COVID-19 vaccines and adverse events of special interest: A multinational Global Vaccine Data Network (GVDN) cohort study of 99 million vaccinated individuals

BACKGROUND

The Global COVID Vaccine Safety (GCoVS) Project, established in 2021 under the multinational Global Vaccine Data Network™ (GVDN®), facilitates comprehensive assessment of vaccine safety. This study aimed to evaluate the risk of adverse events of special interest (AESI) following COVID-19 vaccination from 10 sites across eight countries.

METHODS

Using a common protocol, this observational cohort study compared observed with expected rates of 13 selected AESI across neurological, haematological, and cardiac outcomes. Expected rates were obtained by participating sites using pre-COVID-19 vaccination healthcare data stratified by age and sex. Observed rates were reported from the same healthcare datasets since COVID-19 vaccination program rollout. AESI occurring up to 42 days following vaccination with mRNA (BNT162b2 and mRNA-1273) and adenovirus-vector (ChAdOx1) vaccines were included in the primary analysis. Risks were assessed using observed versus expected (OE) ratios with 95 % confidence intervals. Prioritised potential safety signals were those with lower bound of the 95 % confidence interval (LBCI) greater than 1.5.

RESULTS

Participants included 99,068,901 vaccinated individuals. In total, 183,559,462 doses of BNT162b2, 36,178,442 doses of mRNA-1273, and 23,093,399 doses of ChAdOx1 were administered across participating sites in the study period. Risk periods following homologous vaccination schedules contributed 23,168,335 person-years of follow-up. OE ratios with LBCI > 1.5 were observed for Guillain-Barré syndrome (2.49, 95 % CI: 2.15, 2.87) and cerebral venous sinus thrombosis (3.23, 95 % CI: 2.51, 4.09) following the first dose of ChAdOx1 vaccine. Acute disseminated encephalomyelitis showed an OE ratio of 3.78 (95 % CI: 1.52, 7.78) following the first dose of mRNA-1273 vaccine. The OE ratios for myocarditis and pericarditis following BNT162b2, mRNA-1273, and ChAdOx1 were significantly increased with LBCIs > 1.5.

CONCLUSION

This multi-country analysis confirmed pre-established safety signals for myocarditis, pericarditis, Guillain-Barré syndrome, and cerebral venous sinus thrombosis. Other potential safety signals that require further investigation were identified.

Background rates of adverse events of special interest for COVID-19 vaccines: A multinational Global Vaccine Data Network (GVDN) analysis

BACKGROUND

The Global COVID Vaccine Safety (GCoVS) project was established in 2021 under the multinational Global Vaccine Data Network (GVDN) consortium to facilitate the rapid assessment of the safety of newly introduced vaccines. This study analyzed data from GVDN member sites on the background incidence rates of conditions designated as adverse events of special interest (AESI) for COVID-19 vaccine safety monitoring.

METHODS

Eleven GVDN global sites obtained data from national or regional healthcare databases using standardized methods. Incident events of 13 pre-defined AESI were included for a pre-pandemic period (2015-19) and the first pandemic year (2020). Background incidence rates (IR) and 95% confidence intervals (CI) were calculated for inpatient and emergency department encounters, stratified by age and sex, and compared between pre-pandemic and pandemic periods using incidence rate ratios.

RESULTS

An estimated 197 million people contributed 1,189,652,926 person-years of follow-up time. Among inpatients in the pre-pandemic period (2015-19), generalized seizures were the most common neurological AESI (IR ranged from 22.15 [95% CI 19.01-25.65] to 278.82 [278.20-279.44] per 100,000 person-years); acute disseminated encephalomyelitis was the least common (<0.5 per 100,000 person-years at most sites). Pulmonary embolism was the most common thrombotic event (IR 45.34 [95% CI 44.85-45.84] to 93.77 [95% CI 93.46-94.08] per 100,000 person-years). The IR of myocarditis ranged from 1.60 [(95% CI 1.45-1.76) to 7.76 (95% CI 7.46-8.08) per 100,000 person-years. The IR of several AESI varied by site, healthcare setting, age and sex. The IR of some AESI were notably different in 2020 compared to 2015-19.

