Potential for positive biodiversity outcomes under diet-driven land use change in Great Britain

Background

A shift toward human diets that include more fruit and vegetables, and less meat is a potential pathway to improve public health and reduce food system-related greenhouse gas emissions. Associated changes in land use could include conversion of grazing land into horticulture, which makes more efficient use of land per unit of dietary energy and frees-up land for other uses.

Methods

Here we use Great Britain as a case study to estimate potential impacts on biodiversity from converting grazing land to a mixture of horticulture and natural land covers by fitting species distribution models for over 800 species, including pollinating insects and species of conservation priority.

Results

Across several land use scenarios that consider the current ratio of domestic fruit and vegetable production to imports, our statistical models suggest a potential for gains to biodiversity, including a tendency for more species to gain habitable area than to lose habitable area. Moreover, the models suggest that climate change impacts on biodiversity could be mitigated to a degree by land use changes associated with dietary shifts.

Conclusions

Our analysis demonstrates that options exist for changing agricultural land uses in a way that can generate win-win-win outcomes for biodiversity, adaptation to climate change and public health.

Gastric Radiotherapy in the UK - Current Practice and Opinion on Future Directions

PURPOSE/OBJECTIVE(S)

Gastric radiotherapy (RT) is more commonly practiced in the US compared to the UK, where postoperative chemoradiotherapy (CRT) is reserved for selected high-risk patients, and preoperative CRT is not standard of care pending the results of phase 3 trials, TOPGEAR and CRITICSII. CRT for inoperable, non-metastatic gastric cancer is also not recommended in the UK, despite being listed in NCCN guidelines. Recent systematic review of definitive gastric CRT (dCRT) conducted by the authors found median overall survival of 11-26.4 months, clinical complete response rates of 8-45% and acceptable rates of ≥G3 toxicity, supporting further research. Given these promising findings and perceived low uptake of gastric RT in the UK, we set out to establish current UK practice, opinion and RT technique to inform the development of a UK gastric RT protocol and future clinical trials.

MATERIALS/METHODS

A 19 question survey was developed. Following local ethical approval and pilot by 4 clinical oncologists, the final survey was distributed electronically on 13/12/22 to UK Consultant Clinical Oncologists specializing in esophago-gastric (OG) cancer. Responses were anonymous. Survey was closed 6/2/23 and data analyzed using JISC/spreadsheet software.

RESULTS

A total of 43 clinicians completed the survey. For gastric cancer, 28.6%, 7.1% and 9.5% would agree/strongly agree with use of postoperative (postopRT), preoperative (preopRT) or definitive RT (dRT) respectively, compared to 26.2%, 45.2% and 46.6% for type III gastro-esophageal junction tumors. 93% had prescribed palliative gastric RT in the last 3 years compared to 40.5% postopRT, 16.7% dRT and 9.5% preopRT. Main reasons for infrequent use were; rarely indicated within standard UK practice 88.4%, lack of UK gastric RT protocol 53.5%, toxicity concerns 44.2%. 45Gy/25# was most commonly used for preopRT (66%) and postopRT (86%), and 50Gy/25# for dRT (58%). 96% use IMRT/VMAT, 85% CT simulation with IV/oral contrast, 69% gastric filling protocol and 54% 4DCT. When ranked out of 10 (1 = low 10 = high), clinician confidence in accurately delineating gastric volumes mean rank was 4.33 for postopRT, with 9% rating ≥8/10, and 4.52 for dCRT/preopRT with 17% rating ≥8/10. However, 48.8% were experienced in outlining upper abdominal nodes and 62.8% duodenum. 93% would find a detailed outlining protocol useful, 81.4% wanted some form of peer review, 76.7% a nodal atlas, and 74.4% a workshop with an expert. 77.6% would be supportive of a future clinical trial of dCRT, with 23.4% needing more supporting evidence. No-one would not support a future trial in this setting.

CONCLUSION

Gastric RT is not often practiced in the UK, due to lacking evidence and toxicity concerns. Given the growing evidence and supportive OG community, it is time to consider a trial of dCRT in the UK, which must include detailed RT protocols, atlases and educational materials to improve clinician confidence and ensure good RT quality assurance.

Dose Escalation in Esophageal Cancer: Comparing Pre-Accrual and On-Trial Target Volume Delineation in the UK SCOPE2 Trial

PURPOSE/OBJECTIVE(S)

The ongoing UK SCOPE2 trial evaluates radiotherapy (RT) dose escalation and PET-guided systemic therapy in esophageal cancer, and has an accompanying RT trials quality assurance (RTTQA) program, evolved through the preceding SCOPE trials. We compare pre-accrual with on-trial individual case review (ICR) target volume delineation (TVD).

