Does direct inhibition bring direct benefit?

n this issue of the Journal, Ozaki et al1 provide the first noteworthy evidence of the beneficial effect of the direct renin inhibitor (DRI), aliskiren, combined with reninangiotensin system (RAS) inhibitors in the myocardial recovery process of early acute myocardial infarction (AMI). It is well-known that RAS inhibitors protect against myocardial damage in patients with AMI, but the role of DRIs in myocardial salvage after AMI has not been elucidated. The authors previously reported the negative association of the peak level of CD14+CD16− monocytes, which potentially differentiate into M1-type macrophages, with the extent of myocardial salvage after AMI. In the present study they demonstrate the additive myocardial salvage effect of DRI in combination with RAS inhibitors, which was assessed using cardiac MRI, in negative association with the peak level of CD14+CD16− monocytes.