In the current study, we discovered that simvastatin induced Klf2 expression which directly repressed the enhanced TGFβ1 expression in cardiac microvasculature ECs of TAC induced fibrotic heart to reduce fibroblast proliferation, migration and myofibroblast formation, as well as ECM production, thus ameliorated the pathological cardiac fibrosis, and further improved the cardiac dysfunction induced by the TAC operation. This evidence concerns the gene TGFB1 and persistent truncus arteriosus.