Antithrombotic therapy in high-risk patients after percutaneous coronary intervention; study design, cohort profile and incidence of adverse events

Background Patients with multiple clinical risk factors are a complex group in whom both bleeding and recurrent ischaemic events often occur during treatment with dual/triple antithrombotic therapy after percutaneous coronary intervention. Decisions on optimal antithrombotic treatment in these patients are challenging and not supported by clear guideline recommendations. A prospective observational cohort study was set up to evaluate patient-related factors, platelet reactivity, genetics, and a broad spectrum of biomarkers in predicting adverse events in these high-risk patients. Aim of the current paper is to present the study design, with a detailed description of the cohort as a whole, and evaluation of bleeding and ischaemic outcomes during follow-up, thereby facilitating future research questions focusing on specific data provided by the cohort. Methods We included patients with ≥ 3 predefined risk factors who were treated with dual/triple antithrombotic therapy following PCI. We performed a wide range of haemostatic tests and collected all ischaemic and bleeding events during 6–12 months follow-up. Results We included 524 high-risk patients who underwent PCI within the previous 1–2 months. All patients used a P2Y12 inhibitor (clopidogrel n = 388, prasugrel n = 61, ticagrelor n = 75) in combination with aspirin (n = 397) and/or anticoagulants (n = 160). Bleeding events were reported by 254 patients (48.5%), necessitating intervention or hospital admission in 92 patients (17.5%). Major adverse cardiovascular events (myocardial infarction, stroke, death) occurred in 69 patients (13.2%). Conclusion The high risk for both bleeding and ischaemic events in this cohort of patients with multiple clinical risk factors illustrates the challenges that the cardiologist faces to make a balanced decision on the optimal treatment strategy. This cohort will serve to answer several future research questions about the optimal management of these patients on dual/triple antithrombotic therapy, and the possible value of a wide range of laboratory tests to guide these decisions.

Safety and Efficacy of Triple Therapy With Ticagrelor or Prasugrel Versus Clopidogrel After Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction

Background: Patients on dual antiplatelet therapy following percutaneous coronary intervention often have indications for concomitant oral anticoagulation, known as triple antithrombotic therapy. Majority of literature evaluating triple antithrombotic therapy fails to adequately represent patients with ST-elevation myocardial infarction and those prescribed potent P2Y12 inhibitors, ticagrelor or prasugrel. The purpose of this study was to evaluate the safety and efficacy of triple antithrombotic regimens containing ticagrelor or prasugrel versus clopidogrel after percutaneous coronary intervention in the setting of ST-elevation myocardial infarction. Methods: This was a single-center, retrospective cohort trial. The primary endpoint was net adverse clinical event, defined as the primary efficacy endpoint of death, myocardial infarction, or cerebrovascular accident and the primary safety endpoint of any bleeding event. Results: Between October 2017 and October 2019, a total of 65 patients with ST-elevation myocardial infarction were initiated on triple therapy. Forty-six patients were included in the primary analysis, of which 26 were discharged on triple antithrombotic therapy with clopidogrel and 20 discharged on potent P2Y12 inhibitors (ticagrelor or prasugrel). The primary endpoint occurred in 27% of the clopidogrel group and 40% of the potent P2Y12 inhibitor group ( P = 0.35). Bleeding occurred in 23% of the clopidogrel group and 35% of the potent P2Y12 inhibitor group ( P = 0.37). Conclusions: This small cohort study suggests, in patients with ST-elevation myocardial infarction undergoing percutaneous coronary intervention, the net adverse clinical event rate does not differ between clopidogrel and potent P2Y12 inhibitors in the setting of triple antithrombotic therapy. The results of this exploratory analysis warrant confirmation in a larger, randomized study.

