Diagnostic Value of N-terminal Probrain Natriuretic Peptide (NT-proBNP) in Diastolic Heart Failure

Lee, Young Ju; Baek, Kwang Je; Lee, Kyeong Ryong; Ki, Woong; Kim, Jin Yong

Abstract

PURPOSE: Diagnosis of congestive heart failure (CHF) is difficult in the emergency care setting using clinical diagnostic tests. Although echocardiography is important for making the diagnosis of left ventricular dysfunction, its cost and lack of availability limit its use as a routine screening test. The utility of N-terminal probrain natriuretic peptide (NT-proBNP) testing in the emergency department for differentiating between systolic (SHF) and diastolic heart failure (DHF) are not well established.
METHODS
One-hundred-seven consecutive patients with acute dyspnea, who visited our emergency medical center from January 2006 to August 2006 were prospectively recruited. Patients with acute coronary syndrome and chronic renal failure were excluded from study enrollment. The diagnosis of DHF was based on European study group guidelines on diastolic heart failure. The diagnostic accuracy of NT-proBNP was assessed by receiver operating characteristic curve analysis.
RESULTS
The mean age was 69+/-11 years, and 59% of the patients were women. The median NT-proBNP level among 41 patients (38%) who had SHF was 3817 and 26 patients (24%) who had DHF was 1781 pg/ml versus 550 pg/ml for those 40 patients (37%) who did not have acute CHF (p=0.01). The area under the receiver operating characteristic curve was 0.89 (95% CI of 0.82-0.96). At a cutoff of 700 pg/ml, NT-proBNP had a sensitivity of 87%, a specificity of 78%, and an overall accuracy of 84% for acute CHF (p<0.01). NT-proBNP levels were correlated well with left ventricular systolic and diastolic dysfunction. But, although SHF had significant higher NT-proBNP levels than those with DHF, NT-proBNP levels were unable to differentiate systolic versus diastolic heart failure.
CONCLUSION
NT-proBNP appears to be useful as an aid in the diagnosis of CHF in acute dyspnea patients to the emergency department. Whereas NT-proBNP could not differentiate SHF from DHF, therefore, its clinical major role is still the separation of patients with CHF from those without CHF.