Repolarization heterogeneity of magnetocardiography predicts long-term prognosis in patients with acute myocardial infarction

Abstract

Background: Magnetocardiography (MCG) has been proposed as a noninvasive, diagnostic tool for risk-stratifying patients with acute myocardial infarction (AMI). This study evaluated whether MCG predicts long-term prognosis in AMI.Methods and Results: In 124 AMI patients (95 males, mean age 60±11 years), including 39 with ST-elevation myocardial infarction (MI), a 64-channel MCG was performed within 2 days after AMI. During a mean follow-up period of 68±37 months, major adverse cardiac events (MACE) were evaluated. MACE occurred in 31 (25%) patients, including 20 revascularizations, 8 deaths, and 3 re-infarctions. Non-dipole patterns were observed at 40 ms before the end of the T wave (Te40) in 89 (72%) patients. Non-dipole patterns were observed at T-peak in 77% (24/31) and 54% (50/93) of patients with and without MACE, respectively (P=0.02). Maximum current, field map angles, and distance dynamics were not different between groups. In the multivariate analysis, patients with non-dipole patterns at T-peak had increased age- and sex-adjusted hazard ratios for MACE (relative risk 2.95, 95% confidence interval 1.18-7.35) and lower cumulative MACE-free survival than those with dipole patterns (P=0.02).Conclusions: Non-dipole patterns at T-peak were more frequently observed in patients with MACE and were related to poor long-term prognosis. Thus, repolarization heterogeneity measured by MCG may be a useful predictor for AMI prognosis.