Prognostic prediction in acute heart failure patients with extreme BNP values

BACKGROUND: Some patients have good prognosis despite elevated B-type natriuretic peptide (BNP), while others have ominous outcome with low BNP. We aimed at characterising these groups of patients. METHODS: We analysed patients prospectively included in an acute HF registry. Vital status within 1-year post discharge was ascertained. A receiver-operating characteristic curve was used to define discharge BNP cut-offs for 1-year death prediction. Among survivors, we compared patients with low and not-low BNP (cut-off 400 pg/mL); and among non-survivors those with high vs not-high BNP (cut-off 2000 pg/mL). In the specific subgroups of patients with low and high BNP, mortality predictors were assessed with multivariate Cox-regression analysis. RESULTS: We studied 584 patients, median age 78 years, 62.5% had HF with reduced ejection fraction; and 199 (34.1%) died during the first year. Non-survivors were very homogeneous irrespective of BNP, survivors were substantially different. In patients discharged with BNP <400 pg/mL, increasing age independently predicted death; when BNP ≥2000 pg/mL death predictors were higher NYHA class, and non-use of evidence-based therapy. BNP was outcome associated in both groups. CONCLUSIONS: Different prognostic predictors may play a role in different BNP levels. We suggest that risk stratification in HF would probably be more accurate if made on top of BNP knowledge.