Ticagrelor With or Without Aspirin After PCI: The TWILIGHT Platelet Substudy

Extended Clopidogrel Monotherapy vs DAPT in Patients With Acute Coronary Syndromes at High Ischemic and Bleeding Risk: The OPT-BIRISK Randomized Clinical Trial

Importance

Purinergic receptor P2Y12 (P2Y12) inhibitor monotherapy after a certain period of dual antiplatelet therapy (DAPT) may be an attractive option of maintenance antiplatelet treatment for patients undergoing percutaneous coronary intervention (PCI) who are at both high bleeding and ischemic risk (birisk).

Objective

To determine if extended P2Y12 inhibitor monotherapy with clopidogrel is superior to ongoing DAPT with aspirin and clopidogrel after 9 to 12 months of DAPT after PCI in birisk patients with acute coronary syndromes (ACS).

Design, Setting, and Participants

This was a multicenter, double-blind, placebo-controlled, randomized clinical trial including birisk patients with ACS who had completed 9 to 12 months of DAPT after drug-eluting stent implantation and were free from adverse events for at least 6 months at 101 China centers between February 2018 and December 2020. Study data were analyzed from April 2023 to May 2023.

Interventions

Patients were randomized either to clopidogrel plus placebo or clopidogrel plus aspirin for an additional 9 months.

Main Outcomes and Measures

The primary end point was Bleeding Academic Research Consortium (BARC) types 2, 3, or 5 bleeding 9 months after randomization. The key secondary end point was major adverse cardiac and cerebral events (MACCE; the composite of all-cause death, myocardial infarction, stroke or clinically driven revascularization). The primary end point was tested for superiority, and the MACCE end point was tested for sequential noninferiority and superiority.

Results

A total of 7758 patients (mean [SD] age, 64.8 [9.0] years; 4575 male [59.0%]) were included in this study. The primary end point of BARC types 2, 3, or 5 bleeding occurred in 95 of 3873 patients (2.5%) assigned to clopidogrel plus placebo and 127 of 3885 patients (3.3%) assigned to clopidogrel plus aspirin (hazard ratio [HR], 0.75; 95% CI, 0.57-0.97; difference, -0.8%; 95% CI, -1.6% to -0.1%; P = .03). The incidence of MACCE was 2.6% (101 of 3873 patients) in the clopidogrel plus placebo group and 3.5% (136 of 3885 patients) in the clopidogrel plus aspirin group (HR, 0.74; 95% CI, 0.57-0.96; difference, -0.9%; 95% CI, -1.7% to -0.1%; P < .001 for noninferiority; P = .02 for superiority).

Conclusions and Relevance

Among birisk patients with ACS who completed 9 to 12 months of DAPT after drug-eluting stent implantation and were free from adverse events for at least 6 months before randomization, an extended 9-month clopidogrel monotherapy regimen was superior to continuing DAPT with clopidogrel in reducing clinically relevant bleeding without increasing ischemic events.

Trial Registration

ClinicalTrials.gov Identifier: NCT03431142.

Aspirin-free antiplatelet strategies after percutaneous coronary interventions

Dual antiplatelet therapy (DAPT) with aspirin and a platelet P2Y12 receptor inhibitor is the standard antithrombotic treatment after percutaneous coronary interventions (PCI). Several trials have challenged guideline-recommended DAPT after PCI by testing the relative clinical effect of an aspirin-free antiplatelet approach-consisting of P2Y12 inhibitor monotherapy after a short course (mostly 1-3 months) of DAPT-among patients undergoing PCI without a concomitant indication for oral anticoagulation (OAC). Overall, these studies have shown P2Y12 inhibitor monotherapy after short DAPT to be associated with a significant reduction in the risk of bleeding without an increase in thrombotic or ischaemic events compared with continued DAPT. Moreover, the effects of the P2Y12 inhibitor monotherapy without prior DAPT or following a very short course of DAPT after PCI are being investigated in emerging studies, of which one has recently reported unfavourable efficacy results associated with the aspirin-free approach compared with conventional DAPT. Finally, P2Y12 inhibitor alone has been compared with aspirin alone as chronic therapy after DAPT discontinuation, thus challenging the historical role of aspirin as a standard of care for secondary prevention following PCI. A thorough understanding of study designs, populations, treatments, results, and limitations of trials testing P2Y12 inhibitor monotherapy vs. DAPT or vs. aspirin is required to consider adopting this treatment in clinical practice. This review addresses the use of aspirin-free antiplatelet strategies among patients undergoing PCI without a concomitant indication for OAC, providing an overview of clinical evidence, guideline indications, practical implications, ongoing issues, and future perspectives.

Clinically Driven Revascularization in High-Risk Patients Treated With Ticagrelor Monotherapy After PCI: Insights from the Randomized TWILIGHT Trial

Repeat coronary revascularization is a common adverse event after successful percutaneous coronary intervention. This analysis aimed to assess the effects of ticagrelor monotherapy on repeat clinically driven revascularization (CDR). In the TWILIGHT (Ticagrelor With Aspirin or Alone in High-Risk Patients after Coronary Intervention) trial, after 3 months of ticagrelor plus aspirin, high-risk patients were maintained on ticagrelor and randomly allocated to aspirin or placebo for 1 year. The primary end point of this analysis was CDR within 12 months after randomization. The key secondary end points were major adverse cardiovascular and cerebrovascular events (MACCEs), a composite of all-cause death, myocardial infarction, stroke, or CDR, and net adverse clinical events (NACEs), including the individual components of MACCEs and clinically relevant bleeding. The analysis was performed in the per-protocol population. CDR occurred in 473 of 7,039 patients and was associated with a significantly higher risk of subsequent all-cause death, myocardial infarction, or stroke (adjusted hazard ratios [HRs] 2.92, 95% confidence interval [CI] 1.82 to 4.67). Ticagrelor monotherapy was associated with a similar 12-month risk of CDR (7.1% vs 6.6%; HR 1.09, 95% CI 0.90 to 1.30, p = 0.363) and MACCEs (8.9% vs 8.6%; HR 1.04, 95% CI 0.89 to 1.22, p = 0.619), and a lower risk of NACEs (12.2% vs 14.6%; HR 0.83 95% CI 0.73 to 0.94, p = 0.004) than ticagrelor plus aspirin. In conclusion, among high-risk patients who underwent percutaneous coronary intervention, ticagrelor monotherapy after 3 months of ticagrelor-based dual antiplatelet therapy was associated with a similar risk of CDR and MACCEs and a decrease of NACEs (TWILIGHT: NCT02270242).

The prognostic value of ORBIT risk score in predicting major bleeding in patients with acute coronary syndrome

BACKGROUND

The most significant adverse effect of antithrombotic medication in acute coronary syndrome (ACS) is major bleeding, which is related to increased mortality. Studies on ORBIT risk score in predicting major bleeding in ACS patients are limited.

OBJECTIVE

This research aimed to examine whether the ORBIT score calculated at the bedside can identify major bleeding risk in patients with ACS.

METHODS

This research was retrospective, observational, and conducted at a single center. Analyses of receiver operating characteristics (ROC) were utilized to define the diagnostic value of CRUSADE and ORBIT scores. The predictive performances of the two scores were compared using DeLong's method. Discrimination and reclassification performances were evaluated by the integrated discrimination improvement (IDI), and net reclassification improvement (NRI).

RESULTS

The study included 771 patients with ACS. The mean age was 68.7 ± 8.6 years, with 35.3 % females. 31 patients had major bleeding. Twenty-three of these patients were BARC 3 A, five were BARC 3 B, and three were BARC 3 C. Bleeding history [OR (95 % CI), 2.46 (1.02-5.94), p = 0.021], hemoglobin levels [OR (95 % CI), 0.54 (0.45-0.63), p < 0.001], and age > 74 years [OR (95 % CI), 1.03 (1.01-1.06), p = 0.039] were independent predictors of major bleeding. The ORBIT score was an independent predictor of major bleeding in the multivariate analysis: continuous variables [OR (95 % CI), 2.53 (2.61-3.95), p < 0.001] and risk categories [OR (95 % CI), 3.06 (1.69-5.52), p < 0.001]. Comparison of c-indexes for major bleeding events revealed a non-significant difference for the discriminative ability of the two tested scores (p = 0.07) with a continuous NRI of 6.6 % (p = 0.026) and an IDI of 4.2 % (p < 0.001).

CONCLUSION

In ACS patients, the ORBIT score independently predicted major bleeding.

P2Y12 Inhibitor Monotherapy Combined With Colchicine Following PCI in ACS Patients: The MACT Pilot Study

BACKGROUND

After a brief period of dual antiplatelet therapy, P2Y12 inhibitor monotherapy in the absence of aspirin effectively reduces bleeding without increasing recurrent ischemia in patients undergoing percutaneous coronary intervention (PCI). In addition, early anti-inflammatory therapies may have clinical benefits in acute coronary syndrome (ACS) patients.

