A comparative pharmacodynamic study of ticagrelor versus clopidogrel and ticagrelor in patients undergoing primary percutaneous coronary intervention: the CAPITAL RELOAD study

Switching Platelet P2Y12 Receptor Inhibiting Therapies

Antiplatelet therapy involving aspirin and a P2Y12 receptor inhibitor is fundamental in managing patients with atherothrombotic disease. Switching between P2Y12 inhibitors is frequently observed in clinical settings for various reasons, such as safety, efficacy, patient adherence, or cost concerns. Although it occurs often, the optimal method for switching remains a concern owing to potential drug interactions, which can result in either inadequate platelet inhibition and subsequent thrombotic events or low platelet reactivity and increased bleeding risks due to therapy overlap. This review offers practical guidance on switching P2Y12 inhibitors, drawing from pharmacodynamic and clinical data.

Refractory drug-induced systemic small-vessel vasculitis with two varied extracutaneous manifestations: a case report and review of the literature

BACKGROUND

Clopidogrel and ticagrelor are rarely reported to cause vasculitis via drug hypersensitivity reaction, largely mediated by T cells and immunoglobulin E (IgE). Despite therapeutic advances, the etiology of refractory vasculitides remains incompletely understood. Recently, (non)immunological mechanisms bypassing T cells and IgE have been proposed to explain resistance to standard immunosuppressants. Herein, we report a case of refractory drug-induced systemic small-vessel vasculitis with varied extracutaneous manifestations and incorporate multiple sources of data to provide detailed accounts of complex (non)immunological phenomena involved in this case. Study objectives are to provide an insight about rare presentations of commonly used drugs, upgrade the pathophysiological concepts of drug-induced vasculitis, raise need for further investigation to define causes and risk factors for refractory vasculitis, and discuss most of the current knowledge suggesting novel therapeutic approaches to treat this vasculitis. To our knowledge, this is the first case of the two flares of systemic small-vessel vasculitis in a single patient in response to clopidogrel and ticagrelor exposure, respectively. However, this report is limited by attribution/observer bias.

CASE PRESENTATION

We herein report a 24-year-old Caucasian male student with a medical history of mild seasonal allergic rhinoconjunctivitis, tension-type headaches, posttraumatic arterial stenosis, and previous exposure to ibuprofen, acetylsalicylic acid, and mRNA coronavirus disease 2019 (COVID-19) vaccine who suffered largely from acute urticaria and dyspnea after 20 days of acetylsalicylic acid and clopidogrel introduction. A skin punch biopsy confirmed leukocytoclastic vasculitis. Serologic antibody testing, complement analysis, microbiologic testing, and cancer biomarkers revealed no abnormalities. Regarding the patient's medical history, both acetylsalicylic acid and clopidogrel were exchanged for ticagrelor. Furthermore, the addition of naproxen, cyclosporine, bilastine, prednisolone, and montelukast resulted in complete recovery. After 7 days, diarrhea and hematuria occurred. Urinalysis and computed tomography showed reversible proteinuria with gross hematuria and hypodense changes in kidney medulla, respectively, associated with discontinuation of ticagrelor and naproxen. In addition, the patient recovered completely without any immunosuppression up-titration.

CONCLUSIONS

This case highlights the role of clopidogrel and ticagrelor as possible triggering agents for systemic small-vessel vasculitis and offers an insight into novel therapeutic strategies for refractory vasculitides. Further research is needed to build on the findings of a current report.

Optimal strategy of switching from clopidogrel to ticagrelor in Chinese acute coronary syndrome patients with complicated coronary artery disease: the switching from clopidogrel to ticagrelor (SHIFT-CACS) study

BACKGROUND

The dose and time point for switching from clopidogrel to ticagrelor remain controversial, especially for Chinese acute coronary syndrome (ACS) patients with complicated coronary artery disease (CAD). Hence, the purpose of this study was to further explore the optimal dose and time point for the switching strategy to balance the increase in platelet inhibition and the decrease in adverse events in Chinese ACS patients with complicated CAD managed by percutaneous coronary intervention (PCI).

