Dual antiplatelet therapy in coronary artery disease: from the past to the future prospective

Short-Term DAPT and DAPT De-Escalation Strategies for Patients With Acute Coronary Syndromes: A Systematic Review and Network Meta-Analysis

BACKGROUND

Short-term (≤6 months) dual antiplatelet therapy (DAPT) and DAPT de-escalation become attractive for patients with acute coronary syndrome.

METHODS

A systemic search identified randomized controlled trials that included patients with acute coronary syndrome treated using (1) standard DAPT (12 months) with clopidogrel, prasugrel (standard/low dose), or ticagrelor; (2) extended DAPT (≥18 months); (3) short-term DAPT (≤6 months) followed by P2Y12 inhibitor or aspirin; (4) 12-month DAPT with unguided de-escalation from potent P2Y12 inhibitors to low-dose potent P2Y12 inhibitor or clopidogrel at 1 month; and (5) guided selection DAPT with genotype or platelet function tests. The primary efficacy outcome (major adverse cardiovascular events) was a composite of cardiovascular death, myocardial infarction, or stroke. The primary safety outcome was major or minor bleeding.

RESULTS

This meta-analysis included 32 randomized controlled trials with 103 497 patients. While there were no differences in efficacy between short, unguided de-escalation and guided selection strategies, unguided de-escalation was associated with reduced risk of major adverse cardiovascular events compared with standard DAPT with clopidogrel or ticagrelor (hazard ratio [95% CI], 0.67 [0.49-0.93] and 0.68 [0.50-0.93]). Both short DAPT followed by P2Y12 inhibitor and unguided de-escalation were associated with reduced risks in safety compared with other strategies, including guided selection (hazard ratio [95% CI], 0.66 [0.47-0.93] and 0.48 [0.33-0.71]). Short DAPT followed by a P2Y12 inhibitor was associated with reduced risk of major bleeding and all-cause death compared with standard, extended DAPT (eg, versus DAPT with clopidogrel; hazard ratio [95% CI], 0.64 [0.42-0.97] and 0.60 [0.44-0.82]). By rankogram, unguided de-escalation strategy was the safest and most effective strategy in reducing major adverse cardiovascular events and major or minor bleeding while short DAPT followed by P2Y12 inhibitor was ranked the best for major bleeding and all-cause death.

CONCLUSIONS

In patients with acute coronary syndrome, unguided de-escalation was associated with the lowest risk of major adverse cardiovascular events and major or minor bleeding outcomes, while short DAPT followed by P2Y12 inhibitor was associated with the lowest risk of major bleeding and all-cause death.

Species Differences in Platelet Protease-Activated Receptors

Protease-activated receptors (PARs) are a class of integral membrane proteins that are cleaved by a variety of proteases, most notably thrombin, to reveal a tethered ligand and promote activation. PARs are critical mediators of platelet function in hemostasis and thrombosis, and therefore are attractive targets for anti-platelet therapies. Animal models studying platelet PAR physiology have relied heavily on genetically modified mouse strains, which have provided ample insight but have some inherent limitations. The current review aims to summarize the notable PAR expression and functional differences between the mouse and human, in addition to highlighting some recently developed tools to further study human physiology in mouse models.

P2Y12 Inhibitors for Non-ST-Segment Elevation Acute Coronary Syndrome: A Systematic Review and Network Meta-Analysis

BACKGROUND

For patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS), prasugrel was recommended over ticagrelor in a recent randomized controlled trial, although more data are needed on the rationale. Here, the effects of P2Y12 inhibitors on ischemic and bleeding events in patients with NSTE-ACS were investigated.

METHODS

Clinical trials that enrolled patients with NSTE-ACS were included, relevant data were extracted, and a network meta-analysis was performed.

RESULTS

This study included 37,268 patients with NSTE-ACS from 11 studies. There was no significant difference between prasugrel and ticagrelor for any end point, although prasugrel had a higher likelihood of event reduction than ticagrelor for all end points except cardiovascular death. Compared with clopidogrel, prasugrel was associated with decreased risks of major adverse cardiovascular events (MACE) (hazard ratio [HR], 0.84; 95% CI, 0.71-0.99) and myocardial infarction (HR, 0.82; 95% CI, 0.68-0.99) but not an increased risk of major bleeding (HR, 1.30; 95% CI, 0.97-1.74). Similarly, compared with clopidogrel, ticagrelor was associated with a reduced risk of cardiovascular death (HR, 0.79; 95% CI, 0.66-0.94) and an increased risk of major bleeding (HR, 1.33; 95% CI, 1.00-1.77; P = .049). For the primary efficacy end point (MACE), prasugrel showed the highest likelihood of event reduction (P = .97) and was superior to ticagrelor (P = .29) and clopidogrel (P = .24).

