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

Objectives To 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). Design Prospective observational cohort study. Setting Single centre of the China National Clinical Research Centre for Cardiovascular Disease (NCCMRC). Participants Adults with borderline coronary lesions on ICA (n=141). Interventions Underwent OPM-MCG before ICA and fractional flow reserve measurement. Results Five parameters were included in the final diagnostic model: MAg max -TT, δDt sum -PN, δAg sum -C, δAr sum -N and δAr min -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. Conclusions A 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 number China Clinical Trial Registry (ChiCTR2300072382).