OBJECTIVES

The aim of this study was to investigate the feasibility of ticagrelor or prasugrel P2Y12 inhibitor monotherapy combined with colchicine immediately after PCI in patients with ACS.

METHODS

This was a proof-of-concept pilot trial. ACS patients treated with drug-eluting stents were included. On the day after PCI, low-dose colchicine (0.6 mg daily) was administered in addition to ticagrelor or prasugrel maintenance therapy, whereas aspirin therapy was discontinued. The primary outcome was any stent thrombosis at 3 months. The key secondary outcomes were platelet reactivity measured by the VerifyNow assay (Accriva) before discharge and a reduction in high-sensitivity C-reactive protein (hs-CRP) over 1 month.

RESULTS

We enrolled 200 patients, 190 (95.0%) of whom completed the 3-month follow-up. The primary outcome occurred in 2 patients (1.0%): 1 definite and 1 probable stent thrombosis. The level of platelet reactivity overall was 27 ± 42 P2Y12 reaction units, and only 1 patient had high platelet reactivity (>208 P2Y12 reaction units). The hs-CRP levels decreased from 6.1 mg/L (IQR: 2.6-15.9 mg/L) at 24 hours after PCI to 0.6 mg/L (IQR: 0.4-1.2 mg/L) at 1 month (P < 0.001), and the prevalence of high-inflammation criteria (hs-CRP ≥2 mg/L) decreased from 81.8% to 11.8% (P < 0.001).

CONCLUSIONS

In ACS patients undergoing PCI, it is feasible to discontinue aspirin therapy and administer low-dose colchicine on the day after PCI in addition to ticagrelor or prasugrel P2Y12 inhibitors. This approach is associated with favorable platelet function and inflammatory profiles. (Mono Antiplatelet and Colchicine Therapy [MACT]; NCT04949516).

Single antiplatelet therapy directly after percutaneous coronary intervention in non-ST-segment elevation acute coronary syndrome patients: the OPTICA study

BACKGROUND

Early P2Y12 inhibitor monotherapy has emerged as a promising alternative to 12 months of dual antiplatelet therapy following percutaneous coronary intervention (PCI).

AIMS

In this single-arm pilot study, we evaluated the feasibility and safety of ticagrelor or prasugrel monotherapy directly following PCI in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS).

METHODS

Patients received a loading dose of ticagrelor or prasugrel before undergoing platelet function testing and subsequent PCI using new-generation drug-eluting stents. The stent result was adjudicated with optical coherence tomography in the first 35 patients. Ticagrelor or prasugrel monotherapy was continued for 12 months. The primary ischaemic endpoint was the composite of all-cause mortality, myocardial infarction, definite or probable stent thrombosis or stroke within 6 months. The primary bleeding endpoint was Bleeding Academic Research Consortium type 2, 3 or 5 bleeding within 6 months.

RESULTS

From March 2021 to March 2022, 125 patients were enrolled, of whom 75 ultimately met all in- and exclusion criteria (mean age 64.5 years, 29.3% women). Overall, 70 out of 75 (93.3%) patients were treated with ticagrelor or prasugrel monotherapy directly following PCI. The primary ischaemic endpoint occurred in 3 (4.0%) patients within 6 months. No cases of stent thrombosis or spontaneous myocardial infarction occurred. The primary bleeding endpoint occurred in 7 (9.3%) patients within 6 months.

CONCLUSIONS

This study provides first-in-human evidence that P2Y12 inhibitor monotherapy directly following PCI for NSTE-ACS is feasible, without any overt safety concerns, and highlights the need for randomised controlled trials comparing direct P2Y12 inhibitor monotherapy with the current standard of care.

Differential prognosis of patients that are candidates for standard, short or prolonged dual antiplatelet treatment discharged after an acute coronary syndrome

BACKGROUND

Current evidence supports the efficacy of prolonged dual antiplatelet treatment (DAPT) for patients at high-ischemic risk and low bleeding risk as well as the efficacy and safety of short DAPT in high-bleeding risk (HBR) patients.

METHODS

We evaluated patterns of DAPT candidates in all patients discharged in 2 hospitals after an acute coronary syndrome (ACS). Patients categorized in 3 groups: 1) short-DAPT candidates if they met 1 major o 2 minor criteria for HBR, by the 2019 ARC-HBR criteria; 2) prolonged-DAPT candidates if were not HBR and had recurrent ACS, complex percutaneous coronary interventions or diabetes; 3) standard 12 months DAPT if were not include in the previous 2 groups. Major bleeding (MB) was registered according to 3 or 5 of the BARC consortium definitions.

RESULTS

We included 8252 patients and 3215 (39 %) were candidates for abbreviated DAPT, 3119 (37.8 %) for prolonged DAPT, and 1918 (23.2 %) for 12 m DAPT. Relevant differences were observed between the 3 categories beyond the bleeding risk. Median follow-up was 57 months. Multivariate analysis identified higher risk of all-cause mortality (HR: 1.96 95 % CI 1.45-2.67; p < 0.001), cardiovascular mortality (HR: 2.10 95 % CI 1.39-3.19; p < 0.011), MACE (HR: 1.69 95 % 1.50-2.02; p < 0.001) and MB (sHR: 3.41 95 % CI 1.45-8.02; p = 0.005) in candidates to short DAPT. Candidates to prolonged DAPT had higher risk of MACE (HR: 1.17 95 % CI 1.02-1.35; p = 0.027).

CONCLUSIONS

Almost two thirds of patients discharged after an ACS would be candidates for short or prolonged DAPT and these patients are at higher risk of MACE and mortality.

Platelet P2Y12 Inhibitor Monotherapy after Percutaneous Coronary Intervention: An Emerging Option for Antiplatelet Therapy De-escalation

Antiplatelet therapy is considered essential for secondary prevention of ischemic heart disease. After percutaneous coronary intervention (PCI), temporary dual antiplatelet therapy (DAPT), a combination consisting of aspirin and an oral P2Y12 receptor blocker, is recommended. In the long term, this strategy results in more bleeding than antiplatelet therapy with aspirin alone. Therefore, to reduce bleeding, an increasing trend has been to keep DAPT as short as clinically acceptable, after which aspirin monotherapy is continued. Another option to diminish bleeding is to discontinue aspirin at the moment of DAPT cessation after PCI, and to continue on P2Y12 blocker monotherapy. This survey reviews the evidence on P2Y12 blocker monotherapy. Some clinical guidance will be provided on when and in whom P2Y12 inhibitor monotherapy may be applied after DAPT cessation following PCI.

Preventive effect and mechanism of Tibetan tea extract on thrombosis in arachidonic acid-induced zebrafish determined via RNA-seq transcriptome profiles

Thrombosis is a key pathological event in cardiovascular diseases and is also the most important targeting process for their clinical management. In this study, arachidonic acid (AA) was used to induce thrombus formation in zebrafish larvae. Blood flow, red blood cell (RBCs) aggregation and cellular oxidative stress were measured to evaluate the antithrombotic effect of Tibetan tea (TT). Meanwhile, the potential molecular mechanism was further explored by transcriptome sequencing (RNA-seq). The results indicated that TT could significantly restore heart RBCs intensity of thrombotic zebrafish, whilst decreasing RBCs accumulation in the caudal vein. The transcriptome analysis revealed that the preventive effect of TT on thrombosis could be mostly attributed to changes in lipid metabolism related signaling pathways, such as fatty acid metabolism, glycerollipid metabolism, ECM-receptor interaction and steroid biosynthesis signaling pathway. This study demonstrated that Tibetan tea could alleviate thrombosis by reducing oxidative stress levels and regulating lipid metabolism.

P2Y12 inhibitor monotherapy in patients undergoing percutaneous coronary intervention

For 20 years, dual antiplatelet therapy (DAPT), consisting of the combination of aspirin and a platelet P2Y₁₂ receptor inhibitor, has been the gold standard of antithrombotic pharmacology after percutaneous coronary intervention (PCI). In the past 5 years, several investigations have challenged this paradigm by testing the efficacy and safety of P2Y₁₂ inhibitor monotherapy (that is, without aspirin) following a short course of DAPT. Collectively, these studies suggested a reduction in the risk of major bleeding and no significant increase in thrombotic or ischaemic events compared with guideline-recommended DAPT. Current recommendations are evolving to inform clinical practice on the ideal candidates for P2Y₁₂ inhibitor monotherapy after PCI. Generalizing the results of studies of P2Y₁₂ inhibitor monotherapy requires a thorough understanding of their design, populations, interventions, comparators and results. In this Review, we provide an up-to-date overview on the use of P2Y₁₂ inhibitor monotherapy after PCI, including supporting pharmacodynamic and clinical evidence, practical recommendations and future directions.

