Development and validation of a clinical diagnostic model for myocardial ischaemia in borderline coronary lesions based on optical pumped magnetometer magnetocardiography: a prospective observational cohort study

ObjectivesTo develop and validate a clinical diagnostic model based on optical pumped magnetometer magnetocardiography (OPM-MCG) for the detection of myocardial ischaemia in patients with borderline coronary lesions prior to invasive coronary angiography (ICA).DesignProspective observational cohort study.SettingSingle centre of the China National Clinical Research Centre for Cardiovascular Disease (NCCMRC).ParticipantsAdults with borderline coronary lesions on ICA (n=141).InterventionsUnderwent OPM-MCG before ICA and fractional flow reserve measurement.ResultsFive parameters were included in the final diagnostic model: MAgmax-TT, δDtsum-PN, δAgsum-C, δArsum-N and δArmin-N. 1000 bootstrap replications showed that the area under the receiver operating characteristic curve and 95% CI of the diagnostic model were 0.864 (0.803–0.925), with a sensitivity of 79.4%, specificity of 80.8%, positive predictive value of 79.4% and negative predictive value of 80.8%. Decision curve analysis showed a net benefit from the predictive model when the threshold probability of an ischaemic patient was >12%, suggesting the potential utility of the model in the real world.ConclusionsA nomogram based on five OPM-MCG parameters was developed to assess myocardial ischaemia in patients with borderline coronary lesions and has the potential to reduce the need for unnecessary ICA.Trial registration numberChina Clinical Trial Registry (ChiCTR2300072382).