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Original research
Morpho-mechanistic screening criteria for the echocardiographic detection of rheumatic heart disease
  1. Luke David Hunter1,
  2. Anton Frans Doubell1,
  3. Alfonso Jan Kemp Pecoraro1,
  4. Mark Monaghan2,
  5. Guy Lloyd3,4,5,
  6. Carl Lombard6,7,
  7. Philipus George Herbst1
  1. 1 Division of Cardiology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa
  2. 2 Department of Cardiology, King’s College Hospital, London, UK
  3. 3 Echocardiography Laboratory, Barts Heart Centre, St Bartholomew’s Hospital, London, UK
  4. 4 Institute of Cardiovascular Sciences, University College London, London, UK
  5. 5 William Harvey Research Institute Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
  6. 6 Division of Epidemiology and Biostatistics, Department of Global Health Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
  7. 7 Biostatistics Unit, South African Medical Research Council, Cape Town, South Africa
  1. Correspondence to Dr Luke David Hunter, Division of Cardiology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa; lukehunter1987{at}icloud.com

Abstract

Introduction Screening echocardiography, guided by the current World Heart Federation (WHF) criteria, has important limitations that impede the establishment of large-scale rheumatic heart disease (RHD) control programmes in endemic regions. The criteria misclassify a significant number of normal cases as borderline RHD. Prior attempts to simplify them are limited by incorporation bias due to the lack of an externally validated, accurate diagnostic test for RHD. We set out to assess novel screening criteria designed to avoid incorporation bias and to compare this against the performance of the current WHF criteria.

Methods The performance of the WHF and the morpho-mechanistic (MM) RHD screening criteria (a novel set of screening criteria that evaluate leaflet morphology, motion and mechanism of regurgitation) as well as a simplified RHD MM ‘rule-out’ test (based on identifying a predefined sign of anterior mitral valve leaflet restriction for the mitral valve and any aortic regurgitation for the aortic valve) were assessed in two contrasting cohorts: first, a low-risk RHD cohort consisting of children with a very low-risk RHD profile. and second, a composite reference standard (CRS) RHD-positive cohort that was created using a composite of two criteria to ensure a cohort with the highest possible likelihood of RHD. Subjects included in this group required (1) proven, prior acute rheumatic fever and (2) current evidence of predefined valvular regurgitation on echocardiography.

Results In the low-risk RHD cohort (n=364), the screening specificities for detecting RHD of the MM and WHF criteria were 99.7% and 95.9%, respectively (p=0.0002). The MM rule-out test excluded 359/364 cases (98.6%). In the CRS RHD-positive cohort (n=65), the screening sensitivities for the detection of definite RHD by MM and WHF criteria were 92.4% and 89.2%, respectively (p=0.2231). The MM RHD rule-out test did not exclude any cases from the CRS RHD-positive cohort.

Conclusion Our proposed MM approach showed an equal sensitivity to the WHF criteria but with significantly improved specificity. The MM RHD rule-out test excluded RHD-negative cases while identifying all cases within the CRS RHD-positive cohort. This holds promise for the development of a two-step RHD screening algorithm to enable task shifting in RHD endemic regions.

  • heart valve diseases
  • electrocardiography

Data availability statement

Data are available upon reasonable request.

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Data availability statement

Data are available upon reasonable request.

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Footnotes

  • Twitter @LD_Hunter, @AlfonsoPecorar1

  • Contributors All authors contributed to the conception or design of the work. LDH captured all data. LDH, CL and PGH analysed and interpreted the data. LDH, PGH and AFD drafted the article. All authors were involved in the critical revision and final approval of the version to be published. LDH accepts full responsibility for the finished work and/or the conduct of the study, had access to the data, and controlled the decision to publish.

  • Funding LDH recieved funding from the South African Heart Association through the provision of a research grant.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, conduct, reporting or dissemination plans of this research.

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

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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