A single BNP measurement in acute heart failure does not reflect the degree of congestion

IntroductionMultiple studies found a significant correlation between B-type natriuretic peptide (BNP) level and clinical severity of heart failure (HF). We aim to study the ability of a single BNP measurement to predict the degree of congestion in acute systolic HF.MethodsPatients enrolled in the ESCAPE trial who were admitted with acute systolic HF were divided into tertiles according to baseline BNP level with comparison of the degree of congestion across tertiles using clinical signs of congestion as well as objective parameters of overload checked by the pulmonary artery catheter.ResultsA total of 251 cases (mean age, 56 years; 75% males) were included in the study after excluding patients with normal (n = 43) or extremely elevated BNP (n = 53) due to the known limited significance of BNP in predicting the degree of congestion in the latter 2 instances. These cases were divided into tertiles as follows: tertile 1, BNP less than or equal to 376 pg/mL; tertile 2, BNP 377 to 792 pg/mL; and tertile 3, BNP greater than or equal to 793 pg/mL. There were significant differences across the BNP tertiles in age (P = .03) and body mass index (P = .003). There were no differences between the 3 BNP tertiles with regard to the presence of rales (P = .533), jugular venous distension (P = .245), positive hepatojugular reflux (P = .224), hepatomegaly (P = .489), ascitis (P = .886), lower extremity edema (P = .068), or S3 gallop (P = .512). With regard to hemodynamic markers of congestion measured via the pulmonary artery catheter, there were no significant differences across the BNP tertiles in the right atrial pressure (P = .148), pulmonary capillary wedge pressure (P = .140), pulmonary artery systolic pressure (P = .155), pulmonary artery diastolic pressure (P = .246), and pulmonary artery mean pressure (P = .607).ConclusionAlthough longitudinal BNP follow-up may be valuable in reflecting the degree of congestion, looking at a single BNP measurement alone is not a good marker to predict the level of congestion and should not be used as a “stand-alone” test for determining aggressiveness of diuresis. Management should be guided by the entirety of physical examination, laboratory values, and hemodynamic parameters when available.