Abstract 195: Clinical Significance of Papillary Muscle Late Enhancement Detected via Cardiac Magnetic Resonance Imaging in Patients With Old Myocardial Infarction
BACKGROUND: Contrast-enhanced cardiac magnetic resonance imaging (MRI) can depict PM degeneration as PM-LE, but the clinical significance of PM-LE has been little understood.
OBJECTIVES: To investigate the frequency of late enhancement (LE) of papillary muscle (PM) and its association with left ventricular (LV) geometry and mitral regurgitation (MR) in patients with old myocardial infarction (OMI).
METHODS: Myocardial LE and PM-LE were detected with late gadolinium enhancement imaging in 60 patients with OMI caused by a single culprit coronary artery lesion. LV morphology, LV function, mitral valve geometry, and severity of mitral regurgitation (MR) were also evaluated by cine imaging.
RESULTS: PM-LE was detected in 32 of 60 (53.3%) OMI patients. Unilateral PM-LE was detected in 22 patients (anterolateral PM-LE in 8 and posteromedial PM-LE in 14) and bilateral PM-LE in 10 patients. Although each patient’s OMI was associated with a single culprit coronary artery, the location of PM-LE corresponded to the vascular territory of the culprit coronary artery in only 19 OMI patients (59.3%). Patients with bilateral PM-LE demonstrated larger LVEDV and LVEDS, smaller EF, more severe functional MR, larger coaptation depth and larger mitral valve annulus diameter than patients with unilateral or no PM-LE. In patients with right coronary artery-related OMI, those with unilateral posteromedial PM-LE showed less severe functional MR than those without PM-LE, while in patients with left coronary artery-related OMI, unilateral anterolateral PM-LE did not affect MR severity.
CONCLUSIONS: More than half of patients with OMI showed unilateral or bilateral PM-LE, and bilateral PM-LE was closely related to more severe LV remodeling and functional MR.