CONCLUSION

Background incidence of AESIs exhibited some variability across study sites and between pre-pandemic and pandemic periods. These findings will contribute to global vaccine safety surveillance and research.

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

Experiences of Multidisciplinary Working: Perspectives from the Wessex Ghana Stroke Partnership

INTRODUCTION

Substantial gaps remain in our understanding of stroke in Africa as well as in stroke care, practice and policy on the continent. The effective organization of preventative, therapeutic and rehabilitative stroke services continue to be challenging in many African countries.

METHODOLOGY

In this article we define the nature, function and benefits of effective multidisciplinary team (MDT) working. The experiences and perspectives of members of the MDT were collated by focus group discussions as well as individual and country specific contributions.

RESULTS

The experiences and perspectives of multidisciplinary team members from the United Kingdom and Ghana implementing these practices at the first stroke unit in Korle Bu Teaching Hospital, Accra, with a transparent discussion of successes and challenges faced throughout development of the service, is presented. MDT working has improved outcomes for patients and families who use the services, including encouraging better shared treatment planning and compliance. More stroke rehabilitation services are provided than previously, including greater self-management education and better secondary prevention care.

CONCLUSION

It is hoped that this article will provide an inspirational model for others working to provide stroke care in low-resource settings in Africa and worldwide.

Early standardized clinical judgement for syncope diagnosis in the emergency department

BACKGROUND

The diagnosis of cardiac syncope remains a challenge in the emergency department (ED).

OBJECTIVE

Assessing the diagnostic accuracy of the early standardized clinical judgement (ESCJ) including a standardized syncope-specific case report form (CRF) in comparison with a recommended multivariable diagnostic score.

METHODS

In a prospective international observational multicentre study, diagnostic accuracy for cardiac syncope of ESCJ by the ED physician amongst patients ≥ 40 years presenting with syncope to the ED was directly compared with that of the Evaluation of Guidelines in Syncope Study (EGSYS) diagnostic score. Cardiac syncope was centrally adjudicated independently of the ESCJ or conducted workup by two ED specialists based on all information available up to 1-year follow-up. Secondary aims included direct comparison with high-sensitivity cardiac troponin I (hs-cTnI) and B-type natriuretic peptide (BNP) concentrations and a Lasso regression to identify variables contributing most to ESCJ.

RESULTS

Cardiac syncope was adjudicated in 252/1494 patients (15.2%). The diagnostic accuracy of ESCJ for cardiac syncope as quantified by the area under the curve (AUC) was 0.87 (95% CI: 0.84-0.89), and higher compared with the EGSYS diagnostic score (0.73 (95% CI: 0.70-0.76)), hs-cTnI (0.77 (95% CI: 0.73-0.80)) and BNP (0.77 (95% CI: 0.74-0.80)), all P < 0.001. Both biomarkers (alone or in combination) on top of the ESCJ significantly improved diagnostic accuracy.

CONCLUSION

ESCJ including a standardized syncope-specific CRF has very high diagnostic accuracy and outperforms the EGSYS score, hs-cTnI and BNP.

Utility of echocardiography in patients with suspected acute myocardial infarction in the presence of left bundle-branch block

Background

Rapid identification of acute myocardial infarction (AMI) as life-threatening disorder by clinical assessment, cardiac troponin and the electrocardiogram (ECG) is important for the early initiation of highly effective, evidence-based therapy. Patients presenting with suspected AMI and left bundle branch block (LBBB) to the emergency department (ED) represent a unique diagnostic and therapeutic challenge, as altered ventricular depolarization masks changes in ventricular repolarization associated with myocardial ischemia. Current guidelines suggest, based on expert opinion, early echocardiography as a helpful tool in patients with suspected AMI and LBBB to identify new wall motion abnormalities, which guides further diagnostics strategies in these patients.

Purpose

To evaluate the diagnostic accuracy of echocardiography among patients with suspected AMI and LBBB in the recorded ECG at ED presentation.

