# Basal inferoseptal longitudinal strain deformation may indicate early cardiac involvement in wild-type carpal ATTR

## TL;DR

This study finds that specific heart muscle strain patterns may signal early heart issues in older adults with a certain type of amyloidosis.

## Contribution

The study identifies basal inferoseptal longitudinal strain as a novel early indicator of cardiac involvement in wild-type ATTR amyloidosis.

## Key findings

- Basal inferoseptal longitudinal strain (LS) was significantly lower in patients with elevated troponin-T.
- Basal inferoseptal LS outperformed global longitudinal strain and BNP in identifying high troponin-T levels.
- Segmental strain analysis differentiated early cardiac involvement in wild-type ATTR amyloidosis.

## Abstract

Wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) is now increasingly identified as a cause of heart failure in older adults. This study aimed to clarify the morphological and functional alterations of the left ventricle (LV) that define the early stage of this condition.

We prospectively evaluated 81 patients diagnosed with wild-type ATTR (ATTRwt) amyloidosis (mean age 77 ± 6 years; 88% male), categorized into three groups based on myocardial uptake on radioactive pyrophosphate scintigraphy and histological confirmation: (i) carpal ATTR without cardiac involvement (Group 1, n = 13), (ii) asymptomatic cardiac involvement (Group 2, n = 10) and (iii) overt heart failure (Group 3, n = 58).

Compared with Group 3, Group 1 showed higher absolute global longitudinal strain (GLS) (median 19.0 [13.2–23.8]%, P < .001), a lower apical-sparing ratio (median 0.66 [0.55–1.04], P < .001) and lower brain natriuretic peptide (BNP) (median 13.5 [6–49] pg/mL, P < .001) and troponin-T concentrations (0.012 [0.006–0.022] ng/mL, P < .001), while the estimated glomerular filtration rate remained preserved (64 ± 9 mL/mL/1.73 m², P = .022). Segmental longitudinal strain (LS) differentiated Group 1 from Group 2, with basal inferoseptal LS significantly lower in patients with elevated troponin-T (> 0.014 ng/mL) than in those with lower values (13.9 ± 5.6% vs. 7.4 ± 1.8%, P = .046) in Group 1. A basal inferoseptal LS cutoff of 9.1% identified high troponin-T with an area under the curve (AUC) of 0.833 (P = .005), outperforming GLS (AUC 0.306, P = .217), BNP (AUC 0.667, P = .292), and LV ejection fraction (AUC 0.556, P = .743).

Basal inferoseptal LS impairment may indicate early cardiac involvement in individuals with carpal tunnel syndrome carrying ATTRwt deposits.