P2Y12 Inhibitor Monotherapy after Percutaneous Coronary Intervention

In patients with acute and chronic coronary artery disease undergoing percutaneous coronary intervention (PCI), dual antiplatelet therapy (DAPT) has been the cornerstone of pharmacotherapy for the past two decades. Although its antithrombotic benefit is well established, DAPT is associated with an increased risk of bleeding, which is independently associated with poor prognosis. The improvement of the safety profiles of drug-eluting stents has been critical in investigating and implementing shorter DAPT regimens. The introduction into clinical practice of newer generation oral P2Y₁₂ inhibitors such as prasugrel and ticagrelor, which provide more potent and predictable platelet inhibition, has questioned the paradigm of standard DAPT durations after coronary stenting. Over the last five years, several trials have assessed the safety and efficacy of P2Y₁₂ inhibitor monotherapy after a short course of DAPT in patients treated with PCI. Moreover, ongoing studies are testing the role of P2Y₁₂ inhibitor monotherapy immediately after PCI in selected patients. In this review, we provide up-to-date evidence on the efficacy and safety of P2Y₁₂ inhibitor monotherapy after a short period of DAPT compared to DAPT in patients undergoing PCI as well as outcomes associated with P2Y₁₂ inhibitor monotherapy compared to aspirin for long-term prevention.

Clinical pharmacology of antiplatelet drugs

INTRODUCTION

Platelets play a key role in arterial thrombosis and antiplatelet therapy is pivotal in the treatment of cardiovascular disease. Current antiplatelet drugs target different pathways of platelet activation and show specific pharmacodynamic and pharmacokinetic characteristics, implicating clinically relevant drug-drug interactions.

AREAS COVERED

This article reviews the role of platelets in hemostasis and cardiovascular thrombosis, and discusses the key pharmacodynamics, drug-drug interactions and reversal strategies of clinically used antiplatelet drugs.

EXPERT OPINION

Antiplatelet therapies target distinct pathways of platelet activation: thromboxane A₂ synthesis, adenosine diphosphate-mediated signaling, integrin α_IIbβ₃ (GPIIb/IIIa), thrombin-mediated platelet activation via the PAR1 receptor and phosphodiesterases. Key clinical drug-drug interactions of antiplatelet agents involve acetylsalicylic acid - ibuprofen, clopidogrel - omeprazole, and morphine - oral P2Y₁₂ inhibitors, all of which lead to an attenuated antiplatelet effect. Platelet function and genetic testing and the use of scores (ARC-HBR, PRECISE-DAPT, ESC ischemic risk definition) may contribute to a more tailored antiplatelet therapy. High on-treatment platelet reactivity presents a key problem in the acute management of ST-elevation myocardial infarction (STEMI). A treatment strategy involving early initiation of an intravenous antiplatelet agent may be able to bridge the gap of insufficient platelet inhibition in high ischemic risk patients with STEMI.

P2Y12-inhibitor monotherapy after coronary stenting: are all P2Y12-inhibitors equal?

INTRODUCTION

P2Y₁₂-inhibitor monotherapy following 1-3 months of dual antiplatelet therapy (DAPT) reduces (major) bleeding without an apparent increase in ischemic events and has therefore emerged as an alternative to 6-12 months of DAPT following percutaneous coronary intervention (PCI). However, there are important differences between the available P2Y₁₂-inhibitors (clopidogrel, prasugrel, and ticagrelor) as agents of choice for P2Y₁₂-inhibitor monotherapy.

AREAS COVERED

This review critically appraises the evidence for P2Y₁₂-inhibitor monotherapy after PCI using either clopidogrel, prasugrel, or ticagrelor. Furthermore, we discuss ongoing trials and future directions for research.

EXPERT OPINION

P2Y₁₂-inhibitor monotherapy following 1-3 months of DAPT is an alternative to 6-12 months of DAPT following PCI. Ticagrelor may be considered the current preferred option due to its reliable effect on platelet reactivity and its predominant use in clinical trials. Prasugrel could serve as a useful substitute for those not tolerating ticagrelor, but more research into prasugrel monotherapy is warranted. Alternatively, clopidogrel can be used, although there are concerns of high platelet reactivity, especially when genotyping and/or platelet function testing are not used. Future research will need to address the minimal duration of DAPT before switching to P2Y₁₂-inhibitor monotherapy and what the optimal antithrombotic therapy beyond 12 months is.

Comparative Efficacy and Safety of P2Y12 Inhibitor Monotherapy and Dual Antiplatelet Therapy in Patients with and without Diabetes Mellitus Undergoing Percutaneous Coronary Intervention

Increasing evidence has shown P2Y12 inhibitor monotherapy is a feasible alternative treatment for patients after percutaneous coronary intervention (PCI) with stent implantation in the modern era. However, patients with diabetes mellitus (DM) have a higher risk of ischemic events and more complex coronary artery disease. The purpose of this study is to evaluate the efficacy and safety of this novel approach among patients with DM and those without DM. We conducted a systematic review and meta-analysis of randomized controlled trials that compared P2Y12 inhibitor monotherapy with 12 months of dual antiplatelet therapy (DAPT) in patients who underwent PCI with stent implantation. PubMed, Embase, Cochrane library database, ClinicalTrials.gov, and three other websites were searched for our data from the earliest report to January 2022. The primary efficacy outcome was major adverse cardiovascular and cerebrovascular events (MACCE): a composite of all-cause mortality, myocardial infarction, stent thrombosis, and stroke. The primary safety outcome was major or minor bleeding events. The secondary endpoint was net adverse clinical events (NACE) which are defined as a composite of major bleeding and adverse cardiac and cerebrovascular events. A total of four randomized controlled trials with 29,136 patients were included in our meta-analysis. The quantitative analysis showed a significant reduction in major or minor bleeding events in patients treated with P2Y12 inhibitor monotherapy compared to standard DAPT (OR: 0.68, 95% CI: 0.46-0.99, p = 0.04) without increasing the risk of MACCE (OR: 0.96, 95% CI: 0.85-1.09, p = 0.50). The number of NACE was significantly lower in the patients treated with P2Y12 inhibitor monotherapy (OR: 0.84, 95% CI: 0.72-0.97, p = 0.019). In DM patients, P2Y12 inhibitor monotherapy was associated with a lower risk of MACCE compared to standard DAPT (OR: 0.85, 95% CI: 0.74-0.98, p = 0.02). Furthermore, P2Y12 inhibitor monotherapy was accompanied by a favorable reduction in major or minor bleeding events (OR: 0.80, 95% CI: 0.64-1.05, p = 0.107). In non-DM patients, P2Y12 inhibitor monotherapy showed a significant reduction in major or minor bleeding events (OR: 0.58, 95% CI: 0.38-0.88, p = 0.01), but without increasing the risk of MACCE (OR: 0.99, 95% CI: 0.82-1.19, p = 0.89). Based on these findings, P2Y12 inhibitor monotherapy could significantly decrease bleeding events without increasing the risk of stent thrombosis or myocardial infarction in the general population. The benefit of reducing bleeding events was much more significant in non-DM patients than in DM patients. Surprisingly, P2Y12 inhibitor monotherapy could lower the risk of MACCE in DM patients. Our study supports that P2Y12 inhibitor monotherapy is a promising alternative choice of medical treatment for patients with DM undergoing PCI with stent implantation in the modern era.

Effects of ticagrelor monotherapy vs. clopidogrel monotherapy on platelet reactivity: a randomized, crossover clinical study (SINGLE study)

Increasing clinical trials demonstrated that the discontinuation of aspirin while maintaining a P2Y₁₂ inhibitor monotherapy could decrease the risk of bleeding without losing the antithrombotic effect. However, no data are available on the platelet reactivity of patients undergoing ticagrelor monotherapy vs. clopidogrel. Therefore, we performed this study to observe the efficacy of ticagrelor monotherapy vs. clopidogrel in Chinese patients with chronic coronary syndrome. This randomized, single-blinded, crossover trial enrolled 50 patients who were administered with ticagrelor (90 mg twice daily for 2 weeks) or clopidogrel (75 mg once daily for 2 weeks). Followed by a 2-week washout period, the two groups of patients underwent a crossover trial. Light transmission aggregometry (LTA) and thromboelastography (TEG) assays were used to test platelet reactivity. The platelet aggregation rate (PAgR) of ADP and AA was significantly lower with ticagrelor than clopidogrel (PAgR of ADP, 27.30% (7.30%-42.635%) vs. 35.55% (12.03%-69.25%), P = .0254; PAgR of AA, 77.80% (21.60%-86.43%) vs. 83.10% (67.13%-87.20%), P = .0400). There was no significant difference in PAgR of collagen and epinephrine between the two groups. The TEG assay showed that ADP and AA, which induced the inhibition of platelet aggregation, were significantly higher in the ticagrelor group than those in the clopidogrel group [ADP%, 69.00% (59.68%-88.95%) vs. 60.55% (35.98%-78.35%), P = .0020; AA%, 53.65% (22.75%-79.28%) vs. 15.15% (5.75%-70.25%), P = .0127]. High on-treatment platelet reactivity (HTPR) on ADP was 2.17% with ticagrelor and 19.57% with clopidogrel. HTPR on AA was 50.00% with ticagrelor and 69.57% with clopidogrel. Ticagrelor and clopidogrel caused the inhibition of ADP and AA-induced platelet aggregation. Moreover, ticagrelor monotherapy had a stronger inhibitory effect than clopidogrel monotherapy (except on collagen and epinephrine).

