AGT and aortic valve calcification: Activation of the local RAS in aortic valves has been seen in AS;44,45 angiotensin II is implicated in aortic valve thickening;17 and aortic valve weights (extracted at the time of AVR) are significantly lower in AS patients taking ARBs.46 Retrospective clinical studies show conflicting results however: O'Brien et al.47 reported significant reductions in aortic valve calcification in AS treated with ACEi, while Rosenhek et al.5 found no change in the progression of aortic valve disease or calcification.