After TAC, cardiac function deteriorated in Fgf23fl/fl/cre+ and Fgf23fl/fl/cre− mice compared to sham controls and the evaluation of cardiac Fgf23 synthesis revealed elevated expression in cardiac fibroblasts and endothelial cells after TAC even in Fgf23fl/fl/cre+ mice. This evidence concerns the gene FGF23 and persistent truncus arteriosus.