Effect of Direct Renin Inhibitor, Aliskiren, on Peripheral Blood Monocyte Subsets and Myocardial Salvage in Patients With Primary Acute Myocardial Infarction

Background: It remains unclear whether angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II type 1 receptor blockers (ARBs) have fully delivered the expected reduction in cardiovascular diseases. We investigated the effects of adding the direct renin inhibitor (DRI), aliskiren, to an ACEI or an ARB on monocyte subsets and myocardial salvage in patients with primary acute myocardial infarction (AMI). Methods and Results: Twenty-one consecutive patients were treated with an ACEI or an ARB (non-DRI group), and another 21 consecutive patients received aliskiren combined with an ACEI or an ARB (DRI group). Two monocyte subsets (CD14+CD16- and CD14+CD16+) were measured by flow cytometry. The extent of myocardial salvage 7 days after AMI was evaluated by cardiac magnetic resonance imaging. Both plasma renin activity and aldosterone levels were significantly lower in the DRI group than in the non-DRI group. Peak levels of CD14+CD16- monocyte number and ratio were also significantly lower in the DRI group. The extent of myocardial salvage was significantly higher in the DRI group than in the non-DRI group (44.8 [41.2-53.1] vs. 36.0 [28.5-42.6], P=0.001). Conclusions: A DRI combined with an ACEI or an ARB can better improve the extent of myocardial salvage after AMI than an ACEI or an ARB alone in association with the decrease in circulating CD14+CD16- monocytes. (Circ J 2012; 76: 1461-1468)