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Background: Exercise electrocardiography (ECG) is frequently used as a diagnostic measure in patients with suspected coronary artery disease (CAD). However, it has low sensitivity for the detection of CAD. Magnetocardiography (MCG) has been proposed as an alternative tool to accurately diagnose CAD., Objective: To date, a direct comparison of MCG to ECG has not been performed. This study sought to compare them for predicting the presence of significantly obstructive CAD., Methods: The patients with chest pain or other symptoms suggestive of CAD were enrolled in the analysis. All the patients underwent a clinical evaluation, exercise ECG, MCG test, and coronary angiography (CA). CAD was defined as stenosis ≥70% in at least one major coronary artery on quantitative analysis of CA., Results: We prospectively enrolled 202 consecutive patients who suggested CAD. The prevalence of CAD on CA was 39.1%. Sensitivity and accuracy for CAD diagnosis was higher for MCG compared with exercise ECG (sensitivities 68.4% and 40.5%, p <0.001, specificities 95.1% and 91.1%, p = 0.267, and accuracies 84.7% and 71.3%, p <0.001, respectively). There was no incremental diagnostic value of combined MCG and ECG to detect coronary artery disease (p = 0.357)., Conclusions: For the patients with intermediate to high risk of CAD, MCG exercise test provides better diagnostic accuracy for the detection of relevant obstruction of the epicardial coronaries when directly compared to exercise ECG.

Background: Magnetocardiography (MCG) is a non-invasive technique and to characterize the magnetic field, a pseudo-current conversion was used. The role of MCG in detecting left atrial (LA) dysfunction in patients with paroxysmal atrial fibrillation (PAF) is unknown., Objective: The aim of this study was to evaluate LA function using MCG in patients with PAF and healthy subjects, to identify possible indices to diagnose PAF., Methods: We enrolled a total of 70 subjects including 26 healthy volunteers (group 1) and 22 marathon runners (group 2) who did not exhibit any cardiac abnormalities, and 22 patients with PAF (group 3) which was documented by electrocardiography (ECG). Spatiotemporal activation graph (STAG) in base-apex and left-right direction was reconstructed. The maximum value of LA pseudo-current under rest and peak exercise were measured between the end of the P wave and beginning of the Q wave., Results: LA pseudo-current increase at peak exercise in PAF patients was significantly lower than in healthy volunteers and marathon runners (0.4±0.3 pT in group 3 vs. 0.8±0.3 pT in group 1 vs. 1.1±0.5 pT in group 2, p < 0.001). PAF patients had less pseudo-current increase in STAG at peak exercise than healthy volunteers and marathon runners (46% of 26 PAF patients, 81% of 22 healthy subjects vs. 81% of 22 marathon runners, p = 0.002). Sensitivity, specificity, and the area under the receiver-operator characteristics curve of LA pseudo-current increase at peak exercise for differentiating PAF patients from healthy subjects were 77%, 92%, and 0.896., Conclusions: MCG can provide important non-invasive information for detecting LA dysfunction in PAF patients. Therefore, MCG may help in differentiating PAF patients from healthy subjects.

Background: Magnetocardiography (MCG) has been proposed as a non-invasive and functional technique with high accuracy for diagnosis of myocardial ischemia., Objective: This study sought to develop a novel scoring system of MCG for predicting the presence of significant obstructive coronary artery disease (CAD)., Methods: In a training set of 108 subjects, predictors of ≥70% stenosis in at least one major coronary vessel were prospectively identified from MCG variables. The final model was then retrospectively validated in a separate set of 45 subjects., Results: In the multivariable logistic regression, among those in the training set, elevated scores were predictive of ≥70% stenosis in all subjects (OR: 40.85; 95% CI: 6.28-265.90; p < 0.001). In the validation set, the score had an area under the receiver-operating characteristic curve of 0.91 (p < 0.001) for ≥70% stenosis. At an optimal cutoff, the score had 89% sensitivity, 77% specificity, 74% positive predictive value (PPV), 91% negative predictive value (NPV), and 82% accuracy for ≥70% stenosis. Partitioning the score into three levels of predicted risk, 91% of subjects could be identified or excluding CAD (81% PPV and 84% NPV)., Conclusion: We described an MCG score with high accuracy for predicting the presence of anatomically significant CAD.

Background: Although magnetocardiography (MCG) has been proposed as a non-invasive technique with high accuracy for functional diagnosis of myocardial injury, the validation of MCG against fractional flow reserve FFR in diagnosing coronary artery disease (CAD) has not yet been established. The goal of the study was to determine the diagnostic accuracy of MCG versus invasively determined FFR in patients with suspected or known CAD., Methods: Forty seven patients with suspected CAD (35 men; mean age 69 years) who underwent coronary angiography and FFR measurement were enrolled. FFR ≤ 0.8 was considered to indicate significant myocardial ischemia. The change of ST-segment fluctuation score from rest to stress was calculated from the MCG. In addition, two blinded cardiologists assessed MCG images that were visualized by post-processing method, bull's-eye mapping., Results: The best cut-off value of the percent change of ST-segment fluctuation score was -39.0% with sensitivity of 86.7% and specificity of 73.9%. Sensitivity, specificity, diagnostic accuracy, and the area under the receiver-operator characteristics curve of bull's-eye mapping for the detection of significant CAD were 90.5%, 92.3%, 91.5%, and 0.914 on a patient basis and 90.0%, 93.8%, 92.3%, and 0.919 by coronary territory, respectively., Conclusions: MCG accurately detects functionally significant CAD as defined by using FFR, provides an assessment of ischemic status in agreement with the change of ST-segment fluctuation score, and accurately localizes the ischemic territory in bull's eye mapping. Therefore, MCG may provide an incremental value for prediction of myocardial ischemia non-invasively and safely in clinical practice with fast examination time.