Role of brain natriuretic peptide as a novel prognostic biomarker in acute ischemic stroke

AIM: We investigated to study the prognostic importance of brain natriuretic peptide (BNP) in ischemic stroke. MATERIALS AND METHODS: We prospectively enrolled 100 patients with acute ischemic stroke and measured plasma BNP levels and compared with age- and sex-matched healthy controls. Risk factors, biochemical parameters, lipid profile, carotid and vertebral Doppler, imaging, and cardiac evaluation were done. Stroke severity was assessed by the National Institutes of Health Stroke Scale (NIHSS) score on admission and functional disability by Barthel Index (BI) at 3 months. Ischemic stroke subtype was classified according to the Oxfordshire Community Stroke Project (OCSP). Data were entered in MS Excel, and appropriate statistical analysis was done using the SPSS software version 21.0. A P = 0.05 was considered as significant. RESULTS: Mean age of patients was 55.17 ± 11.37 years with a male:female ratio 3:1. OCSP showed total anterior circulation infarct (TACI) 35, partial anterior circulation infarct 9, lacunar infarct 12, and posterior circulation infarct 44. NIHSS on admission was average 10 ± 7 and BI was 57 ± 30. BNP in patients (435 ng/ml) was very high as compared to controls (<60 ng/ml) (P < 0.001). There was a positive correlation between age and BNP (R(2) = 0.34; P < 0.00); NIHSS and BNP (R(2) = 0.255; P < 0.01), negative correlation between BI and BNP (R(2) = −0.064; P < 0.01). Mean BNP levels across the OCSP showed higher values in TACI (F = 4.609 P = 0.005). Regression analysis showed that BNP can predict BI which was statistically significant. CONCLUSION: Plasma BNP levels was significantly elevated in patients with ischemic stroke. Our study concludes that high BNP levels are seen in large anterior circulation stroke and is a predictor for the poor functional outcome at 3 months. Determination of BNP levels as a biomarker could be helpful in predicting the outcome in stroke patients.