Unexpectedly Low Natriuretic Peptide Levels in Patients With Heart Failure.

Abstract Objectives The purpose of this study was to determine the frequency of unexpectedly low natriuretic peptide (NP) levels in a clinical population. Background Higher NP concentrations are typically observed as a compensatory response to elevated cardiac wall stress. Under these conditions, low NP levels may be indicative of a “NP deficiency.” Methods We identified 3 clinical scenarios in which high B-type natriuretic peptide (BNP) levels would be expected: 1) hospitalization for heart failure (HF); 2) abnormal cardiac structure or function; or 3) abnormal hemodynamics. In Vanderbilt’s electronic health record, 47,970 adult patients had BNP measurements. A total of 13,613 patients had at least 1 of the 3 conditions (hospitalized HF, n = 9,153; abnormal cardiac structure/function, n = 7,041; abnormal hemodynamics, n = 363). We quantified the frequency of low BNP levels. We performed whole exome sequencing of the NPPB gene in a subset of 9 patients. Results Very low BNP levels ( Conclusions A subset of patients with confirmed HF or cardiac dysfunction have unexpectedly low BNP levels. Obesity is the strongest correlate of unexpectedly low BNP levels. Our findings support the possible existence of NP deficiency, which may render some individuals more susceptible to volume or pressure overload.