Prognostic significance of troponin in patients with malignancy (NIHR Health Informatics Collaborative TROP-MALIGNANCY study).

BACKGROUND: Cardiac troponin is commonly raised in patients presenting with malignancy. The prognostic significance of raised troponin in these patients is unclear. OBJECTIVES: We sought to investigate the relation between troponin and mortality in a large, well characterised cohort of patients with a routinely measured troponin and a primary diagnosis of malignancy. METHODS: We used the National Institute for Health Research (NIHR) Health Informatics Collaborative data of 5571 patients, who had troponin levels measured at 5 UK cardiac centres between 2010 and 2017 and had a primary diagnosis of malignancy. Patients were classified into solid tumour or haematological malignancy subgroups. Peak troponin levels were standardised as a multiple of each laboratory's 99th -percentile upper limit of normal (xULN). RESULTS: 4649 patients were diagnosed with solid tumours and 922 patients with haematological malignancies. Raised troponin was an independent predictor of mortality in all patients (Troponin > 10 vs. <1 adjusted HR 2.01, 95% CI 1.73 to 2.34), in solid tumours (HR 1.84, 95% CI 1.55 to 2.19), and in haematological malignancy (HR 2.72, 95% CI 1.99 to 3.72). There was a significant trend in increasing mortality risk across troponin categories in all three subgroups (p < 0.001). CONCLUSION: Raised troponin level is associated with increased mortality in patients with a primary diagnosis of malignancy regardless of cancer subtype. Mortality risk is stable for patients with a troponin level below the ULN but increases as troponin level increases above the ULN in the absence of acute coronary syndrome.

Phenogrouping heart failure with preserved or mildly reduced ejection fraction using electronic health record data.

BACKGROUND: Heart failure (HF) with preserved or mildly reduced ejection fraction includes a heterogenous group of patients. Reclassification into distinct phenogroups to enable targeted interventions is a priority. This study aimed to identify distinct phenogroups, and compare phenogroup characteristics and outcomes, from electronic health record data. METHODS: 2,187 patients admitted to five UK hospitals with a diagnosis of HF and a left ventricular ejection fraction ≥ 40% were identified from the NIHR Health Informatics Collaborative database. Partition-based, model-based, and density-based machine learning clustering techniques were applied. Cox Proportional Hazards and Fine-Gray competing risks models were used to compare outcomes (all-cause mortality and hospitalisation for HF) across phenogroups. RESULTS: Three phenogroups were identified: (1) Younger, predominantly female patients with high prevalence of cardiometabolic and coronary disease; (2) More frail patients, with higher rates of lung disease and atrial fibrillation; (3) Patients characterised by systemic inflammation and high rates of diabetes and renal dysfunction. Survival profiles were distinct, with an increasing risk of all-cause mortality from phenogroups 1 to 3 (p < 0.001). Phenogroup membership significantly improved survival prediction compared to conventional factors. Phenogroups were not predictive of hospitalisation for HF. CONCLUSIONS: Applying unsupervised machine learning to routinely collected electronic health record data identified phenogroups with distinct clinical characteristics and unique survival profiles.

Anti-inflammatory therapy with nebulized dornase alfa for severe COVID-19 pneumonia: a randomized unblinded trial.

Background: Prinflammatory extracellular chromatin from neutrophil extracellular traps (NETs) and other cellular sources is found in COVID-19 patients and may promote pathology. We determined whether pulmonary administration of the endonuclease dornase alfa reduced systemic inflammation by clearing extracellular chromatin. Methods: Eligible patients were randomized (3:1) to the best available care including dexamethasone (R-BAC) or to BAC with twice-daily nebulized dornase alfa (R-BAC + DA) for seven days or until discharge. A 2:1 ratio of matched contemporary controls (CC-BAC) provided additional comparators. The primary endpoint was the improvement in C-reactive protein (CRP) over time, analyzed using a repeated-measures mixed model, adjusted for baseline factors. Results: We recruited 39 evaluable participants: 30 randomized to dornase alfa (R-BAC +DA), 9 randomized to BAC (R-BAC), and included 60 CC-BAC participants. Dornase alfa was well tolerated and reduced CRP by 33% compared to the combined BAC groups (T-BAC). Least squares (LS) mean post-dexamethasone CRP fell from 101.9 mg/L to 23.23 mg/L in R-BAC +DA participants versus a 99.5 mg/L to 34.82 mg/L reduction in the T-BAC group at 7 days; p=0.01. The anti-inflammatory effect of dornase alfa was further confirmed with subgroup and sensitivity analyses on randomised participants only, mitigating potential biases associated with the use of CC-BAC participants. Dornase alfa increased live discharge rates by 63% (HR 1.63, 95% CI 1.01-2.61, p=0.03), increased lymphocyte counts (LS mean: 1.08 vs 0.87, p=0.02) and reduced circulating cf-DNA and the coagulopathy marker D-dimer (LS mean: 570.78 vs 1656.96 µg/mL, p=0.004). Conclusions: Dornase alfa reduces pathogenic inflammation in COVID-19 pneumonia, demonstrating the benefit of cost-effective therapies that target extracellular chromatin. Funding: LifeArc, Breathing Matters, The Francis Crick Institute (CRUK, Medical Research Council, Wellcome Trust). Clinical trial number: NCT04359654.