MATERIALS/METHODS

Prior to recruitment, centers were required to undertake TVD exercises using 3D/4D DICOM datasets with relevant clinical details and a RT planning guidance document (RPGD) provided. Contours were then compared against the RTTQA team-defined gold standard. Exceptions were those who had satisfied QA requirements for a previous esophageal RT trial (NeoSCOPE). For ICRs, prospective reviews (prior RT start, PRs) were undertaken for each center's first submission, plus high-dose cases submitted pending formal safety review. Additional PRs were undertaken at the RTTQA team's discretion. Timely retrospective reviews (within 2 weeks of RT start, TRR) were also undertaken for a random 10% sample. TVDs were assessed for compliance using predefined criteria and the RPGD. Resubmission was requested at reviewer's discretion, usually due to unacceptable variation (UV) from protocol. Clarification was sought before contour approval/resubmission request if appropriate. Review outcomes were then evaluated. PTV6000 was new to SCOPE2, along with a greater emphasis on use of 4DCT than in prior SCOPE trials.

RESULTS

A total of 85 pre-accrual cases from 33 UK centers were reviewed, of which 20 (24%) were resubmissions, and 50 (59%) were accepted. 99 TVD UVs were observed in 49 cases, most commonly in CTVB (42/99, 42%), which included editing for normal structures and elective lymph node regions, followed by ITV (4D cases only, 14/52, 27%) and PTV6000 (13/99, 13%). 121 ICRs from 31 UK centers were available for review. 87 (72%) were PRs and 34 (28%) TRRs. 43 (36%) completed the relevant SCOPE2 exercise. 19 (16%) were resubmissions, and 82 (68%) were accepted. 72 UVs were observed in 45 ICRs; again, most commonly in CTVB (34/72, 48%), PTV6000 (high dose arm only, 11/46, 24%) and ITV (4D only, 5/26, 19%). Of the 45 cases where a UV was recorded, 16 (36%) had completed the relevant SCOPE2 pre-accrual. Comparing area of UV on SCOPE2 pre-accrual cases and ICRs, 3 (19%) contours contained the same (2 = CTVB, 1 = PTV6000), 5 (31%) contained different and 8 (50%) had no UVs at pre-accrual. The rate of UV was significantly lower for ICR than for pre-accrual submissions (0.60 and 1.16 respectively, p = 0.001).

CONCLUSION

Significantly fewer UVs in ICR compared with pre-accrual supports a robust, educational RTTQA program through national collaboration and evolving trial series. CTVB, along with newer volumes of ITV and PTV6000, were recurring UV domains and should inform RPGD development and RTTQA for ongoing recruitment and future trials.

Climate change, land cover change, and overharvesting threaten a widely used medicinal plant in South Africa

Medicinal plants contribute substantially to the well-being of people in large parts of the world, providing traditional medicine and supporting livelihoods from trading plant parts, which is especially significant for women in low-income communities. However, the availability of wild medicinal plants is increasingly threatened; for example, the Natal Lily (Clivia miniata), which is one of the most widely traded plants in informal medicine markets in South Africa, lost over 40% of individuals over the last 90 years. Understanding the species' response to individual and multiple pressures is essential for prioritizing and planning conservation actions. To gain this understanding, we simulated the future range and abundance of C. miniata by coupling Species Distribution Models with a metapopulation model (RAMAS-GIS). We contrasted scenarios of climate change (RCP2.6 vs. RCP8.5), land cover change (intensification vs. expansion), and harvesting (only juveniles vs. all life-stages). All our scenarios pointed to continuing declines in suitable habitat and abundance by the 2050s. When acting independently, climate change, land cover change, and harvesting each reduced the projected abundance substantially, with land cover change causing the most pronounced declines. Harvesting individuals from all life stages affected the projected metapopulation size more negatively than extracting only juveniles. When the three pressures acted together, declines of suitable habitat and abundance accelerated but uncertainties were too large to identify whether pressures acted synergistically, additively, or antagonistically. Our results suggest that conservation should prioritize the protection of suitable habitat and ensure sustainable harvesting to support a viable metapopulation under realistic levels of climate change. Inadequate management of C. miniata populations in the wild will likely have negative consequences for the well-being of people relying on this ecosystem service, and we expect there may be comparable consequences relating to other medicinal plants in different parts of the world.

