Gender Differences in Platelet Reactivity in Patients Receiving Dual Antiplatelet Therapy

Background Cardiovascular risk is still underestimated in women, experiencing higher mortality and worse prognosis after acute cardiovascular events. Gender differences have been reported in thrombotic and hemorrhagic risk during dual antiplatelet therapy (DAPT), thus suggesting a potential variability in platelet reactivity according to sex. The aim of the present study was to assess the role of gender on platelet function and the prevalence of high-on treatment residual platelet reactivity (HRPR) during DAPT in patients with recent acute coronary syndrome or percutaneous coronary revascularization. Methods Patients treated with DAPT (ASA and clopidogrel or ticagrelor) were scheduled for platelet function assessment at 30-90 days post-discharge. By whole blood impedance aggregometry, HRPR was considered for ASPI test >862 AU*min (for ASA) and ADP test values >= 417 AU*min (for ADP-antagonists). Results We included 541 patients on DAPT, 122 (22.6 %) of whom were females. Females were older (p < 0.001), displayed more frequently hypercholesterolemia (p = 0.003), renal failure (p = 0.04), acute presentation (p < 0.001), higher cholesterol levels and platelets count (p < 0.001). Inverse association was demonstrated with smoking (p < 0.001), previous PCI (p = 0.04) and statin use (p = 0.03), creatinine and haemoglobin (p < 0.001). Female gender did not influence mean platelet reactivity or the prevalence of HRPR for ASA (1.7 % vs 1.4 %, OR[95%CI] = 1.14[0.17-4.36], p = 0.99, adjusted OR[95%CI] = 1.54[0.20-11.6], p = 0.68) or ADP-antagonists (26.3 % vs 22.8 %, OR[95%CI] = 1.17[0.52-1.34], p = 0.45, adjusted OR[95%CI] = 1.05[0.59-1.86], p = 0.87). Results did not change when considering separately the 309 patients treated with clopidogrel (34 % vs 31.3 %, OR[95%CI] = 1.13[0.62-2.07], p = 0.76, adjusted OR[95%CI] = 1.35[0.63-2.9], p = 0.44 for females vs males), or patients (n = 232) on ticagrelor (20.4 % vs 11.1 %, OR[95%CI] = 2.27[0.99-5.17], p = 0.06 for females vs males), confirmed after correction for baseline differences (adjusted OR[95%CI] = 1.21[0.28-2.29], p = 0.68). Conclusion In patients receiving dual antiplatelet therapy, gender does not impact on the prevalence of high-on treatment residual platelet reactivity (HRPR) with the major antiplatelet agents ASA, clopidogrel or ticagrelor.