Low-Dose Prasugrel vs. Standard-Dose Clopidogrel for Patients Undergoing Percutaneous Coronary Intervention.

BACKGROUND: Low-dose prasugrel (3.75 mg) is used as maintenance therapy for percutaneous coronary intervention; however, data on long-term outcomes are scarce. METHODS AND RESULTS: We analyzed 5,392 participants in the KiCS-PCI registry who were administered low-dose prasugrel or clopidogrel at discharge between 2008 and 2018 and for whom 2-year follow-up data were available. We adjusted for confounders using matching weight analyses and multiple imputations. Similarly, we used inverse probability- and propensity score-weighted analyses. We also performed instrumental variable analyses. The primary outcomes were acute coronary syndrome (ACS) and bleeding requiring readmission. Secondary outcomes were all-cause death and a composite outcome of ACS, bleeding, heart failure, stroke, coronary bypass requiring admission, and all-cause death. In this cohort, 12.2% of patients were discharged with low-dose prasugrel. Compared with clopidogrel, low-dose prasugrel was associated with a reduced risk of ACS (hazard ratio [HR] 0.58; 95% confidence interval [CI] 0.39-0.85), bleeding (HR 0.62; 95% CI 0.40-0.97), and the composite outcome (HR 0.71; 95% CI 0.59-0.86). Inverse probability-weighted analysis yielded similar results; however, matching weight analysis without multiple imputations and propensity score-matched analyses showed similar outcomes in both groups. Instrumental variable analyses showed reduced risks of ACS and composite outcome for those on low-dose prasugrel. All-cause mortality did not differ in all analyses. CONCLUSIONS: Low-dose prasugrel demonstrates comparable outcomes to clopidogrel in terms of ACS and bleeding.

Comparison of Heart Rates in Patients Initiated on Ticagrelor Versus Other P2Y12 Inhibitors After an Inferior ST Elevation Myocardial Infarction (STEMI).

BACKGROUND: P2Y12 inhibitors have differing associations of bradyarrhythmias. Ticagrelor has been shown to increase adenosine plasma concentrations leading to increases in bradyarrhythmias. While clopidogrel and prasugrel have not been shown to have any association with bradyarrhythmias. OBJECTIVE: The objective of this study was to determine heart rates after ticagrelor initiation compared to clopidogrel/prasugrel in inferior ST Elevation Myocardial Infarction (STEMI) patients. METHODS: This was a retrospective, multicenter study conducted at 3 primary percutaneous coronary intervention (PCI) centers between January 1, 2017 and September 30, 2022. Adult patients were included if they were diagnosed with an inferior STEMI to the right coronary artery (RCA) and treated with PCI followed by an oral P2Y12 inhibitor. The primary outcome was heart rate at 48 hours or discharge, whichever first, after administration of ticagrelor compared to clopidogrel/prasugrel. RESULTS: This study reviewed 331 patients, 172 in the ticagrelor group and 159 in the clopidogrel/prasugrel group. There were no statistical differences between groups regarding the primary outcome, with a median heart rate of 76 beats per minute (bpm) [67-85] in the ticagrelor group versus 73 bpm [66-84] in the clopidogrel/prasugrel group (P = 0.238). No differences were observed between groups regarding any secondary outcomes. CONCLUSION AND RELEVANCE: There were similar heart rates between ticagrelor and clopidogrel/prasugrel. There were also similarities in the ability to tolerate beta-blocker therapy after initiation of a P2Y12 inhibitor. The results of this study suggest that in inferior STEMIs when using ticagrelor as the P2Y12 inhibitor, there are not increased clinical manifestations of bradycardia.

Development of a routine bedside CYP2C19 genotype assessment program for antiplatelet therapy guidance in a community hospital catheterization laboratory.

Genotype based personalized antiplatelet therapy in the setting of percutaneous coronary intervention (PCI) has been studied in clinical trials. Despite the demonstrated risk associated with CYP2C19 loss-of-function (LoF) carriage in clopidogrel-treated PCI patients, real-world implementation of genotyping for PCI has been low. The goal of the current study was to provide CYP2C19 genotype information to the interventionalist prior to the completion of the catheterization to facilitate immediate personalized antiplatelet therapy. Routine personalization of P2Y12 inhibitor therapy for PCI in a community hospital cardiac catheterization laboratory by POC genotyping with the SpartanRx system was first offered in February 2017. A best practice advisory (BPA) based on the Clinical Pharmacogenetics Implementation Consortium Guideline for CYP2C19 genotype and clopidogrel therapy was placed in the electronic health record prescription medication ordering system. By December 2019, 1,052 patients had CYP2C19 genotype testing, 429 patients underwent PCI with genotype guided antiplatelet therapy, and 250 patients underwent PCI without genotype testing and received antiplatelet therapy at the discretion of the treating physician. BPA compliance was 93. 87% of LoF allele carriers were prescribed ticagrelor or prasugrel whereas 96% of non-LoF allele carriers were prescribed clopidogrel. The genotyping results were available within 1 h and made immediately available for decision making by the interventional cardiologist. POC CYP2C19 genotyping is feasible in a community hospital catheterization laboratory and is associated with high rate of best practice compliance.Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03040622.