Potential for positive biodiversity outcomes under diet-driven land use change in Great Britain

Background: A shift toward human diets that include more fruit and vegetables, and less meat is a potential pathway to improve public health and reduce food system-related greenhouse gas emissions. Associated changes in land use could include conversion of grazing land into horticulture, which makes more efficient use of land per unit of dietary energy and frees-up land for other uses. Methods: Here we use Great Britain as a case study to estimate potential impacts on biodiversity from converting grazing land to a mixture of horticulture and natural land covers by fitting species distribution models for over 800 species, including pollinating insects and species of conservation priority. Results: Across several land use scenarios that consider the current ratio of domestic fruit and vegetable production to imports, our statistical models suggest a potential for gains to biodiversity, including a tendency for more species to gain habitable area than to lose habitable area. Moreover, the models suggest that climate change impacts on biodiversity could be mitigated to a degree by land use changes associated with dietary shifts. Conclusions: Our analysis demonstrates that options exist for changing agricultural land uses in a way that can generate win-win-win outcomes for biodiversity, adaptation to climate change and public health.

Treatment planning comparison in the PROTECT-trial randomising proton versus photon beam therapy in oesophageal cancer: results from eight european centres

PURPOSE

To compare dose distributions and robustness in treatment plans from eight European centres in preparation for the European randomized phase-III PROTECT-trial investigating the effect of proton therapy (PT) versus photon therapy (XT) for oesophageal cancer.

MATERIALS AND METHODS

All centres optimized one PT and one XT nominal plan using delineated 4DCT scans for four patients receiving 50.4Gy(RBE) in 28 fractions. Target volume receiving 95% of prescribed dose (V95%_iCTVtotal) should be >99%. Robustness towards setup, range, and respiration was evaluated. The plans were recalculated on a surveillance 4DCT (sCT) acquired at fraction ten and robustness evaluation was performed to evaluate the effect of respiration and inter-fractional anatomical changes.

RESULTS

All PT and XT plans complied with V95%_iCTVtotal>99% for the nominal plan and V95%_iCTVtotal>97% for all respiratory and robustness scenarios. Lung and heart dose varied considerably between centres for both modalities. The difference in mean lung dose and mean heart dose between each pair of XT and PT plans was in median [range] 4.8Gy [1.1;7.6] and 8.4Gy [1.9;24.5], respectively. Patients B and C showed large inter-fractional anatomical changes on sCT. For patient B, the minimum V95%_iCTVtotal in the worst-case robustness scenario was 45% and 94% for XT and PT, respectively. For patient C, the minimum V95%_iCTVtotal was 57% and 72% for XT and PT, respectively. Patient A and D showed minor inter-fractional changes and the minimum V95%_iCTVtotal was >85%.

CONCLUSION

Large variability in dose to the lungs and heart was observed for both modalities. Inter-fractional anatomical changes led to larger target dose deterioration for XT than PT plans.

Adverse childhood experiences and incident coronary heart disease: a counterfactual analysis in the Whitehall II prospective cohort study

Objectives

Adverse childhood experience is thought to be associated with risk of coronary heart disease, but it is not clear which experiences are cardiotoxic, and whether risk increases with the accumulation of adverse childhood experiences.

Methods

Participants were 5149 adults (72.6% men) in the Whitehall II cohort study. Parental death was recorded at phase 1 (median age in years 44.3), and 13 other adverse childhood experiences at phase 5 (55.3). We applied Cox proportional hazards regression with person-time from phase 5 to examine associations of adverse childhood experiences with incident coronary heart disease. We predicted hazard ratios according to count of the experiences, and examined dose-response effect. We finally estimated reduction of coronary heart disease in a hypothetical scenario, the absence of adverse childhood experiences.

Results

Among study participants, 62.9% had at least one adversity, with "financial problems" having the highest prevalence (26.1%). There were 509 first episodes of coronary heart disease during an average 12.9 years follow-up. Among 14 adverse childhood experiences in a multiply adjusted model, "parental unemployment" showed the highest hazard of coronary heart disease incidence (hazard ratio; 95% confidence interval: 1.53; 1.16 to 2.02). No dose-response effect was observed (constant for proportionality in hazard ratio: 1.05, 0.99 to 1.11). Based on the estimates of final model, in the absence of childhood adversities, we estimated a 6.0% reduction in coronary heart disease (0.94; 0.87 to 1.01), but the confidence interval includes one.

Conclusion

Although individual adverse childhood experiences show some association with coronary heart disease, there is no clear relationship with the number of adverse experiences. Further research is required to quantify effects of multiple and combinations of adverse childhood experiences considering timing, duration, and severity.

Pathways to "5-a-day": modeling the health impacts and environmental footprints of meeting the target for fruit and vegetable intake in the United Kingdom

BACKGROUND

Fruit and vegetable consumption in the United Kingdom is currently well below recommended levels, with a significant associated public health burden. The United Kingdom has committed to reducing its carbon emissions to net zero by 2050, and this transition will require shifts towards plant-based diets.

OBJECTIVE

The aim was to quantify the health effects, environmental footprints, and cost associated with 4 different pathways to meeting the United Kingdom's "5-a-day" recommendation for fruit and vegetable consumption.

