Clinical significance of the relative apical sparing pattern of longitudinal strain in patients with cardiac amyloidosis

Abstract

Background The relative apical sparing pattern (RASP) of left ventricular (LV) longitudinal strain (LS) is frequently associated with cardiac amyloidosis (CA). However, some patients with CA do not show the RASP, and their clinical characteristics have not been fully clarified. We sought to investigate the clinical significance of RASP in patients with CA. Methods One hundred consecutive CA patients who were diagnosed by biopsy or myocardial pyrophosphate scintigraphy and evaluated for RASP (mean age: 76 years, male: 77%, LV mean wall thickness: 13.5 mm, light-chain [AL] type: 33 cases, transthyretin [TTR] type: 67 cases) were retrospectively enrolled. The RASP was semi-quantitatively and quantitatively assessed. Semi-quantitative RASP was defined as reduction of LS (≥−10%) in ≥5 (of 6) basal segments relative to preserved LS (<−15%) in ≥1 apical segment. Quantitative RASP was calculated according to the following formula: Quantitative RASP = [Average apical LS] / [Average basal LS + Average mid LS]. We adapted three validated thresholds (>1.00, >0.90, and >0.87) according to the literature. Results Semi-quantitative and binalized quantitative RASP (>1.00, >0.90, and >0.87) were observed in 55, 55, 63, and 65 patients, respectively. RASP in each definition was more prevalent in the TTR group than in the AL group. Additionally, RASP was significantly associated with higher LV wall thickness even after adjustment for the CA subtypes (all, p<0.05, Figure). After the RASP assessment, 35 all-cause deaths and 26 cardiac deaths were observed during the follow-up period (median, 1.1 years). Although these events were significantly associated with poor nutrition, lower blood pressure, higher New York Heart Association class, and the AL group, no association was found with RASP and LV wall thickness. Conclusions The incidence of RASP is low in the case of thin LV wall thickness in CA patients, which may indicate the difficulty of early diagnosis of CA using RASP in patients with mild LV hypertrophy. The prognostic prediction using RASP may be challenging in this cohort. Figure 1 Funding Acknowledgement Type of funding source: None

Italian Real-Life Experience of Patients with Hereditary Transthyretin Amyloidosis Treated with Patisiran

“…A further echocardiogram showed marked hypertrophy (interventricular septal thickness: 20 mm, posterior wall of left ventricle: 14 mm) with slightly reduced pump function (EF 45%), signs of increased filling pressure and a severe reduction of longitudinal deformation indices (global longitudinal strain, GL2D-strain: −6.2%), with an “apical sparing pattern” specific for cardiac amyloidosis ( Figure 1A and B ). 23 Under a clinical suspect of AL amyloidosis and considering the underlying MGUS, a biopsy of the iliac crest bone marrow was performed, which ruled-out the presence of amyloid, as well as of lymphoma or multiple myeloma. At this point, a Congo red histochemical investigation and polarized light test performed on abdominal fat tissues showed the presence of amyloid; however, no immunofluorescence typing was performed.…”

Red flags for the diagnosis of cardiac amyloidosis: simple suggestions to raise suspicion and achieve earlier diagnosis

“…However, the incidence of relative apical sparing has proven to be low in case of mild LVH, thus this pattern may be less useful as a red flag in the early presentation 98 . Eventually, the apical sparing pattern may be seen in other infiltrative cardiomyopathies like Fabry disease 99 …”

“…97 However, the incidence of relative apical sparing has proven to be low in case of mild LVH, thus this pattern may be less useful as a red flag in the early presentation. 98 Eventually, the apical sparing pattern may be seen in other infiltrative cardiomyopathies like Fabry disease. 99 Extensive atrial amyloid infiltration and consequently blunted atrial function have been recently described by Bandera et al with ATTR-CM revealed augmented atrial stiffness and all the three components of the atrial functioning (reservoir, conduit and contraction) were significantly impaired.…”