Left ventricular wall thickness and derived parameters in cardiac amyloidosis

Left ventricular wall thickness (LVWT) is a key echocardiographic parameter in the diagnosis of cardiac amyloidosis (CA), yet its measurement is prone to variability, and traditional thresholds may miss early disease. We aimed to characterize the spectrum of LVWT and derived parameters in patients with transthyretin (ATTR-CA) and light chain (AL-CA) cardiac amyloidosis.

In this retrospective study, we included 1845 patients treated for CA at a tertiary amyloidosis center from 2006 to 2024. Echocardiographic data were analyzed to assess LVWT, relative wall thickness (RWT), and left ventricular mass index (LVMi). Sex differences and inter-/intra-observer variability were also examined.

A significant subset of patients presented with normal or mildly increased LVWT ({less than or equal to}1.2 cm), including 13 % of AL-CA and 6.5 % of ATTR-CA patients. Conversely, 12.2 % of AL-CA patients exhibited markedly elevated LVWT (>2.0 cm). Women had significantly lower LVWT. Despite low LVWT, 68 % of patients with IVST and PWT {less than or equal to}1.2 cm had RWT >0.42. RWT was more sensitive than LVMi in identifying CA and showed no sex difference. Measurement variability was substantial, with a standard error of ∼1.5 mm.

CA presents across a wide range of LVWT values, including within normal limits, especially in women. RWT offers greater sensitivity and may enhance early disease detection. Significant observer variability underscores the need for standardization and incorporation of derived metrics in echocardiographic interpretation. These findings highlight the limitations of echocardiography and support the use of complementary parameters for improved diagnostic accuracy.