Resting Magnetocardiography Accurately Detects Myocardial Ischemia in Chest Pain Patients with normal or non-specific ECG Findings

Background: Magnetocardiography (MCG) is a new imaging technology developed for the rapid, noninvasive detection of ventricular repolarization (VR) abnormalities. We present the first multicenter data evaluating VR by MCG, in subjects with acute or chronic chest pain syndromes. Methods: We studied 153 chest pain patients, 84 presenting to the emergency room, 29 admitted to rule out mocardial infarction, and 40 with stable class 1-2 angina. All were chest pain free at the time of testing. Most (73.2%) had a normal or non-specific 12-lead ECG and normal troponin (91.1%). A resting MCG (CardioMag Imaging, Schenectady, N.Y.) 9-channel (n=113, U.S.) and 36-channel (n=40, Italy) scan was performed, without magnetic shielding. Following the scan a < 5 minute quantitative automated software data analysis was performed. VR (T-wave) was analyzed according to specific preset parameters, and 3 quantitative scores were automatically calculated for each subject resulting in a MCG classification of normal or abnormal. Patients were classified as ischemic based on clinical criteria, which typically were based on results of coronary angiography, stress testing, or troponins. Results: The mean age of the subjects were 59.5 ± 12.9 years (65.2 years in ischemic group versus 54.7 years in nonischemic group, p<0.001). There were 90 men and 63 women. Sixty-three patients (41.8%) had history of coronary artery disease. Almost half the group was determined ischemic by clinical criteria (45.8%). Angiography was performed in 72 patients (positive in 72.2%) and 84 had nuclear stress testing (positive in 64.3%). Troponins were tested in 111 (72.5%). The three quantitative MCG scores were all statistically significant in discriminating between the ischemic and non-ischemic group (p<0.001, 0.0004, 0.0035, respectively). Patients with ischemia as well as patients with an abnormal MCG scan were older and had higher prevalence of hypertension, diabetes, hypercholesterolemia, previous myocardial infarction, and history of coronary artery bypass graft surgery. Conclusion: Magnetocardiographic imaging is rapid, safe, and accurate for the detection of myocardial ischemia, even in subjects with a normal or non-specific 12-lead ECG and normal troponin.