1047Cardiac MR left ventricular myocardial strain derived from deformation fields using balanced steady state free precession cine imaging in patients with cardiac amyloidosis

Abstract

Background: Prior work with speckle tracking echocardiography (STE) has demonstrated that changes in myocardial strain can precede declines in left ventricular (LV) systolic function in infiltrative heart disease. The purpose of this study is to evaluate CMR-derived strain parameters using bright blood cine imaging in a cohort of patients with cardiac amyloidosis, comparing CMR LV strain parameters with those from STE. Methods: Retrospective analysis of 16 consecutive patients (12 males, avg age 62 years) with systemic amyloidosis, 7 (44%) of which with a confirmatory cardiac biopsy. All subjects had CMR findings diagnostic of cardiac amyloidosis. All patients were imaged on a 1.5T scanner (Magnetom Avanto or Aera, Siemens Healthcare, Erlangen, Germany). Balanced steady state free precession (bSSFP) cine short axis and four-chamber images (TR/TE 42/1.2, FA 79 degrees, BW 930, 1.7 x 1.7 x 6 mm3, parallel imaging factor 2) were analyzed using prototype software (Siemens Corp., Corporate Technology, Princeton, New Jersey). As with speckle tracking, the spatio-temporal deformation of LV muscle on cine images was used to derive deformation fields and quantify radial, circumferential, and longitudinal strain indices. Peak CMR and STE values were compared by correlation analysis. Results: Strain analyses were successful on all CMR datasets. Peak CMR systolic strain values, by heart segment and slice, for each direction are shown in Figure 1. CMR peak circumferential, radial, and longitudinal strains demonstrated modest to good correlation with STE (r = 0.57, 0.36, and 0.64) respectively, although the technique significantly underestimated the value of peak strain compared to STE (-7.8% vs. -21.7%, 15.6% vs 34.7%, and -4.3% vs -12.4%, respectively). Mean (standard deviation) peak radial (A), circumferential (B), and longitudinal (C) strain (%) by segment. Mean (standard deviation) peak radial (A), circumferential (B), and longitudinal (C) strain (%) by segment.