Relations of plasma B-type natriuretic peptides (BNP) to tissue Doppler E/e´, left ventricular systolic functions and BNP predictors in African heart failure subjects: The ABU-BNP surveyObiageli Uzoamaka Onyemelukwe1, Albert Imhoagene Oyati1, Solomon Sulei Danbauchi2, Austine Obasohan3
1Department of Medicine, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria
2Department of Medicine, Jos University Teaching Hospital, Jos-Plateau State, Nigeria
3Department of Medicine, University of Benin Teaching Hospital, Edo State, Nigeria
International Medicine 2020; 2(1): 50-60 | DOI: 10.5455/im.52217 PDF
Background: To evaluate the relations of B-type natriuretic peptide (BNP) to tissue Doppler (TD) E/e´, left ventricular systolic functions and BNP’s predictors as well as determine plasma BNP levels in African heart failure (HF) subjects in comparison to healthy controls as there is paucity of data on these in black African population.
Methods: A cross-sectional analytical study done on 184 subjects: 109 decompensated HF patients at the Ahmadu Bello University Teaching Hospital, Nigeria and 75 healthy controls. Simultaneous BNP assessment and echocardiographic determination of systolic function and TD E/e´ were done. Pearson’s Correlation and Binary Logistic Regression analysis determined BNP’s association with parameters. Mann-Whitney U test determined the difference in BNP levels between patients and controls.
Results: Log-transformed (Ln10) BNP inversely correlated with Ln10Ejection fraction (EF) in patients (p=0.005, r = -0.27) and all subjects combined (p<0.001, r = -0.55) with similar trend for Ln10Fractional shortening (FS). BNP significantly (p < 0.001) positively correlated with TD E/e´ in patients (r = 0.46) and all subjects (r = 0.61) respectively. Tissue-Doppler E/e´ > 15 was associated (p=0.01) with higher BNP levels in the unadjusted and adjusted age, sex, body mass index and glomerular filtration rate models of patients with about four times Odd. EF < 40% and FS < 19% as well as EF < 50% and FS < 29% were significantly (p<0.001) associated with higher BNP levels in the unadjusted patient-control model. BNP levels were significantly (p<0.001) higher in patients (median, 412.5 pg/mL) than controls (median, 237.5 pg/mL).
Conclusions:BNP levels can predict systolic dysfunction and independently predict elevated left ventricular filling pressure (LVFP) amidst confounders. BNP levels of Nigerian-Africans are significantly higher in HF patients than controls. BNP and E/e´ provide a better assessment of HF in African HF patients with both systolic and diastolic dysfunctions.
Keywords: Africa, B-type natriuretic peptide, cardiomyopathy, heart failure