Myocardial Work Does Not Have Additional Diagnostic Value in the Assessment of ATTR Cardiac Amyloidosis

BACKGROUND: Reduced LV longitudinal strain (GLS) and increased relative apical sparing (RELAPS) and increased wall thickness have been proposed as features for transthyretin cardiac amyloidosis (ATTR-CA). Myocardial work (MW) has recently been shown as useful afterload independent disease marker, hence we aimed to investigate its use in differentiating ATTR-CA from heart failure with increased septal thickness but no cardiac amyloidosis (CA) (HFnCA). METHODS: This study included patients with HF and increased septal thickness ≥ 14 mm. We included 59 patients with hereditary (ATTRv) and 27 wild type transthyretin amyloidosis (ATTRwt) described as ATTR-CA based on DPD scintigraphy. We also enrolled 30 non-amyloidosis heart failure patients with negative DPD scintigraphy, as a control group. Myocardial work (MW) was used to assess the index (GWI), constructive (GCW) and wasted (GWW) work. Relative wall thickness (RWT) and relative apical sparing (RELAPS) were tested as conventional measures. RESULTS: The RWT and RELAPS were higher in ATTR-CA (p < 0.001) and predicted ATTR-CA (RWT; AUC = 0.84, p < 0.001) and RELAPS (AUC = 0.81, p < 0.001). MW; GWI (p = 0.04), GCW (p = 0.03), GWW (p = 0.001) were all lower in ATTR-CA compared with HFnCA but only GWW predicted ATTR-CA, (AUC = 0.75, p < 0.001). Binary logistic univariate regression analysis showed RWT (p = 0.003, β = 16.2) and RELAPS (p = 0.003, β = 2.3) to be associated with ATTR-CA but not MW. GWI and GCW correlated with NT-proBNP (p < 0.05) and Troponin (p < 0.01), but not RWT or RELAPS. CONCLUSION: Myocardial work had lower accuracy, compared to RWT or RELAPS, in identifying ATTR-CA but was better related to biomarkers. Thus, MW assessment is unlikely to have additional value in improving the diagnosis of heart failure due to ATTR-CA