for all). The primary outcome occurred in 18% (369/2,072) and 17% (488/2,919) of women with myocardial injury during the validation and implementation phase respectively (adjusted hazard ratio 1.11, 95% confidence interval 0.92 to 1.33), compared to 18% (370/2,044) and 15% (513/3,325) of men (adjusted hazard ratio 0.85, 95% confidence interval 0.71 to 1.01).

Patient management

Conclusion

Use of sex-specific thresholds identified five-times more additional women than men with myocardial injury, such that the proportion of women and men with myocardial injury is now similar. Despite this increase, women received approximately half the number of treatments for coronary artery disease as men and their outcomes were not improved.

Acknowledgement/Funding

The British Heart Foundation

P847Performance of the GRACE score in patients with type 1 and type 2 myocardial infarction

Introduction

The Global Registry of Acute Coronary Events (GRACE) score is a widely used risk stratification tool in the evaluation of patients with myocardial infarction. However, the performance of GRACE in patients with myocardial infarction secondary to oxygen supply-demand imbalance in the absence of atherothrombosis (type 2 myocardial infarction), is uncertain. Outcomes in patients with type 2 myocardial infarction are poor, and a risk stratification tool is urgently required.

Methods

We assessed the GRACE score in two cohorts of consecutive patients presenting to the Emergency Department with suspected acute coronary syndrome. One cohort was recruited as part of a stepped wedge cluster randomised controlled trial across ten hospitals in Scotland, and one cohort from a large tertiary centre in Sweden. All diagnoses were adjudicated according to the Fourth Universal Definition. We applied the GRACE 2.0 algorithm to estimate death at one year. We assessed model discrimination using the area under the receiver-operator-curve (AUC), and compared AUC between type 1 and type 2 myocardial infarction using the DeLong test. Calibration was assessed using the Hosmer-Lemeshow (HL) goodness of fit test.

Results

We identified 2,538 and 1,080 patients with type 1 myocardial infarction from the Scottish and Swedish cohorts, with death from any cause occurring in 378 (14.9%) and 112 (10.4%) patients, respectively. The AUC for the GRACE score was 0.843 (0.823–0.864) and 0.848 (0.810–0.886). There were 642 and 247 patients with type 2 myocardial infarction in the Scottish and Swedish cohorts, respectively, with death occurring in 144 (22.4%) and 57 (23.1%) patients. The AUC was 0.708 (0.662–0.754) and 0.733 (0.657–0.808), (P<0.001 for both compared to type 1 myocardial infarction). The results of the HL Test suggest that the calibration of the GRACE 2.0 score needs further improvement (Table).

Evaluation of GRACE 2.0 algorithm Type 1 Myocardial Infarction Type 2 Myocardial Infarction Scotland (n=2,538) Sweden (n=1,080) Scotland (n=642) Sweden (n=247) Deaths 378 (14.9%) 112 (10.4%) 144 (22.4%) 57 (23.0%) AUC (C-statistic) 0.843 (0.823–0.864) 0.848 (0.810–0.886) 0.708 (0.662–0.754) 0.733 (0.657–0.808) P-value for HL <0.001 <0.001 <0.001 <0.001 AUC: Area Under the receiver-operator Curve; HL: Hosmer-Lemeshow test.

Figure 1. ROC curves

Conclusions

The GRACE score provided excellent discrimination for all cause death at one year in two contemporary consecutive patient cohorts with tye 1 myocardial infarction. In patients with type 2 myocardial infarction, GRACE performed well, but recalibration or the development of novel risk scores has the potential to improve risk stratification.

P3593Improving the performance of high-sensitivity cardiac troponin for the diagnosis of myocardial infarction

Background

The Universal Definition of Myocardial Infarction (UDMI) mandates a rise and/or fall in high-sensitivity cardiac troponin (hs-cTn) concentration with at least one measure above the 99th centile of a healthy reference population. However, the 99th centile varies by age, sex, and prevalence of comorbid disease within reference populations, and the application of a single threshold may create diagnostic uncertainty in unselected patients attending the Emergency Department.

Purpose

To compare performance of hs-cTnI at the 99th centile with a model that includes additional clinical variables, for the diagnosis of type 1 myocardial infarction.

Methods

The High-Sensitivity Troponin in the Evaluation of patients with Acute Coronary Syndrome (High-STEACS trial) was a stepped wedge cluster randomised controlled trial of 48,282 consecutive patients across 10 hospitals in Scotland. We evaluated the positive predictive value (PPV) of a hs-cTnI >99th centile for a diagnosis of type 1 myocardial infarction. Patients with ST-segment elevation myocardial infarction (STEMI) were excluded, and all were adjudicated according to the 4th UDMI. The study population was randomly divided into derivation (80%) and internal validation (20%) cohorts. Using generalised additive modelling, we tested the effect of adding clinically relevant variables to hs-cTnI for the prediction of type 1 myocardial infarction in the derivation cohort, and assessed performance of the final model in the validation cohort.