CONCLUSION

Prasugrel and ticagrelor had comparable risks for every end point, although prasugrel had the highest probability of being the best treatment for reducing the primary efficacy end point. This study highlights the need for further studies to investigate optimal P2Y12 inhibitor selection in patients with NSTE-ACS.

Investigation of the small-balloon technique as a method for retrieving dislodged stents

The small-balloon technique used to retrieve a dislodged coronary stent is less studied. We investigated the small-balloon technique to study the capture force and retrieval rate of dislodged proximal or distal stents. We developed a retrieval model for stent dislodgement and performed bench tests to compare proximal and distal capture. We evaluated capture force by capture site in a fixed stent dislodgement model and capture force and retrieval rate by capture site using a retrieval model of stent dislodgement. Three-dimensional (3D)-micro-computed tomography (CT) was used to scan the captured conditions of the distal (DC) and proximal (PC) groups. Stent, balloon shaft, and guiding catheter (GC) diameters were measured. Retrieval areas within GC were calculated and compared. The force was significantly lower in the PC group than in the DC group (p < 0.01). Successful retrieval was achieved in 100% and 84.8% in the PC and DC groups, respectively. The force required to retrieve the dislodged stent was significantly lower in the PC group than that in the DC group (p < 0.01). The force was significantly lower in the successful cases in the DC group than in the unsuccessful cases (p < 0.01). The retrievable areas in the PC and DC groups were 67.5% and 32.7%, respectively, as calculated from the values measured from the 3D-CT images. The success rate of PC was higher than that of DC using the small-balloon technique. The smaller proximal stent gap in the PC method facilitated the retrieval of the dislodgement stent.

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.

Antithrombotic Treatment in Coronary Artery Disease

Coronary artery disease exhibits growing mortality and morbidity worldwide despite the advances in pharmacotherapy and coronary intervention. Coronary artery disease is classified in the acute coronary syndromes and chronic coronary syndromes according to the most recent guidelines of the European Society of Cardiology. Antithrombotic treatment is the cornerstone of therapy in coronary artery disease due to the involvement of atherothrombosis in the pathophysiology of the disease. Administration of antiplatelet agents, anticoagulants and fibrinolytics reduce ischemic risk, which is amplified early post-acute coronary syndromes or post percutaneous coronary intervention; though, antithrombotic treatment increases the risk for bleeding. The balance between ischemic and bleeding risk is difficult to achieve and is affected by patient characteristics, procedural parameters, concomitant medications and pharmacologic characteristics of the antithrombotic agents. Several pharmacological strategies have been evaluated in patients with coronary artery disease, such as the effectiveness and safety of antithrombotic agents, optimal dual antiplatelet treatment schemes and duration, aspirin de-escalation strategies of dual antiplatelet regimens, dual inhibition pathway strategies as well as triple antithrombotic therapy. Future studies are needed in order to investigate the gaps in our knowledge, including special populations.

An Uncommon Case of Acute Coronary Stent Thrombosis

Coronary stent thrombosis is an uncommon complication of percutaneous coronary intervention, which can result in myocardial infarction and often death. We present a case of acute stent thrombosis in a patient with newly diagnosed triple vessel coronary artery disease occurring within less than an hour of stent placement along with a review of the literature.

Supplementation with omega-3 or omega-6 fatty acids attenuates platelet reactivity in postmenopausal women

