What is the clinical evidence from this study?

Study design: Observational. Population: Transthyretin (ATTR) cardiac amyloidosis (n=330). Intervention: Indexed left ventricular wall thickness (by height^2.7) vs. Non-indexed left ventricular wall thickness. Primary outcome: Correlation with indicators of cardiac disease severity (NT-proBNP, relative wall thickness, E/e' ratio, TAPSE).

March 15, 2023Open Access

Left Ventricular Wall Thickness and Severity of Cardiac Disease in Women and Men with Transthyretin Amyloidosis

Key Result

In 330 patients with ATTR-CA (16% female), indexing left ventricular wall thickness by height^2.7 more accurately reflected cardiac disease severity than non-indexed values.

Study Design

Type

Observational (n=330)

Multicenter

Yes

Structured PICO

Does indexing left ventricular wall thickness by body size metrics improve correlation with cardiac disease severity in patients with ATTR-CA compared to non-indexed values?

Population

330 consecutive patients (16% female) diagnosed with transthyretin cardiac amyloidosis evaluated across three centers.

Exposure

Indexing left ventricular wall thickness (interventricular septum and posterior wall) by body surface area, height, or height^2.7

Comparator

Non-indexed left ventricular wall thickness values

Outcome

Relationship between left ventricular wall thickness and indicators of cardiac disease severity (NT-proBNP, relative wall thickness, E/e' ratio, and TAPSE)surrogate

Indexing left ventricular wall thickness by height^2.7 more accurately reflects the severity of cardiac involvement in ATTR-CA than non-indexed values, accounting for sex differences in body size.

Abstract

Abstract Aims Cardiac amyloidosis (CA) is due to a deposition of amyloid fibrils in the heart causing an increase in wall thickness. A left ventricular (LV) wall thickness ≥12 mm plus at least one red flag should raise the suspicion of CA. As normal values of LV wall thickness are lower in women, the adoption or the same cut-off values for men and women could lead to underdiagnosis or delayed diagnosis in women. We investigated the relationship between LV wall thickness and the severity of cardiac involvement in women and men with transthyretin (ATTR) CA. Methods and results We evaluated 330 consecutive patients diagnosed with ATTR-CA at three centres (Pisa, n = 232; Brescia, n = 69; Trieste, n = 29). Interventricular septum (IVS) and posterior wall (PW) thickness values were lower in women (n = 53, 16%) than men, but most differences were abolished when indexing by body surface area (BSA), height, or height2.7, suggesting similar disease severity when accounting for the smaller body size of women. PW thickness indexed for height2.7 was even higher in women. We also searched for correlations between IVS and PW thickness and other indicators of the severity of cardiac disease. IVS values indexed by height2.7 displayed tighter associations with N-terminal pro-B-type natriuretic peptide values than non-indexed IVS values. Similarly, indexed values displayed closer relationships with relative wall thickness, E/e' ratio, and tricuspid annular plane systolic excursion. Conclusions Indexed LV wall thickness values, particularly by height2.7, reflect more accurately the severity of cardiac involvement than non-indexed values.