Platelet function testing in atrial fibrillation patients undergoing percutaneous coronary intervention.

Platelet function testing (PFT) could be a useful clinical tool to guide individualized antithrombotic treatment in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI). We aimed to investigate platelet reactivity (PR) in the context of a contemporary registry. "Real-world" data were retrieved from a nationwide, multicenter, observational study of AF patients on oral anticoagulants (OAC) undergoing PCI. Patients treated with a P2Y12 inhibitor, namely clopidogrel or ticagrelor, as part of double or triple antithrombotic therapy, were submitted to PFT before discharge and were followed up for 12 months. Out of 101 patients included in the study, 66 were submitted to PFT while on clopidogrel and 35 while on ticagrelor; PR was 162.9 ± 68 PRU and 46.02 ± 46 PRU, respectively (P < 0.001). High on-treatment PR (HTPR) was observed in 15 patients under clopidogrel (22.7%); 7 of them escalated to ticagrelor. Low on-treatment PR (LTPR) was found in 9 clopidogrel and 28 ticagrelor-treated patients (13.6% vs. 80%, P < 0.001), of whom only 1 de-escalated to clopidogrel. PR did not differ by OAC regimen. PFT results had no impact on aspirin prescription at discharge, while failed to predict significant bleeding events at follow up. Ticagrelor administration led to lower PR and lower incidence of HTPR in comparison with clopidogrel. Physicians' behavior in response to knowledge of a patient's PR was variable. Further studies are required to elucidate the role of PFT as a tool to guide individualized antithrombotic treatment in this clinical scenario.

One-Year Outcomes in Anticoagulated Atrial Fibrillation Patients Undergoing Percutaneous Coronary Intervention: Insights From the Greek Antiplatelet Atrial Fibrillation Registry.

ABSTRACT: GReek-AntiPlatElet Atrial Fibrillation registry is a multicenter, observational, noninterventional study of atrial fibrillation patients undergoing percutaneous coronary intervention. Primary endpoint included clinically significant bleeding rate at 12 months between different antithrombotic regimens prescribed at discharge; secondary endpoints included major adverse cardiovascular events and net adverse clinical events. A total of 647 patients were analyzed. Most (92.9%) were discharged on novel oral anticoagulants with only 7.1% receiving the vitamin K antagonist. A little over half of patients (50.4%) received triple antithrombotic therapy (TAT)-mostly (62.9%) for ≤1 month-whereas the rest (49.6%) received dual antithrombotic therapy (DAT). Clinically significant bleeding risk was similar between TAT and DAT [Hazard ratio (HR) = 1.08; 95% confidence interval (CI), 0.66-1.78], although among TAT-receiving patients, the risk was lower in those receiving TAT for ≤1 month (HR = 0.50; 95% CI, 0.25-0.99). Anticoagulant choice (novel oral anticoagulant vs. vitamin K antagonist) did not significantly affect bleeding rates ( P = 0.258). Age, heart failure, leukemia/myelodysplasia, and acute coronary syndrome were associated with increased bleeding rates. Risk of major adverse cardiovascular events and net adverse clinical events was similar between ΤAT and DAT (HR = 1.73; 95% CI, 0.95-3.18, P = 0.075 and HR = 1.39; 95% CI, 0.93-2.08, P = 0.106, respectively). In conclusion, clinically significant bleeding and ischemic rates were similar between DAT and TAT, although TAT >1 month was associated with higher bleeding risk.

De-Escalation of Treatment With Oral P2Y12 Receptor Inhibitors: Current Status and Perspectives.

In patients with an acute coronary syndrome undergoing percutaneous coronary intervention, novel P2Y12 receptor inhibitors, prasugrel and ticagrelor, are proposed as "first-line" antiplatelet agents in the absence of contraindications and up to a year from the index event. However, de-escalation of treatment to clopidogrel occurs with a variable frequency in real-life practice, most commonly due to an increased bleeding potential, more frequent side effects, and a higher cost for the novel agents. Pharmacodynamic studies provide most of the data on guidance for de-escalation. Despite positive messages from recent trials and registries, lack of definitive efficacy or safety results of such a strategy remains an obstacle to suggest de-escalation in a routine basis. Carefully designed studies are likely to improve our understanding of the impact of de-escalation and help to better define its position in current pharmacotherapy.