Table 2.
Studies of MCG in patients with ACS.
| Study | Diagnostic criteria of MCG | Indication/Test population (n)/Control (n) | Testing conditions | Specificity/Sensitivity (ROC AUC) | PPV/NPV (ROC AUC) | Reference |
|---|---|---|---|---|---|---|
| Park et al. (8) | ≥1 of the following MCG parameters prespecified as defining ischemia: direction of the main vector from plus to minus pole between −20° and +110°; change in the angle of the main vector ≥45° in a time interval of 30 msec between Tmax/3 and Tmax; change in the distance separating the plus and minus poles ≥20 mm in a time interval of 30 msec between Tmax/3 and Tmax; change in the ratio of the pole strengths ≥0.3 in a time interval of 30 msec between Tmax/3 and Tmax | NSTEMI/Patients presenting with chest pain for whom the criteria for Group 2 according to the ESC guidelines for ACS were applicable, who had coronary angiogram performed within 36 h after admission, were NSTEMI, were hemodynamically stable and had LVEF ≥40%, and who had an abnormal MCG at admission meeting the criteria for ischemia (249)/Patients presenting with chest pain for whom the criteria for Group 2 according to the ESC guidelines for ACS were applicable, who had coronary angiogram performed within 36 h after admission, were NSTEMI, were hemodynamically stable and had LVEF ≥40%, and who had a normal MCG at admission (106) |
Unshielded 9-channel Rest |
– | – | – |
| Tolstrup et al. (14) | Effective magnetic dipole vector analysis, based on an automated analysis of pre-peak (3 parameters) and post-peak (4 parameters) ventricular repolarization | ACS/Patients with acute chest pain with a diagnosis of IHD by gold standard criteria (55)/Patients with acute chest pain without IHD (70) | Unshielded 9-channel Rest |
74%/76% | 70%/80% | Stress testing Troponin Angiography |
| Lim et al. (15) | Field map angle of T wave peak and angle of maximum current of T wave peak identified as best diagnostic discriminators vs. age-matched and young controls, respectively | NSTEMI/Patients with NSTEMI (83)/Age-matched subjects presenting with chest pain, but no clinical evidence to indicate MI (57) Young subjects (165) | Shielded 64-channel |
75%/86% (0.87) (field map angle) 92%/76% (0.93) (angle of maximum current) |
84%/78% 84%/93% |
Angiography Troponin T |
| Ghasemi-Roudsari et al. (23) | Logistic regression model based on 10 parameters measuring depolarization (QR_MMR, QR_interval, QR_angle, RS_MMR, RS_interval, RS_angle, QR_peak, QR_pd, RS_peak, and RS_pd) with a cut-off of 0.2 determined and internally cross-validated as best discriminant for IHD | NSTEMI/Patients with suspected IHD (55) and patients with NSTEMI requiring admission for chest pain (15)/Healthy age-matched subjects (51) and non-IHD patients with chest pain (18) | Unshielded 15-channel Rest |
35%/95% (rule-out) |
NR/98% (0.78) |
– |
| Park et al. (42) | ≥1 of the following MCG parameters prespecified as defining ischemia: direction of the main vector from plus to minus pole between −20° and +110°; change in the angle of the main vector ≥45° in a time interval of 30 msec between Tmax/3 and Tmax; change in the distance separating the plus and minus poles ≥20 mm in a time interval of 30 msec between Tmax/3 and Tmax; change in the ratio of the pole strengths ≥0.3 in a time interval of 30 msec between Tmax/3 and Tmax | NSTEMI/Patients presenting with acute chest pain diagnosed as CAD by coronary angiography and without persistent ST segment elevation on EKG (143)/Subjects presenting with chest pain with normal EKG, troponins, or coronary angiography (42) |
Unshielded 9-channel Rest |
93%/95% (visual) 82.5%/86.4% (automated) |
98%/85% (visual) 94.5%/63.5% (automated) |
EKG TTE Troponin |
