Concordant and Discordant Cardiac Magnetic Resonance Imaging Delayed Hyperenhancement Patterns in Patients with Ischemic and Non-Ischemic Cardiomyopathy.

BACKGROUND AND OBJECTIVES The diagnosis of ischemic (ICM) and non-ischemic cardiomyopathy (NICM) is conventionally determined by the presence or absence of coronary artery disease (CAD) in the setting of a reduced left systolic function. However the presence of CAD may not always indicate that the actual left ventricular (LV) dysfunction mechanism is ischemia, as other non-ischemic etiologies can be responsible. We investigated patterns of myocardial fibrosis using delayed hyperenhancement (DHE) on cardiac magnetic resonance (CMR) in ICM and NICM. SUBJECTS AND METHODS Patients with systolic heart failure who underwent a CMR were prospectively analyzed. The heart failure diagnosis was based on the modified Framingham criteria and LVEF <35%. LV dysfunction was classified as ICM or NICM based on coronary anatomy. RESULTS A total of 101 subjects were analyzed; 34 were classified as ICM and 67 as NICM. The DHE pattern was concordant with the conventional diagnosis in 27 (79.4%) of the patients with ICM and 62 (92.5%) of the patients with NCIM. A discordant NICM DHE pattern was present in 8.8% of patients with ICM, and an ICM pattern was detected 6.0% of the patients with NICM. Furthermore, 11.8% of the patients with ICM and 1.5% of those with NICM demonstrated a mixed pattern. CONCLUSION A subset of patients conventionally diagnosed with ICM or NICM based on coronary anatomy demonstrated a discordant or mixed DHE pattern. CMR-DHE imaging can be helpful to determine the etiology of heart failure in patients with persistent LV systolic dysfunction.