Abstract 531: Correlation of Left Ventricular Strain With Late Gadolinium Enhancement on Cardiac MRI in the Assessment of Cardiac Amyloid
Background: Cardiac involvement in amyloidosis is associated with poor prognosis. Left ventricular strain (LVS) analysis, using 2D speckle-tracking echocardiography, and late gadolinium-enhancement (LGE) on cardiac MRI have each been found to diagnose and predict heart failure in cardiac amyloid. However, correlation between the degree of LVS and LGE on cardiac MRI is unknown.
Hypothesis: We hypothesize that LVS echocardiography will provide information in understanding the systolic changes in patients with cardiac amyloid and that LVS will correlate with the percentage of LV LGE on cardiac MRI in patients with cardiac amyloid.
Methods: We compared LVS in 31 patients with cardiac amyloid to 16 age- and sex-matched, healthy patients. Longitudinal and circumferential strain, apical rotation and LV twist were measured using 2D speckle tracking echocardiography (Velocity Vector Imaging), The percentage of LV LGE on cardiac MRI was correlated with LVS and twist in 11 cardiac amyloid patients.
Results: In cardiac amyloid versus control patients, the mean age was 61+7 years versus 58+8 years (p=0.23) and LVEF was 56+14% versus 64+5% (p=0.03). We found a significant difference in average longitudinal strain between the 2 groups (−12.2+5.41 cardiac amyloid, −19.3+1.49 control, p=0.0002). There was no significance difference in averaged circumferential strain or 2D Doppler diastolic indices. However, early diastolic longitudinal strain rate was significantly lower in the cardiac amyloid group (0.78+0.27 vs 1.01+0.17 in controls, p=0.018). LGE on cardiac MRI correlated strongly with average longitudinal strain (r=0.60, p<0.001) and 4-chamber longitudinal strain (r=0.69, p<0.0001). It also correlated with twist (r = −0.38, p = 0.02) and peak apical rotation (r = −0.55, p = 0.002). There was no correlation with LGE and LV wall thickness.
Conclusions: Cardiac amyloid patients have a reduction in longitudinal function, reflecting subendocardial dysfunction. Longitudinal strain is strongly correlated to the degree of LGE which is an established predictor of cardiac amyloid outcomes. Future studies examining the degree of LVS in predicting outcomes may provide a complementary approach to MRI in diagnosis and management of cardiac amyloid.