METHODS

From July 2017 to December 2017, the prospective, randomized, open-label study (the SwitcHIng from clopidogrel to ticagrelor study) assigned the eligible Chinese ACS patients with complicated CAD managed by PCI (n = 102) for 90 mg of ticagrelor at 12 h (T-90 mg-12 h), 90 mg of ticagrelor at 24 h (T-90 mg-24h) or 180 mg ticagrelor at 24 h (T-180 mg-24 h) after the last dose of clopidogrel. The primary endpoint was the comparison of maximal platelet aggregation (MPA) values at 2 h after switching strategies among the three groups. In addition, the MPA values at baseline, 8 h and before discharge and the rates of high on-treatment platelet reactivity were evaluated, the incidences of bleeding episodes and dyspnea during hospitalization and at 30-day follow-up in our study were also recorded. The MPA was measured by light transmittance aggregometry in our study. A repeated-measures analysis of variance (ANOVA) model and one-way ANOVA were used to compare data for the primary endpoint.

RESULTS

The MPA values were significantly decreased in the T-180 mg-24 h group compared with the T-90 mg-12 h group (P = 0.017) and decreased numerically compared with the T-90 mg-24 h group (P = 0.072) at 2 h. In particular, the MPA values were markedly reduced in the T-90 mg-24 h group compared with the T-90 mg-12 h group at 8 h after switching treatment (P = 0.002). There was no significant difference among the three groups in all bleedings and dyspnea events.

CONCLUSIONS

The optimal treatment strategy recommended in this study for Chinese ACS patients with complicated CAD managed by PCI is 180 or 90 mg of ticagrelor at 24 h after the last dose of clopidogrel. In addition, a negative interaction was detected in this study between the overlap for clopidogrel and ticagrelor at 12 h after the last dose of clopidogrel.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03577652; http://clinicaltrials.gov/ct2/show/NCT03577652.

Pharmacodynamics During Transition Between Platelet P2Y12 Inhibiting Therapies

Several platelet P2Y₁₂ inhibiting agents, both oral and intravenous, are available for clinical use. The oral P2Y₁₂ inhibitors comprise clopidogrel, prasugrel, and ticagrelor. Cangrelor is the only intravenous P2Y₁₂ inhibitor. Numerous pharmacodynamic studies have been performed to assess the impact of P2Y₁₂ inhibitor switching on platelet reactivity profiles and to define the optimal strategy if switching is needed, with the goal of minimizing the risk of having inadequate platelet inhibition due to potential drug-drug interactions occurring during the drug overlap phase. This article provides an overview of pharmacodynamic studies assessing switching between P2Y₁₂ inhibitors and recommendations on switching modalities based on these findings.

Switching P2Y12 Receptor Inhibiting Therapies

Antiplatelet therapy with aspirin and a P2Y₁₂ receptor inhibitor is the cornerstone of treatment of patients with atherothrombotic disease manifestations. Switching between P2Y₁₂ inhibitors occurs commonly in clinical practice for a variety of reasons, including safety, efficacy, adherence, and economic considerations. There are concerns about the optimal approach for switching because of potential drug interactions, which may lead to ineffective platelet inhibition and thrombotic complications, or potential overdosing due to overlap in drug therapy, which might cause excessive platelet inhibition and increased bleeding. This review provides practical considerations of switching based on pharmacodynamic and clinical data available from the literature.

Ischemic and bleeding outcomes after coronary artery bypass grafting among patients initially treated with a P2Y12 receptor antagonist for acute coronary syndromes: Insights on timing of discontinuation of ticagrelor and clopidogrel prior to surgery

BACKGROUND

Clinical outcomes in acute coronary syndrome patients treated with P2Y₁₂ inhibitors who require urgent coronary artery bypass grafting (CABG) have not been well studied.

METHODS

We examined clinical outcomes in acute coronary syndrome patients in relation to the timing of CABG following P2Y₁₂ inhibitor discontinuation (<72 h, 72 h to five days, >5 days). The primary ischemic outcome was a composite of death, reinfarction, need for revascularization, or stroke. The primary safety outcome was bleeding of at least moderate severity as defined by a Universal Definition of Perioperative Bleeding class ≥2.

