Insulin-like Growth Factor Binding Protein 2 predicts mortality risk in heart failure

BACKGROUND: Insulin-like Growth Factor Binding Protein 2 (IGFBP2) showed greater heart failure (HF) diagnostic accuracy than the "grey zone" B-type natriuretic peptides, and may have prognostic utility as well. OBJECTIVES: To determine if IGFBP2 provides independent information on cardiovascular mortality in HF. METHODS: A retrospective study of 870 HF patients from 3 independent international cohorts. Presentation IGFBP2 plasma levels were measured by ELISA, and patients were followed from 1 year (Maastricht, Netherlands) to 6 years (Atlanta, GA, USA and Toulouse, France). Multivariate analysis, Net Reclassification Improvement (NRI) and Integrated Discrimination Improvement (IDI) were performed in the 3 cohorts. The primary outcome was cardiovascular mortality. RESULTS: In multivariate Cox proportional hazards analysis, the highest quartile of IGFBP2 was associated with mortality in the Maastricht cohort (adjusted hazard ratio 1.69 (95% CI, 1.18-2.41), p = 0.004) and in the combined Atlanta and Toulouse cohorts (adjusted hazard ratio 2.04 (95%CI, 1.3-3.3), p = 0.003). Adding IGFBP2 to a clinical model allowed a reclassification of adverse outcome risk in the Maastricht cohort (NRI = 18.7% p = 0.03; IDI = 3.9% p = 0.02) and with the Atlanta/Toulouse patients (NRI of 40.4% p = 0.01, 31,2% p = 0.04, 31.5% p = 0,02 and IDI of 2,9% p = 0,0005, 3.1% p = 0,0005 and 4,2%, p = 0.0005, for a follow-up of 1, 2 and 3 years, respectively). CONCLUSION: In 3 international cohorts, IGFBP2 level is a strong prognostic factor for cardiovascular mortality in HF, adding information to natriuretic monitoring and usual clinical markers, that should be further prospectively evaluated for patients' optimized care.