Methods

We prospectively evaluated the diagnostic accuracy of echocardiography in patients with LBBB presenting with chest discomfort to 26 ED's in three international, prospective, diagnostic studies. Two independent cardiologists centrally adjudicated the final diagnosis in each study according to the universal definition of myocardial infarction. All patients underwent a clinical assessment that included standardized and detailed medical history including assessment of chest pain characteristics, vital signs, physical examination, 12-lead ECG, continuous ECG rhythm monitoring, pulse oximetry, standard blood test, and chest radiography and echocardiography if indicated. We compared echocardiographic findings in patients with LBBB who were diagnosed with an AMI to those without an AMI.

Results

Among 283 patients presenting with chest pain and LBBB to the ED, AMI was the final diagnosis in 36% (102 of 283 patients) of patients. An echocardiography had been performed in 100/283 patients (35%) in the emergency department. AMI was the final diagnosis in 41/100 (41%) of patients. A wall motion abnormality in any region was seen in 77 (77%) of patients with no difference between patients diagnosed with AMI (33 patients, 81%) versus without AMI (44 patients, 75%, p=0.49). Additionally, we found no differences for each wall region (Table 1). Most patients with LBBB had moderately reduced left ventricular ejection fraction (LVEF, median 40%), a dilated left atrium (67%) or left ventricular hypertrophy (55%) without any differences between the two groups (Table 1).

Conclusions

Early echocardiography in patients with suspected AMI and LBBB provided only limited utility to identify patients, which may benefit from immediate coronary angiography. Our findings scrutinize current guidelines and downgrades the utility of echocardiography in this setting.

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): Swiss National Science Foundation, the Swiss Heart Foundation, the European Union, the Cardiovascular Research Foundation Basel, the University Hospital Basel, Queensland Emergency Medicine Research Foundation, Christchurch Heart Institute and Health Research Council and Heart Foundation of New Zealand, Christchurch Emergency Care Foundation

P2723Diagnosis of acute myocardial infarction in the presence of left bundle-branch block

Objective

Patients with suspected acute myocardial infarction (AMI) in the setting of left bundle branch block (LBBB) present an important diagnostic and therapeutic challenge to the clinician.

Methods

We prospectively evaluated incidence of AMI, and diagnostic performance of specific electrocardiographic (ECG) and high-sensitivity cardiac troponin (hs-cTn) criteria in patients presenting with chest discomfort to 26 emergency departments in three international, prospective, diagnostic studies. Presence of LBBB, ECG criteria, and final diagnoses were centrally adjudicated by two independent cardiologists using the fourth universal definition of myocardial infarction.

Results

Among 8830 patients, LBBB was present in 247 patients (2.8%). AMI was the final diagnosis in 30% of patients with LBBB, with similar incidence in those with known LBBB versus those with presumably new LBBB (29% vs 35%, p=0.42). ECG criteria had low sensitivity (1–12%), but high specificity (95–100%). The diagnostic accuracy as quantified by the receiver-operating-characteristics curve of hs-cTnT and hs-cTnI concentrations at presentation (AUC 0.91; 95% CI 0.85–0.96 and 0.89; 95% CI 0.83–0.95) as well as that of their 0/1h and 0/2h changes was very high. A diagnostic algorithm (Figure 1) combining ECG criteria with hs-cTnT/I concentrations and their absolute changes at 1h or 2h derived in cohort 1 (45 of 45 (100%) of patients with AMI correctly identified), showed high efficacy and accuracy when externally validated in cohort 2 & 3 (28 of 29 patients, 97%).

Figure 1

Conclusion

Most patients presenting with suspected AMI and LBBB will be found to have diagnoses other than AMI. Combining ECG criteria with Hs-cTn testing at 0/1h or 0/2h allows early and accurate diagnosis of AMI in LBBB.

