Abstract 16540: Left Ventricular Longitudinal Strain Analysis Using Four-Dimensional Computed Tomography for the Detection of Apical Sparing in Cardiac Amyloidosis

Introduction: Cardiac computed tomography (CT) not only allows for coronary artery evaluation but also enables myocardial assessment, including left ventricular (LV) ejection fraction (LVEF) and extracellular volume fraction. Advanced software makes it possible to analyze LV longitudinal strain (LS) on CT (Figures A and B).

Hypothesis: LS analysis using four-dimensional cardiac CT is helpful for the differential diagnosis of LV hypertrophied myocardial diseases and detect cardiac amyloidosis (CA).

Methods: We analyzed 45 patients with LV hypertrophied myocardial diseases who underwent cardiac CT using 256-detector row or 320-detector row CT in our institutions since 2009. Fifteen patients of them were diagnosed with CA (69 ± 9 years, 12 males), the other 15 patients were diagnosed with hypertrophic cardiomyopathy (HCM) (63 ± 16 years, nine males), and the rest of the 15 patients were diagnosed with aortic valve stenosis (AS) (83 ± 8 years, seven males). We analyzed LV global LS (GLS) and segmental LS using specific software and four-dimensional CT data. We evaluated relative apical LS as the value dividing the average LS of apical segments by the sum of the average LS of basal segments and mid-ventricular segments (Figure C). If the value was ≥ 1, apical sparing was defined as present. We compared the LS data and the percentage of apical sparing among those three myocardial diseases.

Results: There was no significant difference in LVEF among the three groups (54 ± 12%, 58 ± 13%, and 50 ± 18%, respectively; P = 0.39). There was no significant difference in LV global LS among the three groups (-12.2 ± 3.2%, -11.2 ± 5.0%, and -11.0 ± 5.4%, respectively; P = 0.75). Apical sparing was observed in 6 cases (40%) of CA, which was significantly higher than in one case (7%) of HCM or AS (P = 0.02).

Conclusions: Advanced image analysis software has made LVLS analysis by cardiac CT possible. It is considered helpful in detecting apical sparing, specifically in CA.