METHODS

Dietary data based on 18,006 food diaries from 4528 individuals participating in the UK National Diet and Nutrition Survey (2012/13-2016/17) constituted the baseline diet. Linear programming was used to model the hypothetical adoption of the 5-a-day (400 g) recommendation, which was assessed according to 4 pathways differing in their prioritization of fruits versus vegetables and UK-produced versus imported varieties. Increases in fruit and vegetable consumption were substituted for consumption of sweet snacks and meat, respectively. Changes in life expectancy were assessed using the IOMLIFET life table model. Greenhouse gas emissions (GHGEs), blue water footprint (WF), and total diet cost were quantified for each 5-a-day diet.

RESULTS

Achieving the 5-a-day target in the United Kingdom could increase average life expectancy at birth by 7-8 mo and reduce diet-related GHGEs by 6.1 to 12.2 Mt carbon dioxide equivalents/y; blue WFs would change by -0.14 to +0.07 km3/y. Greater reductions in GHGEs were achieved by prioritizing increased vegetable consumption over fruit, whereas the greatest reduction in WF was obtained by prioritizing vegetable varieties produced in the United Kingdom. All consumption pathways increased diet cost (£0.34-£0.46/d).

CONCLUSIONS

Benefits to both population and environmental health could be expected from consumption pathways that meet the United Kingdom's 5-a-day target for fruit and vegetables. Our analysis identifies cross-sectoral trade-offs and opportunities for national policy to promote fruit and vegetable consumption in the United Kingdom.

The impact of life course exposures to neighbourhood deprivation on health and well-being: a review of the long-term neighbourhood effects literature

Background

In this review article, we detail a small but growing literature in the field of health geography that uses longitudinal data to determine a life course component to the neighbourhood effects thesis. For too long, there has been reliance on cross-sectional data to test the hypothesis that where you live has an effect on your health and well-being over and above your individual circumstances.

Methods

We identified 53 articles that demonstrate how neighbourhood deprivation measured at least 15 years prior affects health and well-being later in life using the databases Scopus and Web of Science.

Results

We find a bias towards US studies, the most common being the Panel Study of Income Dynamics. Definition of neighbourhood and operationalization of neighbourhood deprivation across most of the included articles relied on data availability rather than a priori hypothesis.

Conclusions

To further progress neighbourhood effects research, we suggest that more data linkage to longitudinal datasets is required beyond the narrow list identified in this review. The limited literature published to date suggests an accumulation of exposure to neighbourhood deprivation over the life course is damaging to later life health, which indicates improving neighbourhoods as early in life as possible would have the greatest public health improvement.

The Promise of Proton Beam Therapy for Oesophageal Cancer: A Systematic Review of Dosimetric and Clinical Outcomes

AIMS

Due to its physical advantages over photon radiotherapy, proton beam therapy (PBT) has the potential to improve outcomes from oesophageal cancer. However, for many tumour sites, high-quality evidence supporting PBT use is limited. We carried out a systematic review of published literature of PBT in oesophageal cancer to ascertain potential benefits of this technology and to gauge the current state-of-the-art. We considered if further evaluation of this technology in oesophageal cancer is desirable.

MATERIALS AND METHODS

A systematic literature search of Medline, Embase, Cochrane Library and Web of Science using structured search terms was carried out. Inclusion criteria included non-metastatic cancer, full articles and English language studies only. Articles deliberating technical aspects of PBT planning or delivery were excluded to maintain a clinical focus. Studies were divided into two sections: dosimetric and clinical studies; qualitatively synthesised.

RESULTS

In total, 467 records were screened, with 32 included for final qualitative synthesis. This included two prospective studies with the rest based on retrospective data. There was heterogeneity in treatment protocols, including treatment intent (neoadjuvant or definitive), dose, fractionation and chemotherapy used. Compared with photon radiotherapy, PBT seemed to reduce dose to organs at risk, especially lung and heart, although not for all reported parameters. Toxicity outcomes, including postoperative complications, were reduced compared with photon radiotherapy. Survival outcomes were reported to be at least comparable with photon radiotherapy.

CONCLUSION

There is a paucity of high-quality evidence supporting PBT use in oesophageal cancer. Wide variation in intent and treatment protocols means that the role and 'gold-standard' treatment protocol are yet to be defined. Current literature suggests significant benefit in terms of toxicity reduction, especially in the postoperative period, with comparable survival outcomes. PBT in oesophageal cancer holds significant promise for improving patient outcomes but requires robust systematic evaluation in prospective studies.

Proposal for the delineation of neoadjuvant target volumes in oesophageal cancer

PURPOSE

To define instructions for delineation of target volumes in the neoadjuvant setting in oesophageal cancer.