Changes in the investigation and management of suspected myocardial infarction and injury during COVID-19: a multi-centre study using routinely collected healthcare data.

Objective: The COVID-19 pandemic was associated with a reduction in the incidence of myocardial infarction (MI) diagnosis, in part because patients were less likely to present to hospital. Whether changes in clinical decision making with respect to the investigation and management of patients with suspected MI also contributed to this phenomenon is unknown. Methods: Multicentre retrospective cohort study in three UK centres contributing data to the National Institute for Health Research Health Informatics Collaborative. Patients presenting to the Emergency Department (ED) of these centres between 1st January 2020 and 1st September 2020 were included. Three time epochs within this period were defined based on the course of the first wave of the COVID-19 pandemic: pre-pandemic (epoch 1), lockdown (epoch 2), post-lockdown (epoch 3). Results: During the study period, 10,670 unique patients attended the ED with chest pain or dyspnoea, of whom 6,928 were admitted. Despite fewer total ED attendances in epoch 2, patient presentations with dyspnoea were increased (p < 0.001), with greater likelihood of troponin testing in both chest pain (p = 0.001) and dyspnoea (p < 0.001). There was a dramatic reduction in elective and emergency cardiac procedures (both p < 0.001), and greater overall mortality of patients (p < 0.001), compared to the pre-pandemic period. Positive COVID-19 and/or troponin test results were associated with increased mortality (p < 0.001), though the temporal risk profile differed. Conclusions: The first wave of the COVID-19 pandemic was associated with significant changes not just in presentation, but also the investigation, management, and outcomes of patients presenting with suspected myocardial injury or MI.

Office measurement vs. ambulatory blood pressure monitoring: associations with mortality in patients with or without diabetes.

BACKGROUND AND AIMS: Guidelines suggest similar blood pressure (BP) targets in patients with and without diabetes and recommend ambulatory BP monitoring (ABPM) to diagnose and classify hypertension. It was explored whether different levels of ambulatory and office BP and different hypertension phenotypes associate with differences of risk in diabetes and no diabetes. METHODS: This analysis assessed outcome data from the Spanish ABPM Registry in 59 124 patients with complete available data. The associations between office, mean, daytime, and nighttime ambulatory BP with the risk in patients with or without diabetes were explored. The effects of diabetes on mortality in different hypertension phenotypes, i.e. sustained hypertension, white-coat hypertension, and masked hypertension, compared with normotension were studied. Analyses were done with Cox regression analyses and adjusted for demographic and clinical confounders. RESULTS: A total of 59 124 patients were recruited from 223 primary care centres in Spain. The majority had an office systolic BP >140 mmHg (36 700 patients), and 23 128 (40.6%) patients were untreated. Diabetes was diagnosed in 11 391 patients (19.2%). Concomitant cardiovascular (CV) disease was present in 2521 patients (23.1%) with diabetes and 4616 (10.0%) without diabetes. Twenty-four-hour mean, daytime, and nighttime ambulatory BP were associated with increased risk in diabetes and no diabetes, while in office BP, there was no clear association with no differences with and without diabetes. While the relative association of BP to CV death risk was similar in diabetes compared with no diabetes (mean interaction P = .80, daytime interaction P = .97, and nighttime interaction P = .32), increased event rates occurred in diabetes for all ABPM parameters for CV death and all-cause death. White-coat hypertension was not associated with risk for CV death (hazard ratio 0.86; 95% confidence interval 0.72-1.03) and slightly reduced risk for all-cause death in no diabetes (hazard ratio 0.89; confidence interval 0.81-0.98) but without significant interaction between diabetes and no diabetes. Sustained hypertension and masked hypertension in diabetes and no diabetes were associated with even higher risk. There were no significant interactions in hypertensive phenotypes between diabetes and no diabetes and CV death risk (interaction P = .26), while some interaction was present for all-cause death (interaction P = .043) and non-CV death (interaction P = .053). CONCLUSIONS: Diabetes increased the risk for all-cause death, CV, and non-CV death at every level of office and ambulatory BP. Masked and sustained hypertension confer to the highest risk, while white-coat hypertension appears grossly neutral without interaction of relative risk between diabetes and no diabetes. These results support recommendations of international guidelines for strict BP control and using ABPM for classification and assessment of risk and control of hypertension, particularly in patients with diabetes. CLINICAL TRIAL REGISTRATION: Not applicable.

