Alterations in multi-layer strain in AL amyloidosis

Background Cardiac involvement in AL amyloidosis portends a poor prognosis. 2D-speckle tracking echocardiography (2D-STE) strain can identify subclinical cardiac involvement. This study performed multilayer and multiplanar 2D-STE myocardial strain analysis. Methods We compared 75 AL amyloidosis patients to 49 hypertensive patients and 49 healthy controls. Longitudinal strain was obtained from epicardial, mid-myocardial and endocardial layers; segmental strain was measured from mid-myocardial basal, mid and apical segments. Results Global longitudinal strain was reduced in epicardial (-14.3 +/- -4.0% vs. -17.4 +/- 2.2% vs. -17.5 +/- -2.0%, p < .001), mid-myocardial (-16.3 +/- -4.5% vs. -19.7 +/- 2.5% vs. -19.7 +/- -2.2%, p < .001) and endocardial layers (-18.7 +/- -4.9% vs. -22.2 +/- 3.0% vs. -22.3 +/- -2.6%, p < .001) in amyloid patients compared to hypertensive and healthy controls. Segmental strain confirmed significant reduction in basal (-11.2 +/- -3.9% vs. -17.6 +/- 2.7% vs. -20.9 +/- -3.4%, p < .001) and mid (-14.8 +/- -4.3% vs. -19.2 +/- 2.5% vs. -19.6 +/- -2.2%, p < .001) LV segments in the AL amyloid group. Receiver operating curve analysis demonstrated that an optimal cut-off of -16% for basal segmental strain better differentiated AL amyloid from hypertensive group (sensitivity 96%, specificity 70%, AUC 0.93), compared to relative apical sparing (AUC of 0.85). Conclusion Strain demonstrated myocardial involvement in all layers in AL amyloidosis, with reduced basal segmental longitudinal strain a likely marker of early disease.