MATERIALS AND METHODS

Radiation oncologists of five European centres participated in the following consensus process: [1] revision of published (MEDLINE) and national/institutional delineation guidelines; [2] first delineation round of five cases (patient 1-5) according to national/institutional guidelines; [3] consensus meeting to discuss the results of step 1 and 2, followed by a target volume delineation proposal; [4] circulation of proposed instructions for target volume delineation and atlas for feedback; [5] second delineation round of five new cases (patient 6-10) to peer review and validate (two additional centres) the agreed delineation guidelines and atlas; [6] final consensus on the delineation guidelines depicted in an atlas. Target volumes of the delineation rounds were compared between centres by Dice similarity coefficient (DSC) and maximum/mean undirected Hausdorff distances (H_max/H_mean).

RESULTS

In the first delineation round, the consistency between centres was moderate (CTVtotal: DSC = 0.59-0.88; H_mean = 0.2-0.4 cm). Delineations in the second round were much more consistent. Lowest variability was obtained between centres participating in the consensus meeting (CTVtotal: DSC: p < 0.050 between rounds for patients 6/7/8/10; H_mean: p < 0.050 for patients 7/8/10), compared to validation centres (CTVtotal: DSC: p < 0.050 between validation and consensus meeting centres for patients 6/7/8; H_mean: p < 0.050 for patients 7/10). A proposal for delineation of target volumes and an atlas were generated.

CONCLUSION

We proposed instructions for target volume delineation and an atlas for the neoadjuvant radiation treatment in oesophageal cancer. These will enable a more uniform delineation of patients in clinical practice and clinical trials.

Trading water: virtual water flows through interstate cereal trade in India

Cereals are an important component of the Indian diet, providing 47% of the daily dietary energy intake. Dwindling groundwater reserves in India especially in major cereal-growing regions are an increasing challenge to national food supply. An improved understanding of interstate cereal trade can help to identify potential risks to national food security. Here, we quantify the trade between Indian states of five major cereals and the associated trade in virtual (or embedded) water. To do this, we modelled interstate trade of cereals using Indian government data on supply and demand; calculated virtual water use of domestic cereal production using state- and product-specific water footprints and state-level data on irrigation source; and incorporated virtual water used in the production of internationally-imported cereals using country-specific water footprints. We estimate that 40% (94 million tonnes) of total cereal food supply was traded between Indian states in 2011-12, corresponding to a trade of 54.0 km3 of embedded blue water, and 99.4 km3 of embedded green water. Of the cereals traded within India, 41% were produced in states with over-exploited groundwater reserves (defined according to the Central Ground Water Board) and a further 21% in states with critically depleting groundwater reserves. Our analysis indicates a high dependency of Indian cereal consumption on production in states with stressed groundwater reserves. Substantial changes in agricultural practices and land use may be required to secure future production, trade and availability of cereals in India. Diversifying production systems could increase the resilience of India's food system.

Comparing Proton to Photon Radiotherapy Plans: UK Consensus Guidance for Reporting Under Uncertainty for Clinical Trials

In the UK, the recent introduction of high-energy proton beam therapy into national clinical practice provides an opportunity for new clinical trials, particularly those comparing proton and photon treatments. However, comparing these different modalities can present many challenges. Although protons may confer an advantage in terms of reduced normal tissue dose, they can also be more sensitive to uncertainty. Uncertainty analysis is fundamental in ensuring that proton plans are both safe and effective in the event of unavoidable discrepancies, such as variations in patient setup and proton beam range. Methods of evaluating and mitigating the effect of these uncertainties can differ from those approaches established for photon therapy treatments, such as the use of expansion margins to assure safety. These differences should be considered when comparing protons and photons. An overview of the effect of uncertainties on proton plans is presented together with an introduction to some of the concepts and terms that should become familiar to those involved in proton therapy trials. This report aims to provide guidance for those engaged in UK clinical trials comparing protons and photons. This guidance is intended to take a pragmatic approach considering the tools that are available to practising centres and represents a consensus across multidisciplinary groups involved in proton therapy in the UK.

Association of attrition with mortality: findings from 11 waves over three decades of the Whitehall II study

BACKGROUND

Attrition, the loss of participants as a study progresses, is a considerable challenge in longitudinal studies. This study examined whether two forms of attrition, 'withdrawal' (formal discontinued participation) and 'non-response' (non-response among participants continuing in the study), have different associations with mortality and whether these associations differed across time in a multi-wave longitudinal study.

METHODS

Participants were 10 012 civil servants who participated at the baseline of the Whitehall II cohort study with 11 data waves over an average follow-up of 28 years. We performed competing-risks analyses to estimate sub-distribution HRs and 95% CIs, and likelihood ratio tests to examine whether hazards differed between the two forms of attrition. We then applied linear regression to examine any trend of hazards against time.

