Can magnetocardiography detect patients with non-ST-segment elevation myocardial infarction?

Background and aim. Magnetocardiography (MCG) has been proposed as a noninvasive diagnostic tool to risk-stratify patients with myocardial infarction (MI) and ischemia. The purpose of this study is to find the MCG parameters that are sensitive enough to detect the non-ST-segment elevation myocardial infarction (NSTEMI) patients. Methods. MCG data were recorded and analyzed from 165 young controls (mean age=27.2±9.0 years), 57 age-matched controls (mean age=55.9±10.5 years) and 83 NSTEMI patients (mean age=59.7±11.1 years). The MCG recordings were obtained using a 64-channel MCG system in a magnetically shielded room. Statistical analyses were performed for 24 parameters derived from QRS-, R-, T-wave, and ST-T period. Binary boundaries to detect NSTEMI patients out of control subjects were found using the receiver operating characteristic (ROC) curve for each parameter. Results. Fifteen parameters showed a significant difference (P<0.05 and P<0.01) between NSTEMI and both of the control groups. For detection of NSTEMI, the angle of the maximum current and the filed map angle on T-wave peak showed the highest diagnostic performance from 75% to 92% including accuracy, sensitivity, specificity, positive predictive value, and negative predictive value (area under ROC curve=0.87-0.93). Conclusions. Our study showed that MCG has potential clinical application for detection of NSTEMI and should be further investigated.