Ticagrelor With or Without Aspirin in Chinese Patients Undergoing Percutaneous Coronary Intervention: A TWILIGHT China Substudy

BACKGROUND

The risk/benefit tradeoff of dual antiplatelet therapy after percutaneous coronary intervention may vary in East Asian patients as compared with their non-East Asian counterparts.

METHODS

The double-blind, placebo-controlled, randomized TWILIGHT trial (Ticagrelor With Aspirin or Alone in High-Risk Patients After Coronary Intervention) enrolled patients undergoing high-risk percutaneous coronary intervention. After 3 months of treatment with ticagrelor plus aspirin, event-free and adherent patients remained on ticagrelor and were randomly assigned to receive aspirin or placebo for 1 year. The primary end point was Bleeding Academic Research Consortium type 2, 3, or 5 bleeding; the key secondary end point was the first occurrence of death from any cause, nonfatal myocardial infarction, or nonfatal stroke.

RESULTS

Of 9006 enrolled and 7119 randomized patients in TWILIGHT, 1169 patients (13.0%) were enrolled at 27 Chinese sites in this prespecified substudy, of whom 1028 (14.4%) patients were randomized after 3 months. The incidence of the primary end point was 6.2% in the ticagrelor+aspirin group versus 3.5% in the ticagrelor+placebo group between randomization and 1 year (hazard ratio, 0.56 [95% CI, 0.31-0.99]; P=0.048). The key secondary end point occurred in 3.4% of patients in the ticagrelor+aspirin group versus 2.4% in the ticagrelor+placebo group (hazard ratio, 0.70 [95% CI, 0.33-1.46]; P=0.34). There was no interaction between the region of randomization (China versus the rest of the world) and randomized treatment assignment in terms of the primary or key secondary end points.

CONCLUSIONS

Ticagrelor monotherapy significantly reduced clinically relevant bleeding without increasing ischemic events as compared with ticagrelor plus aspirin in Chinese patients undergoing high-risk percutaneous coronary intervention.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02270242.

Antiplatelet therapy after percutaneous coronary intervention

Antiplatelet therapy is key to reducing local thrombotic complications and systemic ischaemic events among patients undergoing percutaneous coronary interventions (PCI), but it is inevitably associated with increased bleeding. The continuous refinement in stent technologies, together with the high incidence of ischaemic recurrences after PCI and the understanding of prognostic implications associated with bleeding, have led to a substantial evolution in antiplatelet treatment regimens over the past decades. Numerous investigations have been conducted to better stratify patients undergoing PCI according to their ischaemic and bleeding risks and to implement antithrombotic regimens accordingly. Evidence from these investigations have resulted in a number of antithrombotic treatment options as recommended by recent guidelines. In this State-of-the-Art review we provide the rationale, summarise the evidence, and discuss current and future directions of antiplatelet treatment regimens after PCI.

Platelet P2Y12 inhibiting therapy in adjunct to vascular dose of rivaroxaban or aspirin: A pharmacodynamic study of dual pathway inhibition versus dual antiplatelet therapy

AIM

Dual-pathway inhibition (DPI) by adding a vascular dose of rivaroxaban to a single antiplatelet agent has emerged as a promising antithrombotic strategy. However, in most studies the antiplatelet agent of choice used in adjunct to a vascular dose of rivaroxaban was aspirin, and data with a P2Y12 inhibitor and how this DPI regimen compares with standard dual antiplatelet therapy (DAPT) is limited.

METHODS AND RESULTS

This investigation was a sub-study analysis conducted in selected cohorts of patients with stable atherosclerotic disease enrolled from a larger prospective, open-label, parallel-group pharmacodynamics (PD) study. We analyzed data from 40 patients treated with either clopidogrel or ticagrelor-based DAPT first, and clopidogrel or ticagrelor-based DPI thereafter. PD measures explored key pathways involved in thrombus formation and included markers of: 1) P2Y12 reactivity, 2) platelet-mediated global thrombogenicity, 3) cyclooxygenase-1 activity, 3) TRAP-induced platelet aggregation; 4) tissue factor (TF)-induced platelet aggregation, and 5) thrombin generation. As compared to DAPT, on a background of the same P2Y12 inhibitor (clopidogrel or ticagrelor), DPI was associated with reduced thrombin generation, increased markers of cyclooxygenase-1 activity and TRAP-induced platelet aggregation and no differences in markers of P2Y12 signaling, platelet-mediated global thrombogenicity and TF-induced platelet aggregation. In an analysis according to P2Y12 inhibitor type, ticagrelor reduced markers of platelet-mediated global thrombogenicity, P2Y12 signaling and rates of high platelet reactivity compared to clopidogrel.

CONCLUSIONS

Compared to DAPT with aspirin and a P2Y12 inhibitor, the use of a P2Y12 inhibitor in adjunct to a vascular dose of rivaroxaban as part of a DPI strategy is associated with similar effects on platelet-mediated global thrombogenicity but reduced thrombin generation. A DPI strategy with ticagrelor is associated with enhanced antithrombotic efficacy, the clinical implications of which warrant larger scale investigations.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03718429.

Safety and efficacy of ticagrelor monotherapy according to drug-eluting stent type: the TWILIGHT-STENT study

BACKGROUND

In the TWILIGHT trial, ticagrelor monotherapy after a short course of dual antiplatelet therapy (DAPT) was shown to be a safe bleeding avoidance strategy in high-risk patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES).

AIMS

The aim of this study was to evaluate the effects of ticagrelor monotherapy after three-month DAPT in patients undergoing PCI, according to DES type.

METHODS

In the current sub-analysis from TWILIGHT, patients were stratified into three groups based on DES type: durable polymer everolimus-eluting stents (DP-EES), durable polymer zotarolimus-eluting stents (DP-ZES), and biodegradable polymer DES (BP-DES). Bleeding and ischaemic outcomes were assessed at one year after randomisation.

RESULTS

Out of 5,769 patients, 3,014 (52.2%) had DP-EES, 1,350 (23.4%) had DP-ZES and 1,405 (24.4%) had BP-DES. Compared with ticagrelor plus aspirin, ticagrelor monotherapy had significantly lower BARC type 2, 3 or 5 bleeding compared with DAPT; DP-EES (3.8% vs 6.7%; HR 0.56, 95% CI: 0.41-0.78), DP-ZES (4.6% vs 6.9%; HR 0.66, 95% CI: 0.42-1.04) and BP-DES (4.2% vs 7.9%; HR 0.52, 95% CI: 0.33-0.81; p_interaction=0.76). Ticagrelor monotherapy resulted in similar rates of death, MI, or stroke: DP-EES (4.2% vs 4.3%; HR 0.97; 95% CI: 0.68-1.37); DP-ZES (4.1% vs 3.1%; HR 1.32; 95% CI: 0.75-2.33); BP-DES (3.9% vs 4.2%; HR 0.92; 95% CI: 0.54-1.55; p_interaction=0.60). In both unadjusted and covariate-adjusted analyses, DES type was not associated with any differences in ischaemic or bleeding complications.

CONCLUSIONS

As compared with ticagrelor plus aspirin, ticagrelor monotherapy after a short DAPT duration lowered bleeding complications without increasing the ischaemic risk, irrespective of DES type. We observed no significant differences among DES types.

Ticagrelor monotherapy in patients at high bleeding risk undergoing percutaneous coronary intervention: TWILIGHT-HBR

AIMS

Patients at high bleeding risk (HBR) represent a prevalent subgroup among those undergoing percutaneous coronary intervention (PCI). Early aspirin discontinuation after a short course of dual antiplatelet therapy (DAPT) has emerged as a bleeding avoidance strategy. The aim of this study was to assess the effects of ticagrelor monotherapy after 3-month DAPT in a contemporary HBR population.