Postmenopausal women are at increased risk for a cardiovascular event due to platelet hyperactivity. There is evidence suggesting that ω-3 polyunsaturated fatty acids (PUFAs) and ω-6 PUFAs have cardioprotective effects in these women. However, a mechanistic understanding of how these fatty acids regulate platelet function is unknown. In this study, we supplemented postmenopausal women with fish oil (ω-3 fatty acids) or evening primrose oil (ω-6 fatty acids) and investigated the effects on their platelet activity. The effects of fatty acid supplementation on platelet aggregation, dense granule secretion, and activation of integrin αIIbβ3 at basal levels and in response to agonist were tested in postmenopausal women following a supplementation and washout period. Supplementation with fish oil or primrose oil attenuated the thrombin receptor PAR4-induced platelet aggregation. Supplementation with ω-3 or ω-6 fatty acids decreased platelet dense granule secretion and attenuated basal levels of integrin αIIbβ3 activation. Interestingly, after the washout period following supplementation with primrose oil, platelet aggregation was similarly attenuated. Additionally, for either treatment, the observed protective effects post-supplementation on platelet dense granule secretion and basal levels of integrin activation were sustained after the washout period, suggesting a long-term shift in platelet reactivity due to fatty acid supplementation. These findings begin to elucidate the underlying mechanistic effects of ω-3 and ω-6 fatty acids on platelet reactivity in postmenopausal women. Hence, this study supports the beneficial effects of fish oil or primrose oil supplementation as a therapeutic intervention to reduce the risk of thrombotic events in postmenopausal women. https://clinicaltrials.gov/ct2/show/NCT02629497.

Comparison of Unguided De-Escalation Versus Guided Selection of Dual Antiplatelet Therapy After Acute Coronary Syndrome: A Systematic Review and Network Meta-Analysis

BACKGROUND

The benefit of dual antiplatelet therapy (DAPT) for reducing ischemic events is greatest in the early period of acute coronary syndrome, and recent randomized controlled trials have investigated the unguided de-escalation strategy of changing potent P2Y₁₂ inhibitors to less potent or reduced-dose P2Y₁₂ inhibitors 1 month after acute coronary syndrome. However, it remains unclear which strategy is more effective and safer: the uniform unguided de-escalation strategy versus the personalized guided selection of DAPT with genotype or platelet function tests.

METHODS

PubMed, EMBASE, and Cochrane Central were searched for articles published from database inception to September 10, 2021. Randomized controlled trials investigating DAPT using clopidogrel, low-dose prasugrel, standard-dose prasugrel, ticagrelor, unguided de-escalation strategy, and guided selection strategy for patients with acute coronary syndrome were included. Hazard ratios and relative risk estimates were extracted from each study. The estimates were pooled using a random-effects network meta-analysis. The primary efficacy outcome was major adverse cardiovascular events, defined as a composite of cardiovascular death, myocardial infarction, or stroke. The primary safety outcome was major or minor bleeding. Secondary outcomes were all-cause death, cardiovascular death, myocardial infarction, stroke, stent thrombosis, and major bleeding.

RESULTS

This study included 19 randomized controlled trials with 69 746 patients. Compared with guided selection of DAPT, unguided de-escalation of DAPT was associated with a decreased risk of the primary safety outcome (hazard ratio, 0.48 [95% CI, 0.33-0.72]) without increased risks of major adverse cardiovascular events (hazard ratio, 0.82 [95% CI, 0.53-1.28]) or any secondary outcomes. The results were similar when the guided selection strategy was divided into platelet function-guided and genotype-guided strategies.

CONCLUSIONS

Compared with guided selection of DAPT, unguided de-escalation of DAPT decreased bleeding without increasing ischemic events in patients after acute coronary syndrome. If a strategy of de-escalation is chosen, these findings do not support the routine use of personalized guiding tests.

REGISTRATION

URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42021273082.

Impact of perioperative antithrombotic strategies on clinical events in non-cardiac surgery

Antithrombotic therapy including antiplatelet agents and anticoagulants are prescribed for secondary prevention in patients with established cardiovascular disease. Although antithrombotic therapy is often interrupted before non-cardiac surgery with or without perioperative bridging anticoagulation, the impact on thrombotic and bleeding events remains uncertain. A total of 360 patients chronically treated with antithrombotic therapy for secondary prevention underwent elective non-cardiac surgery under general anesthesia, with the complete interruption of antithrombotic agents. The study endpoints included all-cause death, thrombotic events, and major bleeding complications after surgical procedures. Of 360 patients, 190 (52.8%) and 200 (55.6%) received antiplatelet and anticoagulation perioperatively. Atrial fibrillation (32.8%) and coronary artery disease (22.5%) were the major indications for antithrombotic regimens. Antithrombotic therapy was interrupted from 5 [2, 7] days before the surgery to 4 [2, 7] days postoperatively. Perioperative bridging therapy with unfractionated heparin was employed in 113 (31.4%) patients. During the hospitalization, one (0.3%) patient died due to non-cardiovascular causes. Thrombotic events and major bleeding occurred in two (0.6%) and eight (2.2%) patients. Bridging therapy with heparin was significantly associated with an increased risk of bleeding events (5.3% vs. 0.8%, p = 0.02). Pre-operative bridging therapy with heparin and operative duration were significantly associated with bleeding complications. In the present study, complete interruption of antithrombotic therapy resulted in a few thrombotic events in patients undergoing elective non-cardiac surgery. Bridging therapy with heparin and longer operative duration were significantly associated with post-operative bleeding complications.

