Clinical Significance of B-Type Natriuretic Peptide in the Assessment of Untreated Hypertension

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Abstract
Background Recent studies suggest that B-type natriuretic peptide (BNP) is an important predictor of cardiac events in hypertensive patients. Methods and Results The relationship between the plasma BNP level and various clinical parameters was examined in 154 untreated hypertensive patients without heart failure or atrial fibrillation (mean age: 58.0±10.7; mean blood pressure: 164.5±15.2/99.1±9.7 mmHg; mean BNP: 32.7±36.7 pg/ml). First, the patients were divided into 2 groups based on BNP: normal (18.5 pg/ml, mean 51.4±40.4, n=85). The elevated BNP group had a significantly greater electrocardiographic voltage index (SV1+RV5; 3.7±1.2 vs 3.2±0.8 mV, p=0.0029), cardiothoracic ratio/chest radiography (CTR; 49.1 vs 46.9%, p=0.0037), left ventricular mass index (LVMI; 122.2±31.7 vs 103.1±26.4 g/m2, p=0.0005) and deceleration time (DT; 241±39 vs 208±30 ms, p=0.0001), as well as a smaller E-wave to A-wave (E/A ratio) (0.80±0.22 vs 0.96±0.28, p=0.0003), compared with the normal BNP group. There were no significant differences in casual blood pressure, body mass index, serum creatinine and ejection fraction between the 2 groups. Next, the patients were divided into 3 groups based on BNP: normal (1+RV5, DT and LVMI. In all patients, logarithmic BNP was positively correlated with the age, pulse pressure, SV1+RV5, CTR, ventricular wall thickness, DT, LVMI and negatively correlated with hemoglobin, renin and E/A ratio. Using multiple regression analysis, renin and DT were significantly associated with BNP. No gender differences in the relationship between BNP and clinical parameters were found. Conclusions Results suggest that BNP is a useful indicator for the initial assessment of the severity of essential hypertension, detecting both cardiac hypertrophy and diastolic dysfunction, and may also be valuable for risk stratification. (Circ J 2008; 72: 770 - 777)