Low-dose prasugrel versus standard-dose ticagrelor in east Asian patients with acute coronary syndrome.

Low-dose prasugrel demonstrated a similar effectiveness profile to clopidogrel in East Asian ACS patients, but its comparison with another new-generation potent P2Y12 inhibitor, ticagrelor, remains unclear. To compare the effectiveness and safety of low-dose prasugrel against those of standard-dose ticagrelor in East Asian patients with ACS. This retrospective cohort study used Taiwan's National Health and Welfare Database. This study included ACS patients who underwent percutaneous coronary intervention and, at discharge between January 1, 2018 and December 31, 2020, were prescribed with low-dose prasugrel plus aspirin or standard-dose ticagrelor plus aspirin. Stabilized inverse probability of treatment weighting was used to balance the covariates across these two groups. The primary effectiveness outcome was a composite of acute myocardial infarction, ischemic stroke, and cardiovascular death; the secondary effectiveness outcome was each of the individual components of the primary outcome, transient ischemic attack, and repeat revascularization. The primary safety outcome was a composite of intracranial hemorrhage and gastrointestinal bleeding, and the two secondary safety outcomes were intracranial hemorrhage and gastrointestinal bleeding. A total of 24,807 patients were included in this study. Among them, 1,493 were low-dose prasugrel users and 23,314 were standard-dose ticagrelor users. No significant differences were found in primary effectiveness [HR: 0.97 (0.74-1.28)] or primary safety outcomes [HR: 1.22 (0.73-2.01)] between the two study groups. For East Asian patients with ACS, low-dose prasugrel provides comparable effectiveness without increasing bleeding risk compared to standard-dose ticagrelor. Low-dose prasugrel may be an appropriate alternative for East Asian populations.

Prasugrel Monotherapy After Percutaneous Coronary Intervention With Biodegradable-Polymer Platinum-Chromium Everolimus Eluting Stent for Japanese Patients With Chronic Coronary Syndrome (ASET-JAPAN).

BACKGROUND: P2Y12 inhibitor monotherapy without aspirin immediately after percutaneous coronary intervention (PCI) has not been tested in East Asian patients, so in this study we aimed to assess the safety and feasibility of reduced dose (3.75 mg/day) prasugrel monotherapy in Japanese patients presenting with chronic coronary syndrome (CCS).Methods and Results: ASET-JAPAN is a prospective, multicenter, single-arm pilot study that completed enrolment of 206 patients from 12 Japanese centers in September 2022. Patients with native de-novo coronary lesions and a SYNTAX score <23 were treated exclusively with biodegradable-polymer platinum-chromium everolimus-eluting stent(s). Patients were loaded with standard dual antiplatelet therapy (DAPT) and following successful PCI and optimal stent deployment, they received low-dose prasugrel (3.75 mg/day) monotherapy for 3 months. The primary ischemic endpoint was a composite of cardiac death, spontaneous target-vessel myocardial infarction, or definite stent thrombosis. The primary bleeding endpoint was Bleeding Academic Research Consortium (BARC) type 3 or 5. At 3-month follow-up, there were no primary bleeding or ischemic events, or any stent thrombosis. CONCLUSIONS: This pilot study showed the safety and feasibility of prasugrel monotherapy in selected low-risk Japanese patients with CCS. This "aspirin-free" strategy may be a safe alternative to traditional DAPT following PCI.

Impact of Low-Dose Prasugrel on Platelet Reactivity in Chronic Phase of Post-Percutaneous Coronary Intervention (CHAPERON): a Prospective Cohort Study.