Antiplatelet Therapy for Atherothrombotic Disease in 2022—From Population to Patient-Centered Approaches

Antiplatelet agents, with aspirin and P2Y₁₂ receptor antagonists as major key molecules, are currently the cornerstone of pharmacological treatment of atherothrombotic events including a variety of cardio- and cerebro-vascular as well as peripheral artery diseases. Over the last decades, significant changes have been made to antiplatelet therapeutic and prophylactic strategies. The shift from a population-based approach to patient-centered precision medicine requires greater awareness of individual risks and benefits associated with the different antiplatelet strategies, so that the right patient gets the right therapy at the right time. In this review, we present the currently available antiplatelet agents, outline different management strategies, particularly in case of bleeding or in perioperative setting, and develop the concept of high on-treatment platelet reactivity and the steps toward person-centered precision medicine aiming to optimize patient care.

Anti-platelet medications and risk of intracranial hemorrhage in patients with metastatic brain tumors

Antiplatelet medication was not associated with an increased risk of ICH in patients with metastatic brain tumors.

Combined antiplatelet agents and anticoagulation was not associated with an increased risk of ICH compared with single-agent use.

Although intracranial hemorrhage (ICH) is frequent in the setting of brain metastases, there are limited data on the influence of antiplatelet agents on the development of brain tumor–associated ICH. To evaluate whether the administration of antiplatelet agents increases the risk of ICH, we performed a matched cohort analysis of patients with metastatic brain tumors with blinded radiology review. The study population included 392 patients with metastatic brain tumors (134 received antiplatelet agents and 258 acted as controls). Non–small cell lung cancer was the most common malignancy in the cohort (74.0%), followed by small cell lung cancer (9.9%), melanoma (4.6%), and renal cell cancer (4.3%). Among those who received an antiplatelet agent, 86.6% received aspirin alone and 23.1% received therapeutic anticoagulation during the study period. The cumulative incidence of any ICH at 1 year was 19.3% (95% CI, 14.1-24.4) in patients not receiving antiplatelet agents compared with 22.5% (95% CI, 15.2-29.8; P = .22, Gray test) in those receiving antiplatelet agents. The cumulative incidence of major ICH was 5.4% (95% CI, 2.6-8.3) among controls compared with 5.5% (95% CI, 1.5-9.5; P = .80) in those exposed to antiplatelet agents. The combination of anticoagulation plus antiplatelet agents did not increase the risk of major ICH. The use of antiplatelet agents was not associated with an increase in the incidence, size, or severity of ICH in the setting of brain metastases.

Relationship between platelet aggregation and stroke risk after percutaneous coronary intervention: a PENDULUM analysis

In patients undergoing percutaneous coronary intervention (PCI) with a stent, high on-treatment platelet reactivity may be associated with an increased risk of stroke. This post hoc analysis of the PENDULUM registry compared the risk of post-PCI stroke according to on-treatment P2Y₁₂ reaction unit (PRU) values. Patients aged ≥ 20 years who underwent PCI were stratified by baseline PRU (at 12 and 48 h post-PCI) as either high (HPR, > 208), optimal (OPR, > 85 to ≤ 208), or low on-treatment platelet reactivity (LPR, ≤ 85). The incidences of non-fatal ischemic and non-ischemic stroke through to 12 months post-PCI were recorded. Almost all enrolled patients (6102/6267 [97.4%]) had a risk factor for ischemic stroke, and most were receiving dual antiplatelet therapy. Of the 5906 patients with PRU data (HPR, n = 2227; OPR, n = 3002; LPR, n = 677), 47 had a non-fatal stroke post-PCI (cumulative incidence: 0.68%, ischemic; 0.18%, non-ischemic stroke). Patients with a non-fatal ischemic stroke event had statistically significantly higher post-PCI PRU values versus those without an event (P = 0.037). The incidence of non-fatal non-ischemic stroke was not related to PRU value. When the patients were stratified by PRU ≤ 153 versus > 153 at 12–48 h post-PCI, a significant difference was observed in the cumulative incidence of non-fatal stroke at 12 months (P = 0.044). We found that patients with ischemic stroke tended to have higher PRU values at 12–48 h after PCI versus those without ischemic stroke.

