utility of n-terminal pro-brain natriuretic peptide in detecting diastolic dysfunction in asymptomatic hypertensive patients: comparison with echocardiography

Introduction: data suggest that brain natriuretic peptide (bnp) and nt pro-bnp partially reflect ventricular pressure and could have a role in the early detection of diastolic abnormalities in hypertensive patients with normal systolic function. this study aimed to assess the role of nt pro-bnp for early detection of diastolic dysfunction in patients with hypertension and to correlate its level with echocardiographic parameters of diastolic dysfunction. methods: this is a comparative cross-sectional study. hundred cases of asymptomatic hypertensive patients with normal left ventricular (lv) systolic function and 100 healthy subjects were subjected to echocardiography and measurement of serum nt-pro bnp who received care at outpatient department of internal medicine, b.p. koirala institute of health sciences, nepal. results: both systolic and diastolic blood pressures were significantly higher (≥160 and/or 100 mm hg) in cases compared to controls (<120/80 mm hg). echocardiographic parameters of diastolic dysfunction: e/a ratio, e/e’ratio, deceleration time and isovolumetric relaxation time showed a significant difference between cases and controls. mean serum nt-probnp was significantly higher in patients with hypertension (213.19 ±184.3 pg/ml) compared to controls (58.51 ± 11.01 pg/ml) (p = 0.008). there was no significant difference in mean serum nt-pro bnp levels between cases with no lv diastolic dysfunction (n=14) and controls (n=100) but it showed a significant difference between cases with lv diastolic dysfunction of all grades (n=86) and controls (n=100) (p = 0.00). nt-probnp levels were higher in both group of patients with e/a ratios <0.9 and 0.9-1.5 (245.72 ± 166.73 pg/ml and 210.69 + 143.53 pg/ml respectively) as compared to controls. mean serum nt-probnp levels were significantly higher in patients with ivrt >90 ms (270.43 ± 180.81 pg/ml) as compared to controls (p = 0.03) but the difference was not significant between cases with ivrt of 60-90 ms (152.02 ± 100.23 pg/ml) and controls (p = 0.09). nt-probnp levels were significantly higher in all groups of patients with e/e’ ratios <8, 8-12, >12 (197 ± 121.25 pg/ml, 263.12 ± 122.52 pg/ml and 180 ± 106.56 pg/ml respectively) compared to controls. conclusion: mean serum nt-probnp was significantly higher in patients with hypertension as compared to controls. there is some correlation between echocardiographic parameters of diastolic dysfunction and serum nt-probnp. hence, nt-probnp may be useful for early detection of lv diastolic dysfunction in patients with hypertension.