PURPOSE: Asians often face the problems of clopidogrel resistance and East Asian paradox. This study aimed to evaluate the effects of P2Y12 inhibitors, including low-dose prasugrel 2.5 mg, on the P2Y12 reaction unit (PRU) in the chronic phase after percutaneous coronary intervention (PCI). METHODS: A total of 348 patients were studied. PRU was measured 6-12 months after PCI and subsequently, 6 months later using a P2Y12 assay, respectively. This study evaluated the proportion of bleeding risk (PRU ≤ 85) and ischemic risk (PRU ≥ 239) as primary endpoints, and the prediction of bleeding risk and ischemic risk using multivariable logistic regression analysis. RESULTS: At baseline, 136 patients (39%) received prasugrel 3.75 mg, 48 patients (14%) received prasugrel 2.5 mg, and 164 patients (47%) received clopidogrel 75 mg. Clopidogrel 75 mg had a significantly higher proportion of ischemic risk within one year after PCI than the other groups, and was an independent predictor for ischemic risk with reference of prasugrel 3.75 mg. In addition, switching from clopidogrel 75 mg to prasugrel 2.5 mg significantly lowered and aggregated the PRU value. Whereas, dose reduction of prasugrel had a significantly lower proportion of bleeding risk over one year after PCI than the continuation of prasugrel 3.75 mg, and was an independent predictor for bleeding risk with reference of continuation of prasugrel 3.75 mg. CONCLUSIONS: Prasugrel 2.5 mg has a lower ischemic risk and a more stable PRU value compared with clopidogrel treatment. Prasugrel also contributes to a decline in bleeding risk with concomitant dose reduction. TRIAL REGISTRATION: University Hospital Medical Information Network (UMIN), ID: UMIN000029541, Date: October 16, 2017 ( https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000033395 ).

Real-world evidence of switching P2Y12 receptor-inhibiting therapies to prasugrel after PCI in patients with ACS: results from EFF-K registry.

BACKGROUND: Potent P2Y12 inhibitors are recommended for up to 12 months after percutaneous coronary intervention (PCI) in patients diagnosed with acute coronary syndrome (ACS). However, the prescription pattern is diverse in real world practice, which includes various switching between antiplatelet regimens. In this study, we analyzed the prescription patterns of prasugrel, and assessed the safety and effectiveness of P2Y12 inhibitors switching patterns in a real world registry of patients subjected to PCI after ACS. METHODS: The EFF-K study included 3077 ACS patients receiving prasugrel-based dual antiplatelet therapy. The cohort was divided into those who were administered with prasugrel as the primary antiplatelet treatment (naïve cohort) or as a substitute agent after clopidogrel or ticagrelor pre-treatment (switch cohort). The primary endpoint was a net adverse clinical event (NACE; a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, or TIMI major bleeding unrelated to coronary-artery bypass grafting). RESULTS: A total of 3077 patients diagnosed with ACS were included in the analysis. Among the total population, 726 patients (23.6%) were classed as the naïve cohort and 2351 patients (76.4%) as the switch cohort. Baseline characteristics showed that the switch cohort had more comorbidities, such as hypertension, diabetes mellitus, heart failure and previous PCI. The major cause of switching to prasugrel in the switch cohort was the necessity for a more potent antiplatelet agent (56.3%). During a 12-month follow-up period, 51 patients (1.7%) experienced at least one NACE. The incidence of NACE did not differ between the naïve and switch cohort (1.5% vs. 1.7%, Hazard ratio 1.17, 95% Confidence interval 0.56-2.43, P = 0.677). In subgroup analysis, no significant interaction was observed between the treatment strategy and the incidence of NACE across various subgroups. CONCLUSIONS: Dual antiplatelet therapy with prasugrel seems to be safe and effective both as a primary treatment and as a substitute for other P2Y12 inhibitors in a real world registry of Asian ACS patients receiving PCI. TRIAL REGISTRATION: KCT0002356, registered June 13, 2017.

Thrombogenicity and endothelial progenitor cells function during Acute myocardial infarction - comparison of Prasugrel versus Ticagrelor.

BACKGROUND: Thrombin generation (TG), platelet function and circulating endothelial progenitor cells (EPCs) have an important role in the pathophysiology of coronary artery disease (CAD). To date, the effect of novel P2Y12 inhibitors on these aspects has mostly been studied in the sub-acute phase following myocardial infarction. OBJECTIVES: Comparing the effects of prasugrel and ticagrelor on TG and EPCs in the acute phase of ST-segment elevation myocardial infarction (STEMI). METHODS: STEMI patients were randomized to either ticagrelor or prasugrel treatment. TG, platelet reactivity and EPCs were evaluated prior to P2Y12 inhibitor loading dose (T0), and one day following (T1). RESULTS: Between December 2018 - July 2021, 83 consecutive STEMI patients were randomized to ticagrelor (N = 42) or prasugrel (N = 41) treatment. No differences were observed at T0 for all measurements. P2Y12 reactivity units (PRU) at T1 did not differ as well (prasugrel 13.2 [5.5-20.8] vs. ticagrelor 15.8 [4.0-26.3], p = 0.40). At T1, prasugrel was a significantly more potent TG inhibitor, with longer lag time to TG initiation (7.7 ± 7.5 vs. 3.9 ± 2.1 min, p < 0.01), longer time to peak (14.1 ± 12.6 vs. 8.3 ± 9.7 min, p = 0.03) and a lower endogenous thrombin potential (AUC 2186.1 ± 1123.1 vs. 3362.5 ± 2108.5 nM, p < 0.01). Furthermore, EPCs measured by percentage of cells expressing CD34 (2.6 ± 4.1 vs. 1.1 ± 1.1, p = 0.01) and CD133 (2.3 ± 1.8 vs. 1.4 ± 1.5, p = 0.01) and number of colony forming units (CFU, 2.1 ± 1.5 vs. 1.1 ± 1.0, p < 0.01) were significantly higher in the prasugrel group. CONCLUSION: Among STEMI patients, prasugrel as compared to ticagrelor was associated with more potent TG inhibition and improved EPCs count and function.