Results

We included 47,101 consecutive patients (61±17 years, 47% female), of whom 9,057 (19%) had at least one hs-cTnI >99th centile (7,207 in derivation and 1,850 in validation cohorts). There were 4,087 (45%) patients with type 1 myocardial infarction, with 3239 (45%) and 848 (46%) in the derivation and validation cohorts, respectively. Across the study population, PPV for type 1 myocardial infarction reduced markedly with increasing age (Figure). Age, sex, chest pain, ischaemia on the electrocardiogram, creatinine and rate of change of hs-cTnI were included in the model. Comorbidities (ischaemic heart disease, diabetes, stroke and hyperlipidaemia) did not improve model performance. In the validation cohort, the area under the curve (AUC) for type 1 myocardial infarction using the 99th centile alone was 0.72 (95% CI 0.70–0.74), whereas the AUC for the optimised model was 0.84 (95% CI 0.82–0.85) (p<0.001 by DeLong's test for difference, see Figure).

Figure 1

Conclusion

The diagnostic performance of the 99th centile for type 1 myocardial infarction is poor, particularly in older populations. A simple model including readily available clinical features improves diagnostic performance and with further external validation could support more individualised treatment decisions.

Acknowledgement/Funding

British Heart Foundation

249High-sensitivity cardiac troponin and the universal definition of myocardial infarction: a randomised controlled trial

Background

The Universal Definition of Myocardial Infarction recommends the 99th centile diagnostic threshold using a high-sensitivity cardiac troponin (hs-cTn) assay and the classification of patients by the etiology of myocardial injury. Whether implementation of this definition improves risk stratification, treatment or outcomes is unknown.

Methods

In a stepped-wedge cluster randomized controlled trial, we implemented a high-sensitivity troponin assay and the recommendations of the Universal Definition in 48,282 consecutive patients with suspected acute coronary syndrome across ten hospitals. In a pre-specified secondary analysis, we compared the primary outcome of myocardial infarction or cardiovascular death, and secondary outcome of non-cardiovascular death at one year across diagnostic categories as per the Fourth Universal Definition. We applied competing risks methodology in all analyses, using a cumulative incidence function and determining the cause-specific hazard ratio (csHR) for competing outcomes.

Results

Cardiac troponin concentrations were elevated in 21.5% (10,360/48,282) of all trial participants. Implementation increased the diagnosis of type 1 myocardial infarction by 11% (510/4,471), type 2 myocardial infarction by 22% (205/916), acute myocardial injury by 36% (443/1,233) and chronic myocardial injury by 43% (389/898). The risk and rate of the primary outcome was highest in those with type 1 myocardial infarction, whereas the risk and rate of non-cardiovascular death was highest in those with acute myocardial injury (Table, Figure). Despite increases in anti-platelet therapy and coronary revascularization after implementation, the primary outcome was unchanged in patients with type 1 myocardial infarction (csHR 1.00, 95% CI 0.82 to 1.21), or in any other category.

Adjusted csHR for competing outcomes Myocardial infarction or cardiovascular death Non-cardiovascular death Adjusted csHR (95% CI) Adjusted csHR (95% CI) Type 1 myocardial infarction 5.64 (5.12 to 6.22) 0.83 (0.72 to 0.96) Type 2 myocardial infarction 3.50 (2.94 to 4.15) 1.72 (1.44 to 2.06) Acute myocardial injury 4.38 (3.80 to 5.05) 2.65 (2.33 to 3.00) Chronic myocardial injury 3.88 (3.31 to 4.55) 2.06 (1.77 to 2.40) Cox regression models adjusted for age, sex, diabetes, ischaemic heart disease, season, days since trial onset and site of recruitment (as a random effect).

Cumulative incidence and number at risk

Conclusions

Implementation of the recommendations of the Universal Definition identified patients with different risks of future cardiovascular and non-cardiovascular events, but did not improve outcomes. Greater understanding of the underlying mechanisms and effective strategies for the investigation and treatment of patients with myocardial injury and infarction are required if we are to improve outcomes.

Acknowledgement/Funding

British Heart Foundation

P3598Cardiac Cycle - The effect of exercise on cardiac troponin release

Introduction

International guidelines recommend the use of low concentrations of high-sensitivity cardiac troponin to risk stratify patients with suspected acute coronary syndrome, however, troponin concentration may also rise due to physical exercise. Interpreting cardiac troponin concentration in this context is challenging because the magnitude and duration of troponin elevation following physical exercise is uncertain.

Purpose

To determine the effect of intensity and duration of physical exercise on cardiac troponin concentration.

Methods

We invited 10 physically active healthy volunteers (7 male and 3 female; mean age: 34±7) to attend 3 study visits, during which they underwent exercise on a stationary bicycle at prespecified intensities and durations. The first visit involved low intensity cycling (50–60% of the participant's lactate threshold [LT]) for 60 minutes. During the second visit, participants cycled at high intensity (80–90% LT) for 60 minutes and during the third study visit, participants cycled at moderate intensity (60–70% LT) for 4 hours. High-sensitivity cardiac troponin I (hs-cTnI) concentration was measured at the start of exercise and every hour up to 6 hours during each study visit and subsequently at 1, 2 and 7 days after each exercise visit.

