Quantitative characterization of myocardial infarction by cardiovascular magnetic resonance predicts future cardiovascular events in patients with ischemic cardiomyopathy

BACKGROUND: Cardiovascular magnetic resonance (CMR) can provide quantitative data of the myocardial tissue utilizing high spatial and temporal resolution along with exquisite tissue contrast. Previous studies have correlated myocardial scar tissue with the occurrence of ventricular arrhythmia. This study was conducted to evaluate whether characterization of myocardial infarction by CMR can predict cardiovascular events in patients with ischemic cardiomyopathy (ICM). RESULTS: We consecutively studied 86 patients with ICM (LVEF < 50%, mean LVEF: 26 ± 12%) with CMR before revascularization or medication therapy ± implantable cardiac defibrillator, determined the amount of myocardial scar, and followed for development of cardiovascular events. Thirty-three patients (38%) had cardiovascular events (mean follow-up: 20 ± 16 months). Patients who developed cardiovascular events had larger scar volume and scar percentage of the myocardium than those who did not develop cardiovascular events (16.8 ± 12.4 cm3 vs. 11.7 ± 12.6 cm3, p = 0.023 and 10.2 ± 6.9% vs. 7.2 ± 6.7%, p = 0.037, respectively). There were no significant differences in LVEDV, LVESV and LVEF between the patients with and without cardiovascular events (231 ± 76 ml vs. 230 ± 88 ml; 180 ± 73 ml vs. 175 ± 90 ml; and 25 ± 10% vs. 27 ± 13%, respectively). CONCLUSION: Quantification of the scar volume and scar percentage by CMR is superior to LVEDV, LVESV, and LVEF in prognosticating the future likelihood of the development of cardiovascular events in patients with ICM.