Levels of Circulating Intermediate Monocytes Decrease after Aortic Valve Replacement in Patients with Severe Aortic Stenosis.

Aortic valve stenosis (AS) is a chronic inflammatory disease. We have previously shown that severe AS is associated with increased levels of circulating intermediate monocytes. Haemodynamics are considered to influence levels of circulating monocyte subsets; we therefore hypothesized that aortic valve replacement may result in changes in the distribution of circulating monocyte subsets. In the present study, we evaluated levels of circulating monocyte subsets in patients with severe AS undergoing surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR). Levels of classical (CD14++CD16–), intermediate (CD14++CD16+), and non-classical (CD14+CD16++) CD86-positive monocytes were determined by flow cytometry in peripheral blood of patients with severe AS before (baseline) and at 3- and 6-month follow-ups (FUP) after SAVR (n = 25 patients) or TAVR (n = 44 patients). Absolute and relative levels of circulating intermediate monocytes decreased from median 39.9/µL (interquartile range [IQR]: 31.7–53.6/µL) and 6.7% (5.6–8.1%) at baseline to 31.6/µL (24.3–42.4/µL; p < 0.001) and 5.4% (4.4–6.7%; p < 0.001) at 6-month FUP after aortic valve replacement, respectively. The decrease in levels of circulating intermediate monocytes appeared earlier (between baseline and 3-month FUP) in the TAVR group compared with the SAVR group (between 3- and 6-month FUP). In conclusion, levels of circulating intermediate monocytes decrease after SAVR or TAVR in patients with severe AS.