Clinic and ambulatory blood pressures, blood pressure phenotypes and mortality in patients with a previous stroke.

There is scarce evidence of the role of clinic and ambulatory BP indices, as well as blood pressure phenotypes in the prognosis of stroke survivors. We aimed to evaluate the association between ambulatory BP indices and mortality in patients with a previous stroke. Our study was an observational cohort study from individuals included in the Spanish Ambulatory Blood Pressure Registry from March 2004 to December 2014. The Cox model was used to estimate associations between usual clinic and ambulatory BP and mortality, adjusted for confounders and additionally for alternative measures of BP. Two thousand one hundred and eighty-three patients with a previous stroke were included. During a median of 9.2 years, 632 (28.9%) patients died: 236 (10.8%) from cardiovascular causes. In the confounder-adjusted model, clinic systolic BP was not associated with the risk of all-cause or cardiovascular mortality. In contrast, systolic BP indices obtained through ABPM (24 h, day and night) were all associated with all-cause and cardiovascular death. In the simultaneous adjustment of daytime and night-time systolic BP, only night-time systolic BP remained significantly associated with all-cause and cardiovascular death: HR 1.35 (95% CI 01.21-1.51) and 1.44 (1.20-1.72), respectively. For diastolic BP, only night-time BP was associated with all-cause and cardiovascular mortality: HR 1.32 (1.18-1.48) and 1.57 (1.31-1.88), respectively. According to the circadian pattern, a riser pattern was associated with all-cause and cardiovascular mortality: HR 1.49 (1.18-1.87) and 1.70 (1.14-2.52), respectively. In conclusion, in patients who have suffered a stroke, night-time BP is the BP estimate most closely associated with all-cause and cardiovascular mortality.

SCORE and SCORE2 in East Asian Population: A Performance Comparison.

Background: Systematic COronary Risk Evaluation 2 (SCORE2) and SCORE2-Older Persons (OP) models have been proposed as new cardiovascular risk evaluation tools. Objectives: This study evaluated the performance of SCORE/SCORE-OP and SCORE2/SCORE2-OP in the East Asian population by using population-based cohort data from the National Health Insurance Service (NHIS) Health Screening Cohort of Korea. Methods: A total of 324,384 NHIS examinees from 2004 to 2005 were divided into 5 age groups: 40-49 years, 50-59 years, 60-69 years,70-79 years, and more than 80 years. The examinees had their predicted cardiovascular disease risks calculated by using SCORE, SCORE2, SCORE-OP, and SCORE2-OP models. The low-risk model was applied on the basis of the cohort's observed event rates. The observed and predicted cardiovascular risks were compared. Results: A total of 324,384 subjects were included (mean age 51.4 ± 7.3 years; women, 37.9% for the SCORE/SCORE2 group and mean age 73.0 ± 2.8 years; women, 47.5% for the SCORE/SCORE2-OP group). Over a median follow-up of 9 years, cardiovascular events occurred in 15.0% and 28.9% in SCORE/SCORE2 and SCORE/SCORE2-OP groups, respectively. The SCORE/SCORE-OP model underestimated cardiovascular disease risk in young men (aged 40-49 years) and women (aged 40-59 years) and overestimated it in older age groups. In contrast, SCORE2/SCORE2-OP invariably overestimated the risk in all age groups and sexes. SCORE2/SCORE2-OP showed no improvement in Harrell's concordance index (C-index) compared with SCORE/SCORE-OP. Calibration plots favored SCORE2 over SCORE but not SCORE2-OP over SCORE-OP. Conclusions: Both SCORE2/SCORE2-OP and SCORE/SCORE-OP overestimated cardiovascular disease risk with low performance. SCORE2/SCORE2-OP showed slight improvement over older versions, but modifications are necessary for the East Asian population.