METHODS AND RESULTS

This prespecified analysis of the TWILIGHT trial evaluated the treatment effects of early aspirin withdrawal followed by ticagrelor monotherapy in HBR patients undergoing PCI with drug-eluting stents. After 3 months of ticagrelor plus aspirin, event-free patients were randomized to 12 months of aspirin or placebo in addition to ticagrelor. A total of 1064 (17.2%) met the Academic Research Consortium definition for HBR. Ticagrelor monotherapy reduced the incidence of the primary endpoint of Bleeding Academic Research Consortium (BARC) 2, 3, or 5 bleeding compared with ticagrelor plus aspirin in HBR (6.3% vs. 11.4%; hazard ratio (HR) 0.53, 95% confidence interval (CI) 0.35-0.82) and non-HBR patients (3.5% vs. 5.9%; HR 0.59, 95% CI 0.46-0.77) with similar relative (Pinteraction = 0.67) but a trend towards greater absolute risk reduction in the former [-5.1% vs. -2.3%; difference in absolute risk differences (ARDs) -2.8%, 95% CI -6.4% to 0.8%, P = 0.130]. A similar pattern was observed for more severe BARC 3 or 5 bleeding with a larger absolute risk reduction in HBR patients (-3.5% vs. -0.5%; difference in ARDs -3.0%, 95% CI -5.2% to -0.8%, P = 0.008). There was no significant difference in the key secondary endpoint of death, myocardial infarction, or stroke between treatment arms, irrespective of HBR status.

CONCLUSIONS

Among HBR patients undergoing PCI who completed 3-month DAPT without experiencing major adverse events, aspirin discontinuation followed by ticagrelor monotherapy significantly reduced bleeding without increasing ischaemic events, compared with ticagrelor plus aspirin. The absolute risk reduction in major bleeding was larger in HBR than non-HBR patients.

Antithrombotic Therapy With Ticagrelor in Atrial Fibrillation Subjects After Percutaneous Coronary Intervention

Background: Warfarin, along with aspirin and clopidogrel, has long been recommended for patients with atrial fibrillation (AF) who are undergoing percutaneous coronary intervention with a drug-eluting stent (PCI-DES). However, this triple therapy has been known to increase the risk of bleeding complications. Meanwhile, there is no evidence from prospective trials on the use of ticagrelor in a dual therapy. We here aimed to compare the antiplatelet drug ticagrelor as a dual antithrombotic agent to aspirin and clopidogrel in bleeding events.

Methods: In this multicenter, active-controlled, open-label, randomized trial, patients with AF taking warfarin who had undergone PCI-DES were randomly assigned to the ticagrelor therapy group (Dual group) or the clopidogrel plus aspirin therapy group (Triple group). The primary and secondary endpoints were overall bleeding events and major bleeding events, respectively, according to the Thrombolysis in Myocardial Infarction (TIMI) criteria at 6 months. Cardiovascular events [re-PCI, surgical bypass, myocardial infarction (MI), heart failure, rehospitalization due to angina pectoris, stent thrombosis and death due to cardiovascular causes] at 6 months were also recorded.

Results: A total of 296 patients from 12 medical centers in China were randomized after PCI-DES to either the Dual therapy group (n = 148) or the Triple group (n = 146) for 6 months. The overall incidence of bleeding events at 6 months was 36.49% in the Dual therapy group and 35.62% in the Triple group [hazard ratio, 0.930; 95% confidence interval (CI), 0.635 to 1.361; P = 0.7088]. The incidence of the secondary endpoint over 6 months was 4.73% in the Dual therapy group and 1.37% in the Triple group (hazard ratio, 0.273; 95% CI, 0.057 to 1.315; P = 0.1056). Cardiovascular event occurrence was also comparable in both groups at 6 months (18.24 vs. 16.44%; hazard ratio, 0.845; 95% CI, 0.488 to 1.465; P = 0.5484).

Conclusions: The incidence of total bleeding events in AF patients treated with ticagrelor was comparable to that in patients treated with clopidogrel plus aspirin at 6 month; Meanwhile, the incidence of cardiovascular events were also comparable between the groups.

Clinical Trial Registration: MANJUSRI, ClinicalTrials.gov# NCT02206815, 2014, August 1^st

Antithrombotics in Complex Percutaneous Coronary Interventions: Type and Duration of Treatment

Patients undergoing complex percutaneous coronary intervention (PCI) are at an increased risk of atherothrombotic complications. Although dual antiplatelet therapy is the mainstay of treatment for patients undergoing PCI with stent implantation, deciding its type and duration in complex PCI patients has long been considered a challenge for clinicians. This is because the beneficial effects of prolonged treatment and/or more potent antiplatelet agents’ use in preventing ischemic events are hindered by a concomitant increase in bleeding complications. The aim of this review is to highlight current evidence regarding the optimal antithrombotic therapy regimens used in complex PCI patients, focusing on the evaluation of both safety and efficacy outcomes as well as addressing future perspectives.

Clinical outcomes according to lesion complexity in high bleeding risk patients treated with 1-month dual antiplatelet therapy following PCI: Analysis from the Onyx ONE clear study

OBJECTIVES

To compare clinical outcomes in high bleeding risk (HBR) patients with and without complex percutaneous coronary intervention (PCI) treated with Resolute Onyx zotarolimus-eluting stents (ZES) after 1-month dual antiplatelet therapy (DAPT).

BACKGROUND

PCI with 1-month DAPT has been demonstrated to be safe in HBR patients treated with Resolute Onyx ZES. Whether these outcomes are consistent in patients with complex lesions is uncertain.

METHODS

Among HBR patients who were event-free 1 month after PCI with ZES and treated thereafter with single antiplatelet therapy (SAPT), the clinical outcomes between 1 month and 1 year were compared after complex PCI (3 vessels treated, ≥ 3 lesions treated, total stent length > 60 mm, bifurcation with ≥ 2 stents implanted, atherectomy, or left main, surgical bypass graft or chronic total occlusion PCI) versus noncomplex PCI. Propensity score adjustment was performed to adjust for baseline differences among complex and noncomplex patients.

RESULTS

Complex patients (N = 401, 26.6% of total) had a higher prevalence of hyperlipidemia, diabetes mellitus and previous myocardial infarction (MI). Between 1 month and 1 year, rates of MI (7.1% vs. 4.0%, p = 0.02) and cardiac death/MI (9.3% vs. 6.1%, p = 0.04) were higher among complex versus noncomplex patients, although stent thrombosis rates were similar. After adjustment for baseline characteristics, differences in outcomes were no longer significant between groups.

CONCLUSIONS

Higher rates of ischemic outcomes in complex PCI patients were largely explained by baseline clinical differences, rather than lesion complexity, among HBR patients treated with 1-month DAPT following PCI with Resolute Onyx ZES.

Guided and unguided de-escalation from potent P2Y12 inhibitors among patients with ACS: a meta-analysis

AIM

Optimal dual antiplatelet therapy (DAPT) in patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) intends to balance ischemic and bleeding risks. Various DAPT de-escalation strategies, defined as switching from a full-dose potent to a reduced dose or less potent P2Y12 inhibitor, have been evaluated in several ACS-PCI trials. We aimed to compare DAPT de-escalation to standard DAPT with full dose potent P2Y12 inhibitors in ACS patients who underwent PCI.

METHODS & RESULTS

PubMed, Google Scholar and Cochrane Central Register of Controlled Trials were searched for eligible randomised controlled trials. Aspirin monotherapy trials were excluded. Five randomised trials (n = 10,779 patients) that assigned DAPT de-escalation (genetically guided to clopidogrel n = 1,242; platelet function guided to clopidogrel n = 1,304; unguided to clopidogrel n = 1,672; unguided to lower dose n = 1,170) versus standard DAPT (control group n = 5,391) were included in this analysis. DAPT de-escalation was associated with a significant reduction in Bleeding Academic Research Consortium ≥ 2 bleeding (HR 0.57, 95% CI 0.42-0.78; I2 = 77%) as well as major adverse cardiac events, represented in most trials by the composite of cardiovascular mortality, myocardial infarction, stent thrombosis and stroke (HR 0.77, 95% CI 0.62-0.96; I2 = 0%). Notwithstanding the limited power, consistency was noted across various de-escalation strategies.

CONCLUSION

De-escalation of DAPT after PCI for ACS, both unguided and guided by genetic or platelet function testing, was associated with lower rates of clinically relevant bleeding and ischemic events as compared to standard DAPT with potent P2Y12 inhibitors based on five open-label RCTs reviewed.

