NT-proBNP levels and diastolic dysfunction in beta-thalassaemia major patients

Abstract

Background: The early diagnosis and treatment of heart failure in beta-thalassaemic patients is related to survival. Iron alone or in combination with other factors causes diastolic dysfunction, which usually precedes systolic dysfunction. NT-proBNP is a sensitive biomarker of ventricular dysfunction.

Aim: To evaluate NT-proBNP in non heart failure beta-thalassaemic patients.

Methods: Fifty-two beta-thalassaemia major patients (mean age: 27.2+/-12.5 years) with normal LV systolic function, underwent NT-proBNP measurement and a thorough Doppler-echocardiographic and pulsed tissue-Doppler study, 4 days following blood transfusion. Fifty-two age matched healthy controls were also studied.

Results: NT-proBNP and E/E' ratio were increased in thalassaemic patients compared with controls [(469+/-171 vs 262+/-51 pmol/l, p<0.001) and (10.8+/-4.0 vs 6.6+/-1.1, p<0.001)] and were well correlated (r: 0.54, p<0.01). Although NT-proBNP levels were increased in patients with higher E/E' ratios (E/E' <8: 354+/-119, 8-15: 516+/-177, >15: 565+/-114 pmol/l, ANOVA p: 0.002) this increase only became statistically significant in the 3rd decade of life, while E/E' ratio increased in the 4th decade.

Conclusion: NT-proBNP increases in beta-thalassaemia major patients and is related to age and LV diastolic dysfunction. NT-proBNP appears to be an early biomarker of LV diastolic dysfunction, compared with the conventional Echo-Doppler indexes.