Acknowledgement/Funding

European Union, Swiss National Foundation, University Hospital Basel, University Basel

P2674Rapid rule-out of myocardial infarction with a novel high precision point-of-care troponin assay appears safe and effective

Background

High sensitivity troponin assays were developed to improve analytical sensitivity and precision at the decision cut-points for the diagnosis and rule out of acute myocardial infarction (AMI). Central laboratory assays have achieved this but point of care assays, which have the ability to accelerate decision making due to much shorter turnaround times, have remained lacking.

Purpose

To ascertain the threshold for decision making and subsequent clinical utility for ruling out AMI on presentation in patients attending the emergency department acutely with chest pain, using a high precision point of care troponin assay (TnI Nx), (i-STAT, Abbott).

Methods

We measured arrival TnI-Nx concentrations in stored plasma samples in adults presenting acutely to the emergency department with chest pain. The primary outcome was an AMI or cardiac death on index admission or within 30 days. We used 2000 bootstrapped data sets to derive and validate a suitable threshold for TnI-Nx before calculating diagnostic test performance. We pre-specified this threshold must have a <1% false negative rate for the primary outcome. We compared this with a core laboratory high sensitivity troponin I (hs-TnI) (Abbott Architect) using the early rule-out cut-point (European Society of Cardiology) at the limit of detection (2 ng/L).

Results

We recruited 1320 patients of whom 192 (14.1%) had the primary outcome. The TnI-Nx threshold was determined to be 8 ng/L with subsequent sensitivity of 99.0% (95% confidence interval: 97.3% to 100%), negative predictive value of 99.7% (99.2% to 100%) and specificity of 59.0% (56.0% to 62.0%). The hs-TnI had a sensitivity of 99.5% (98.2% to 100%), negative predictive value of 99.7% (99.0% to 100%), and specificity of 28.4% (25.8% to 31.2%) at 2ng/L.

Conclusion

A high precision point of care assay, TnI-Nx, with a decision threshold of 8ng/L, has comparable rule out performance compared with a core laboratory high sensitivity assay and therefore could potentially be used for early decision making in the assessment of acute chest pain.

Acknowledgement/Funding

Research grant from Abbott Point of Care. Senior Research Fellowship from ECF, CMRF and CDHB. Clinical Research Fellowship from NZ HRC

P1735Two-hour algorithm for early diagnosis of acute myocardial infarction using a novel high-sensitivity cardiac troponin I assay

Background

We aimed to derive and externally validate a 0/2h-algorithm using the novel high-sensitivity cardiac troponin I (hs-cTnI-Access) assay.

Methods

We enrolled patients presenting to the emergency department with symptoms suggestive of acute myocardial infarction (AMI) in two prospective chest pain trials. Two independent cardiologists adjudicated the final diagnosis including all available medical information including cardiac imaging. Hs-cTnI concentrations were measured at presentation and after 2h. Primary diagnostic endpoint was the derivation and validation of an hs-cTnI-Access specific 0/2h-algorithm. Primary prognostic endpoint was overall survival of patients after 30- and 720-days of follow-up.

Results

AMI was the adjudicated final diagnosis in 164/1131 (14.5%) patients in the derivation and in 88/1280 (6.9%) patients in the validation cohort. Median hs-cTnI Access concentrations at presentation were significantly higher in patients with AMI as compared to patients with non-AMI in both cohorts (104 ng/L versus 3.4 ng/L and 29 ng/L vs. 2.3 ng/L, p-value both <0.001) Applying the derived hs-cTnI-Access 0/2h-algorithm (Figure 1A) to the validation cohort (Figure 1B), 77.9% of patients were ruled-out (sensitivity 97.7% [95% CI, 92–99.7], negative predictive value [NPV] 99.8% [95% CI, 99.3–100]), and 5.8% of patients were ruled-in (specificity 98.6% [95% CI, 97.7–99.2], positive predictive value [PPV] 77% [95% CI, 65.8–86]). Among 1617 patients ruled-out for AMI in both cohorts together, 3 (0.2%) patients with AMI have been missed, of whom 2 patients had type 2 myocardial infarction (both with tachyarrhythmia). Patients ruled-out by the 0/2h-algorithm had a survival rate of 98.4% and 99.9% after two years or one year of follow up in both cohorts, respectively.