Ticagrelor monotherapy in patients with chronic kidney disease undergoing percutaneous coronary intervention: TWILIGHT-CKD

AIMS

The aim of this study was to assess the impact of chronic kidney disease (CKD) on the safety and efficacy of ticagrelor monotherapy among patients undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

In this prespecified subanalysis of the TWILIGHT trial, we evaluated the treatment effects of ticagrelor with or without aspirin according to renal function. The trial enrolled patients undergoing drug-eluting stent implantation who fulfilled at least one clinical and one angiographic high-risk criterion. Chronic kidney disease, defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2, was a clinical study entry criterion. Following a 3-month period of ticagrelor plus aspirin, event-free patients were randomly assigned to aspirin or placebo on top of ticagrelor for an additional 12 months. Of the 6835 patients randomized and with available eGFR at baseline, 1111 (16.3%) had CKD. Ticagrelor plus placebo reduced the primary endpoint of Bleeding Academic Research Consortium (BARC) type 2, 3, or 5 bleeding as compared with ticagrelor plus aspirin in both patients with [4.6% vs. 9.0%; hazard ratio (HR) 0.50, 95% confidence interval (CI) 0.31-0.80] and without (4.0% vs. 6.7%; HR 0.59, 95% CI 0.47-0.75; Pinteraction = 0.508) CKD, but the absolute risk reduction was greater in the former group. Rates of death, myocardial infarction, or stroke were not significantly different between the two randomized groups irrespective of the presence (7.9% vs. 5.7%; HR 1.40, 95% CI 0.88-2.22) or absence of (3.2% vs. 3.6%; HR 0.90, 95% CI 0.68-1.20; Pinteraction = 0.111) CKD.

CONCLUSION

Among CKD patients undergoing PCI, ticagrelor monotherapy reduced the risk of bleeding without a significant increase in ischaemic events as compared with ticagrelor plus aspirin.

Single antiplatelet therapy with use of prasugrel in patients undergoing percutaneous coronary intervention

OBJECTIVES

We aimed to assess the ischemic and bleeding risks of single antiplatelet therapy (SAPT) with prasugrel compared with standard dual antiplatelet therapy (DAPT) (aspirin plus clopidogrel for 1 year) in patients with chronic coronary syndrome (CCS) treated with new generation drug-eluting stents (DES).

BACKGROUND

To date, data on SAPT with potent P2Y12 inhibitors in the absence of aspirin immediately after PCI are limited.

METHODS

Between January 2009 and November 2019, all CCS patients undergoing percutaneous coronary intervention (PCI) enrolled to the Bern PCI registry were considered for analysis. We performed propensity score matching in a 1:4 fashion to compare patients who received SAPT with prasugrel versus standard DAPT. The primary ischemic endpoint was a composite of cardiovascular death, myocardial infarction, and stroke and the primary bleeding endpoint was BARC 3 or 5 bleeding, both assessed at 1 year.

RESULTS

After propensity score matching, the final study population consisted of 225 patients with SAPT and 889 with DAPT. There was no significant difference in rates of the primary ischemic (5.2% vs. 4.2%, p = .50) or the primary bleeding (1.5% vs. 2.0%, p = .60) endpoints between groups. SAPT was not associated with an increased risk of definite stent thrombosis (0.9% vs. 0.8%, p = .83).

CONCLUSIONS

Among selected CCS patients undergoing PCI with DES, SAPT with prasugrel was not associated with an excess of ischemic events compared with standard DAPT. No difference in bleeding was observed either. The results may serve as the basis for larger trials assessing the potential benefits and risks of SAPT.

Impact of Age on the Safety and Efficacy of Ticagrelor Monotherapy in Patients Undergoing PCI

OBJECTIVES

The aim of this study was to assess the impact of age on the safety and efficacy of ticagrelor monotherapy after percutaneous coronary intervention (PCI).

BACKGROUND

As the risk for bleeding and ischemic complications after PCI increases with age, the authors conducted a pre-specified analysis of the TWILIGHT (Ticagrelor With Aspirin or Alone in High-Risk Patients After Coronary Intervention) trial to evaluate the possible benefits of ticagrelor monotherapy according to age.

METHODS

The TWILIGHT trial enrolled patients undergoing PCI with drug-eluting stents who fulfilled at least 1 clinical and 1 angiographic high-risk criterion. Age ≥65 years was a clinical entry criterion. After 3 months of dual-antiplatelet therapy with ticagrelor, event-free patients were randomized to ticagrelor plus placebo or ticagrelor plus aspirin for an additional 12 months. The primary endpoint was Bleeding Academic Research Consortium type 2, 3, or 5 bleeding. The key secondary endpoint was the composite of all-cause death, myocardial infarction, or stroke.

RESULTS

A total of 3,113 patients (47.7%) were ≥65 years of age. At 1 year after randomization, ticagrelor monotherapy significantly reduced BARC type 2, 3, or 5 bleeding (4.5% vs. 8.2%; hazard ratio: 0.53; 95% confidence interval: 0.40 to 0.71) without increasing ischemic events (4.2% vs. 4.4%; hazard ratio: 0.96; 95% confidence interval: 0.68 to 1.35) compared with ticagrelor plus aspirin among patients ≥65 years of age. These findings were consistent in patients <65 years of age with respect to the primary (p_interaction = 0.62) and key secondary (p_interaction = 0.77) endpoints and across different age categories.

CONCLUSIONS

A strategy of ticagrelor monotherapy following 3 months of dual-antiplatelet therapy significantly reduced clinically relevant bleeding compared with ticagrelor plus aspirin without an increase in ischemic events, irrespective of age.

Left Main Disease and Bifurcation Percutaneous Coronary Intervention: Focus on Antithrombotic Therapy

Revascularization of both left main and bifurcation lesions is currently considered an important feature of complex percutaneous coronary intervention (PCI), whereas stenting distal left main bifurcation is fairly challenging. Recent evidence shows that such lesions are associated with an increased risk of ischemic events. There is no universal consensus on the optimal PCI strategy or the appropriate type and duration of antithrombotic therapy to mitigate the thrombotic risk. Prolonged dual antiplatelet therapy or use of more potent P2Y12 inhibitors have been investigated in the context of this high-risk subset of the population undergoing PCI. Thus, while complex PCI is a growing field in interventional cardiology, left main and bifurcation PCI constitutes a fair amount of the total complex procedures performed recently, and there is cumulative interest regarding antithrombotic therapy type and duration in this subset of patients, with decision-making mostly based on clinical presentation, baseline bleeding, and ischemic risk, as well as the performed stenting strategy.

P2Y12 blocker monotherapy after percutaneous coronary intervention

For secondary prevention of coronary artery disease (CAD) antiplatelet therapy is essential. For patients undergoing a percutaneous coronary intervention (PCI) temporary dual antiplatelet platelet therapy (DAPT: aspirin combined with a P2Y12 blocker) is mandatory, but leads to more bleeding than single antiplatelet therapy with aspirin. Therefore, to reduce bleeding after a PCI the duration of DAPT is usually kept as short as clinically acceptable; thereafter aspirin monotherapy is administered. Another option to reduce bleeding is to discontinue aspirin at the time of DAPT cessation and thereafter to administer P2Y12 blocker monotherapy. To date, five randomised trials have been published comparing DAPT with P2Y12 blocker monotherapy in 32,181 stented patients. Also two meta-analyses addressing this novel therapy have been presented. P2Y12 blocker monotherapy showed a 50-60% reduction in major bleeding when compared to DAPT without a significant increase in ischaemic outcomes, including stent thrombosis. This survey reviews the findings in the current literature concerning P2Y12 blocker monotherapy after PCI.

Sex Differences Among Patients With High Risk Receiving Ticagrelor With or Without Aspirin After Percutaneous Coronary Intervention: A Subgroup Analysis of the TWILIGHT Randomized Clinical Trial

Importance

Shortened dual antiplatelet therapy followed by potent P2Y12 receptor inhibitor monotherapy reduces bleeding without increasing ischemic events after percutaneous coronary intervention (PCI).

Objective

To explore sex differences and evaluate the association of sex with outcomes among patients treated with ticagrelor monotherapy vs ticagrelor plus aspirin.

Design, Setting, and Participants

This was a prespecified secondary analysis of TWILIGHT, an investigator-initiated, placebo-controlled randomized clinical trial conducted at 187 sites across 11 countries. Study participants included patients who underwent successful PCI with drug-eluting stents, were planned for discharge with ticagrelor plus aspirin, and who had at least 1 clinical and at least 1 angiographic feature associated with high risk of ischemic or bleeding events. Data were analyzed from May to July 2020.

Interventions

At 3 months after PCI, patients adherent to ticagrelor and aspirin without major adverse event were randomized to either aspirin or placebo for an additional 12 months along with ticagrelor.

Main Outcomes and Measures

The primary end point was Bleeding Academic Research Consortium (BARC) type 2, 3, or 5 bleeding at 12 months after randomization. The primary ischemic end point was a composite of death, myocardial infarction, or stroke.