RESULTS

Among 508 patients (95 ticagrelor, 413 clopidogrel), the timing of CABG following P2Y₁₂ inhibitor discontinuation was <72 h in 32.1%, 72 h to five days in 23.2% and >5 days in 44.7%. Compared with CABG within 72 h, CABG 72 h to five days (adjusted odds ratio (OR) 0.35; 95% confidence interval (CI) 0.14-0.85; p=0.02) but not >5 days (adjusted OR 0.62; 95% CI 0.33-1.16; p=0.14) after P2Y₁₂ inhibitor discontinuation was associated with lower odds of the primary ischemic outcome. Compared with CABG within 72 h, CABG 72 h to five days (adjusted OR 0.38; 95% CI 0.22-0.66; p=0.001) and >5 days (adjusted OR 0.33; 95% CI 0.20-0.53; p<0.001) after P2Y₁₂ inhibitor discontinuation were associated with lower rates of Universal Definition of Perioperative Bleeding class ≥2 bleeding.

CONCLUSIONS

CABG within 72 h after P2Y₁₂ inhibitor discontinuation is associated with excess ischemia and bleeding. The rates of ischemic and bleeding events were comparable in patients undergoing CABG 72 h to five days compared with >5 days after P2Y₁₂ inhibitor discontinuation.

A randomised study for optimising crossover from ticagrelor to clopidogrel in patients with acute coronary syndrome

Ticagrelor has been endorsed by guidelines as the P2Y12 inhibitor of choice in patients with acute coronary syndrome. Clinically, some patients on ticagrelor will require a switch to clopidogrel; however, the optimal strategy and pharmacodynamics effects of switching remain unknown. Patients with an indication to switch were randomly assigned to either a bolus arm (Clopidogrel 600 mg bolus followed by 75 mg daily, n=30) or a no-bolus arm (Clopidogrel 75 mg daily, n=30). Blood samples were collected at baseline, 12, 24, 48, 54, 60 and 72 hours (h) for assessment of platelet reactivity. The primary outcome was P2Y12 reactivity units (PRU) at 72 h. Secondary outcomes included: PRUs at each time point, incidence of high on-treatment platelet reactivity (HPR), major adverse cardiac events (MACE) and TIMI bleeding at 30 days. Serial PRUs increased after switching to clopidogrel in both groups. At 72 h, no difference in PRU was observed (165.8 ± 71.0 vs 184.1 ± 67.7, bolus vs no bolus, respectively, p=0.19). At 48 h the PRUs were significantly lower in the bolus arm (114 ± 73.1 vs 165.1 ± 70.5, respectively; p=0.0076) and at 72 h, there was a significant reduction in incidence of HPR (26.7 % vs 56.7 %, p=0.02). No differences in MACE or TIMI bleeding were observed. Although a bolus strategy was not associated with improved platelet inhibition at 72 h; at 48 h, platelet inhibition was superior with reduced incidence of HPR. Larger studies will be required to determine its clinical significance. Until then, decision for giving a bolus of clopidogrel at the time of a switch may in part be dependent on the indication for switching, especially if there are concerns for bleeding risk.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Ticagrelor versus prasugrel in patients with high on-clopidogrel treatment platelet reactivity after PCI: The ISAR-ADAPT-PF study

Patients with high on-treatment platelet reactivity (HTPR) on clopidogrel are at high risk for adverse cardiovascular events after percutaneous coronary intervention (PCI). The aim of the ISAR-ADAPT-PF study was to assess the antiplatelet efficacy of ticagrelor versus prasugrel in patients with HTPR on clopidogrel. In a prospective and randomized clinical study, 70 patients with HTPR on clopidogrel loading dose (LD) within 24 h post PCI were assigned to receive either ticagrelor [180 mg LD followed by 90 mg maintenance dose (MD) twice daily] or prasugrel (60 mg LD followed by 10 mg MD once daily). The adenosine diphosphate-induced platelet aggregation assessed on the Multiplate analyzer on day 2 after randomization (primary end point) was as follows: the mean difference between the two treatment groups was 6 aggregation units (AU) × min with an upper 95% confidence interval (CI) of 41 AU × min, which was greater than the predefined noninferiority margin of 18 AU × min (P for noninferiority = 0.29). However, no significant differences in absolute platelet reactivity levels between ticagrelor- versus prasugrel-treated patients at that time point were observed (138 ± 100 AU × min vs. 132 ± 64 AU × min, P for superiority = 0.77). In conclusion, neither drug was statistically more effective for inhibition of platelet aggregation in patients with HTPR on clopidogrel post PCI, although the study could not formally demonstrate the assumed noninferiority of ticagrelor versus prasugrel.

