The Correlation of Brain Natriuretic Peptide (BNP), Pulmonary Arterial Pressure, and St. George Respiratory Questionnaire (SGRQ) and Their Changes with a Trial of an Angiotensin Converting Enzyme Inhibitor

Abstract

Background: Pulmonary hypertension is considered as a poor prognosis factor in patients with chronic obstructive pulmonary disease (COPD). There has been reported brain natriuretic peptide (pro-BNP) is related with increased right ventricular (RV) workloads. However, there are few studies that evaluate the relationship between BNP and pulmonary arterial pressure (PAP), RV function and St. George Respiratory Questionnaire (SGRQ) score in patients with COPD, and the effects of angiotensin converting enzyme inhibitor (ACEI) on these parameters. Methods: Pulmonary function test, echocardiography, blood BNP, and SGRQ score were evaluated in stabilized moderate degree COPD patients (FEV1/FVC＜70%, 50%≤FEV1＜80%) aged 45 years and over, without worsening of symptoms within recent 3 months. After treating with ramipril 10 mg for 3 months, the same evaluation was repeated. Results: Twenty-two patients were included in this study. BNP was significantly correlated with PAP (Pearson coefficient ρ=0.51, p=0.02), but not with RV ejection fraction (EF) and predicted FEV1%. The values for predicted FEV1% showed significant correlation with SGRQ total score and activity score, but not with BNP or PAP. After ramipril treatment, PAP showed significant decrease (42.8±8.1vs.34.5±4.5 mm Hg p=0.0003), tricuspid annular plane systolic excursion significant increase (21.5±3.3vs.22.7±3.1 mm p=0.009). BNP showed a tendency to decrease without statistical significance (40.8±59.6vs.18.0±9.1 pg/mL p=0.55). SGRQ scores showed no significant change. Conclusion: BNP showed significant correlation with resting PAP, which means BNP could be used as markers for pulmonary hypertension. Treatment with ACEI didn`t show significant change in the Level of BNP, while pulmonary hypertension and RV function were improved.