BNP vs. clinical acumen. (Heart of the Matter).

After more than a decade of study, testing for B-type natriuretic protein has recently been shown to have promise in the diagnosis of congestive heart failure.

But it remains uncertain to what extent measurement of BNP can improve upon clinical judgments.

The concentration of natriuretic proteins increases in heart failure and is closely correlated to increases in a number of neurohormones, including norepinephrine and endothelin. One of three natriuretic proteins, BNP increases in concentration in heart failure as a result of increase in the stretch of the cardiomyocyte. BNP was once referred to as brain natriuretic protein, but it is actually elaborated in the myocardium.

Epidemiologic studies in Europe have shown that the concentration of BNP has a role in identifying patients with early heart failure. Recently Dr. Alan S. Maisel and his associates reported that BNP concentration measured in patients evaluated in the emergency department can distinguish dyspnea occurring as a result of heart failure from that due to primary lung disease and other, undetermined causes (N. Engl. J. Med. 347[3]:161-67, 2002).

The ability to perform the BNP test within 15 minutes at the bedside could provide a unique diagnostic tool to identify cardiac dyspnea and aid in the early diagnosis of heart failure.