Study protocol for a multicentre comparative diagnostic accuracy study of tools to establish the presence and severity of peripheral arterial disease in people with diabetes mellitus: the DM PAD study

Pasha Normahani; Laura Burgess; John Norrie; David Mark Epstein; Neghal Kandiyil; Athanasios Saratzis; Sasha Smith; Kamlesh Khunti; M Edmonds; Raju Ahluwalia; Trusha Coward; Tim Hartshorne; Simon Ashwell; Joseph Shalhoub; Elizabeth Pigott; Alun H Davies; Usman Jaffer; DM PAD study investigators

doi:10.1136/bmjopen-2022-066950

Study protocol for a multicentre comparative diagnostic accuracy study of tools to establish the presence and severity of peripheral arterial disease in people with diabetes mellitus: the DM PAD study

BMJ Open. 2022 Nov 3;12(11):e066950. doi: 10.1136/bmjopen-2022-066950.

Authors

Pasha Normahani^{1

2}, Laura Burgess³, John Norrie^{4

5}, David Mark Epstein⁶, Neghal Kandiyil⁷, Athanasios Saratzis⁸, Sasha Smith³, Kamlesh Khunti⁹, M Edmonds¹⁰, Raju Ahluwalia¹⁰, Trusha Coward¹¹, Tim Hartshorne¹², Simon Ashwell¹³, Joseph Shalhoub^{3

2}, Elizabeth Pigott¹⁴, Alun H Davies^{3

2}, Usman Jaffer^{3

2}; DM PAD study investigators

Affiliations

¹ Department of Surgery and Cancer, Imperial College London, London, UK p.normahani@imperial.ac.uk.
² Vascular Unit, Imperial College Healthcare NHS Trust, London, UK.
³ Department of Surgery and Cancer, Imperial College London, London, UK.
⁴ Usher Institute, Edinburgh Clinical Trials Unit, University of Edinburgh, Edinburgh, UK.
⁵ Edinburgh Clinical Trials Unit, Edinburgh, UK.
⁶ Faculty of Economics and Business Sciences, University of Granada, Granada, Spain.
⁷ Department of Radiology, University Hospitals of Leicester NHS Trust, Leicester, UK.
⁸ The Leicester Vascular Institute, University of Leicester, Leicester, UK.
⁹ Diabetes Research Centre, University of Leicester, Leicester, UK.
¹⁰ King's Diabetes Centre, King's College Hospital NHS Foundation Trust, London, UK.
¹¹ Podiatry Services, Central London Community Healthcare Trust, London, UK.
¹² Vascular Studies Unit, University Hospitals of Leicester NHS Trust, Leicester, UK.
¹³ Diabetes Care Centre, South Tees Hospitals NHS Foundation Trust, Middlesbrough, UK.
¹⁴ Patient co-investigator, London, UK.

Abstract

Introduction: Peripheral arterial disease (PAD) is a key risk factor for cardiovascular disease, foot ulceration and lower limb amputation in people with diabetes. Early diagnosis of PAD can enable optimisation of therapies to manage these risks. Its diagnosis is fundamental, though challenging in the context of diabetes. Although a variety of diagnostic bedside tests are available, there is no agreement as to which is the most accurate in routine clinical practice.The aim of this study is to determine the diagnostic performance of a variety of tests (audible waveform assessment, visual waveform assessment, ankle brachial pressure index (ABPI), exercise ABPI and toe brachial pressure index (TBPI)) for the diagnosis of PAD in people with diabetes as determined by a reference test (CT angiography (CTA) or magnetic resonance angiography (MRA)). In selected centres, we also aim to evaluate the performance of a new point-of-care duplex ultrasound scan (PAD-scan).

Methods and analysis: A prospective multicentre diagnostic accuracy study (ClinicalTrials.gov Identifier NCT05009602). We aim to recruit 730 people with diabetes from 18 centres across the UK, covering primary and secondary healthcare. Consenting participants will undergo the tests under investigation. Reference tests (CTA or MRA) will be performed within 6 weeks of the index tests. Imaging will be reported by blinded consultant radiologists at a core imaging lab, using a validated scoring system, which will also be used to categorise PAD severity. The presence of one or more arterial lesions of ≥50% stenosis, or tandem lesions with a combined value of ≥50%, will be used as the threshold for the diagnosis of PAD. The primary outcome measure of diagnostic performance will be test sensitivity.

Ethics and dissemination: The study has received approval from the National Research Ethics Service (NRES) (REC reference 21/PR/1221). Results will be disseminated through research presentations and papers.

Trial registration number: NCT05009602.

Keywords: diabetic foot; diabetic nephropathy & vascular disease; diagnostic radiology; vascular medicine; vascular surgery.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Ankle Brachial Index / adverse effects
Diabetes Mellitus*
Humans
Multicenter Studies as Topic
Peripheral Arterial Disease* / diagnosis
Prospective Studies
Ultrasonography, Doppler, Duplex

Associated data

ClinicalTrials.gov/NCT05009602