Prognostic Value of Insulin-Like Growth Factor-Binding Protein 7 in Patients with Heart Failure and Preserved Ejection Fraction

BACKGROUND: The prognostic merit of insulin-like growth factor-binding protein 7 (IGFBP7) is unknown in heart failure and preserved ejection fraction (HFpEF). METHODS AND RESULTS: Baseline IGFBP7 (BL-IGFBP7; n = 302) and 6-month change (Δ; n = 293) were evaluated in the Irbesartan in Heart Failure and Preserved Ejection Fraction (I-PRESERVE) trial. Primary outcome was all-cause mortality or cardiovascular hospitalization with median follow-up of 3.6 years; secondary outcomes included HF events. Median BL-IGFBP7 concentration was 218 ng/mL. BL-IGFBP7 was significantly correlated with age (R² = 0.13; P < .0001), amino-terminal pro-B-type NP (R² = 0.22; P < .0001), and estimated glomerular filtration rate (eGFR; R² = 0.14; P < .0001), but not with signs/symptoms of HFpEF. BL-IGFBP7 was significantly associated with the primary outcome (hazard ratio [HR] = 1.007 per ng/mL; P < .001), all-cause mortality (HR = 1.008 per ng/mL; P < .001), and HF events (HR = 1.007 per ng/mL; P < .001). IGFBP7 remained significant for each outcome after adjustment for ln amino-terminal pro-B-type NP and eGFR but not all variables in the I-PRESERVE prediction model. After 6 months, IGFBP7 did not change significantly in either treatment group. ΔIGFBP7 was significantly associated with decrease in eGFR in patients randomized to irbesartan (R² = 0.09; P = .002). ΔIGFBP7 was not independently associated with outcome. CONCLUSIONS: Higher concentrations of IGFBP7 were associated with increased risk of cardiovascular events, but after multivariable adjustment this association was no longer present. Further studies of IGFBP7 are needed to elucidate its mechanism. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov, NCT00095238.