AGT and heart failure: The current study also provides evidence supporting the critical role that myeloid cells play in nonischemic heart failure.47,48 Previous work has documented the expansion of the cardiac macrophage pool during the early phases of Ang II infusion,49 but the functional role of monocyte derived-macrophages in this model is controversial.50,51 Here, it is shown that the cardiac remodeling response to Ang II stimulation is highly dependent on the participation of bone marrow-derived CCR2+ monocytes and macrophages.