Platelet reactivity expressed as a novel platelet reactivity score is associated with higher inflammatory state after coronary artery bypass grafting.

Introduction: Despite therapy, patients operated using a cardiopulmonary bypass demonstrate increased platelet aggregation, which rebounds to above preoperative levels. The aim of the study was to test the interaction between platelet reactivity/activation and selected inflammatory markers in the post-operative period.

Material And Methods: In total, 103 patients with non-ST elevation acute coronary syndrome (NSTE-ACS) who were not eligible for percutaneous coronary interventions (PCI), and required urgent revascularization, were included. Platelet reactivity was measured using the PFA-100 platelet analyser, multiple electrode aggregometry, and was expressed as a novel platelet reactivity score (PRS). Patients were divided using their PRS scores into high platelet relativity or low platelet reactivity subgroups (HPR or LPR). Platelet basal activation was measured using immunoassays for soluble P-selectin and soluble CD40L. We measured high-sensitivity C-reactive protein (CRP), and used immunoassays for tumour necrosis factor α (TNF-α) and interleukin 6 (IL-6) as inflammation markers.

Results: Significant differences between HPR and LPR groups were found for CRP (mg/l): 81.5 vs. 44.6, < 0.02; and TNF-α (pg/l): 3.51 vs. 2.37, < 0.02. A significant association was found between CRP, TNF-α, IL-6 and platelet reactivity (platelet reactivity score). Cohen's k showed: CRP = 0.49, < 0.0001, TNF-α = 0.37, < 0.002. Perioperative myocardial infarction and rhythm disturbances occurred more frequently in the high platelet reactivity group: 7 (16.3%) vs. 2 (3.3%), < 0.04, and 9 (20.9%) vs. 4 (6.7%), < 0.04, respectively.

Conclusions: Inflammatory parameters CRP and TNF-α are strongly associated with platelet reactivity (expressed as PRS) in cardiopulmonary bypass graft patients. Platelet hyperreactivity in the early post-operative period combined with a systemic inflammatory state correlates with a higher risk of post-operative rhythm disturbances and myocardial infarction.