RESUMO
Background: Chronic renal failure (CKD) is associated with the presence of increased platelet reactivity and lower clinical benefit of clopidogrel. Ticagrelor has a more favorable pharmacodynamic and pharmacokinetic profile compared to clopidogrel, which has translated into better clinical outcomes in patients with acute coronary syndrome (ACS). We conducted a prospective mechanistic cohort study in order to investigate the impact of renal failure on the pharmacokinetics and pharmacodynamics of ticagrelor in patients with acute ACS. Methods: Patients were divided into two groups based on their estimated renal clearances (eGFR ≥ 60 mL/min and eGFR < 60 mL/min). Platelet function was determined using the VerifyNow system at baseline, after the ticagrelor loading dose and at discharge. In addition, levels of ticagrelor and its active metabolite (AR-C124910XX) were determined in the first hour after loading dose. Results: 48 patients were recruited (eGFR ≥ 60 mL/min: 35 and eGFR < 60 mL/min: 13). There were no significant differences between the groups in terms of platelet inhibition after the loading or after 7 days of treatment (p = 0.219). However, the levels of ticagrelor and its active metabolite were lower in subjects with normal renal function than in CKD, especially at 4 (p = 0.02 and 0.04 respectively) and 6 h of loading (p = 0.042 and 0.08 respectively). Conclusion: No differences in platelet inhibition were observed after treatment with ticagrelor in patients with different renal function, although patients with renal impairment showed higher levels of ticagrelor and AR-C124910XX after 4 h of the loading dose.