Usefulness of the PRECISE-DAPT score at differentiating between ticagrelor and prasugrel for dual antiplatelet therapy initiation.

As a part of dual antiplatelet therapy (DAPT), prasugrel or ticagrelor is prescribed along with aspirin to patients of acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). We aimed to assess if the PRECISE-DAPT score, which provides prediction of bleeding during DAPT, could be used to choose between prasugrel and ticagrelor for DAPT initiation. 181 patients out of which 71 received prasugrel and 110 received ticagrelor were enrolled in this prospective cohort study. PRECISE-DAPT score was calculated for everyone and was used to dichotomize patients into two subgroups (score <25 and ≥25). After balancing potential confounders in baseline characteristics of the subgroups using propensity scores, comparison of a composite outcome of 4-point major adverse cardiovascular events (4P-MACE) (i.e., cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, or coronary revascularization due to stent thrombosis) and bleeding (any type as defined by the Bleeding Academic Research Consortium) within 1-year post-PCI was performed among the subgroups using Cox proportional hazards regression. Prasugrel was associated with lower and comparatively higher 4P-MACE events in subgroups with score ≥25 (HR: 0.17; 95% CI, 0.04-0.77) and score <25 (HR: 3.58; 95% CI, 0.62-20.70) respectively. For bleeding outcome, prasugrel trended towards more clinical benefit for scores ≥25 (HR: 0.44; 95% CI, 0.10-1.93) than <25 (HR: 0.93; 95% CI, 0.13-6.58). Therefore, prasugrel was associated with better clinical effectiveness and trended towards a lower bleeding risk compared to ticagrelor within 1-year post-PCI for those with a high PRECISE-DAPT score (≥25). This finding requires validation through larger studies.

Thrombus remodelling by reversible and irreversible P2Y12 inhibitors.

Pharmacological inhibition of the platelet ADP-receptor P2Y12 is a cornerstone in the prevention of atherothrombotic events in adult patients with acute coronary syndrome (ACS). Thienopyridines such as clopidogrel and prasugrel exert their antithrombotic effect by means of active metabolites that irreversibly inhibit P2Y12. Due to the short half-life of these metabolites, a subpopulation of ADP-responsive platelets will form in between dosing. With increased platelet turnover rate or poor patient compliance, the fraction of ADP-responsive platelets will increase, potentially increasing the risk for new thrombotic events. In contrast, the reversible P2Y12 inhibition produced by direct-acting ADP blockers such as ticagrelor and cangrelor inhibit the entire platelet population. In this study, we evaluated the impact of these pharmacological differences on thrombus formation in an ex vivo flow chamber model. A customized image analysis pipeline was used for automatized, large-scale identification and tracking of single platelets incorporated into the thrombus, enabling quantitative analysis of the relative contribution of inhibited and uninhibited platelets to thrombus growth and consolidation. Comparative experiments were conducted using the irreversible and reversible P2Y12 inhibitors prasugrel active metabolite (PAM) and ticagrelor, respectively. Our results show that PAM inhibited thrombus platelet recruitment more gradually than ticagrelor, with a slower onset of inhibition. Further, we show that the presence of a small fraction (<10%) of uninhibited platelets did not abrogate the antithrombotic effect of PAM to any significant extent. Finally, we demonstrate a gradual enrichment of inhibited platelets in the thrombus shell due to selective recruitment of inhibited platelets to the thrombus periphery.

Comparison of clinical outcomes with cangrelor plus aspirin versus oral dual antiplatelet therapy in patients supported with venoarterial extracorporeal membrane oxygenation.

