Imaging in population science: cardiovascular magnetic resonance in 100,000 participants of UK Biobank - rationale, challenges and approaches

PMCID: PMC3668194SEP was directly funded by the National Institute for Health Research Cardiovascular Biomedical Research Unit at Barts. SN acknowledges support from the Oxford NIHR Biomedical Research Centre and from the Oxford British Heart Foundation Centre of Research Excellence. SP and PL are funded by a BHF Senior Clinical Research fellowship. RC is supported by a BHF Research Chair and acknowledges the support of the Oxford BHF Centre for Research Excellence and the MRC and Wellcome Trust. PMM gratefully acknowledges training fellowships supporting his laboratory from the Wellcome Trust, GlaxoSmithKline and the Medical Research Council

Prospective study design and data analysis in UK Biobank

Population-based prospective studies, such as UK Biobank, are valuable for generating and testing hypotheses about the potential causes of human disease. We describe how UK Biobank's study design, data access policies, and approaches to statistical analysis can help to minimize error and improve the interpretability of research findings, with implications for other population-based prospective studies being established worldwide.</p

Impact of detecting potentially serious incidental findings during multi-modal imaging [version 3; referees: 2 approved, 1 approved with reservations]

Background: There are limited data on the impact of feedback of incidental findings (IFs) from research imaging.  We evaluated the impact of UK Biobank’s protocol for handling potentially serious IFs in a multi-modal imaging study of 100,000 participants (radiographer ‘flagging’ with radiologist confirmation of potentially serious IFs) compared with systematic radiologist review of all images. Methods: Brain, cardiac and body magnetic resonance, and dual-energy x-ray absorptiometry scans from the first 1000 imaged UK Biobank participants were independently assessed for potentially serious IFs using both protocols. We surveyed participants with potentially serious IFs and their GPs up to six months after imaging to determine subsequent clinical assessments, final diagnoses, emotional, financial and work or activity impacts. Results: Compared to systematic radiologist review, radiographer flagging resulted in substantially fewer participants with potentially serious IFs (179/1000 [17.9%] versus 18/1000 [1.8%]) and a higher proportion with serious final diagnoses (21/179 [11.7%] versus 5/18 [27.8%]). Radiographer flagging missed 16/21 serious final diagnoses (i.e., false negatives), while systematic radiologist review generated large numbers of non-serious final diagnoses (158/179) (i.e., false positives). Almost all (90%) participants had further clinical assessment (including invasive procedures in similar numbers with serious and non-serious final diagnoses [11 and 12 respectively]), with additional impact on emotional wellbeing (16.9%), finances (8.9%), and work or activities (5.6%). Conclusions: Compared with systematic radiologist review, radiographer flagging missed some serious diagnoses, but avoided adverse impacts for many participants with non-serious diagnoses. While systematic radiologist review may benefit some participants, UK Biobank’s responsibility to avoid both unnecessary harm to larger numbers of participants and burdening of publicly-funded health services suggests that radiographer flagging is a justifiable approach in the UK Biobank imaging study. The potential scale of non-serious final diagnoses raises questions relating to handling IFs in other settings, such as commercial and public health screening

Improving public health by improving clinical trial guidelines and their application.

Evidence generated from randomized controlled trials forms the foundation of cardiovascular therapeutics and has led to the adoption of numerous drugs and devices that prolong survival and reduce morbidity, as well as the avoidance of interventions that have been shown to be ineffective or even unsafe. Many aspects of cardiovascular research have evolved considerably since the first randomized trials in cardiology were conducted. In order to be large enough to provide reliable evidence about effects on major outcomes, cardiovascular trials may now involve thousands of patients recruited from hundreds of clinical sites in many different countries. Costly infrastructure has developed to meet the increasingly complex organizational and operational requirements of these clinical trials. Concerns have been raised that this approach is unsustainable, inhibiting the reliable evaluation of new and existing treatments, to the detriment of patient care. These issues were considered by patients, regulators, funders, and trialists at a meeting of the European Society of Cardiology Cardiovascular Roundtable in October 2015. This paper summarizes the key insights and discussions from the workshop, highlights subsequent progress, and identifies next steps to produce meaningful change in the conduct of cardiovascular clinical research