Clinical trial registration: UMIN000020332.

Ischemic and Bleeding Events in PENDULUM Patients With High Bleeding Risk and High Platelet Reactivity

BACKGROUND

The balance between thrombotic and bleeding risk is of great concern in high bleeding risk (HBR) patients. This study evaluated the relationship between perioperative antiplatelet reactivity and thrombotic and bleeding events in patients at HBR undergoing percutaneous coronary intervention (PCI).Methods and Results:In this post hoc analysis of the PENDULUM (Platelet rEactivity in patieNts with DrUg eLUting stent and balancing risk of bleeding and ischeMic event) registry, patients undergoing PCI were categorized as HBR or non-HBR, and stratified as having high platelet reactivity (HPR; P2Y₁₂reaction unit [PRU] >208) or non-HPR (PRU ≤208). Cumulative incidences of cardiovascular and cerebrovascular events (Journal of the American College of Cardiologyexpert definitions) and bleeding events (Bleeding Academic Research Consortium criteria) were assessed 12 months after index PCI. The incidence of ischemic and bleeding events was ~3-fold higher in HBR vs. non-HBR patients. Thrombotic/ischemic events were significantly more common in the HPR subgroup in HBR patients (hazard ratio [HR]: 1.59; 95% confidence interval [CI]: 1.11-2.28; P=0.012), but there was no difference in non-HBR patients. After adjustment for covariates, HPR in HBR patients remained an independent factor for thrombotic and ischemic events (HR: 1.69; 95% CI: 1.13-2.54; P=0.011), but not for bleeding events (HR: 1.56; 95% CI: 0.78-3.11; P=0.210).

CONCLUSIONS

Maintaining adequate PRU levels during PCI is an important factor in improving clinical outcomes, especially for HBR patients.

Evolution of the fabric of cardiovascular science: Saga of an enduring process of refinement

BACKGROUND

The core elements of cardiovascular science have been established by scholarly pursuits of numerous scientists across centuries. In this article, we have tried to trace the evolutionary journey of cardiovascular science from a rudimentary form in ancient period to a robust scientific discipline in modern times.

METHODS

A literature search of relevant, peer-reviewed, published articles was undertaken from indexed databases (Medline & Pubmed, Scopus, Embase, CINAHL Plus, Web of Science and Google Scholar).

RESULTS

Cardiovascular science has its roots in antiquity, when Greek scholars mostly relied on philosophical thoughts and ancient texts. This was followed by addition of few structural details to the theory of circulation by Galen based on animal dissection. Arab scholar Ibn al-Nafis provided new insights regarding circulation pathway in humans. Nevertheless, an erroneous concept prevailed into the onset of European Renaissance. Even with legalization of human dissection, little headway could be made till sixteenth century due to persistent reliance of anatomists on ancient Galenic principles. During seventeenth century, the circulatory pathway (as we know it today) was established due to significant contributions from scholars like Harvey and Malpighi. Their efforts were based on findings from experiments and logical conclusions. Eighteenth century witnessed the emergence of autopsy based methods which led to valuable contributions from Vieussens, Thebesius, Morgagni and Hunter regarding normal and pathologic anatomy of cardiovascular system. With structural details mostly established, researchers during nineteenth century focussed on innovations in diagnostic methods based on human experiments. Further development of advanced human experiment models during twentieth century led to emergence of contemporary treatment methods for various cardiac conditions. In the twenty-first century, cardiovascular science is undergoing comprehensive progress at an exponential rate due to technological advances.

CONCLUSION

The evolutionary journey of cardiovascular science as a discipline across centuries has been intriguing and eventful.

De-Escalation of Dual Antiplatelet Therapy in Patients With Acute Coronary Syndromes

BACKGROUND

Balancing the effects of dual antiplatelet therapy (DAPT) in the era of potent P2Y₁₂ inhibitors has become a cornerstone of acute coronary syndrome (ACS) management. Recent randomized controlled trials (RCTs) have investigated DAPT de-escalation to decrease the risk of bleeding outcomes.