BACKGROUND: Patients with refractory cardiogenic shock from an acute myocardial infarction may receive percutaneous coronary intervention (PCI) and require the use of venoarterial extracorporeal membrane oxygenation (VA-ECMO). The purpose of this study was to compare bleeding and thrombotic events in patients treated with cangrelor plus aspirin versus oral dual antiplatelet therapy (DAPT) while supported with VA-ECMO. METHODS: We conducted a retrospective review of patients who received PCI, were supported with VA-ECMO, and were treated with either cangrelor plus aspirin or oral DAPT from February 2016 through May 2021 at Allegheny General Hospital. The primary objective was the incidence of major bleeding, defined as Bleeding Academic Research Consortium (BARC) type 3 or greater. The incidence of thrombotic events was a secondary objective. RESULTS: Thirty-seven patients were included, 19 in the cangrelor plus aspirin group, and 18 in the oral DAPT group. All the patients in the cangrelor group received a dose of 0.75 mcg/kg/min. Major bleeding occurred in 7 patients (36.8%) in the cangrelor group compared to 7 patients (38.9%) in the oral DAPT group (p = 0.90). No patient developed stent thrombosis. Two patients (10.5%) in the cangrelor group had a thrombotic event versus 3 patients (16.7%) in the oral DAPT group (p = 0.66). CONCLUSIONS: Bleeding and thrombotic events were comparable between patients receiving cangrelor plus aspirin versus oral DAPT while on VA-ECMO.

Delayed ischemic events with low-dose prasugrel medication for stent-assisted coil embolization in intracranial aneurysm patients.

OBJECTIVE: Much emphasis has been put on the use of antiplatelet medication for the prevention of ischemic events in the treatment of cerebral aneurysms with stent assistance. In this regard, the effectiveness and safety of a low-dose prasugrel regimen during the periprocedural period was recently reported. The purpose of this study was to present the outcomes of patients on low-dose prasugrel regimens during the follow-up period after stent-assisted coil embolization (SACE) of cerebral aneurysms. METHODS: For the 396 consecutive patients undergoing SACE procedures, low-dose prasugrel therapy (5 mg of prasugrel and 100 mg of aspirin) was recommended for 3 months after the endovascular treatment. The authors performed a retrospective review of a single-center experience focusing on delayed ischemic events beyond 1 month after treatment. The mean follow-up period was 24.6 ± 11.3 months. RESULTS: In this cohort of patients on a low-dose prasugrel regimen, cerebral infarction occurred in 1 patient (0.3%, 95% CI 0%-1.8%) beyond 1 month after SACE. No intracranial hemorrhage occurred. Overall ischemic events occurred in 14 patients (3.5%, 95% CI 2.1%-5.9%), all within 6 months of the coiling procedure. All patients had transient symptoms. The events occurred within 2 months after cessation of prasugrel in 11 patients (78.6%). Prasugrel maintenance for 6 months was found to result in lower ischemic events compared with maintenance for 3 months. CONCLUSIONS: For patients undergoing SACE, a low-dose prasugrel regimen was a safe and reliable treatment option for the prevention of delayed ischemic events. Transient ischemic events often occurred within 2 months of stopping prasugrel medication.

Comparative effects of guided vs. potent P2Y12 inhibitor therapy in acute coronary syndrome: a network meta-analysis of 61 898 patients from 15 randomized trials.

AIMS: Guidelines recommend the use of potent P2Y12 inhibitors over clopidogrel for the reduction of ischaemic events in patients with acute coronary syndrome (ACS). However, this comes at the expense of increased bleeding. A guided selection of P2Y12 inhibiting therapy has the potential to overcome this limitation. We aimed at evaluating the comparative safety and efficacy of guided vs. routine selection of potent P2Y12 inhibiting therapy in patients with ACS. METHODS AND RESULTS: We performed a network meta-analysis of randomized controlled trials (RCTs) comparing different oral P2Y12 inhibitors currently recommended for the treatment of patients with ACS (clopidogrel, prasugrel, and ticagrelor). RCTs including a guided approach (i.e. platelet function or genetic testing) vs. standard selection of P2Y12 inhibitors among patients with ACS were also included. Incidence rate ratios (IRR) and associated 95% confidence intervals (CIs) were estimated. P-scores were used to estimate hierarchies of efficacy and safety. The primary efficacy endpoint was major adverse cardiovascular events (MACE) and the primary safety endpoint was all bleeding. A total of 61 898 patients from 15 RCTs were included. Clopidogrel was used as reference treatment. A guided approach was the only strategy associated with reduced MACE (IRR: 0.80, 95% CI: 0.65-0.98) without any significant trade-off in all bleeding (IRR: 1.22, 95% CI: 0.96-1.55). A guided approach and prasugrel were associated with reduced myocardial infarction. A guided approach, prasugrel, and ticagrelor were associated with reduced stent thrombosis. Ticagrelor was also associated with reduced total and cardiovascular mortality. Prasugrel was associated with increased major bleeding. Prasugrel and ticagrelor were associated with increased minor bleeding. The incidence of stroke did not differ between treatments. CONCLUSION: In patients with an ACS, compared with routine selection of potent P2Y12 inhibiting therapy (prasugrel or ticagrelor), a guided selection of P2Y12 inhibiting therapy is associated with the most favourable balance between safety and efficacy. These findings support a broader adoption of guided approach for the selection of P2Y12 inhibiting therapy in patients with ACS. STUDY REGISTRATION NUMBER: This study is registered in PROSPERO (CRD42021258603). KEY QUESTION: A guided selection of P2Y12 inhibiting therapy using platelet function or genetic testing improves outcomes among patients undergoing percutaneous coronary intervention. Nevertheless, the comparative safety and efficacy of a guided versus routine selection of potent P2Y12-inhibiting therapy in acute coronary syndrome has not been explored. KEY FINDING: In a comprehensive network meta-analysis including the totality of available evidence and using clopidogrel as treatment reference, a guided approach was the only strategy associated with reduced major adverse cardiovascular events without any significant trade-off in bleeding. Prasugrel and ticagrelor increased bleeding and only ticagrelor reduced mortality. TAKE HOME MESSAGE: A guided selection of P2Y12-inhibiting therapy represents the strategy associated with the most favourable balance between safety and efficacy. These findings support a broader adoption of guided P2Y12 inhibiting therapy in patients with acute coronary syndrome.

