One-year prognosis and the role of brain natriuretic peptide levels in patients with chronic cor pulmonale

Data on the clinical outcomes and role of brain natriuretic peptide (BNP) levels in patients with chronic cor pulmonale are limited. A total of 69 patients with chronic cor pulmonale, admitted for dyspnea (January 2007 to September 2011) to three university hospitals, were retrospectively reviewed. All of the patients had right ventricular (RV) dysfunction on echocardiography. The median age was 70.0 yr, and chronic obstructive pulmonary disease (40.6%) and tuberculosis-destroyed lung (TDL, 27.5%) were the leading causes of chronic cor pulmonale. At the 1-yr follow-up, the mortality rate was 15.9%, and the readmission rate was 53.7%; patients with TDL had higher mortality (31.6% vs. 10.0%; P=0.059) and readmission rates (78.9% vs. 43.8%; P=0.009) than those with non-TDL diseases. The area under the receiver operating characteristic curve for admission BNP levels to predict readmission was 0.788 (95% confidence interval [CI], 0.673-0.904), and the sensitivity and specificity of the cut-off value were 80.6% and 77.4%, respectively. In multivariate analysis, high admission BNP levels were a significant risk factor for subsequent readmission (hazard ratio, 1.049; 95% CI, 1.005-1.094). Additionally, admission BNP levels were well correlated with cardiac troponin I (r=0.558), and delta BNP also correlated with delta RV systolic pressure (n=25; r=0.562). In conclusion, among hospitalized patients with chronic cor pulmonale, admission high BNP levels are a significant risk factor for subsequent readmission. Therefore, more intensive monitoring and treatment are needed in patients with higher BNP levels.