Optimal P2Y12 Inhibitor in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention: A Network Meta-Analysis

OBJECTIVES

The study sought to compare the clinical efficacy and safety of P2Y12 inhibitors in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous intervention (PPCI).

BACKGROUND

Limited data exist regarding the comparative efficacy and safety of P2Y12 inhibitors in STEMI patients undergoing PPCI.

METHODS

Clinical trials enrolling STEMI patients were identified and relevant data was extracted. Major adverse cardiovascular events (MACE) were defined as the composite of all cause mortality, MI, and target vessel revascularization. Network meta-analysis was performed using Bayesian methods.

RESULTS

A total of 37 studies with 88,402 STEMI patients and 5,077 MACE were analyzed. Outcomes at 1 month (22 studies and 60,783 patients) suggest that prasugrel was associated with: lower MACE than clopidogrel (standard dose odds ratio [OR]: 0.59, 95% confidence interval [CI]: 0.50 to 0.69; high-dose OR: 0.60, 95% CI: 0.51 to 0.71; upstream OR: 0.79, 95% CI: 0.66 to 0.94), and ticagrelor (standard dose OR: 0.69, 95% CI: 0.56 to 0.84; upstream OR: 0.72, 95% CI: 0.50 to 1.05); lower mortality and MI than clopidogrel and standard ticagrelor; lower stroke risk than standard clopidogrel and standard or upstream ticagrelor; and lower stent thrombosis than standard or upstream clopidogrel. At 1-year (10 studies, n = 40,333) prasugrel was associated with lower mortality and MACE than other P2Y12 inhibitors. MACE was particularly lower with prasugrel in studies where patients received bivalirudin, drug-eluting stents, and but not glycoprotein IIb/IIIa inhibitor.

CONCLUSIONS

In STEMI patients undergoing PPCI, prasugrel and ticagrelor are more efficacious than clopidogrel; in addition, prasugrel was superior to ticagrelor particularly in conjunction with bivalirudin and drug-eluting stents.

Ticagrelor in Triple Antithrombotic Therapy: Predictors of Ischemic and Bleeding Complications

BACKGROUND

Patients on dual antiplatelet therapy following percutaneous coronary intervention often have indications for concurrent oral anticoagulation or triple antithrombotic therapy (TT). Although TT may decrease ischemic complications, it may confer increased bleeding risk.

HYPOTHESIS

We hypothesize that the use of ticagrelor in TT is associated with higher risk of complications; accordingly, we sought to determine predictors of complications in patients on TT.

METHODS

Patients discharged on TT after percutaneous coronary intervention were followed prospectively for 12 months. The primary endpoint was a composite of ischemic (death, myocardial infarction, stroke) and major bleeding complications or net adverse clinical event (NACE). A major secondary endpoint was BARC (Bleeding Academic Research Consortium) types 2, 3, or 5 bleeding. Outcomes were compared between ticagrelor- and clopidogrel-treated patients. Multivariable analyses were performed to elucidate predictors of complications.

RESULTS

Twenty-seven of 152 patients discharged on TT were on ticagrelor. NACE occurred in 52% of patients and BARC 2, 3, or 5 bleeding occurred in 18%. There was no difference in the primary or secondary outcome between ticagrelor vs clopidogrel subgroup. On logistic regressions, use of TT in patients with acute coronary syndrome (P = 0.002) and bridging in with ticagrelor (P = 0.02) were associated with increased NACE. Low estimated glomerular filtration rate was an independent predictor of bleeding (P = 0.03).

CONCLUSIONS

The risk of bleeding and ischemic complications among patients on TT is similar between those on ticagrelor and clopidogrel. However, caution with use of bridging anticoagulation should be taken when using ticagrelor.

The impact of switching P2Y12 receptor inhibitor therapy during index hospitalization: a systematic review

PURPOSE

With the availability of novel P2Y12 receptor inhibitors, patients presenting with acute coronary syndrome (ACS) may receive more than one type of this drug during index hospitalization. We sought to determine the effect of switching from clopidogrel to a novel P2Y12 receptor inhibitor on the occurrence of major adverse cardiovascular events (MACE) and bleeding.