Low incidence of hemorrhagic complications both during and after surgical procedures in patients maintained on prasugrel single antiplatelet therapy.

BACKGROUND AND PURPOSE: Prasugrel (Pra) is a third-generation thienopyridine that inhibits platelet aggregation via irreversible blockade of P2Y12 receptors. While several published studies have examined the use of Pra and acetylsalicylic acid (ASA) in coronary and neurovascular stenting procedures, there is only anecdotal evidence regarding the use of Pra as single antiplatelet therapy (SAPT) in open surgical procedures. This topic has become important because previous studies have revealed that neurovascular devices with antithrombotic coatings can be implanted using non-invasive procedures in patients maintained on Pra SAPT. MATERIAL AND METHODS: Patients who underwent open surgery under Pra SAPT between March 2020 and February 2022 were evaluated retrospectively. Adequate platelet inhibition both before and after the procedures was verified in all patients using Multiplate (Roche Diagnostics) and VerifyNow (Accriva) tests. Intraoperative and postoperative hemorrhagic events were recorded based on reviews of the procedure reports and interviews with the surgeons. RESULTS: The study enrolled 21 patients who underwent 23 open surgical procedures while maintained on Pra SAPT. The procedures included one extirpation of a brain arteriovenous malformation, seven extra-intracranial bypass surgeries, four ventriculoperitoneal shunts, one eye enucleation for an intractable orbital infection, two gastrostomies, one bone flap reinsertion after craniectomy, one decompressive craniectomy, one case requiring cranial surgical wound care, one colporrhaphy, one transurethral resection of urinary bladder cancer, two tumor oophorectomy/hysterectomy procedures, and one aneurysm clipping. None of the 23 procedures resulted in excessive intraoperative or postoperative hemorrhage. CONCLUSION: In a small retrospective series of patients who required antiplatelet therapy for neurovascular indications, Pra SAPT resulted in no significant increase in the incidence of perioperative and postoperative hemorrhagic complications.

Durable Polymer Versus Biodegradable Polymer Drug-Eluting Stents After Percutaneous Coronary Intervention in Patients with Acute Coronary Syndrome: The HOST-REDUCE-POLYTECH-ACS Trial.

