Predictive value of B-type natriuretic peptides in detecting latent left ventricular diastolic dysfunction in [beta]-thalassemia major

• Published in: The American heart journal 2010-01, Vol.159 (1), p.68
• Main Authors: Kremastinos, Dimitrios Th, Hamodraka, Eftihia, Parissis, John, Tsiapras, Dimitrios, Dima, Kleanthi, Maisel, Alan
• Format: Article
• Language: English
• Subjects: Age; Cardiovascular disease; Chelation therapy; Drug therapy; Heart failure; Hematology; Peptides; Regression analysis; Variance analysis
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/j.ahj.2009.10.025

Background β-Thalassemia major is a unique disease characterized by early diastolic dysfunction, related exclusively to iron myocardial deposition. N-terminal-proBNP(amino-terminal) (NT-proBNP) and B-type natriuretic peptide (BNP) are sensitive biomarkers for the detection of asymptomatic left ventricular (LV) dysfunction, and they have important diagnostic and prognostic implications. Using β-thalassemia as a model disease with isolated diastolic dysfunction, we sought to investigate the predictive value of NT-proBNP and BNP levels in comparison with the conventional and new Doppler echocardiography indexes in detecting this disorder. Methods Seventy β-thalassemia major patients (mean age 27.2 ± 12.5 years) with normal LV systolic function (mean LV ejection fraction = 59% ± 6.8%), and 50 healthy age-matched adults (control group: mean age 25.5 ± 10.1 years, mean LV ejection fraction = 60% ± 4.5%) were included. All subjects were studied thoroughly by tissue Doppler echocardiography and blood samples were taken for plasma NT-proBNP and BNP measurements at the same time. To examine LV diastolic function, patients were divided in 3 groups according to the E mitral/E mitral annulus ratio (E/E'): group A, patients without diastolic dysfunction: E/E' ratio 15. Results NT-proBNP and BNP levels were higher in thalassemic patients compared with the control group (NT-proBNP levels: 80 ± 19 vs 21 ± 4 pg/mL,P< .001; BNP levels: 34 ± 6 vs 9 ± 3 pg/mL,P< .001). NT-proBNP levels showed a statistically significant increase in group C in comparison to groups A and B, which was also detected between groups A and B (A vs B:P< .05). BNP levels were also significantly increased in group C in comparison to the other 2 groups, but there was no statistically significant difference between groups A and B. Using receiver operating characteristic analysis, NT-proBNP at a cut point of 49.2 pg/mL was highly accurate (area under curve: 0.97,P< .001) in ruling out diastolic dysfunction (E/E'