Artificial Intelligence-Derived Risk Prediction: A Novel Risk Calculator Using Office and Ambulatory Blood Pressure.

BACKGROUND: Quantification of total cardiovascular risk is essential for individualizing hypertension treatment. This study aimed to develop and validate a novel, machine-learning-derived model to predict cardiovascular mortality risk using office blood pressure (OBP) and ambulatory blood pressure (ABP). METHODS: The performance of the novel risk score was compared with existing risk scores, and the possibility of predicting ABP phenotypes utilizing clinical variables was assessed. Using data from 59 124 patients enrolled in the Spanish ABP Monitoring registry, machine-learning approaches (logistic regression, gradient-boosted decision trees, and deep neural networks) and stepwise forward feature selection were used. RESULTS: For the prediction of cardiovascular mortality, deep neural networks yielded the highest clinical performance. The novel mortality prediction models using OBP and ABP outperformed other risk scores. The area under the curve achieved by the novel approach, already when using OBP variables, was significantly higher when compared with the area under the curve of the Framingham risk score, Systemic Coronary Risk Estimation 2, and Atherosclerotic Cardiovascular Disease score. However, the prediction of cardiovascular mortality with ABP instead of OBP data significantly increased the area under the curve (0.870 versus 0.865; P=3.61×10-28), accuracy, and specificity, respectively. The prediction of ABP phenotypes (ie, white-coat, ambulatory, and masked hypertension) using clinical characteristics was limited. CONCLUSIONS: The receiver operating characteristic curves for cardiovascular mortality using ABP and OBP with deep neural network models outperformed all other risk metrics, indicating the potential for improving current risk scores by applying state-of-the-art machine learning approaches. The prediction of cardiovascular mortality using ABP data led to a significant increase in area under the curve and performance metrics.

Therapeutically targeting the unique disease landscape of pediatric high-grade gliomas.

Pediatric high-grade gliomas (pHGG) are a rare yet devastating malignancy of the central nervous system's glial support cells, affecting children, adolescents, and young adults. Tumors of the central nervous system account for the leading cause of pediatric mortality of which high-grade gliomas present a significantly grim prognosis. While the past few decades have seen many pediatric cancers experiencing significant improvements in overall survival, the prospect of survival for patients diagnosed with pHGGs has conversely remained unchanged. This can be attributed in part to tumor heterogeneity and the existence of the blood-brain barrier. Advances in discovery research have substantiated the existence of unique subgroups of pHGGs displaying alternate responses to different therapeutics and varying degrees of overall survival. This highlights a necessity to approach discovery research and clinical management of the disease in an alternative subtype-dependent manner. This review covers traditional approaches to the therapeutic management of pHGGs, limitations of such methods and emerging alternatives. Novel mutations which predominate the pHGG landscape are highlighted and the therapeutic potential of targeting them in a subtype specific manner discussed. Collectively, this provides an insight into issues in need of transformative progress which arise during the management of pHGGs.

COVID-19 in non-hospitalised adults caused by either SARS-CoV-2 sub-variants Omicron BA.1, BA.2, BA.4/5 or Delta associates with similar illness duration, symptom severity and viral kinetics, irrespective of vaccination history.