OBJECTIVES

The aim of this study was to compare the efficacy and safety outcomes of various DAPT strategies in patients with ACS, including de-escalation from a potent P2Y₁₂ inhibitor to clopidogrel or low-dose prasugrel.

METHODS

MEDLINE and EMBASE were searched through January 2021 for RCTs investigating the efficacy and safety of DAPT in patients with ACS, and a network meta-analysis was conducted. The primary efficacy outcome was a composite of cardiovascular death, myocardial infarction, and stroke. The primary bleeding outcome was trial-defined major or minor bleeding.

RESULTS

Our search identified 15 eligible RCTs, including 55,798 patients with ACS. De-escalation therapy was associated with reduced risk of primary bleeding outcomes (HR: 0.48 [95% CI: 0.30-0.77] vs clopidogrel; HR: 0.32 [95% CI: 0.20-0.52] vs ticagrelor; HR: 0.36 [95% CI: 0.24-0.55] vs standard-dose prasugrel; and HR: 0.40 [95% CI: 0.22-0.75] vs low-dose prasugrel) without negatively affecting primary efficacy outcomes. There were no significant differences in ischemic or bleeding outcomes between de-escalation to clopidogrel or low-dose prasugrel.

CONCLUSIONS

Compared with other established uses of DAPT, de-escalation was the most effective strategy for ACS treatment, resulting in fewer bleeding events without increasing ischemic events.

Differential Impact of Clinical and Genetic Factors on High Platelet Reactivity in Patients with Coronary Artery Disease Treated with Clopidogrel and Prasugrel

AIM

High platelet reactivity (HPR) is associated with increased risks of thrombotic events in patients with coronary artery disease. The recently developed ABCD-GENE score identified five clinical and genetic factors (age, body mass index, chronic kidney disease, diabetes, and the CYP2C19 loss-of-function allele) for HPR, although the significance of various stages of each factor is unclear.

METHODS

Four prospective studies were pooled, in which platelet reactivity was measured using the VerifyNow assay with clopidogrel and prasugrel; genotyping of CYP2C19 was also performed. Each component of the ABCD-GENE score was divided into three subcategories. VerifyNow P2Y12 reactivity units ＞208 were defined as HPR.

RESULTS

A total of 184 patients were included, of which 111 (60%) and 51 (28%) had HPR with clopidogrel and prasugrel. Chronic kidney disease had an impact on HPR on both clopidogrel and prasugrel, whereas the impact of diabetes was more evident in patients treated with prasugrel. Although the number of CYP2C19 loss-of-function alleles was clearly associated with a likelihood of HPR with clopidogrel, P2Y12 reactivity units with prasugrel treatment were also significantly and progressively higher in patients with more CYP2C19 loss-of-function alleles.

CONCLUSIONS

Clinical and genetic factors had a differential effect on a P2Y12 inhibitor reactivity with clopidogrel and prasugrel in patients with coronary artery disease. The severity of the factors also had a different impact on HPR.

Potent P2Y12 inhibitors versus Clopidogrel in elderly patients with acute coronary syndrome: Systematic review and meta-analysis

BACKGROUND

Potent P2Y12 inhibitors reduce cardiovascular events but increase bleeding in patients presenting with acute coronary syndrome (ACS). Elderly patients are at increased risk of bleeding and whether the benefit-risk ratio of potent P2Y12 inhibitors remains favorable is not known.

OBJECTIVES

To investigate the efficacy and safety of potent P2Y12 inhibitors versus clopidogrel in elderly patients with ACS.

METHODS

PUBMED and EMBASE were searched through July 2020 for randomized control trials (RCTs) or subgroup analyses of RCTs investigating potent P2Y12 inhibitors (prasugrel or ticagrelor) or clopidogrel in elderly (age ≥ 65 years) patients with ACS. The primary outcome was major adverse cardiovascular events (MACE).

RESULTS

Our search identified 9 RCTs with a total of 10,792 elderly patients. When compared with clopidogrel, potent P2Y12 inhibitors had similar risk of MACE (hazard ratio (HR): 0.94; 95%; confidence interval (CI) [0.85-1.06], P = .31, I² = 9%), all-cause mortality (HR: 0.89; 95% CI [0.74-1.07], P = .22, I² = 29%), reduced the risk of cardiovascular death (HR: 0.82; 95% CI [0.68-0.98], P = .03, I² = 16%) but increased the risk of major bleeding (HR: 1.27; 95% CI [1.04-1.56], P = .02, I² = 0%). In a subgroup analysis, ticagrelor reduced all-cause mortality (HR: 0.73; 95% CI [0.55-0.98]) and cardiovascular death (HR: 0.70; 95% CI [0.54-0.90]) compared with clopidogrel.

