Enhanced platelet NLRP3 inflammasome expression in patients with acute coronary syndrome and stable coronary artery disease: A prospective observational study

Background and purpose: Nucleotide-binding domain leucine-rich repeat containing protein (NLRP3) inflammasome contributes to the development and progression of atherosclerosis and cardiovascular diseases. Enhanced expression of NLRP3 in monocytes has been reported in patients with coronary artery disease (CAD). However, NLRP3 expression in platelets, an important link between inflammation and atherosclerosis/thrombosis in CAD patients has not been evaluated. The purpose of this study was to explore the expression of NLRP3 in platelets with acute coronary syndrome (ACS) and stable CAD. Methods: This prospective observational study included 60 treatment-naïve patients with newly diagnosed ACS, 60 patients with stable CAD, and 60 age- and sex-matched healthy individuals with normal coronary arteries (NCA). Platelet NLRP3 expression was evaluated by flow cytometry in venous blood samples, and compared among the 3 groups. Multivariate regression analysis was conducted to identify the risk of ACS. Results: Platelet NLRP3 expression was highest in the ACS group, followed by the stable CAD, and lowest in the NCA group (P < 0.001 for ACS vs. stable CAD, 44.7 ± 21.3 vs. 25.9 ± 15.9, as well as for stable CAD, vs. NCA, 25.9 ± 15.9 vs. 12.4 ± 7.2). Higher platelet NLRP3 correlated with higher plasma interleukin-1β and interleukin-18 (r = 0.662 and 0.324, respectively; P < 0.001 for both). In multivariate regression analysis, higher platelet NLRP3 was independently associated with ACS (odds ratio 1.06, 95% CI: 1.02–1.10 vs. stable CAD; odds ratio 1.23, 95% CI: 1.06–1.42 vs. NCA). Conclusion: Platelet NLRP3 expression was highest in the ACS group, followed by the stable CAD group, and lowest in the NCA group. Also, higher platelet NLRP3 expression was independently associated the ACS.