Global longitudinal strain and NT-proBNP for functional evaluation in transthyretin amyloid cardiomyopathy

Introduction and objectives Transthyretin amyloid cardiomyopathy (ATTR-CM) is an increasingly recognized cause of heart failure with preserved ejection fraction. However, conventional measures of systolic function, including left ventricular ejection fraction (LVEF), often fail to detect myocardial dysfunction at early stages. Global longitudinal strain (GLS) has emerged as a sensitive echocardiographic marker capable of identifying subclinical myocardial impairment before changes in LVEF become apparent. This study aimed to evaluate the incremental value of GLS and N-terminal pro-B-type natriuretic peptide (NT-proBNP) for functional stratification in patients with ATTR-CM. Methods A cross-sectional study was conducted, including patients with confirmed ATTR-CM who underwent comprehensive clinical, biomarker, and echocardiographic evaluation. The relationship between GLS, NT-proBNP levels, and clinical variables with respect to New York Heart Association (NYHA) functional class was analyzed using correlation analyses and multivariable ordinal regression models. Results Overall, this study included 60 patients, with a mean age of 75.5 ± 10 years and a male predominance (60%). Although LVEF remained preserved in 73.3% of cases, GLS was markedly reduced (−11.6% ± 4.0%), showing progressive worsening across higher NYHA classes along with attenuation of the apical sparing pattern. Log-transformed NT-proBNP correlated significantly with GLS ( ρ = −0.488; P < .001) and with NYHA class ( ρ = 0.361; P = .008), remaining an independent predictor of functional severity (OR, 1.68; 95%CI, 1.06–2.66). Conclusions These findings support that impairment of longitudinal deformation precedes conventional systolic dysfunction, and that incorporating GLS into multimodal diagnostic strategies could optimize risk stratification in ATTR-CM.