| Lant et al. (43) | Abnormalities of the mean time isointegral MFM | Acute MI/ Patients with MI with a history of prolonged cardiac pain and diagnostic enzyme level elevations who were either previously diagnosed using standard 12-lead EKG, as having anterior (4) or inferior (7) Q wave MI or non-Q wave MI (11)/Normal controls (9) | Shielded NR Rest |
– | – | Body surface potential mapping |
| Kwon et al. (44) | Algorithm of weighted maximum of posteriori as a function of five prespecified MCG variables, T_FMA, T_FMA—R_FMA, TT_CAMx, TT_CAMx—R_FMA, and TT_CMD |
ACS and non-ACS CAD/Patients admitted to hospital with suspected ACS diagnosed as CAD with angiographically proven ≥50% stenosis of a vessel (237) Subgroup of patients with chest pain and angiographically proven CAD, but with no abnormality of EKG or troponin (102)/Patients with angiographically proven non-obstructive CAD (127) Healthy subjects (89) |
Shielded 64-channel Rest |
85%/84% | 91%/74% | – |
| Park et al. (45) | ≥1 of the following MCG parameters prespecified as defining ischemia: direction of the main vector from plus to minus pole between −20° and +110°; change in the angle of the main vector ≥45° in a time interval of 30 msec between Tmax/3 and Tmax; change in the distance separating the plus and minus poles ≥20 mm in a time interval of 30 msec between Tmax/3 and Tmax; change in the ratio of the pole strengths ≥0.3 in a time interval of 30 msec between Tmax/3 and Tmax | Unstable angina/Patients with symptoms of unstable angina, who were diagnosed with CAD angiographically (53)/Patients with normal troponin levels in whom CAD could be ruled out (33) | Unshielded 9-channel Rest |
94%/94% | 91%/96% | EKG Troponin |
| Lin et al. (46) | Analysis based on three MCG parameters (pre-peak repolarization [angle, trajectory, and angular deviation], post-peak repolarization [angle, trajectory, and angular deviation] and the pre-post angle change) and map morphology | ACS/Patients presenting with chest pain, and diagnosed CAD with angiographically proven ≥70% stenosis (190)/Patients with angiographically proven non-obstructive CAD (97) | Shielded 9-channel Rest |
73%/89% | – | EKG |
| Leithäuser et al. (47) | ≥1 of the following MCG parameters prespecified as defining ischemia: direction of the main vector from plus to minus pole between −20° and +110°; change in the angle of the main vector ≥45° in a time interval of 30 msec between Tmax/3 and Tmax; change in the distance separating the plus and minus poles ≥20 mm in a time interval of 30 msec between Tmax/3 and Tmax; change in the ratio of the pole strengths ≥0.3 in a time interval of 30 msec between Tmax/3 and Tmax | NSTEMI with BBB/Patients presenting with ACS without ST-segment elevation who have BBB-EKG (QRS duration >120 msec) (62; four with prior MI)/NR | Unshielded NR Rest |
97%/88% | 99%/71% | TTE Troponin |
| Park et al. (48) | NR | NSTEMI/Patients with acute chest pain with NSTEMI and with angiographically proven CAD (264; 62 with BBB)/- | NR Rest |
94%/87% | 98%/71% | TTE Troponin |
α = average angle of direction for the abnormal current vector during ventricle repolarization period.
MCG, magnetocardiography; ACS, acute coronary syndrome; ROC, receiver operating curve; AUC, area under the curve; PPV, positive predictive value; NPV, negative predictive value; Tmax, peak intensity of the T wave; Tmax/3, one-third of peak intensity; NSTEMI, non-ST segment elevation myocardial infarction; ESC, European society of cardiology; LVEF, left ventricular ejection fraction; IHD, ischemic heart disease; MI, myocardial infarction; CAD, coronary artery disease; EKG, electrocardiography; TTE, transthoracic echocardiography; MFM, magnetic field map; NR, not reported; BBB, bundle branch block.