CCN2 and heart failure: Moreover, there was a progressive increase of atrial mRNA levels of collagen 1a, 3a and connective tissue growth factor (CTGF) with progression of LV hypertrophy, while the increase of atrial transforming growth factor-β (TGFβ) and matrix metalloproteinase 2 coincided with LA dilatation and the transition from compensatory hypertrophy to heart failure [103,109].