MSTN and heart failure: Fig 1B shows gene expression of stress and fibrosis markers in the myocardial samples from our study. Significantly increased expression of BNP (p = 0.04) and MSTN (p = 0.04) indicates ongoing cardiac stress and cardiomyocyte atrophic process characteristic of end-stage remodeling in heart failure (10). Unchanged levels of markers of fibrosis (ACTA2, COL1A1 and TGFβ1) suggest a mature fibrotic scar without active pro-fibrotic gene expression.