Monocyte–Platelets Aggregates as Cellular Biomarker of Endothelium-Dependent Coronary Vasomotor Dysfunction in Patients with Coronary Artery Disease

Monocyte–platelet aggregates (MPA) are increased in patients with acute coronary syndrome. We investigated whether MPA are associated with the presence of functionally significant coronary stenoses or with coronary arterial endothelial dysfunction. One hundred forty five patients undergoing elective coronary angiography were prospectively enrolled. Functional significance of coronary stenosis was assessed by fractional flow reserve (FFR). Thirty randomly selected patients underwent pacing protocol to evaluate Coronary endothelium-dependent vasomotor function (CVF). Whole blood was drawn to evaluate MPA. In patients with FFR ≤ 0.8 (FFRpos, n = 75), MPA did not significantly differ from FFR >0.8 patients (FFRneg, n = 70) (38.1 % [25.7–56.6] vs 34.0 % [20.5–49.9], p = 0.08). CVF was similar in FFRpos and FFRneg patients (percent vessel diameter change, %VDC = 7.19 % [6.01–10.9] vs 8.0 % [0.81–9.80], p = 0.78). Yet, patients with abnormal CVF showed higher MPA as compared to patients with preserved CVF (28.3 % [28.8–53.4] vs 20.5 % [17.0–32.9], p = 0.01). Moreover, MPA was inversely correlated with %VDC (R2 = 0.26, p < 0.01). MPA levels are significantly higher in patients with abnormal coronary vasomotor function regardless of the presence of functionally significant coronary stenosis.