BACKGROUND: Large-scale randomized comparison of drug-eluting stents (DES) based on durable polymer versus biodegradable polymer technology is currently insufficient in patients with acute coronary syndrome (ACS). The present study aimed to prove the noninferiority of the durable polymer DES (DP-DES) compared with the biodegradable polymer DES (BP-DES) in such patients. METHODS: The HOST-REDUCE-POLYTECH-ACS (Harmonizing Optimal Strategy for Treatment of Coronary Artery Diseases-Comparison of Reduction of Prasugrel Dose or Polymer Technology in ACS Patients) trial is an investigator-initiated, randomized, open-label, adjudicator-blinded, multicenter, noninferiority trial comparing the efficacy and safety of DP-DES and BP-DES in patients with ACS. The primary end point was a patient-oriented composite outcome (a composite of all-cause death, nonfatal myocardial infarction, and any repeat revascularization) at 12 months. The key secondary end point was device-oriented composite outcome (a composite of cardiac death, target-vessel myocardial infarction, or target lesion revascularization) at 12 months. RESULTS: A total of 3413 patients were randomized to receive the DP-DES (1713 patients) and BP-DES (1700 patients). At 12 months, patient-oriented composite outcome occurred in 5.2% in the DP-DES group and 6.4% in the BP-DES group (absolute risk difference, -1.2%; Pnoninferiority<0.001). The key secondary end point, device-oriented composite outcome, occurred less frequently in the DP-DES group (DP-DES vs BP-DES, 2.6% vs 3.9%; hazard ratio, 0.67 [95% CI, 0.46-0.98]; P=0.038), mostly because of a reduction in target lesion revascularization. The rate of spontaneous nonfatal myocardial infarction and stent thrombosis were extremely low, with no significant difference between the 2 groups (0.6% versus 0.8%; P=0.513 and 0.1% versus 0.4%; P=0.174, respectively). CONCLUSIONS: In ACS patients receiving percutaneous coronary intervention, DP-DES was noninferior to BP-DES with regard to patient-oriented composite outcomes at 12 months after index percutaneous coronary intervention. Registration: URL: https://wwwclinicaltrials.gov; Unique identifier: NCT02193971.

Potent P2Y12 inhibitors versus clopidogrel to predict adherence to antiplatelet therapy after an acute coronary syndrome: insights from IDEAL-LDL.

BACKGROUND: Superiority of potent P2Y12 inhibitors over clopidogrel after an acute coronary syndrome (ACS) has been well established, however potent P2Y12 inhibition is responsible for more adverse events, which may influence patient adherence to treatment. Aim of the present study is to investigate the adherence to the prescribed P2Y12 inhibitor (P2Y12i) in patients on dual antiplatelet therapy (DAPT) after an ACS. METHODS: In an IDEAL-LDL trial substudy, we included 344 patients after ACS discharged on DAPT. The primary outcome was the difference between potent P2Y12i and clopidogrel in terms of adherence, as well as other predictors of adherence to the antiplatelet regimen. Secondary outcomes included the prevalence of DAPT continuation and its predictors and the antiplatelet regimen selection after DAPT. RESULTS: Adherence to the potent P2Y12i and to clopidogrel was observed in 140/178 (78.7%) and 111/166 (66.9%) patients (p = 0.016), respectively. In the multivariate model, after adjustment for P2Y12i switching during the first year of therapy, there was no difference observed in adherence between potent P2Y12i and clopidogrel (odds ratio [OR] = 0.98, 95% confidence interval [CI] = 0.55-1.74). Significant predictors included history of cardiovascular disease (CVD) (OR = 0.51, 95% CI = 0.31-0.86) and percutaneous coronary intervention (PCI) index event treatment (OR = 2.58, 95% CI = 1.38-4.82). Of patients, 72% continued DAPT >12 months and female gender was a negative predictor of DAPT prolongation (adjusted OR = 0.43, 95% CI = 0.21-0.90). DAPT was continued until the end of follow-up in 42.7%, while 54.6% resumed with single antiplatelet regimen. CONCLUSIONS: Adherence to DAPT was not affected by the P2Y12i potency, whereas history of CVD and PCI treatment were associated with reduced and increased adherence, respectively. CLINICAL TRIAL REGISTRATION: NCT02927808, https://clinicaltrials.gov/ct2/show/NCT02927808.

Protease-activated receptor-mediated platelet aggregation in patients with type 2 diabetes on potent P2Y12 inhibitors.

BACKGROUND: Antiplatelet therapy is a cornerstone in the secondary prevention of ischemic events following percutaneous coronary intervention (PCI). The new P2Y12 receptor inhibitors prasugrel and ticagrelor have been shown to improve patients' outcomes. Whether or not these drugs have equal efficacy in individuals with or without diabetes is disputed. Furthermore, platelets can be activated by thrombin, which is, at least in part, independent of P2Y12 -mediated platelet activation. Protease-activated receptor (PAR)-1 and -4 are thrombin receptors on human platelets. We sought to compare the in vitro efficacy of prasugrel (n = 121) and ticagrelor (n = 99) to inhibit PAR-mediated platelet aggregation in individuals with type 2 diabetes (prasugrel n = 26, ticagrelor n = 29). MATERIALS AND METHODS: We compared P2Y12 -, PAR-1- and PAR-4-mediated platelet aggregation as assessed by multiple electrode platelet aggregometry between prasugrel- and ticagrelor-treated patients without and with type 2 diabetes who underwent acute PCI. RESULTS: Overall, there were no differences of P2Y12 -, PAR-1- and PAR-4-mediated platelet aggregation between prasugrel- and ticagrelor-treated patients. However, both drugs inhibited P2Y12 -mediated platelet aggregation stronger, and thereby to a similar extent in patients with type 2 diabetes than in those without diabetes. There was no correlation between either P2Y12 -, or PAR-1- or PAR-4-mediated platelet aggregation and levels of HbA1c or the body mass index (BMI). However, we observed patients with high residual platelet reactivity in response to PAR-1 and PAR-4 stimulation in all cohorts. CONCLUSION: Prasugrel and ticagrelor inhibit P2Y12 - and PAR-mediated platelet aggregation in individuals with diabetes to a similar extent, irrespective of HbA1c levels and BMI.