Results

Study participants had a median hs-cTnI concentration of 1.8 ng/L (interquartile range [IQR] 0.8–5.7 ng/L) at baseline. Cardiac troponin concentration was elevated following moderate- and high-intensity exercise (P=0.006 and P<0.001, respectively) but not following low-intensity exercise (P=0.137). Troponin concentrations were significantly higher following the shorter duration of high-intensity exercise (peak hs-cTnI concentration = 13 ng/L [IQR 6.5–27.1 ng/L]) compared to the longer duration moderate-intensity exercise (peak hs-cTnI concentration = 6.9 ng/L [2.9–7.9 ng/L]; P-value <0.001). Following both moderate- and high-intensity exercise, cardiac troponin concentration returned to baseline within 48 hours (Figure 1).

Troponin concentrations ng/L / time

Conclusions

Our study suggests that elevation in cardiac troponin concentration is associated with the intensity rather than duration of physical exercise, and that exercise-induced troponin elevations resolve within 48 hours. These findings have important implications for the interpretation of cardiac troponin in the risk stratification and diagnosis of patients who present with symptoms suggestive of acute coronary syndrome following physical exercise.

Acknowledgement/Funding

British Heart Foundation

Radial artery vasomotor function following transradial cardiac catheterisation

Aims

To determine the reproducibility of flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) in the assessment of radial artery vasomotor function, and to examine the effect of transradial catheterisation on radial artery injury and recovery.

Methods

Radial artery FMD and NMD were examined in 20 volunteers and 20 patients on four occasions (two visits at least 24 hours apart, with two assessments at each visit). In a further 10 patients, radial artery FMD was assessed in the catheterised arm prior to, at 24 hours and 3 months following cardiac catheterisation.

Results

There were no differences in baseline radial artery diameter (2.7±0.4 mm vs 2.7±0.4 mm), FMD (13.4±6.4 vs 12.89±5.5%) or NMD (13.6±3.8% vs 10.1±4.3%) between healthy volunteers and patients (p>0.05 for all comparisons). Mean differences for within and between day FMD were 2.53% (95% CIs −15.5% to 20.5%) and −4.3% (−18.3% to 9.7%) in patients. Compared to baseline, radial artery FMD was impaired at 24 hours (8.7±4.1% vs 3.9±2.9%, p=0.015) but not 3 months (8.7±4.1% vs 6.2±4.4, p=0.34) following transradial catheterisation.

Conclusions

Radial FMD is impaired early after transradial catheterisation but appears to recover by 3 months. While test–retest variability was demonstrated, our findings suggest that transradial access for cardiac catheterisation may afford a potential model of vascular injury and repair in vivo in man.

Perioperative myocardial injury in patients receiving cardiac output-guided haemodynamic therapy: a substudy of the OPTIMISE Trial

BACKGROUND

Evidence suggests that cardiac output-guided haemodynamic therapy algorithms improve outcomes after high-risk surgery, but there is some concern that this could promote acute myocardial injury. We evaluated the incidence of myocardial injury in a perioperative goal-directed therapy trial.

METHODS

Patients undergoing major gastrointestinal surgery (n=723) were randomly assigned to cardiac output-guided haemodynamic therapy (intervention group) or usual care as part of the OPTIMISE trial. At four participating sites, 288 patients were enrolled in a biomarker substudy. Serum high-sensitivity cardiac troponin I (TnI) concentration and N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration were measured before and at 24 and 72 h after surgery.

RESULTS

Median preoperative TnI and NT-ProBNP concentrations were 4.3 ng litre(-1) and 144 pg ml(-1), respectively. After surgery, 67 (46%) patients in the intervention group and 68 (48%) patients receiving usual care had TnI concentrations above the 99th centile upper reference limit (P=0.82). Peak serum TnI concentration was similar in the intervention and usual care groups (median [interquartile range]: 10.0 [5.3-21.5] vs 7.8 [5.0-21.8] ng litre(-1); P=0.85), and no differences were observed in serum TnI concentrations over 72 h (repeated-measures anova, P=0.51). Likewise, there were no differences in peak NT-proBNP concentration between intervention and usual care groups (645 [362-1169] vs 659 [381-1028] pg ml(-1); P=0.86) or in serial NT-proBNP concentrations over 72 h (P=0.20).

CONCLUSIONS

Myocardial injury is common among patients undergoing major gastrointestinal surgery. In this study, the frequency was not affected by cardiac output-guided fluid and low-dose inotropic therapy.

Cardiovascular effects of particulate air pollution exposure: time course and underlying mechanisms

Air pollution is now recognized as an important independent risk factor for cardiovascular morbidity and mortality and may be responsible for up to 3 million premature deaths each year worldwide. The mechanisms underlying the observed effects are poorly understood but are likely to be multifactorial. Here, we review the acute and chronic effects of air pollution exposure on the cardiovascular system and discuss how these effects may explain the observed increases in cardiovascular morbidity and mortality.