Antithrombotic Therapy in Patients Taking Oral Anticoagulants and Undergoing Percutaneous Coronary Intervention: Time to Be Bold and Wise

Finding the optimal antithrombotic therapy in patients undergoing percutaneous coronary intervention (PCI) with an indication for long-term oral anticoagulants remains a challenge.1 The ultimate goal is to find the best antithrombotic regimen—the right drugs, at the right doses, for the right duration—to prevent ischemic events while minimizing bleeding. Clinical decision-making requires therefore consideration of ischemic and bleeding risk, whether assessed intuitively or by risk score, taking into account clinical presentation (acute or chronic coronary syndrome), comorbidities (ie, diabetes and renal impairment), coronary anatomy, and other factors.2,3 Patients with atrial fibrillation (AF) treated with coronary stenting account for most of these cases. In this scenario, based on large randomized trials and meta-analyses,4 most recent European guidelines endorse—with the highest class of recommendation—a short course of triple antithrombotic therapy (≤1 week) followed by a dual therapy with a nonvitamin K antagonist oral anticoagulant (NOAC) and a P2Y12 inhibitor (preferably clopidogrel).5,6 An alternative regimen consisting of prolonged triple therapy (ie, up to 1 month) is deemed as reasonable in patients at high ischemic and low bleeding risk, but it is based primarily on ‟expert opinion” rather than evidence.5,6 Noteworthy, a non-negligible proportion of patients undergoing PCI receive a combination of anticoagulant and antiplatelet agents for reasons other than AF, such as mechanical valve prostheses, venous thromboembolism, and ventricular thrombosis. In this setting, the evidence is less robust,5,7 and the management remains poorly standardized. Given the difficulty of treating these patients, a nonuniform prescription of antithrombotic regimens persists for both type and duration. Therefore, data from real-world are welcome and useful to understand if and how clinicians integrate novel evidence and follow guidelines recommendations in daily practice. In this issue of the Journal of Cardiovascular Pharmacology, Tanner et al8 presented the results of a real-world retrospective study investigating patients undergoing PCI and having an indication for oral anticoagulation because of various clinical conditions from an Irish high-volume PCI center. Over a 1-year period, 133 of 1650 (or 8.1%) consecutive patients treated with PCI were discharged with a combination of oral antiplatelet and anticoagulant agents,8 which is in line with contemporary cohorts from other European real-world registries.3,9 Most patients had a diagnosis of AF, were discharged on triple antithrombotic therapy, and received a NOAC in preference of vitamin K antagonists as currently advised.5,6 The mean duration of triple therapy was 6 weeks that is—particularly in the case of AF—longer than what guidelines recommend (1-week duration as default strategy), but somewhat justifiable considering that 80% of stent thrombosis in patients with early aspirin discontinuation occurs within the first month after PCI.10 Approximately the same number of patients were discharged on dual antithrombotic therapy with either clopidogrel or aspirin (about 9% in both groups). This approach deviates from guidelines recommendations, which support the use of clopidogrel over aspirin in combination with oral anticoagulants5,6 and reflects the enduring belief that aspirin is a ‟must-have” drug after PCI. Concerns for possible clopidogrel resistance can also partly explain this attitude. However, clinically meaningful events (ie, stent thrombosis) remain rare even in patients with apparent poor responsiveness to clopidogrel.11 Accordingly, the use of platelet function or genetic testing to guide antithrombotic therapy remains debated and should be considered in selected patients only.5,12 It is also worth noting that Tanner et al8 reported infrequent use of intracoronary imaging at their institution (less than 1%). Considering the importance of a high-quality PCI to reduce the risk of stent-related complications,5 a more extensive use of intracoronary imaging remains desirable for stent optimization, especially in patients planned for early aspirin discontinuation. At a glance, the study reveals a substantial heterogeneity in the combination as well as the duration of antithrombotic agents prescribed at discharge, which reflects the complexity of the clinical scenario and uncertainty of clinicians in deciding which therapy represents the optimum for each individual patient. In such struggling situations, the clinical judgment might benefit from validated tools to stratify the risk and guide decision-making. However, in this real-world study, the decision to adopt a more intense and/or prolonged antithrombotic therapy seemed decoupled from the thrombotic and bleeding risk predicted by risk scores (ie, CHA2DS2-VASc and HAS-BLED), meaning that the prescription was based on the discretion of the treating physicians and confirming a sort of disaffection of clinicians for risk scores. As a note, the HAS-BLED score, which is currently recommended by guidelines for bleeding risk prediction, has been generated from vitamin K antagonists–treated patients and might be less practical in the contemporary NOACs era. In this context, the recently proposed and validated Academic Research Consortium for High Bleeding Risk criteria should be preferred for bleeding risk stratification after PCI.2,3 Among other prediction models, the PRECISE-DAPT score, which has been previously validated in patients on single and dual antiplatelet therapy,13 has been recently proposed to predict the risk of bleeding and select the optimal antithrombotic strategy in AF patients treated with PCI.14 Altogether, data presented by Tanner et al8 reinforce the concept that an individualized approach in patients with recent coronary stenting and an indication for long-term oral anticoagulation is critical. Bleeding and ischemic risk factors have continuous and dynamic interactions with each therapeutic intervention and need to be comprehensively taken into account to select the optimal treatment (Fig. 1).2,3 The exercise of carefully assessing clinical, laboratory, and procedural factors remains essential to guide decision-making in this conundrum.FIGURE 1.: Finding the optimal antithrombotic therapy in patients taking oral anticoagulants and undergoing percutaneous coronary intervention. ACS, acute coronary syndrome; CAD, coronary artery disease; PAD, peripheral artery disease.The time has come to be bold and wise in choosing the antithrombotic therapy in patients taking an oral anticoagulant and undergoing PCI. We have to be bold in trusting evidence that early cessation of aspirin (1 week or shortly after) is safe and warranted in most cases. We have to be wise in recognizing that in the subset of patients in whom concerns about ischemic risk prevail (ie, acute presentation, high thrombotic burden, and/or complex PCI), continuing aspirin for 1 month (or slightly more) should be advised, and triple therapy duration tailored to the patient's need.