A portable prototype magnetometer to differentiate ischemic and non-ischemic heart disease in patients with chest pain

PLoS One. 2018 Jan 19;13(1):e0191241. doi: 10.1371/journal.pone.0191241. eCollection 2018.


Background: Magnetocardiography (MCG) is a non-invasive technique used to measure and map cardiac magnetic fields. We describe the predictive performance of a portable prototype magnetometer designed for use in acute and routine clinical settings. We assessed the predictive ability of the measurements derived from the magnetometer for the ruling-out of healthy subjects and patients whose chest pain has a non-ischemic origin from those with ischemic heart disease (IHD).

Methods: MCG data were analyzed from a technical performance study, a pilot clinical study, and a young healthy reference group. Participants were grouped to enable differentiation of those with IHD versus non-IHD versus controls: Group A (70 IHD patients); Group B (69 controls); Group C (37 young healthy volunteers). Scans were recorded in an unshielded room. Between-group differences were explored using analysis of variance. The ability of 10 candidate MCG predictors to predict normal/abnormal cases was analyzed using logistic regression. Predictive performance was internally validated using repeated five-fold cross-validation.

Results: Three MCG predictors showed a significant difference between patients and age-matched controls (P<0.001); eight predictors showed a significant difference between patients and young healthy volunteers (P<0.001). Logistic regression comparing patients with controls yielded a specificity of 35.0%, sensitivity of 95.4%, and negative predictive value for the ruling-out of IHD of 97.8% (area under the curve 0.78).

Conclusion: This analysis represents a preliminary indication that the portable magnetometer can help rule-out healthy subjects and patients whose chest pain has a non-ischemic origin from those with IHD.

Publication types

  • Clinical Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Coronary Syndrome / diagnosis
  • Aged
  • Case-Control Studies
  • Chest Pain / diagnosis
  • Diagnosis, Differential
  • Female
  • Heart Diseases / diagnosis*
  • Humans
  • Logistic Models
  • Magnetocardiography / instrumentation*
  • Magnetocardiography / statistics & numerical data
  • Male
  • Middle Aged
  • Myocardial Ischemia / diagnosis*
  • Non-ST Elevated Myocardial Infarction / diagnosis
  • Pilot Projects
  • Predictive Value of Tests

Grant support

This research was supported by the Medical Technologies Innovation & Knowledge Centre (IKC): http://www.medical-technologies.leeds.ac.uk/, and was funded by the Engineering and Physical Sciences Research Council (EPSRC): https://www.epsrc.ac.uk/, grant numbers EP/G032483/1, EP/I019103/1, and EP/J017620/1, and was funded by Creavo Medical Technologies Ltd., UK (formerly Quantum Imaging Ltd., UK). This publication combined data from two studies conducted at the University of Leeds and Leeds General Infirmary. Professor Mark Kearney, British Heart Foundation Professor of Cardiovascular and Diabetes Research and Director of Leeds Institute of Cardiovascular and Metabolic Medicine, was the lead investigator for both studies. The first study was Leeds University funded and managed. Creavo Medical Technologies Ltd.: http://www.creavomedtech.com/ (formerly known as Quantum Imaging Ltd.) were sponsors of the second study, but the study was designed and run by Leeds General Infirmary and data management and monitoring function was performed by the North American Science Associates Ltd. (NAMSA), an external independent contract research organisation. The protocol for this study was clearly defined a priori and is available for review in a nationally recognised registry (protocol NCT02359773 available on ClinicalTrials.gov). Data were analysed for this publication by author(s), who are now employees of Creavo Medical Technologies Ltd., but who were not employed by the company at the time of the studies. The manuscript development was supported by Bollin Strategies – funded by Creavo Medical Technologies Ltd., but under editorial control of the authors. The guidance and input by Professor Kearney and his colleagues on the interpretation and publication of these data maintained independence of interpretation from the funder.