BACKGROUND: SARS-CoV-2 variant Omicron rapidly evolved over 2022, causing three waves of infection due to sub-variants BA.1, BA.2 and BA.4/5. We sought to characterise symptoms and viral loads over the course of COVID-19 infection with these sub-variants in otherwise-healthy, vaccinated, non-hospitalised adults, and compared data to infections with the preceding Delta variant of concern (VOC). METHODS: In a prospective, observational cohort study, healthy vaccinated UK adults who reported a positive polymerase chain reaction (PCR) or lateral flow test, self-swabbed on alternate weekdays until day 10. We compared participant-reported symptoms and viral load trajectories between infections caused by VOCs Delta and Omicron (sub-variants BA.1, BA.2 or BA.4/5), and tested for relationships between vaccine dose, symptoms and PCR cycle threshold (Ct) as a proxy for viral load using Chi-squared (χ2) and Wilcoxon tests. RESULTS: 563 infection episodes were reported among 491 participants. Across infection episodes, there was little variation in symptom burden (4 [IQR 3-5] symptoms) and duration (8 [IQR 6-11] days). Whilst symptom profiles differed among infections caused by Delta compared to Omicron sub-variants, symptom profiles were similar between Omicron sub-variants. Anosmia was reported more frequently in Delta infections after 2 doses compared with Omicron sub-variant infections after 3 doses, for example: 42% (25/60) of participants with Delta infection compared to 9% (6/67) with Omicron BA.4/5 (χ2 P < 0.001; OR 7.3 [95% CI 2.7-19.4]). Fever was less common with Delta (20/60 participants; 33%) than Omicron BA.4/5 (39/67; 58%; χ2 P = 0.008; OR 0.4 [CI 0.2-0.7]). Amongst infections with an Omicron sub-variants, symptoms of coryza, fatigue, cough and myalgia predominated. Viral load trajectories and peaks did not differ between Delta, and Omicron, irrespective of symptom severity (including asymptomatic participants), VOC or vaccination status. PCR Ct values were negatively associated with time since vaccination in participants infected with BA.1 (ß = -0.05 (CI -0.10-0.01); P = 0.031); however, this trend was not observed in BA.2 or BA.4/5 infections. CONCLUSION: Our study emphasises both the changing symptom profile of COVID-19 infections in the Omicron era, and ongoing transmission risk of Omicron sub-variants in vaccinated adults. TRIAL REGISTRATION: NCT04750356.

A blunted nocturnal blood pressure decline is associated with all-cause and cardiovascular mortality.

OBJECTIVE: It has been suggested that a blunted nocturnal blood pressure (BP) decline is associated with a poor prognosis. Nevertheless, it remains unclear if an abnormal dipping is deleterious per se or it merely reflects an elevated BP during sleep. We aimed to assess the prognostic value of nocturnal BP decline, with or without concomitant elevated nocturnal BP. METHODS: Vital status and cause of death were obtained from death certificates in 59 124 patients, enrolled in the Spanish ABPM Registry between 2004 and 2014 (median follow-up: 10 years). The association between night-to-day ratio (NDR) and dipping patterns (extreme dippers, dippers, reduced dippers, and risers) with all-cause and cardiovascular mortality were evaluated by Cox-proportional models adjusted for clinical confounders and 24 h blood pressure. RESULTS: NDR was associated with all-cause mortality [hazard ratio for 1SD change: 1.15; 95% confidence interval (CI) 1.13-1.17]. Reduced dippers (1.13; 1.06-1.20) and risers (1.41; 1.32-1.51) were associated with an increased risk of all-cause death, whereas extreme dippers (0.90; 0.79-1.02) were not. Elevated NDR (≥0.9) in the absence of elevated night SBP (<120 mmHg) was associated with an increased risk of death (1.13; 1.04-1.22), as well as elevated night SBP but normal NDR (1.38; 1.26-1.50), and the combination of both abnormalities (1.56; 1.46-1.66). Similar results were obtained for cardiovascular mortality. CONCLUSION: Abnormalities in the circadian pattern are associated with an increased risk of all-cause and cardiovascular mortality. This is maintained even in the absence of nocturnal BP elevation.

Prognostic Relevance of Short-Term Blood Pressure Variability. The Spanish ABPM Registry.

BACKGROUND: The prognostic relevance of short-term blood pressure (BP) variability in hypertension is not clearly established. We aimed to evaluate the association of short-term BP variability, with all-cause and cardiovascular mortality in a large cohort of patients with hypertension. METHODS: We selected 59 124 patients from the Spanish Ambulatory Blood Pressure Monitoring Registry from 2004 to 2014 (median follow-up: 9.7 years). Systolic and diastolic BP SD and coefficient of variation from daytime and nighttime, weighted SD, weighted coefficient of variation, average real variability (mean of differences between consecutive readings), and BP variability ratio (ratio between systolic and diastolic 24-hour SD) were calculated through baseline 24-hour ambulatory BP monitoring. Association with all-cause and cardiovascular mortality were assessed by Cox regression models adjusted for clinical confounders and BP. RESULTS: Patients who died during follow-up had higher values of BP variability compared with those remaining alive. In adjusted models systolic and diastolic daytime and weighted SD and coefficient of variation, average real variability, as well as systolic nighttime SD and BP variability ratio were all significantly associated with all-cause and cardiovascular mortality. Hazard ratios for 1-SD increase in the systolic components ranged from 1.05 to 1.12 for all-cause mortality and from 1.07 to 1.17 for cardiovascular mortality. A daytime SD≥13 mm Hg, a nighttime and a weighted SD≥12 mm Hg, and an average real variability ≥10 mm Hg, all systolic, were independently associated with mortality. CONCLUSIONS: Short-term blood pressure variability shows a relatively weak but significant association with all-cause and cardiovascular mortality in patients with hypertension.

