Relative apical sparing in patients with severe aortic stenosis: prevalence and significance. (25th November 2020) - Abecasis, J
Abstract: : Relative apical sparing (RAS) of LV longitudinal strain (LS) is a red flag for diagnostic suspicion of amyloid cardiomyopathy (AC). However, it may present in pts with aortic stenosis (AS), where the prevalence of transthyretin AC is being increasingly reported. Aim: To describe the prevalence of RAS deformation pattern in patients with AS and its clinical significance. Methods: We prospectively studied 53 pts (71±8y, 54.7% men) with severe symptomatic AS - mean gradient (AVM): 54.6 mmHg; aortic valve area 0.74cm 2, referred for surgical replacement with no previous history of ischemic cardiomyopathy. Beyond ECG and transthoracic echo (TTE), all pts underwent CMR, with tissue characterization before surgery. RAS was defined as average apical LS / average basal LS + average mid LS >1 at 2D LV LS analysis. Aortic valve replacement and septal myocardial biopsy were already performed in 26 pts. AS severity indexes, LV remodelling and tissue characterization were compared in both groups, with and without RAS. Results: RAS was present in 16 pts (30.8%). There were neither pseudoinfarct pattern or low voltage at ECG, nor infiltration suspicion from CMR study (native T1 value 1047ms [IQR 1028–1084]; ECV 22% [IQR 18–25]). Furthermore, none of the pts had suspicion of amyloid deposition at histopathology. Median CMR LVEF was 64.5% [IQR 51.3–70.8%] and 36 pts (67.9%) had non-ischemic DE, with a median fraction of 6.0% [IQR 4.9–12.7%] of LV mass. Comparing both groups, RAS cohort showed a significantly higher AVM, relative wall thickness, maximum septal thickness, peak systolic dispersion and higher LV indexed mass, DE and lower LVEF at CMR. RAS group has also higher NT pro BNP (Table). Conclusions: RAS is common in this group of pts despite the absence of clinical and histological signs of myocardial infiltration. RAS occurs with worse indexes of LV remodeling and fibrosis consistent with a more advanced stage of the disease. Funding Acknowledgement: Type of funding source: None