Figure 1

Conclusions

Diagnostic performance of the hs-cTnI Access 0/2h-algorithm for triage of AMI is excellent with high safety for rule-out and high accuracy for rule-in.

Acknowledgement/Funding

European Union, Swiss National Foundation, University Hospital Basel, University Basel

Validation of NICE diagnostic guidance for rule out of myocardial infarction using high-sensitivity troponin tests

OBJECTIVE

To validate the National Institute for Health and Care Excellence (NICE) recommended algorithms for high-sensitivity troponin (hsTn) assays in adults presenting with chest pain.

METHODS

International post hoc analysis of three prospective, observational studies from tertiary hospital emergency departments. The primary endpoint was cardiac death or acute myocardial infarction (AMI) within 24 hours of presentation, and the secondary endpoint was major adverse cardiac events (MACE) at 30 days.

RESULTS

15% of patients were diagnosed with non-ST elevation myocardial infarction (MI) on admission. The hsTnI algorithm classified 2506/3128 (80.1%) of patients as 'ruled out' with 50 (2.0%) missed MI. 943/3128 (30.1%) of patients had a troponin I level below the limit of detection on admission with 2 (0.2%) missed MI. For the hsTnT algorithm, 1794/3374 (53.1%) of patients were 'ruled out' with 7 (0.4%) missed MI. 490/3374 (14.5%) of patients had a troponin T below the limit of blank on admission with no MI. MACE at 30 days occurred in 10.7% and 8.5% of patients 'ruled out' defined by the hsTnI and hsTnT algorithms, respectively.

CONCLUSIONS

The NICE algorithms could identify patients with low probability of AMI within 2 hours; however, neither strategy performed as predicted by the NICE diagnostic guidance model. Additionally, the rate of MACE at 30 days was sufficiently high that the algorithms should only be used as one component of a more extensive model of risk stratification.

TRIAL REGISTRATION NUMBER

ACTRN12611001069943, NCT00470587; post-results.

The Efficacy of COPD Outreach in Reducing Length of Stay and Improving Quality of Life

COPD exacerbations results in prolonged hospitalisation, re-admissions, reduces health-related quality of life (HRQoL) and increases mortality. The study aimed to assess the efficacy of a COPD Outreach service in reducing average length of stay (ALOS), reducing readmissions within 90 days of admission, improving HRQoL and reducing mortality among COPD patients with acute exacerbations (AECOPD). AECOPD data for a 2 year period commencing September 2011 was analysed. The COPD Assessment test (CAT) quantified HRQoL at enrolment and 6 weeks post Outreach. COPD Outreach had an ALOS of 2.47 days compared to ALOS 8.59 days and 8.5 days for all AECOPD before and during an operational COPD Outreach. Re-admission rates among patients enrolled in COPD Outreach were 36.3%. CAT improved from mean 19.3 to 13.5. Mortality was 4.9% among Outreach patients and 2.5% for overall AECOPD in 2012-2013. COPD Outreach reduced ALOS and improved HRQoL for selected patients with AECOPD. It did not reduce re-admissions or mortality.

Assessment of liver function in chickens using galactose and indocyanine green clearances

Values for galactose and indocyanine green (ICG) clearances, and plasma and serum biochemical markers of liver dysfunction were determined in normal chickens and following coeliotomy, and compared with birds after partial hepatectomy. Clearance tests, and serum and plasma biochemistry were performed 4h, and 4 and 7 days after surgery. Coeliotomy and manipulation of the liver did not delay clearance of either compound. Partial hepatectomy resulted in elevation of galactose single point concentrations but did not significantly alter galactose clearance (GEC) values. Clearance values of ICG were not significantly altered. Biochemical values were not significantly elevated in birds after a partial hepatectomy in comparison with birds after coeliotomy. Galactose single point concentrations have the potential to become a simple, relatively non-invasive method of screening for liver disease, with GEC tests having the potential to quantify the degree of loss of functional hepatic mass.