RESULTS

Attrition rate at data collections ranged between 13% and 34%. There were 495 deaths recorded from cardiovascular disease and 1367 deaths from other causes. Study participants lost due to attrition had 1.55 (95% CI 1.26 to 1.89) and 1.56 (1.39 to 1.76) times higher hazard of cardiovascular and non-cardiovascular mortality than responders, respectively. Hazards for withdrawal and non-response did not differ for either cardiovascular (p value =0.28) or non-cardiovascular mortality (p value =0.38). There was no linear trend in hazards over the 11 waves (cardiovascular mortality p value =0.11, non-cardiovascular mortality p value =0.61).

CONCLUSION

Attrition can be a problem in longitudinal studies resulting in selection bias. Researchers should examine the possibility of selection bias and consider applying statistical approaches that minimise this bias.

Are there sensitive neighbourhood effect periods during the life course on midlife health and wellbeing?

Since the turn of the century there has been an explosion in the number of epidemiological studies that have analysed neighbourhood effects on health and wellbeing. The vast majority of these studies are cross-sectional in nature and assume that a contemporaneous place of residence captures a meaningful neighbourhood effect. Over the same time frame, social epidemiology has focussed increasingly on life course effects. This paper aims to bring these two areas of study together and tests whether there a certain ages during the life course when neighbourhoods are more important for our health and wellbeing than others. We use two British birth cohort studies (1958 National Child Development Study and British Cohort Study 1970) each comprising approximately 6,000 sample members at midlife linked to historic census measures used to derived Townsend neighbourhood deprivation scores over the life course. We find little evidence to support our hypothesis that adolescence is a key period of neighbourhood effect, rather we find late-early-adulthood neighbourhood deprivation and midlife neighbourhood deprivation are more strongly related to mid-life health and wellbeing. We are not able to conclude whether these effects are causal and encourage further investigation of selection mechanisms into neighbourhoods and mediation throughout the life course using our newly created dataset.

Total Center Percutaneous Coronary Intervention Volume and 30-Day Mortality: A Contemporary National Cohort Study of 427 467 Elective, Urgent, and Emergency Cases

BACKGROUND

The relationship between procedural volume and prognosis after percutaneous coronary intervention (PCI) remains uncertain, with some studies finding in favor of an inverse association and some against. This UK study provides a contemporary reassessment in one of the few countries in the world with a nationally representative PCI registry.

METHODS AND RESULTS

A nationwide cohort study was performed using the national British Cardiovascular Intervention Society registry. All adult patients undergoing PCI in 93 English and Welsh NHS hospitals between 2007 and 2013 were analyzed using hierarchical modeling with adjustment for patient risk. Of 427 467 procedures (22.0% primary PCI) in 93 hospitals, 30-day mortality was 1.9% (4.8% primary PCI). 87.1% of centers undertook between 200 and 2000 procedures annually. Case mix varied with center volume. In centers with 200 to 399 PCI cases per year, a smaller proportion were PCI for ST-segment-elevation myocardial infarction (8.4%) than in centers with 1500 to 1999 PCI cases per year (24.2%), but proportionally more were for ST-segment-elevation myocardial infarction with cardiogenic shock (8.4% versus 4.3%). For the overall PCI cohort, after risk adjustment, there was no significant evidence of worse, or better, outcomes in lower volume centers from our own study, or in combination with results from other studies. For primary PCI, there was also no evidence for increased or decreased mortality in lower volume centers.

CONCLUSIONS

After adjustment for differences in case mix and clinical presentation, this study supports the conclusion of no trend for increased mortality in lower volume centers for PCI in the UK healthcare system.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrials.gov. Unique identifier: NCT02184949.

Neutrophil Counts and Initial Presentation of 12 Cardiovascular Diseases: A CALIBER Cohort Study

BACKGROUND

Neutrophil counts are a ubiquitous measure of inflammation, but previous studies on their association with cardiovascular disease (CVD) were limited by small numbers of patients or a narrow range of endpoints.

OBJECTIVES

This study investigated associations of clinically recorded neutrophil counts with initial presentation for a range of CVDs.

METHODS

We used linked primary care, hospitalization, disease registry, and mortality data in England. We included people 30 years or older with complete blood counts performed in usual clinical care and no history of CVD. We used Cox models to estimate cause-specific hazard ratios (HRs) for 12 CVDs, adjusted for cardiovascular risk factors and acute conditions affecting neutrophil counts (such as infections and cancer).

