Yiseul Kim, Presenter: Nothing to Disclose

Sung Mok Kim MD, Abstract Co-Author: Nothing to Disclose

Seong-Yoon Ryu MD, Abstract Co-Author: Nothing to Disclose

Yeon Hyeon Choe MD, PhD, Abstract Co-Author: Nothing to Disclose

The aims of the study was to assess the potential role of extracellular volume fraction (ECV) and noncontrast T1 mapping for detection of cardiac involvement in patients with primary amyloid light-chain (AL) amyloidosis.

This study included 26 AL amyloidosis patients (56 ± 9 years, 14 males) with cardiac involvement based on histologic analysis, who underwent 1.5-T CMR including precontrast and postcontrast T1 mapping (shortened modified look-locker inversion recovery [ShMOLLI] sequence) and late gadolinium enhancement (LGE) imaging from October 2011 to November 2013. ECV and pre T1 values were analyzed with all parameters of LV function measured in CMR and two-dimensional transthoracic echocardiography. Additionally, ECV and pre T1 values were further studied by categorizing the patients by well-known prognostic parameters including NT-pro BNP (threshold = 1800pg/mL) and serum free light chain difference (threshold = 18mg/dL): group I, no elevation of two parameters; group II, elevation of one of those two parameters; and group III, elevation of both parameters.

As ECV increased, LV ejection fraction decreased (CMR, r = -0.625, P < 0.001; echocardiogram, r = -0.543, P = 0.004) and normalized LV mass index increased (CMR, r = 0.494, P = 0.010). In addition, ECV was negatively correlated with diastolic dysfunction parameters such as e’ (r = -0.474, P = 0.014), and deceleration time (r = -0.625, P < 0.001). However, pre T1 mapping was only correlated with normalized LV mass index (r = 0.446, P = 0.022). In comparison of categorized patient’s groups, pre T1 mapping appeared higher in the group with worse prognostic parameters [1023.2 ms (1059.4-1132.6), 1141.9 ms (1109.4-1166.7), and 1169.2 ms (1133.1-1201.1) in group I, II, and III, P=0.047]. Meanwhile, ECV appeared more prominently higher in the group with worse prognostic parameters [0.44 (0.40-0.50), 0.56 (0.52-0.58), and 0.59 (0.56-0.67), P=0.004].

ECV correlates well with the prognostic markers of AL amyloidosis as well as with left ventricular systolic and diastolic function. Further studies are needed to assess the prognostic significance of ECV elevation.

ECV is potentially more sensitive for detecting early disease than LGE imaging and elevated ECV may represent a direct marker of cardiac amyloid load.

Kim, Y, Kim, S, Ryu, S, Choe, Y, Extracellular Volume Fraction and Noncontrast T1 Mapping using 1.5-T Cardiac MRI in AL Cardiac Amyloidosis.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045757.html