Even though a more recent placebo-controlled trial on 16 patients with CHF showed correction of endothelial dysfunction and improved non-endothelium dependent vasodilation [123], other randomized, placebo-controlled studies have failed so far to show any significant GH-mediated improvement of cardiac performance in patients with heart failure, despite significant increases in IGF-I [124, 125]. This evidence concerns the gene IGF1 and heart failure.