RESULTS

Among 775,231 individuals in the cohort, 154,179 had complete blood counts performed under acute conditions and 621,052 when they were stable. Over a median 3.8 years of follow-up, 55,004 individuals developed CVD. Adjusted HRs comparing neutrophil counts 6 to 7 versus 2 to 3 × 10⁹/l (both within the 'normal' range) showed strong associations with heart failure (HR: 2.04; 95% confidence interval [CI]: 1.82 to 2.29), peripheral arterial disease (HR: 1.95; 95% CI: 1.72 to 2.21), unheralded coronary death (HR: 1.78; 95% CI: 1.51 to 2.10), abdominal aortic aneurysm (HR: 1.72; 95% CI: 1.34 to 2.21), and nonfatal myocardial infarction (HR: 1.58; 95% CI: 1.42 to 1.76). These associations were linear, with greater risk even among individuals with neutrophil counts of 3 to 4 versus 2 to 3 × 10⁹/l. There was a weak association with ischemic stroke (HR: 1.36; 95% CI: 1.17 to 1.57), but no association with stable angina or intracerebral hemorrhage.

CONCLUSIONS

Neutrophil counts were strongly associated with the incidence of some CVDs, but not others, even within the normal range, consistent with underlying disease mechanisms differing across CVDs. (White Blood Cell Counts and Onset of Cardiovascular Diseases: a CALIBER Study [CALIBER]; NCT02014610).

Low eosinophil and low lymphocyte counts and the incidence of 12 cardiovascular diseases: a CALIBER cohort study

BACKGROUND

Eosinophil and lymphocyte counts are commonly performed in clinical practice. Previous studies provide conflicting evidence of association with cardiovascular diseases.

METHODS

We used linked primary care, hospitalisation, disease registry and mortality data in England (the CALIBER (CArdiovascular disease research using LInked Bespoke studies and Electronic health Records) programme). We included people aged 30 or older without cardiovascular disease at baseline, and used Cox models to estimate cause-specific HRs for the association of eosinophil or lymphocyte counts with the first occurrence of cardiovascular disease.

RESULTS

The cohort comprised 775 231 individuals, of whom 55 004 presented with cardiovascular disease over median follow-up 3.8 years. Over the first 6 months, there was a strong association of low eosinophil counts (<0.05 compared with 0.15-0.25×10(9)/L) with heart failure (adjusted HR 2.05; 95% CI 1.72 to 2.43), unheralded coronary death (HR 1.94, 95% CI 1.40 to 2.69), ventricular arrhythmia/sudden cardiac death and subarachnoid haemorrhage, but not angina, non-fatal myocardial infarction, transient ischaemic attack, ischaemic stroke, haemorrhagic stroke, subarachnoid haemorrhage or abdominal aortic aneurysm. Low eosinophil count was inversely associated with peripheral arterial disease (HR 0.63, 95% CI 0.44 to 0.89). There were similar associations with low lymphocyte counts (<1.45 vs 1.85-2.15×10(9)/L); adjusted HR over the first 6 months for heart failure was 2.25 (95% CI 1.90 to 2.67). Associations beyond the first 6 months were weaker.

CONCLUSIONS

Low eosinophil counts and low lymphocyte counts in the general population are associated with increased short-term incidence of heart failure and coronary death.

TRIAL REGISTRATION NUMBER

NCT02014610; results.

Acute myocardial infarction: a comparison of short-term survival in national outcome registries in Sweden and the UK

BACKGROUND

International research for acute myocardial infarction lacks comparisons of whole health systems. We assessed time trends for care and outcomes in Sweden and the UK.

METHODS

We used data from national registries on consecutive patients registered between 2004 and 2010 in all hospitals providing care for acute coronary syndrome in Sweden and the UK. The primary outcome was all-cause mortality 30 days after admission. We compared effectiveness of treatment by indirect casemix standardisation. This study is registered with ClinicalTrials.gov, number NCT01359033.

FINDINGS

We assessed data for 119,786 patients in Sweden and 391,077 in the UK. 30-day mortality was 7·6% (95% CI 7·4-7·7) in Sweden and 10·5% (10·4-10·6) in the UK. Mortality was higher in the UK in clinically relevant subgroups defined by troponin concentration, ST-segment elevation, age, sex, heart rate, systolic blood pressure, diabetes mellitus status, and smoking status. In Sweden, compared with the UK, there was earlier and more extensive uptake of primary percutaneous coronary intervention (59% vs 22%) and more frequent use of β blockers at discharge (89% vs 78%). After casemix standardisation the 30-day mortality ratio for UK versus Sweden was 1·37 (95% CI 1·30-1·45), which corresponds to 11,263 (95% CI 9620-12,827) excess deaths, but did decline over time (from 1·47, 95% CI 1·38-1·58 in 2004 to 1·20, 1·12-1·29 in 2010; p=0·01).