Comparison of Bleeding Rates between Oral Anticoagulants in Combination with Dual Antiplatelet Therapy (Triple Therapy) in a Real-World Cohort

Background: Triple antithrombotic therapy including an anticoagulant, P2Y12 inhibitor, and aspirin increases bleed risk up to 27%. The components of this regimen can vary, which may impact bleed risk. Objective: To compare the safety of various triple antithrombotic regimens. Methods: An Institutional Review Board approved retrospective cohort study was conducted from 2014 to 2017. Patients admitted to a large urban health system on triple therapy were evaluated for inclusion. The primary outcome compared rates of International Society of Thrombosis and Hemostasis major and clinically relevant nonmajor bleeding during index admission or within 90 days in patients receiving warfarin, rivaroxaban, or apixaban; aspirin; and a P2Y12 inhibitor. A multivariable logistic regression assessed the association between bleeding, antithrombotic use, and relevant confounding variables. Results: Three hundred and seventy-two patients were included: 238 patients received warfarin, 63 received rivaroxaban, and 71 received apixaban. Forty-five patients (12.1%) experienced a bleed, 25 of which (55.6%) were major. The rate of bleeding was 12.2% (n = 29) with warfarin, 14.3% (n = 9) with rivaroxaban, and 9.9% (n = 7) with apixaban ( P = .7335). The use of prasugrel versus clopidogrel (OR 4.35, 95% CI 1.20-15.72; P = .025) and admission hemoglobin less than 12 mg/dL (OR 2.54, 95% CI 1.28-5.04; P = .008) were identified as risk factors associated with bleeding in the model. Conclusion: In patients on triple antithrombotic therapy, choice of oral anticoagulant did not impact bleeding rates, but use of prasugrel and a low baseline hemoglobin were associated with increased bleed rates which warrants further investigation.

Antithrombotic Therapy in Complex Percutaneous Coronary Intervention Patients Requiring Chronic Anticoagulation

The optimal antithrombotic treatment in patients receiving oral anticoagulation undergoing percutaneous coronary intervention (PCI) has been a field of intensive research. Although triple antithrombotic therapy had been, until lately, the strategy of choice, recent evidence points to the superiority of dual antithrombotic therapy regarding bleeding prevention, without significantly compromising efficacy. In the further challenging scenario of complex PCI, associated with a higher ischemic risk, the efficacy of an aspirin-free strategy, adopted shortly after the index event is under question, rendering decision-making a fairly difficult scenario for clinicians. Since patients with an indication for oral anticoagulation undergoing complex PCI are underrepresented in randomized trials, there are scarce data regarding the optimal treatment strategy in such patients. This review aims to analyze and compare different approaches regarding the type and duration of antithrombotic regimens, focusing on both safety and efficacy outcomes, as well as to discuss recent guidelines’ suggestions regarding the therapeutic approach in patients receiving oral anticoagulation undergoing PCI procedures of increased complexity.

Impact of Platelet Reactivity in ACS Patients on Clinical Outcomes with Triple Antithrombotic Therapy

Optimal antithrombotic therapy after percutaneous coronary intervention (PCI) in patients on oral anticoagulants (OAC) remains a clinical conundrum. In fact, combining an OAC with dual antiplatelet therapy (triple antithrombotic therapy, TAT) increases the risk of bleeding. Clopidogrel is the only thienopyridine recommended in TAT patients. Whether its response plays a relevant role in this setting remains uncertain. We aimed to evaluate the level of platelet reactivity inhibition (PRI) achieved by oral TAT in Acute Coronary Syndrome (ACS) patients undergoing PCI and its relationship with outcomes. We performed a multicenter prospective observational study and assessed PRI by vasodilator-stimulated phosphoprotein (VASP) index following a loading dose of clopidogrel. The primary endpoint was the incidence of major adverse cerebral or cardiovascular events (MACCE) at six months based on High on Treatment Platelet Reactivity (HTPR, VASP > 50%). The secondary endpoint was the incidence of bleeding at six months based on Low on Treatment Platelet Reactivity (LTPR, VASP < 16%). 491 patients were followed up for six months: 7.7% experienced MACCE and 17.3% experienced bleeding. There was no significant relationship between HTPR and MACCE, neither between LTPR and bleeding. Vitamin-K antagonist (VKA) treatment was associated with more MACCE and bleeding events, and the majority of events occurred within the first months. VASP index failed to predict outcomes in post-ACS patients with TAT. We confirm that direct acting OAC should be prioritized over VKA in TAT regimen.