Results

Of 9006 enrolled patients, 7119 underwent randomization (mean [SD] age, 63.9 [10.2] years; 5421 [76.1%] men). Women were older (mean [SD] age, 65.5 [9.6] years in women vs 63.4 [10.3] years in men) with higher prevalence of chronic kidney disease (347 women [21.2%] vs 764 men [14.7%]). The primary bleeding end point occurred more often in women than men (hazard ratio [HR], 1.32; 95% CI, 1.06-1.64; P = .01). After multivariate adjustment, incremental bleeding risk associated with female sex was no longer significant (adjusted HR, 1.20; 95% CI, 0.95-1.52; P = .12). Ischemic end points were similar between sexes. Ticagrelor plus placebo vs ticagrelor plus aspirin was associated with lower risk of BARC type 2, 3, or 5 bleeding in women (adjusted HR, 0.62; 95% CI, 0.42-0.92; P = .02) and men (adjusted HR, 0.57; 95% CI, 0.44-0.73; P < .001; P for interaction = .69). Ischemic end points were similar between treatment groups in both sexes.

Conclusions and Relevance

These findings suggest that the higher bleeding risk in women compared with men was mostly attributable to baseline differences, whereas ischemic events were similar between sexes. In this high-risk PCI population, the benefits of early aspirin withdrawal with continuation of ticagrelor were generally comparable in women and men.

Trial Registration

ClinicalTrials.gov Identifier: NCT02270242.

Overview of Aspirin and Platelet Biology

Aspirin (ASA) has historically been one of the most important drugs in cardiology and has long been the cornerstone of antiplatelet therapy. Although its role in acute coronary syndrome remains undisputed, emerging data suggest that reappraisal of the efficacy of long-term ASA in some primary and secondary prevention may be warranted. The aim of this review is to place these new results in the context of previous evidence on aspirin by appraising the current body of evidence on its use of for cardiovascular diseases. This overview first summarizes the history of the discovery of aspirin, as well as its pharmacology and the concept of ASA resistance. We subsequently recapitulate the evidence of ASA on primary prevention and secondary prevention starting from the classical studies in order to serve as an introductory background to the examination of the most recent clinical trials that will be performed in the rest of the articles of this Supplement. Although the benefit of ASA in acute coronary syndrome remains incontrovertible, emerging evidence challenge the universal need for primary prevention, or for lifelong treatment in secondary prevention or all adults with stable coronary disease who are at highest risk for ASA-induced bleeding. The role of aspirin is quickly changing in recent times and this review provides a review for the clinician about the current role of this drug in cardiovascular care.

Dual Antiplatelet Therapy De-escalation Strategies

Dual antiplatelet therapy (DAPT), the combination of aspirin (ASA), and a P2Y₁₂ inhibitor, protects against stent thrombosis and new atherothrombotic events after a stent implantation or an acute coronary syndrome, but exposes patients to an increased risk of bleeding. In most current practices, the P2Y₁₂ inhibitor is stopped at 6 to 12 months and ASA is continued indefinitely. The advent of safer stents, with less risk of stent thrombosis, has challenged this standard of care, however. A number of alternative strategies involving earlier de-escalation of the antiplatelet therapy have therefore been proposed. In these approaches, standard DAPT is switched to a less potent antithrombotic combination at an earlier time-point than recommended by guidelines. Three different de-escalation variations have been tested to date. The first one maintains DAPT but switches from the potent P2Y₁₂ inhibitors ticagrelor or prasugrel to either a lower dose or to clopidogrel, while maintaining ASA. The 2 other approaches involve changing DAPT to a single antiplatelet at some earlier time-point after the percutaneous coronary intervention procedure, by stopping either the P2Y₁₂ inhibitor or ASA. These strategies have all demonstrated some benefit in clinical trials so far, but especially the contribution of ASA in secondary prevention is clearly evolving as its role in increasing bleeding complications while not providing increased ischemic benefit is becoming more and more clear. In contemporary practice, the type and duration of DAPT should now be based on an individualized decision, and the de-escalation strategies, if used wisely, can be added to the existing options.

Patient-tailored antithrombotic therapy following percutaneous coronary intervention

Dual antiplatelet therapy has long been the standard of care in preventing coronary and cerebrovascular thrombotic events in patients with chronic coronary syndrome and acute coronary syndrome undergoing percutaneous coronary intervention, but choosing the optimal treatment duration and composition has become a major challenge. Numerous studies have shown that certain patients benefit from either shortened or extended treatment duration. Furthermore, trials evaluating novel antithrombotic strategies, such as P2Y12 inhibitor monotherapy, low-dose factor Xa inhibitors on top of antiplatelet therapy, and platelet function- or genotype-guided (de-)escalation of treatment, have shown promising results. Current guidelines recommend risk stratification for tailoring treatment duration and composition. Although several risk stratification methods evaluating ischaemic and bleeding risk are available to clinicians, such as the use of risk scores, platelet function testing , and genotyping, risk stratification has not been broadly adopted in clinical practice. Multiple risk scores have been developed to determine the optimal treatment duration, but external validation studies have yielded conflicting results in terms of calibration and discrimination and there is limited evidence that their adoption improves clinical outcomes. Likewise, platelet function testing and genotyping can provide useful prognostic insights, but trials evaluating treatment strategies guided by these stratification methods have produced mixed results. This review critically appraises the currently available antithrombotic strategies and provides a viewpoint on the use of different risk stratification methods alongside clinical judgement in current clinical practice.

One-Year COMBO Stent Outcomes in Acute Coronary Syndrome: from the COMBO Collaboration

PURPOSE

The COMBO biodegradable polymer sirolimus-eluting stent includes endothelial progenitor cell capture (EPC) technology for rapid endothelialization, which may offer advantage in acute coronary syndromes (ACS). We sought to analyze the performance of the COMBO stent by ACS status and ACS subtype.

METHODS

The COMBO collaboration (n = 3614) is a patient-level pooled dataset from the MASCOT and REMEDEE registries. We evaluated outcomes by ACS status, and ACS subtype in patients with ST segment elevation myocardial infarction (STEMI) or non-STEMI (NSTEMI) versus unstable angina (UA). The primary endpoint was 1-year target lesion failure (TLF), composite of cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization. Secondary outcomes included stent thrombosis (ST).

RESULTS

We compared 1965 (54%) ACS and 1649 (46.0%) non-ACS patients. ACS presentations included 40% (n = 789) STEMI, 31% (n = 600) NSTEMI, and 29% (n = 576) UA patients. Risk of 1-year TLF was greater in ACS patients (4.5% vs. 3.3%, HR 1.51 95% CI 1.01-2.25, p = 0.045) without significant differences in definite/probable ST (1.1% vs 0.5%, HR 2.40, 95% CI 0.91-6.31, p = 0.08). One-year TLF was similar in STEMI, NSTEMI, and UA (4.8% vs 4.8% vs. 3.7%, p = 0.60), but definite/probable ST was higher in STEMI patients (1.9% vs 0.5% vs 0.7%, p = 0.03). Adjusted outcomes were not different in MI versus UA patients.

CONCLUSIONS

Despite the novel EPC capture technology, COMBO stent PCI was associated with somewhat greater risk of 1-year TLF in ACS than in non-ACS patients, without significant differences in stent thrombosis. No differences were observed in 1-year TLF among ACS subtypes.

Recovery of platelet reactivity following cessation of either aspirin or ticagrelor in patients treated with dual antiplatelet therapy following percutaneous coronary intervention: a GLOBAL LEADERS substudy

Cessation of one component of dual antiplatelet therapy (DAPT) following percutaneous coronary intervention (PCI) has been associated with increased risk of ischemic events but it is uncertain whether discontinuation of aspirin is preferable to discontinuation of the oral P2Y₁₂ inhibitor. The GLOBAL LEADERS study compared two antiplatelet strategies following PCI, cessation of aspirin at 1 month with continued ticagrelor monotherapy for 23 months versus standard DAPT for 12 months followed by aspirin monotherapy for a further 12 months. We assessed recovery of platelet reactivity after withdrawal of either aspirin or ticagrelor at 1 month and 12 months, respectively, in this study. Platelet aggregation (PA) was assessed before cessation of DAPT ('baseline') and after 2, 7, and 14 days post-cessation using Multiplate whole-blood aggregometry with collagen, thrombin-receptor-activating peptide (TRAP), adenosine diphosphate (ADP) and arachidonic acid (AA) as agonists. Following cessation of aspirin at 1 month, there was marked recovery of PA induced by AA (baseline [mean ± SD]: 11.1 ± 7.4 U vs. 14 days: 64.9 ± 19.6 U, p < .0001) and collagen (37.4 ± 22.9 U vs. 79.8 ± 13.8 U, p < .0001), whereas PA induced by ADP (18.6 ± 6.6 vs. 69.1 ± 20.5, p < .0001) and collagen (34.4 ± 18.7 U vs. 43.0 ± 21.0, p = .0018) recovered following cessation of ticagrelor at 12 months. There were no significant changes in TRAP-induced PA in either group. In conclusion, cessation of either component of DAPT leads to substantial increase in platelet reactivity with differential effects on different pathways of platelet activation when aspirin or the P2Y₁₂ inhibitor is stopped. Further work is required to determine which patients receive net benefit from long-term continuation of DAPT.