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

Assessing the stability and suitability of haematology parameters for diagnosing and monitoring iron deficiency

Iron deficiency is a common laboratory finding and can be associated with numerous medical conditions, in addition to dietary insufficiency. It represents the most common cause of anaemia worldwide and is acknowledged as a significant cause of morbidity and mortality. Accurate investigation of iron status is essential, not only with regard to diagnosis, but also for evaluating response to treatment………………This study had two aims. Firstly, to determine if it was possible to prolong the analysis window of %HYPO to support its availability to community clinicians and secondly, to determine the analysis window for CHr. By repeat testing samples over a 24- hour period and comparing results to baseline we determined sample stability and identified the most suitable parameter to implement in a high- throughput medical laboratory for community monitoring of iron status. [Taken from Introduction

Impact of detecting potentially serious incidental findings during multi-modal imaging [version 2; referees: 2 approved, 1 approved with reservations]

Background: There are limited data on the impact of feedback of incidental findings (IFs) from research imaging.  We evaluated the impact of UK Biobank’s protocol for handling potentially serious IFs in a multi-modal imaging study of 100,000 participants (radiographer ‘flagging’ with radiologist confirmation of potentially serious IFs) compared with systematic radiologist review of all images. Methods: Brain, cardiac and body magnetic resonance, and dual-energy x-ray absorptiometry scans from the first 1000 imaged UK Biobank participants were independently assessed for potentially serious IFs using both protocols. We surveyed participants with potentially serious IFs and their GPs up to six months after imaging to determine subsequent clinical assessments, final diagnoses, emotional, financial and work or activity impacts. Results: Compared to systematic radiologist review, radiographer flagging resulted in substantially fewer participants with potentially serious IFs (179/1000 [17.9%] versus 18/1000 [1.8%]) and a higher proportion with serious final diagnoses (21/179 [11.7%] versus 5/18 [27.8%]). Radiographer flagging missed 16/21 serious final diagnoses (i.e., false negatives), while systematic radiologist review generated large numbers of non-serious final diagnoses (158/179) (i.e., false positives). Almost all (90%) participants had further clinical assessment (including invasive procedures in similar numbers with serious and non-serious final diagnoses [11 and 12 respectively]), with additional impact on emotional wellbeing (16.9%), finances (8.9%), and work or activities (5.6%). Conclusions: Compared with systematic radiologist review, radiographer flagging missed some serious diagnoses, but avoided adverse impacts for many participants with non-serious diagnoses. While systematic radiologist review may benefit some participants, UK Biobank’s responsibility to avoid both unnecessary harm to larger numbers of participants and burdening of publicly-funded health services suggests that radiographer flagging is a justifiable approach in the UK Biobank imaging study. The potential scale of non-serious final diagnoses raises questions relating to handling IFs in other settings, such as commercial and public health screening

Multicentre Genome Wide Association Study Identifies Risk Alleles for Progressive Chronic Lymphocytic Leukaemia [Conference Abstract]

