Patients' response to dual antiplatelet therapy (DAPT) is subject to variations and its monitoring allows to individualize this therapy. In this study, we evaluated if a strategy of tailored DAPT after platelet function testing could reduce high on-treatment platelet reactivity (HPR) and improve outcome of patients treated with stent implantation. In 257 patients undergoing percutaneous angioplasty, platelet function was measured by light transmittance aggregometry (LTA) using 10 µM/L adenosine-diphosphate (ADP) and 1 mM arachidonic acid (AA) as agonists. Patients with HPR by ADP (≥70%) were switched to double-dose clopidogrel, ticlopidine, prasugrel or ticagrelor; in patients with HPR by AA (≥20%) acetylsalicylic acid dose was increased if not contraindicated. Platelet function analysis was repeated 48 hours after therapy variation. At 20-month follow-up major adverse cardiovascular events (MACE) and bleedings were assessed. HPR was detected in 97/257 (37.7%) patients: 69/257 (26.8%) had HPR by ADP and 71/257 (27.6%) had HPR by AA. In patients with HPR by ADP or by AA, tailored DAPT determined a significant reduction in residual platelet reactivity. No significant difference in MACE or bleeding occurrence was documented in HPR patients treated with tailored DAPT vs. those without HPR. HPR patients treated with tailored DAPT had significant lower follow-up MACE and deaths vs. 139 HPR patients not switched, even after propensity score analysis. These results suggest that a DAPT tailored on platelet testing can improve antiplatelet response in HPR patients, possibly reducing their thrombotic events to a level similar to non-HPR patients, without increasing the risk of bleeding.
Keywords: Dual antiplatelet therapy; Percutaneous coronary intervention; Shifting therapy.