IGF1 and heart failure: Of these, 136 records were excluded: these were not IGF-1 and HF (n = 113), not heart failure (n = 1), not blood sample or venous blood sample (n = 4), review or meta-analysis (n = 1), the reports of studies that was no HF group (n = 2), or the studies of which did not have control group (n = 11), use duplicate samples (n = 1), not detailed data available (n = 4).