The increased incidence of chronic lymphocytic leukemia (CLL) in first-degree relatives of affected patients indicates an element of genetic susceptibility to this malignancy, borne out in large scale genome-wide association studies (GWAS), which have identified over 40 constitutional risk alleles. Given the important genetic contribution to CLL susceptibility we hypothesized that constitutional genetic variants also affect disease progression. We employed GWAS methods in a large United Kingdom multi-center cohort study of well-characterized predominantly early-stage CLL cases to identify risk alleles for progressive CLL. We conducted six GWAS for single nucleotide polymorphisms (SNPs) associating with progressive CLL incorporating a total of 774 cases of European ancestry recruited to 6 clinical centers across the United Kingdom. CLL cases were genotyped on the Illumina OmniExpress platform and genotypes were determined using Illumina GenomeStudio software. After imputation, we combined the association test statistic for 5,199,911 autosomal SNPs common to all 6 GWAS after exclusion of those with an imputation quality score of <0.9 and a minor allele frequency (MAF) of < 2.5%, and conducted a meta-analysis under a fixed-effect model. The primary outcome assessed was time to first treatment (TTFT), defined as the interval between CLL diagnosis and first treatment or last follow-up. Pooling data from the 6 GWAS identified 5 SNPs at two genomic locations that surpassed genome-wide significance (P ≤ 5 x 10-8) for association with TTFT. The strongest statistical evidence for an association with progressive disease was for rs736456 (hazard ratio (HR) = 1.76, 95% confidence interval (CI) = 1.45-2.14; P = 1.26 x 10-8), which maps to chromosome 10q26.13. The second strongest association with progressive disease was for rs3778076 (HR = 2.03, 95% CI = 1.58-2.62; P = 3.89 x 10-8) which maps to chromosome 6p. Both markers showed consistent direction and magnitude of effect sizes across all six GWAS with no evidence of heterogeneity, and retained prognostic significance in multivariate models for disease progression, particularly in models restricted to Binet A patients. Whilst not as powerful as IGVH status, rs736456 and rs3778076 had prognostic utility equivalent to CD38 status, and are particularly powerful when considered together, identifying 5% of CLL patients carrying 2 or more risk alleles at high risk of progressive disease (Figure). To identify cis-regulated genes at each locus associated with progressive disease we interrogated gene expression data derived from a meta-analysis of 31,624 blood samples collated by the eQTLGen consortium. Of the thirteen genes annotated to within 1Mb of the chromosome 10 association signal rs736456 is eQTL for the PLEKHA1 gene (TAPP-1)(Benjamini-Hochberg corrected P-value [P BH] = 1.29 x 10-15). Of the 27 genes annotated to within 1Mb of the chromosome 6 signal, rs3778076 is eQTL for 5 genes including UHRF1BP1 (PBH = 6.73 x 10-139) and C6ORF106 (PBH = 3.54 x 10-64). Annotated genes at both loci have been implicated in modulating B-cell receptor or innate immune responses, key pathways in CLL pathogenesis. Data on post-treatment survival were available on 390 CLL cases, with 231 deaths and 159 censored at last follow-up, and neither the lead SNP at chromosome 10 or chromosome 6 were significantly associated with post-treatment survival in patients primarily treated with regimens that included chlorambucil, fludarabine or cyclophosphamide. It will be important to determine whether these markers predict overall survival in patients treated with novel targeted therapies. Taken together, these data identify rs736456 and rs3778076 as prognostic in early stage CLL patients demonstrating that progression of CLL from asymptomatic to symptomatic disease is determined by constitutional genetic variation as well as the more established somatic drivers. Constitutional genetic markers have the advantage of being easy to perform, highly reproducible and inexpensive making them ideal for incorporation into multivariate prognostication models for early stage CLL. Figure Disclosures Fegan: Roche: Honoraria; Janssen: Honoraria; Gilead: Honoraria; Abbvie: Consultancy, Other: Conference attendance sponsorship. Forconi: Gilead Sciences: Research Funding; Janssen-Cilag: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Speakers Bureau; Novartis: Honoraria; Menarini: Consultancy; Abbvie: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Speakers Bureau; Roche: Honoraria. Schuh: AbbVie: Consultancy, Speakers Bureau; Genentech: Consultancy, Speakers Bureau; Pharmacyclics: Consultancy, Speakers Bureau; Verastem: Speakers Bureau; Gilead: Speakers Bureau; Seattle Genetics: Speakers Bureau; Jazz Pharmaceuticals: Speakers Bureau; Bristol-Myers Squibb: Research Funding; Janssen: Speakers Bureau; Kite: Speakers Bureau. Hillmen: Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses, Research Funding; Roche: Research Funding; Gilead: Research Funding; Apellis: Research Funding; Acerta: Membership on an entity's Board of Directors or advisory committees. Pratt: Binding Site, Amgen, Takeda, Janssen, Gilead: Consultancy, Honoraria, Other: Travel support