METHODS

We conducted a literature search on SCOPUS for English language entries until 7 March 2015. Out of 188 citations, seven studies encompassing 16,431 patients were selected for analysis of (i) switching to a novel P2Y12 agent (switching group) versus continued clopidogrel or (ii) switching to a novel P2Y12 agent (switching group) versus upfront novel agent initiation during index hospitalization

RESULTS

MACE was significantly lower in the switching group (odds ratio (OR) 0.77, 95 % confidence interval (CI) 0.63-0.96, p = 0.02), whereas bleeding was higher (OR 1.55, 1.29-1.85, p < 0.01) compared with continued clopidogrel. Conversely, MACE was similar with switching to a novel agent and upfront novel therapy initiation (OR 1.01, 95 % CI 0.8-1.29, p = 0.90), but bleeding was higher in the switching group (OR 1.24, 95 % CI 1.03-1.48, p = 0.02).

CONCLUSIONS

The current study suggests that switching to a novel P2Y12 agent in patients with ACS and/or patients undergoing coronary stenting is more efficacious than continuing clopidogrel. In this cohort, switching to a novel agent did not result in worse ischemic outcomes than upfront initiation of novel therapies. However, switching was associated with greater bleeding compared with both continued clopidogrel as well as upfront use of novel P2Y12 agents.

Current state and novel approaches of antiplatelet therapy

An unresolved problem with clinical use of antiplatelet therapy is that a significant number of individuals either still get thrombosis or run the risk of life-threatening bleeding. Antiplatelet drugs are widely used clinically, either chronically for people at risk of athero/thrombotic disease or to prevent thrombus formation during surgery. However, a subpopulation may be resistant to standard doses, while the platelet targets of these drugs are also critical for the normal hemostatic function of platelets. In this review, we will briefly examine current antiplatelet therapy and existing targets while focusing on new potential approaches for antiplatelet therapy and improved monitoring of effects on platelet reactivity in individuals, ultimately to improve antithrombosis with minimal bleeding. Primary platelet adhesion-signaling receptors, glycoprotein (GP)Ib-IX-V and GPVI, that bind von Willebrand factor/collagen and other prothrombotic factors are not targeted by drugs in clinical use, but they are of particular interest because of their key role in thrombus formation at pathological shear.

Ticagrelor: a review of its use in adults with acute coronary syndromes

Ticagrelor (Brilique™, Brilinta®), a cyclopentyl-triazolopyrimidine, is an orally active, reversible, and selective adenosine diphosphate (ADP) receptor antagonist indicated for use in patients with acute coronary syndromes (ACS). Ticagrelor has a faster onset of action and provides greater inhibition of platelet aggregation than clopidogrel. In the large well-designed, PLATO study in adult patients with ACS, 12 months' treatment with ticagrelor was more effective than clopidogrel in reducing the incidence of the primary composite endpoint of myocardial infarction, stroke, or cardiovascular (CV) death. Ticagrelor also reduced all-cause mortality relative to clopidogrel, although statistical significance of this was not confirmed in hierarchical testing. Benefit with ticagrelor was seen both in invasively and noninvasively managed patients. Ticagrelor was generally well tolerated and was not associated with an increased risk of major bleeding relative to clopidogrel. However, the incidences of non-coronary artery bypass grafting (CABG)-related bleeding, and major or minor bleeding, as well as some non-hemorrhagic adverse events, including dyspnea (usually of mild or moderate severity) and ventricular pauses (largely asymptomatic) were higher with ticagrelor. In addition, the ATLANTIC study showed that although pre-hospital administration of ticagrelor did not improve pre-percutaneous coronary intervention (PCI) coronary reperfusion in ACS patients relative to in-hospital administration, ticagrelor was safe in both instances, with no significant between-group differences in non-CABG-related major and minor bleeding events. Although further comparative studies with other antiplatelet agents, including prasugrel, are required to position it more definitively, current evidence indicates that ticagrelor is a useful option for the prevention of thrombotic CV events in ACS patients managed invasively or noninvasively.