Safety and efficacy of P2Y12 inhibitor monotherapy in patients undergoing percutaneous coronary interventions

Introduction: Antiplatelet therapy represents a key strategy for the prevention of thrombotic complications in patients with both acute and chronic coronary syndromes, particularly those undergoing percutaneous coronary intervention (PCI). Nevertheless, dual antiplatelet therapy (DAPT) is associated with a bleeding risk proportionate to its duration. Ever growing appreciation of the prognostic implications associated with bleeding and the development of safer stent platforms over the past years have led to a number of novel antiplatelet treatment strategies being tested among patients undergoing PCI. Areas covered: P2Y₁₂ inhibitor monotherapy after ashort course DAPT has emerged as ableeding reduction strategy to mitigate such risk while still preventing thrombotic complications. In this review we describe the latest evidence regarding the safety and efficacy of P2Y₁₂ inhibitor monotherapy in patients undergoing PCI in different clinical settings. Expert opinion: P2Y₁₂ inhibitor monotherapy after a brief period of DAPT has emerged as an effective approach to reduce the risk of bleeding without any tradeoff in efficacy (i.e., thrombotic complications). This strategy has shown consistent findings in a number of different clinical settings of patients undergoing PCI. Nevertheless, unanswered questions on the ideal patient and the precise P2Y₁₂ monotherapy regimen warrant further investigation.

One-Month Dual Antiplatelet Therapy Following Percutaneous Coronary Intervention With Zotarolimus-Eluting Stents in High-Bleeding-Risk Patients

Supplemental Digital Content is available in the text.

Background:

Despite treatment guidance endorsing shortened dual antiplatelet therapy (DAPT) duration in high bleeding risk (HBR) patients after drug-eluting stents, limited evidence exists to support these recommendations. The present study was designed to examine the safety and effectiveness of 1-month DAPT duration following percutaneous coronary intervention with zotarolimus-eluting stents in HBR patients.

Methods:

Onyx ONE Clear was a prospective, multicenter, nonrandomized study evaluating the safety and effectiveness of 1-month DAPT followed by single antiplatelet therapy in HBR patients undergoing percutaneous coronary intervention with Resolute Onyx drug-eluting stents. The primary analysis of cardiac death or myocardial infarction between 1 month and 1 year was performed in the prespecified one-month clear population of patients pooled from the Onyx ONE US/Japan study and Onyx ONE randomized controlled trial. One-month clear was defined as DAPT adherence and without major adverse events during the first month following percutaneous coronary intervention.

Results:

Among patients enrolled in Onyx ONE US/Japan (n=752) and Onyx ONE randomized controlled trial (n=1018), 1506 patients fulfilled one-month clear criteria. Mean HBR characteristics per patient was 1.6 with 44.7% having multiple risks. By 2 months and 1 year, respectively, 96.9% and 89.3% of patients were taking single antiplatelet therapy. Between 1 month and 1 year, the rate of the primary end point was 7.0%. The 1-sided upper 97.5% CI was 8.4%, less than the performance goal of 9.7% (P<0.001).

Conclusions:

Among HBR patients who were event free before DAPT discontinuation at 1 month, favorable safety and effectiveness through 1 year support treatment with Resolute Onyx drug-eluting stents as part of an individualized strategy for shortened DAPT duration following percutaneous coronary intervention.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier NCT03647475.

Ticagrelor alone vs. ticagrelor plus aspirin following percutaneous coronary intervention in patients with non-ST-segment elevation acute coronary syndromes: TWILIGHT-ACS

Aims 

The aim of this study was to determine the effect of ticagrelor monotherapy on clinically relevant bleeding and major ischaemic events in relation to clinical presentation with and without non-ST elevation acute coronary syndromes (NSTE-ACS) among patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES).

Methods and results 

We conducted a pre-specified subgroup analysis of The Ticagrelor With Aspirin or Alone in High Risk Patients After Coronary Intervention (TWILIGHT) trial, which enrolled 9006 patients with high-risk features undergoing PCI with DES. After 3 months of dual antiplatelet therapy (DAPT) with ticagrelor plus aspirin, 7119 adherent and event-free patients were randomized in a double-blind manner to ticagrelor plus placebo versus ticagrelor plus aspirin for 12 months. The primary outcome was Bleeding Academic Research Consortium (BARC) type 2, 3, or 5 bleeding while the composite of all-cause death, myocardial infarction (MI), or stroke was the key secondary outcome. Among patients with NSTE-ACS (n = 4614), ticagrelor monotherapy reduced BARC 2, 3, or 5 bleeding by 53% [3.6% vs. 7.6%; hazard ratio (HR) 0.47; 95% confidence interval (CI) 0.36–0.61; P &lt; 0.001) and in stable patients (n = 2503) by 24% (4.8% vs. 6.2%; HR 0.76; 95% CI 0.54–1.06; P = 0.11; nominal Pint = 0.03). Rates of all-cause death, MI, or stroke among those with (4.3% vs. 4.4%; HR 0.97; 95% CI 0.74–1.28; P = 0.84) and without (3.1% vs. 3.2%; HR 0.96; 95% CI 0.61–1.49; P = 0.85) NSTE-ACS were similar between treatment arms irrespective of clinical presentation (Pint = 0.96).

Conclusion 

Among patients with or without NSTE-ACS who have completed an initial 3-month course of DAPT following PCI with DES, ticagrelor monotherapy reduced clinically meaningful bleeding events without increasing ischaemic risk as compared with ticagrelor plus aspirin. The benefits of ticagrelor monotherapy with respect to bleeding events were more pronounced in patients with NSTE-ACS.

Trial registration

Clinicaltrials.gov identifier: NCT02270242.

Effect of ticagrelor monotherapy on mortality after percutaneous coronary intervention: a systematic review and meta-analysis of randomized trials including 26 143 patients

Aims

Optimal timing and strategy of antiplatelet monotherapy after dual-antiplatelet therapy (DAPT) consisting of aspirin and P2Y12 inhibitor for patients who underwent percutaneous coronary intervention (PCI) is still being debated. The aim of this study was to evaluate the effect of ticagrelor monotherapy after short-term DAPT after PCI on mortality.

Methods and results

A systematic review and meta-analysis was performed using PubMed to search for ticagrelor monotherapy after short-term DAPT comparing conventional DAPT in patients who underwent PCI. Three randomized trials encompassing 26 143 patients [ticagrelor monotherapy after 1–3 months of DAPT (n = 13 062) vs. conventional therapy (n = 13 081)] were included. The efficacy endpoint of all-cause mortality was significantly lower with the ticagrelor monotherapy group vs. the conventional therapy group [risk ratio (RR) = 0.80, 95% confidence interval (CI) 0.65–0.98; P = 0.03; I2 = 0%; number needed to treat for benefit (NNTB) = 320]. The safety endpoint of Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding was also significantly lower with the ticagrelor monotherapy group vs. the conventional therapy group (RR = 0.67, 95% CI 0.49–0.92; P = 0.01; I2 = 65%; NNTB = 156). There were no significant differences in ischaemic stroke, acute myocardial infarction, and stent thrombosis. The favourable effects of the ticagrelor monotherapy vs. the conventional therapy on all-cause mortality and BARC type 3 or 5 bleeding were consistent in the subset of patients presenting acute coronary syndromes (n = 15 157).

Conclusion

Ticagrelor monotherapy after short-term DAPT of 1–3 months was associated with decreased all-cause mortality and BARC type 3 or 5 bleeding not offset by increase of cardiac death, ischaemic stroke, acute myocardial infarction, and stent thrombosis.

The Role of Aspirin After High-Risk Percutaneous Coronary Intervention: The Ticagrelor with Aspirin or Alone in High-Risk Patients After Coronary Intervention Clinical Trial Experience

Traditionally, aspirin has played a significant role in both primary and secondary prevention of cardiovascular disease. However, emerging antithrombotic regimens with better efficacy and safety have challenged the foundation of aspirin. Aspirin-free strategies consisting of P2Y12 inhibitor monotherapy following percutaneous coronary intervention (PCI) have now been tested in several large randomized controlled trials. In this article, we provide a contemporary overview of these data and suggest an algorithm to inform clinical decision with respect to antiplatelet pharmacotherapy after PCI.