BNP levels are related to days of hospitalization independently to the pathology in critical care settings

Background: Increased brain natriuretic peptide (BNP) levels have been related to several conditions, such as acute heart failure (AHF), pulmonary embolism (PE) and acute coronary syndromes (ACS). Particularly among elderly patients, a longer hospitalization is related to higher morbidity and mortality. The usefulness of BNP as a prognostic factor is amply demonstrated in different subpopulations of both medical and surgical patients. Aims: To evaluate the relationship between BNP levels and length of in-hospital stay in patients with PE, ACS, AHF, septic and cardiogenic shock admitted to our internal medicine department (IMD). Methods: We retrospectively evaluated 500 consecutive patients admitted to our IMD. BNP was evaluated at the admission in all the patients. Each patient underwent a complete diagnostic workup. We evaluated the curve-fit correlation between BNP levels and days of hospitalization using SPSS 13.0 for windows systems. Results: Mean age was 80 ± 9.85 years, males representing 58 % of the sample. AHF represented 74.9 %, ACS 13.5 %, PE 11.6 % of the sample. We found that BNP levels and days of hospitalization were better described by a logarithmic regression model (R2: 0.674, p\0.0001) (Figure 1). Conclusions: Among elderly patients admitted in an IMDs, higher BNP levels are associated to longer hospitalizations independently to the pathology. This relationship is better described by a logarithmic regression model. However, larger cohorts are required to validate this observation.