Role of NT-proBNP in Evaluation of Functional Status in Congestive Heart Failure

Background and Objectives:NT-proBNP, a sensitive and specific marker of congestive heart failure (CHF), is also useful in monitoring the effectiveness of treatment and in predicting prognosis. However, the usefulness of NT-proBNP for measuring the functional capacity as a component of the quality of life (QoL) in patients with CHF remains to be discovered. The Korean Activity Scale/Index (KASI) is a Koreanized tool for measuring the functional capacity in patients with cardiac diseases during daily activities, thus representing the physical domain of the QoL. The purpose of this study was to evaluate the relationship between NT-proBNP and the KASI. Subjects and Methods:Between July, 2003 and September, 2003, the NT-proBNP levels were measured in 76 patients with CHF that visited the OPD or who were hospitalized. They were asked to fill out a selfadministered questionnaire, from which their KASI scores were obtained. NYHA Fc and Heart Failure scores were also obtained from a history taking and physical examination conducted by the investigator. Results: The level of NT-proBNP increased with increasing NYHA Fc (p<0.001 by Kruskall-Wallis test). The Spearman correlation coefficient between NT-proBNP and the KASI score was -0.730 (p<0.001), which was higher than that between the HF and KASI scores (rho=-0.557, p<0.001). The level of NT-proBNP also had a positive correlation with the HF score (rho=0.706, p<0.001). Conclusion:The level of NT-proBNP has a strong negative correlation with the KASI score, reflecting the functional capacity during daily activities. This suggests that NT-proBNP is useful in measuring the functional capacity as an element of the QoL in patients with CHF. (Korean Circulation J 2004;34(9):894-899)