CONCLUSIONS

Among elderly patients with ACS, potent P2Y12 inhibitors reduce cardiovascular death but increase bleeding with no difference in MACE or all-cause death when compared with clopidogrel. Further RCTs are needed to refine P2Y12 inhibitor selection for elderly patients with ACS.

Validation of the ABCD-GENE score to identify high platelet reactivity in east Asian patients undergoing percutaneous coronary intervention

BACKGROUND

High platelet reactivity (HPR) is associated with subsequent thrombotic events in patients undergoing percutaneous coronary intervention (PCI). Recently, the ABCD-GENE score was developed to identify patients at risk for HPR, incorporating both clinical and genetic factors. However, this score was derived and validated in mostly Caucasian subjects and it has not been validated in an East Asian population.

METHOD

Individual patient data from 4 prospective studies were pooled, in which platelet reactivity was measured using the VerifyNow assay on clopidogrel and genotyping of CYP2C19 was performed after PCI. Study populations included patients with general stable coronary artery disease, hemodialysis, age ≥75 and/or body weight <50 kg, and acute coronary syndrome. VerifyNow P2Y12 reactivity units >208 was defined as HPR.

RESULTS

Of 184 patients, 111 (60%) had HPR on clopidogrel. In the receiver operating characteristics curve analyses, the ABCD-GENE score significantly predicted HPR on clopidogrel (AUC 0.78, best cut-off value 9, p < 0.001). Across the 4 studies and their combinations, the diagnostic ability and cut-off values of ABCD-GENE score for HPR on clopidogrel were consistent.

CONCLUSIONS

The ABCD-GENE score had significant and moderate diagnostic ability for HPR on clopidogrel in Japanese patients undergoing PCI. The predictivity was consistent across a broad spectrum of patient populations, suggesting the applicability of this novel scoring system in clinical practice worldwide.

Advances in the Protective Mechanism of NO, H2S, and H2 in Myocardial Ischemic Injury

Myocardial ischemic injury is among the top 10 leading causes of death from cardiovascular diseases worldwide. Myocardial ischemia is caused mainly by coronary artery occlusion or obstruction. It usually occurs when the heart is insufficiently perfused, oxygen supply to the myocardium is reduced, and energy metabolism in the myocardium is abnormal. Pathologically, myocardial ischemic injury generates a large number of inflammatory cells, thus inducing a state of oxidative stress. This sharp reduction in the number of normal cells as a result of apoptosis leads to organ and tissue damage, which can be life-threatening. Therefore, effective methods for the treatment of myocardial ischemic injury and clarification of the underlying mechanisms are urgently required. Gaseous signaling molecules, such as NO, H₂S, H₂, and combined gas donors, have gradually become a focus of research. Gaseous signaling molecules have shown anti-apoptotic, anti-oxidative and anti-inflammatory effects as potential therapeutic agents for myocardial ischemic injury in a large number of studies. In this review, we summarize and discuss the mechanism underlying the protective effect of gaseous signaling molecules on myocardial ischemic injury.

P2Y12 inhibitor monotherapy versus aspirin monotherapy after short-term dual antiplatelet therapy for percutaneous coronary intervention: Insights from a network meta-analysis of randomized trials

BACKGROUND

A number of trials have assessed the efficacy and safety of short-term dual antiplatelet therapy (DAPT) in patients who undergo percutaneous coronary intervention (PCI). However, whether to continue aspirin or a P₂Y₁₂ inhibitor after a short course of DAPT is actively debated.

METHODS

PUBMED and EMBASE were searched through March 2020 for randomized controlled trials evaluating short-term DAPT (≤6 months) when compared with longer-term (≥12 months) DAPT among patients undergoing PCI. The ischemic outcomes were all-cause death, myocardial infarction, stent thrombosis, and stroke. The safety outcome was major and/or clinically relevant bleeding. The primary objective was to investigate the outcomes with aspirin monotherapy (Aspirin group) versus P₂Y₁₂ inhibitor monotherapy (P2Y12i group) after short-term DAPT.

