087 Left ventricle shape and trabeculations in idiopathic dilated cardiomyopathy assessed by cardiac magnetic resonance imaging

Abstract

Idiopathic dilated cardiomyopathies (IDC) frequently develop left ventricle (LV) hypertrabeculation which bring to doubt about the diagnostic of LV non compaction (LVNC). The high spatial resolution of cardiac magnetic resonance imaging (CMR) allows distinguishing myocardial trabeculations explaining the exponential rise in the number of reports describing LVNC. To study the correlation between the LV shape and myocardial trabeculations regarding the BNP level in a population of IDC. Between November 2007 and November 2009, 48 IDC were prospectively assessed by CMR. Patients with echocardiographic LV ejection fraction (LVEF) > 45%, severe valvulopathy or usual criteria of LVNC were excluded. Patients with significant coronary artery disease (coronary stenosis > 50%) at the angiogram or subendocardium gadolinium delayed enhancement at the CMR were considered as ischemic cardiomyopathy and were excluded. LV end-diastolic volume (EDV) and end-systolic volume were measured by summing cine-CMR LV short axis slice. Sphericity index (SI) was defined as the ratio of LV end-diastolic diameter (EDD) on LV length measured respectively in midventricular short axis and midventricular 4 chambers cine-CMR views. LV trabeculation index (LVTI) was defined as the ratio of trabeculated on compacted layers thickness in a 16-segment model excluding apex. BNP was measured for each patient. Mean age was 52 ± 14 years with 29 (60%) men. Mean LVEF was 25 ± 10% with a mean indexed EDD of 37 ± 5 mm/m 2 and EDV of 135 ± 45 ml/m 2 . LVTI was not correlate with indexed EDV (r = 0.14; p = 0.34) and LVEF (r = 0.02, p = 0.9) but it was linearly correlated with SI (r = 0.26; p = 0.046) and had a tendency to have a negative correlation with BNP level (r = −0.26; p = 0.07). These results suggest that LV myocardial trabeculation thickness increases linearly with the LV shape sphericity and has a tendency to decrease with the rise of LV pressure regime assessed by BNP level.