Article Text

Original research
Impact of chronic kidney disease on case ascertainment for hospitalised acute myocardial infarction: an English cohort study
  1. Patrick Bidulka1,
  2. Jemima Scott2,3,
  3. Dominic M Taylor2,3,
  4. Udaya Udayaraj4,5,
  5. Fergus Caskey2,3,
  6. Lucy Teece6,
  7. Michael Sweeting6,
  8. John Deanfield7,8,
  9. Mark de Belder7,
  10. Spiros Denaxas9,10,
  11. Clive Weston11,
  12. David Adlam12,
  13. Dorothea Nitsch1
  1. 1Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
  2. 2Population Health Sciences, University of Bristol, Bristol, UK
  3. 3Richard Bright Renal Service, North Bristol NHS Trust, Southmead Hospital, Bristol, UK
  4. 4Oxford Kidney Unit, Churchill Hospital, Oxford, Oxfordshire, UK
  5. 5Nuffield Department of Medicine, University of Oxford, Oxford, Oxfordshire, UK
  6. 6Biostatistics Research Group, Department of Health Sciences, University of Leicester, Leicester, Leicestershire, UK
  7. 7National Institute for Cardiovascular Outcomes Research (NICOR), Barts Health NHS Trust, London, UK
  8. 8Institute of Cardiovascular Sciences, University College London, London, UK
  9. 9Institute of Health Informatics, Faculty of Population Health Sciences, University College London, London, UK
  10. 10Health Data Research UK, London, UK
  11. 11Glangwili General Hospital, Carmarthen, Carmarthenshire, UK
  12. 12Department of Cardiovascular Sciences, University of Leicester and NIHR Leicester Biomedical Research Centre, Leicester, Leicestershire, UK
  1. Correspondence to Patrick Bidulka; patrick.bidulka1{at}


Objectives Acute myocardial infarction (AMI) case ascertainment improves for the UK general population using linked health data sets. Because care pathways for people with chronic kidney disease (CKD) change based on disease severity, AMI case ascertainment for these people may differ compared with the general population. We aimed to determine the association between CKD severity and AMI case ascertainment in two secondary care data sets, and the agreement in estimated glomerular filtration rate (eGFR) between the same data sets.

Methods We used a cohort study design. Primary care records for people with CKD or risk factors for CKD, identified using the National CKD Audit (2015–2017), were linked to the Myocardial Ischaemia National Audit Project (MINAP, 2007–2017) and Hospital Episode Statistics (HES, 2007–2017) secondary care registries. People with an AMI recorded in either MINAP, HES or both were included in the study cohort. CKD status was defined using eGFR, derived from the most recent serum creatinine value recorded in primary care. Moderate–severe CKD was defined as eGFR <60 mL/min/1.73 m2, and mild CKD or at risk of CKD was defined as eGFR ≥60 mL/min/1.73 m2 or eGFR missing. CKD stages were grouped as (1) At risk of CKD and Stages 1–2 (eGFR missing or ≥60 mL/min/1.73 m2), (2) Stage 3a (eGFR 45–59 mL/min/1.73 m2), (3) Stage 3b (eGFR 30–44 mL/min/1.73 m2) and (4) Stages 4–5 (eGFR <30 mL/min/1.73 m2).

Results We identified 6748 AMIs: 23% were recorded in both MINAP and HES, 66% in HES only and 11% in MINAP only. Compared with people at risk of CKD or with mild CKD, AMIs in people with moderate–severe CKD were more likely to be recorded in both MINAP and HES (42% vs 11%, respectively), or MINAP only (22% vs 5%), and less likely to be recorded in HES only (36% vs 84%). People with AMIs recorded in HES only or MINAP only had increased odds of death during hospitalisation compared with those recorded in both (adjusted OR 1.61, 95% CI 1.32 to 1.96 and OR 1.60, 95% CI 1.26 to 2.04, respectively). Agreement between eGFR at AMI admission (MINAP) and in primary care was poor (kappa (K) 0.42, SE 0.012).

Conclusions AMI case ascertainment is incomplete in both MINAP and HES, and is associated with CKD severity.

  • Audit
  • Myocardial infarction

Data availability statement

Data may be obtained from a third party and are not publicly available. Due to data sharing agreements, we are not able to share these data. Researchers interested in using these data should consult the websites for the NCKDA ( and MINAP (

This is an open access article distributed in accordance with the Creative Commons Attribution 4.0 Unported (CC BY 4.0) license, which permits others to copy, redistribute, remix, transform and build upon this work for any purpose, provided the original work is properly cited, a link to the licence is given, and indication of whether changes were made. See:

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Data availability statement

Data may be obtained from a third party and are not publicly available. Due to data sharing agreements, we are not able to share these data. Researchers interested in using these data should consult the websites for the NCKDA ( and MINAP (

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  • PB and JS contributed equally.

  • DA and DN contributed equally.

  • Contributors JS, DT, DN, DA, FC and UU conceived the study. JS, DT, DN, DA, FC, UU and PB designed the study. PB and DN had access to and analysed the data. PB and JS drafted the manuscript. PB, JS, DT, UU, FC, LT, MS, JD, MdB, SD, CW, DA and DN (all authors) critically appraised the results and edited the manuscript. All authors approved the final version of the manuscript. The lead authors confirm all authors meet ICJME authorship criteria, and no one who meets ICJME criteria have been excluded. PB and DN are the guarantors of this study, and accept full responsibility for the work and conduct of the study, had access to the data, and controlled the decision to publish.

  • Funding This work was supported by Kidney Research UK (grant number IN_008_20180304) and the Health Foundation (grant number 1725841). JS is a Doctoral Research Fellow funded by the NIHR (NIHR 300906). DA is funded by a joint research grant from the British Heart Foundation (SP/16/5/32415) and Cancer Research UK (C53325/A21134).

  • Competing interests All authors have completed an ICJME form. PB, JS, DT, FC, LT, MdB and SD have nothing to declare. UU declares a grant from the Health Foundation to undertake quality improvement unrelated to this work. MS declares funding from Cancer Research UK (C53325/A21134) and British Heart Foundation (SP/16/5/32415) for research activities related to this work looking at acute myocardial infarction ascertainment in a cancer population. JS declares Doctoral research funding from the NIHR for related research looking at acute myocardial infarction care for people with chronic kidney disease. JD declares grants from British Heart Foundation paid to his institution unrelated to this work. JD also declares consulting fees from Novo Nordisk, and honoraria from Amgen, Boehringer Ingelheim, Merck, Pfizer, Aegerion, Novartis, Sanofi, Takeda, Novo Nordisk and Bayer, unrelated to this work. JD is also member of a study steering committee with Novo Nordisk. CW declares he is clinical lead of the Myocardial Ischaemia National Audit Project. DA reports research funding and in-kind support from AstraZeneca for unrelated research and educational funding from Abbott Vascular to support a clinical research fellow doing unrelated research. DA has conducted consultancy for General Electric to support general research funds. DN is the UK Kidney Association Director of Informatics Research. DN is also on the steering group for two GlaxoSmithKline funded studies that investigate kidney function in children and adults in sub-Saharan Africa.

  • Patient and public involvement Patients and/or the public were involved in the design, or conduct, or reporting, or dissemination plans of this research. Refer to the Methods section for further details.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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