Rationale for a New Low-Dose Triple Single Pill Combination for the Treatment of Hypertension.

Two recent large trials showed the potential of single pill combinations (SPCs) with ≥3 low-dose components among people with hypertension who were untreated or receiving monotherapy. In both trials, these 'hypertension polypills' were superior to usual care, achieving >80% BP control without increasing withdrawal due to side effects. However, there are no such products available for prescribers. To address this unmet need, George Medicines developed GMRx2 with telmisartan/amlodipine/indapamide in three strengths (mg): 10/1.25/0.625, 20/2.5/1.25; 40/5/2.5. Two pivotal trials are ongoing to support FDA submission for the treatment of hypertension, including initial treatment. These assess efficacy and safety of GMRx2 compared to: placebo, and each of the three possible dual combinations. Regulatory submissions are planned for 2024, with the aim of providing access to GMRx2 in developed and developing regions. Wider implementation of GMRx2-based treatment strategies will be guided by further research to inform access and appropriate scale up.

ACHIEVE conference proceedings: implementing action plans to reduce and control hypertension burden in Africa.

The prevalence of hypertension, the commonest risk factor for preventable disability and premature deaths, is rapidly increasing in Africa. The African Control of Hypertension through Innovative Epidemiology, and a Vibrant Ecosystem [ACHIEVE] conference was convened to discuss and initiate the co-implementation of the strategic solutions to tame this burden toward achieving a target of 80% for awareness, treatment, and control by the year 2030. Experts, including the academia, policymakers, patients, the WHO, and representatives of various hypertension and cardiology societies generated a 12-item communique for implementation by the stakeholders of the ACHIEVE ecosystem at the continental, national, sub-national, and local (primary) healthcare levels.

Combined analyses of within-host SARS-CoV-2 viral kinetics and information on past exposures to the virus in a human cohort identifies intrinsic differences of Omicron and Delta variants.

The emergence of successive Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) during 2020 to 2022, each exhibiting increased epidemic growth relative to earlier circulating variants, has created a need to understand the drivers of such growth. However, both pathogen biology and changing host characteristics-such as varying levels of immunity-can combine to influence replication and transmission of SARS-CoV-2 within and between hosts. Disentangling the role of variant and host in individual-level viral shedding of VOCs is essential to inform Coronavirus Disease 2019 (COVID-19) planning and response and interpret past epidemic trends. Using data from a prospective observational cohort study of healthy adult volunteers undergoing weekly occupational health PCR screening, we developed a Bayesian hierarchical model to reconstruct individual-level viral kinetics and estimate how different factors shaped viral dynamics, measured by PCR cycle threshold (Ct) values over time. Jointly accounting for both interindividual variation in Ct values and complex host characteristics-such as vaccination status, exposure history, and age-we found that age and number of prior exposures had a strong influence on peak viral replication. Older individuals and those who had at least 5 prior antigen exposures to vaccination and/or infection typically had much lower levels of shedding. Moreover, we found evidence of a correlation between the speed of early shedding and duration of incubation period when comparing different VOCs and age groups. Our findings illustrate the value of linking information on participant characteristics, symptom profile and infecting variant with prospective PCR sampling, and the importance of accounting for increasingly complex population exposure landscapes when analysing the viral kinetics of VOCs. Trial Registration: The Legacy study is a prospective observational cohort study of healthy adult volunteers undergoing weekly occupational health PCR screening for SARS-CoV-2 at University College London Hospitals or at the Francis Crick Institute (NCT04750356) (22,23). The Legacy study was approved by London Camden and Kings Cross Health Research Authority Research and Ethics committee (IRAS number 286469). The Legacy study was approved by London Camden and Kings Cross Health Research Authority Research and Ethics committee (IRAS number 286469) and is sponsored by University College London Hospitals. Written consent was given by all participants.