B-type natriuretic peptide: a biomarker for the diagnosis and risk stratification of patients with septic shock.

BACKGROUND: The importance of cardiomyocyte damage during sepsis has been a recent subject of interest. The progression of sepsis results in the upregulation of proinflammatory cytokines, which act in concert to damage cardiomyocytes and produce cardiac contractile dysfunction. B-type natriuretic peptide (BNP) is a neurohormone released from the ventricles of the heart in response to myocardial dysfunction. The goal of this study was to examine the relationship between BNP levels and the severity of sepsis independent of congestive heart failure.

DESIGN: Prospective, nonrandomized control study.

SETTING: University hospital.

PATIENTS: Forty-nine patients were divided into 3 groups: 13 patients with septic shock, 18 with early sepsis, and 18 age-matched healthy control subjects. We excluded patients with septic shock who had comorbid conditions (congestive heart failure or renal failure); sepsis severity was determined using the Sequential Organ Failure Assessment scoring system. Patients with sepsis were followed up for 21 days.

MAIN OUTCOME MEASURES: Serum BNP levels, determined at the time of diagnosis of sepsis and on patient improvement or deterioration.

RESULTS: Patients with septic shock had significantly higher BNP levels on admission compared with the other 2 groups (P < .05). The BNP levels were not significantly elevated in patients with early sepsis. Plasma BNP levels for patients with septic shock were positively correlated with Sequential Organ Failure Assessment scores (r(2) = 0.74, P < .05) and prognosticated survival.

CONCLUSIONS: This study confirms the relationship between BNP level elevation and severity of sepsis independent of congestive heart failure. It also supports the utility of BNP level as a marker for mortality in septic shock.