INTERPRETATION

We found clinically important differences between countries in acute myocardial infarction care and outcomes. International comparisons research might help to improve health systems and prevent deaths.

FUNDING

Seventh Framework Programme for Research, National Institute for Health Research, Wellcome Trust (UK), Swedish Association of Local Authorities and Regions, Swedish Heart-Lung Foundation.

Comparison of random forest and parametric imputation models for imputing missing data using MICE: a CALIBER study

Multivariate imputation by chained equations (MICE) is commonly used for imputing missing data in epidemiologic research. The “true” imputation model may contain nonlinearities which are not included in default imputation models. Random forest imputation is a machine learning technique which can accommodate nonlinearities and interactions and does not require a particular regression model to be specified. We compared parametric MICE with a random forest-based MICE algorithm in 2 simulation studies. The first study used 1,000 random samples of 2,000 persons drawn from the 10,128 stable angina patients in the CALIBER database (Cardiovascular Disease Research using Linked Bespoke Studies and Electronic Records; 2001–2010) with complete data on all covariates. Variables were artificially made “missing at random,” and the bias and efficiency of parameter estimates obtained using different imputation methods were compared. Both MICE methods produced unbiased estimates of (log) hazard ratios, but random forest was more efficient and produced narrower confidence intervals. The second study used simulated data in which the partially observed variable depended on the fully observed variables in a nonlinear way. Parameter estimates were less biased using random forest MICE, and confidence interval coverage was better. This suggests that random forest imputation may be useful for imputing complex epidemiologic data sets in which some patients have missing data.

Prognostic models for stable coronary artery disease based on electronic health record cohort of 102 023 patients

Aims

The population with stable coronary artery disease (SCAD) is growing but validated models to guide their clinical management are lacking. We developed and validated prognostic models for all-cause mortality and non-fatal myocardial infarction (MI) or coronary death in SCAD.

Methods and results

Models were developed in a linked electronic health records cohort of 102 023 SCAD patients from the CALIBER programme, with mean follow-up of 4.4 (SD 2.8) years during which 20 817 deaths and 8856 coronary outcomes were observed. The Kaplan–Meier 5-year risk was 20.6% (95% CI, 20.3, 20.9) for mortality and 9.7% (95% CI, 9.4, 9.9) for non-fatal MI or coronary death. The predictors in the models were age, sex, CAD diagnosis, deprivation, smoking, hypertension, diabetes, lipids, heart failure, peripheral arterial disease, atrial fibrillation, stroke, chronic kidney disease, chronic pulmonary disease, liver disease, cancer, depression, anxiety, heart rate, creatinine, white cell count, and haemoglobin. The models had good calibration and discrimination in internal (external) validation with C-index 0.811 (0.735) for all-cause mortality and 0.778 (0.718) for non-fatal MI or coronary death. Using these models to identify patients at high risk (defined by guidelines as 3% annual mortality) and support a management decision associated with hazard ratio 0.8 could save an additional 13–16 life years or 15–18 coronary event-free years per 1000 patients screened, compared with models with just age, sex, and deprivation.

Conclusion

These validated prognostic models could be used in clinical practice to support risk stratification as recommended in clinical guidelines.

Threshold haemoglobin levels and the prognosis of stable coronary disease: two new cohorts and a systematic review and meta-analysis

BACKGROUND

Low haemoglobin concentration has been associated with adverse prognosis in patients with angina and myocardial infarction (MI), but the strength and shape of the association and the presence of any threshold has not been precisely evaluated.

METHODS AND FINDINGS

A retrospective cohort study was carried out using the UK General Practice Research Database. 20,131 people with a new diagnosis of stable angina and no previous acute coronary syndrome, and 14,171 people with first MI who survived for at least 7 days were followed up for a mean of 3.2 years. Using semi-parametric Cox regression and multiple adjustment, there was evidence of threshold haemoglobin values below which mortality increased in a graded continuous fashion. For men with MI, the threshold value was 13.5 g/dl (95% confidence interval [CI] 13.2-13.9); the 29.5% of patients with haemoglobin below this threshold had an associated hazard ratio for mortality of 2.00 (95% CI 1.76-2.29) compared to those with haemoglobin values in the lowest risk range. Women tended to have lower threshold haemoglobin values (e.g, for MI 12.8 g/dl; 95% CI 12.1-13.5) but the shape and strength of association did not differ between the genders, nor between patients with angina and MI. We did a systematic review and meta-analysis that identified ten previously published studies, reporting a total of only 1,127 endpoints, but none evaluated thresholds of risk.

CONCLUSIONS

There is an association between low haemoglobin concentration and increased mortality. A large proportion of patients with coronary disease have haemoglobin concentrations below the thresholds of risk defined here. Intervention trials would clarify whether increasing the haemoglobin concentration reduces mortality.