RESULTS

Our search identified 17 eligible trials enrolling a total of 54,625 patients comparing different DAPT duration. Either of the 2 monotherapy groups did not increase the risk of ischemic outcomes when compared with the long-term DAPT group, without difference between the Aspirin versus the P2Y12i groups. However, both monotherapy groups significantly reduced bleeding when compared with long-term DAPT (Aspirin group: hazard ratio [95% CI]: 0.62 [0.45-0.86], P=.004 and P2Y12i group: 0.68 [0.50-0.93], P=.015). There was no difference in bleeding between the Aspirin versus P2Y12i groups (hazard ratio=0.91 [0.58-1.43], P=.70).

CONCLUSIONS

Among patients undergoing PCI, short-term DAPT with continuation of either aspirin or P2Y12i reduced bleeding without increasing ischemic outcomes when compared with long-term DAPT. The choice of antiplatelet therapy after short-term DAPT should be evaluated in well-powered trials.

Prevalence of the Academic Research Consortium for High Bleeding Risk Criteria and Prognostic Value of a Simplified Definition

BACKGROUND

The Academic Research Consortium for High Bleeding Risk (ARC-HBR) criteria have been suggested as the standard definition of HBR. However, the prevalence of individual criteria and their prognostic value for long-term bleeding events after percutaneous coronary intervention are scarcely studied.Methods and Results:The study population comprised 1,193 patients treated with everolimus-eluting stents between 2010 and 2011. Data on all 17 major and minor criteria of the ARC-HBR definition were retrospectively collected, and applied to this study population. Major bleeding was defined as the occurrence of a BARC type 3 or 5 bleeding event. A simplified definition was developed by excluding the low-frequency criterion, and the prognostic value was assessed by a receiver-operating characteristic curve. Mean follow-up was 2,996±433 days and there were 656 HBR patients (55.0%). The cumulative incidence of major bleeding was significantly higher in the HBR group than in the non-HBR group (16.2% vs. 5.7% at 8 years, P<0.001). The frequencies of 6 of the 17 criteria were less than 1%. The prognostic value of the simplified definition made by excluding these 6 criteria for major bleeding was comparable to that of the original (c-statistic=0.598 and 0.600, P=0.08).

CONCLUSIONS

Some risk criteria of the ARC-HBR definition are observed infrequently. Our simplified definition identified patients with long-term bleeding risk as successfully as the original definition.

Serum interleukin-18 levels as a predictor for patients with genetic dysfunction of cytochrome P450 2C19 in dual antiplatelet therapy with clopidogrel

BACKGROUND

P2Y₁₂ reaction unit (PRU) is an index of platelet activity upon treatment with clopidogrel. In spite of suitable P2Y₁₂ reactions in dual antiplatelet therapy (DAPT) with clopidogrel after percutaneous coronary intervention (PCI), cardiovascular events actually occur in some patients, possibly due to a genetic dysfunction of cytochrome P450 2C19 (CYP2C19), which is a major metabolic enzyme of clopidogrel. As testing the CYP2C19 phenotypes to predict such patients may lack general versatility in daily clinical practice, the aim of this study was to examine whether measuring the blood levels of some cytokines in patients showing desirable PRUs in DAPT with clopidogrel could be a substitute for testing the CYP2C19 phenotypes.

METHODS

We analyzed relationships among PRU, serum levels of 51 cytokines, and CYP2C19 phenotypes in 22 patients receiving DAPT with aspirin and clopidogrel after PCI.

RESULTS

Seventeen, 18, and 19 of 22 patients indicated PRU ≤ 208, PRU ≤ 230, and PRU ≤ 262, respectively. Approximately 60% of the patients had a genetically metabolic dysfunction of CYP2C19, and the serum levels of interleukin-18 were independently increased in those patients (p = 0.024 in patients with PRU ≤ 208, p = 0.021 with PRU ≤ 230, and p = 0.020 with PRU ≤ 262). The area under the curves in plot receiver operating characteristics curves for the serum levels of interleukin-18 were 0.94, 0.96, and 0.90 in the non-extensive metabolizer patients with PRU ≤ 208, PRU ≤ 230, and PRU ≤ 262, respectively.

CONCLUSIONS

The serum levels of interleukin-18 may be a predictor to diagnose patients who receive undesirable DAPT with clopidogrel, possibly due to the genetic dysfunction of CYP2C19 in spite of suitable P2Y₁₂ reactions after PCI.