The developmental journey of therapies targeting purine receptors: from basic science to clinical trials.

Since the discovery of ATP as an extracellular signalling molecule in 1972, purinergic signalling, mediated by extracellular purines and pyrimidines has been identified in virtually all mammalian tissues and is implicated in regulating fundamental cellular processes. In recent years, there has been an increasing focus on the pathophysiology and potential therapeutic interventions based on purinergic signalling. A vast range of compounds targeting purine receptors are in clinical development, and many more are in preclinical studies, which highlights the fast growth in this research field. As a tribute to Professor Geoffrey Burnstock's legacy in purinergic signalling, we present here a brief review of compounds targeting purine receptors that are in different stages of clinical trials. The review highlights the 50-year journey from basic research on purinergic receptors to clinical applications of therapies targeting purine receptors.

Early P2Y12 Inhibitor Single Antiplatelet Therapy for High-Bleeding Risk Patients After Stenting　- PENDULUM Mono 24-Month Analysis.

BACKGROUND: In PENDULUM mono, Japanese patients with high bleeding risk (HBR) received short-term dual antiplatelet therapy (DAPT) followed by single antiplatelet therapy (SAPT) with prasugrel after percutaneous coronary intervention (PCI). One-year data from PENDULUM mono showed better outcomes with prasugrel monotherapy after short-term DAPT compared with matched patients in the PENDULUM registry with longer DAPT durations according to guidelines at that time. This study presents 2-year results.Methods and Results: We compared 24-month data from PENDULUM mono (n=1,107; de-escalation strategy group) and the PENDULUM registry (n=2,273; conventional strategy group); both were multicenter, non-interventional, prospective registry studies, using the inverse probability of treatment weighting (IPTW) method. In the PENDULUM mono group, the cumulative incidence of clinically relevant bleeding (CRB) at 24 months post-PCI (primary endpoint) was 6.8%, and that of major adverse cardiac and cerebrovascular events (MACCE) was 8.9%. After IPTW adjustment, the cumulative incidence of CRB was 5.8% and 7.2% in PENDULUM mono and the PENDULUM registry, respectively (hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.57-1.04; P=0.086), and that of MACCE was 8.0% and 9.5%, respectively (HR 0.77; 95% CI 0.59-1.01; P=0.061). CONCLUSIONS: Japanese PCI patients with HBR prescribed prasugrel SAPT after short-term DAPT had a lower ischemic event risk than those prescribed long-term DAPT, and this was particularly relevant for ischemic events after 1 year.

Antiplatelet Use in Ischemic Stroke.

OBJECTIVE: A literature review of antiplatelet agents for primary and secondary stroke prevention, including mechanism of action, cost, and reasons for lack of benefit. DATA SOURCES: Articles were gathered from MEDLINE, Cochrane Reviews, and PubMed databases (1980-2021). Abstracts from scientific meetings were considered. Search terms included ischemic stroke, aspirin, clopidogrel, dipyridamole, ticagrelor, cilostazol, prasugrel, glycoprotein IIb/IIIa inhibitors. STUDY SELECTION AND DATA EXTRACTION: English-language original and review articles were evaluated. Guidelines from multiple countries were reviewed. Articles were evaluated independently by 2 authors. DATA SYNTHESIS: An abundance of evidence supports aspirin and clopidogrel use for secondary stroke prevention. In the acute phase (first 21 days postinitial stroke), these medications have higher efficacy for preventing further stroke when combined, but long-term combination therapy is associated with higher hemorrhage rates. Antiplatelet treatment failure is influenced by poor adherence and genetic polymorphisms. Antiplatelet agents such as cilostazol may provide extra benefit over clopidogrel and aspirin, in certain racial groups, but further research in more diverse ethnic populations is needed. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: This review presents the data available on the use of different antiplatelet agents poststroke. Dual therapy, recurrence after initiation of secondary preventative therapy, and areas for future research are discussed. CONCLUSIONS: Although good evidence exists for the use of certain antiplatelet agents postischemic stroke, there are considerable opportunities for future research to investigate personalized therapies. These include screening patients for platelet polymorphisms that confer antiplatelet resistance and for randomized trials including more racially diverse populations.