Assessment of platelet functional activity in healthy individuals and patients receiving antiplatelet therapy. Possible inconsistencies between aggregation and flow cytometry tests.

Platelet functional activity was assessed in healthy volunteers (HV, n=92), patients with stable angina pectoris (SA, n=42) and acute coronary syndrome (ACS, n=73), treated with acetylsalicylic acid (ASA) + clopidogrel and ASA + ticagrelor, respectively. In all HV and patients we have compared parameters of platelet aggregation (maximum light transmission and velocity, Tmax and Vmax) and parameters, characterizing exposure of platelet activation markers, evaluated by flow cytometry. HV platelets were activated by 10 µM, 1 µM TRAP, and 20 µM, 5 µM, 2.5 µM ADP; patient platelets were activated by 10 µM TRAP and by 20 µM and 5 µM ADP. Strong and significant correlations between the aggregation and flow cytometry parameters (the r correlation coefficient from 0.4 up to >0.6) most frequently were registered in HV platelet during activation by 1 µM TRAP and in SA patients during platelet activation by 20 µM and 5 µM ADP. However, in many other cases these correlations were rather weak (r < 0.3) and sometimes statistically insignificant. In HV the differences in PAC-1 binding parameters between platelets activated by 10 µM TRAP (the strongest agonist) and all ADP concentrations were negligible (≤ 10%), while CD62P binding (at all ADP concentrations) and LTA parameters for (5 µM and 2.5 µM ADP) were significantly lower (by 40-60%). Antiplatelet therapy in patients decreased all parameters as compared to HV, but to varying extents. For 10 µM TRAP the MFI index for PAC-1 binding (40-50% decrease) and for both ADP concentrations the Tmax values (60-85% decrease) appeared to be the most sensitive in comparison with the other parameters that decreased to a lesser extent. The data obtained indicate a possibility of inconsistency between different LTA and flow cytometry parameters in assessing platelet activity and efficacy of antiplatelet drugs.

Assessment of the relationship between C-reactive protein-to-albumin ratio and slow coronary flow in patients with stable angina pectoris.

BACKGROUND: The relationship between severity of coronary artery disease and inflammatory parameters has been previously demonstrated. However, there is a lack of data regarding the role of C-reactive protein-to-albumin ratio (CAR) in slow coronary flow (SCF) in patients with stable angina pectoris (SAP). In this study, we aimed to investigate the relationship between CAR and presence of SCF in patients with SAP. PATIENTS AND METHODS: This study enrolled 217 patients undergoing coronary angiography for SAP. SCF was detected in 81 (37.3%) patients, and the control group included 136 patients. All clinical, demographical, and laboratory parameters were entered into a dataset and compared between SCF group and the controls. RESULTS: The mean age of the patients was 66.1 ± 12.1 years (male: 57.1%). C-reactive protein and CAR were significantly higher in patients with SCF compared with controls (P = 0.004 and < 0.001, respectively). Logistic regression analysis demonstrated that high CAR level was an independent determinant of SCF (odds ratio: 1.023; 95% confidence interval: 1.013-1.034; P < 0.001). CONCLUSION: Higher CAR level may be a valuable predictor of SCF in patients with SAP who undergo coronary angiography. Inflammation may play an important role in the pathogenesis of SCF.