A Critical Appraisal of Aspirin in Secondary Prevention: Is Less More?

Antiplatelet Therapy in Patients Requiring Oral Anticoagulation and Undergoing Percutaneous Coronary Intervention

Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor is fundamental in all patients undergoing percutaneous coronary intervention (PCI) to prevent coronary thrombosis. In patients with atrial fibrillation (AF), an oral anticoagulant gives protection against ischemic stroke or systemic embolism. AF-PCI patients are at high bleeding risk and decision-making regarding the optimal antithrombotic therapy remains challenging. Dual antithrombotic therapy (DAT) has been shown to reduce bleeding events but at the cost of a higher risk of stent thrombosis. Further studies are needed to clarify the optimal duration of triple antithrombotic therapy (TAT) or DAT and the role of more potent antiplatelet drugs.

P2Y12 Receptor Inhibitor for Antiaggregant Therapies: From Molecular Pathway to Clinical Application

Platelets play a significant role in hemostasis, forming plugs at sites of vascular injury to limit blood loss. However, if platelet activation is not controlled, it can lead to thrombotic events, such as myocardial infarction and stroke. To prevent this, antiplatelet agents are used in clinical settings to limit platelet activation in patients at risk of arterial thrombotic events. However, their use can be associated with a significant risk of bleeding. An enhanced comprehension of platelet signaling mechanisms should facilitate the identification of safer targets for antiplatelet therapy. Over the past decade, our comprehension of the breadth and intricacy of signaling pathways that orchestrate platelet activation has expanded exponentially. Several recent studies have provided further insight into the regulation of platelet signaling events and identified novel targets against which to develop novel antiplatelet agents. Antiplatelet drugs are essential in managing atherothrombotic vascular disease. The current antiplatelet therapy in clinical practice is limited in terms of safety and efficacy. Novel compounds have been developed in response to patient variability and resistance to aspirin and/or clopidogrel. Recent studies based on randomized controlled trials and systematic reviews have definitively demonstrated the role of antiplatelet therapy in reducing the risk of cardiovascular events. Antiplatelet therapy is the recommended course of action for patients with established atherosclerosis. These studies compared monotherapy with a P2Y12 inhibitor versus aspirin for secondary prevention. However, in patients undergoing percutaneous coronary intervention, it is still unclear whether the efficacy of P2Y12 inhibitor monotherapy after a short course of dual antiplatelet therapy depends on the type of P2Y12 inhibitor. This paper focuses on the advanced-stage evaluation of several promising antiplatelet drugs.

The pharmacology of antiplatelet agents for primary, secondary, and tertiary prevention of ischemic stroke

INTRODUCTION

Ischemic etiology accounts for two thirds of all strokes in which platelet activation and aggregation play a major role. A variety of antiplatelet therapies have been tested for primary, secondary, and tertiary prevention, with certain patient subtypes benefiting more than others from a specific regimen.

AREAS COVERED

This review aims at synthetizing current evidence on pharmacology of antiplatelet agents approved for primary, secondary, and tertiary stroke prevention and their application among possible patient subtypes that may benefit more from their administration.

EXPERT OPINION

Management of ischemic stroke has largely evolved over the past decades. A better understanding of stroke pathophysiology has allowed to identify patients who can benefit most from antiplatelet therapies, with varying degrees of benefit depending on whether these agents are being used for primary, secondary, or tertiary prevention. Importantly, the antiplatelet treatment regimens currently available have expanded and no longer limited to aspirin but include other drugs such as P2Y12 and phosphodiesterase inhibitors, also used in combination, as well as precision medicine approaches using genetic testing aiming at optimizing the safety and efficacy in this population.

Ticagrelor or Clopidogrel Monotherapy vs Dual Antiplatelet Therapy After Percutaneous Coronary Intervention: A Systematic Review and Patient-Level Meta-Analysis

Importance

Among patients undergoing percutaneous coronary intervention (PCI), it remains unclear whether the treatment efficacy of P2Y12 inhibitor monotherapy after a short course of dual antiplatelet therapy (DAPT) depends on the type of P2Y12 inhibitor.

Objective

To assess the risks and benefits of ticagrelor monotherapy or clopidogrel monotherapy compared with standard DAPT after PCI.

Data Sources

MEDLINE, Embase, TCTMD, and the European Society of Cardiology website were searched from inception to September 10, 2023, without language restriction.

Study Selection

Included studies were randomized clinical trials comparing P2Y12 inhibitor monotherapy with DAPT on adjudicated end points in patients without indication to oral anticoagulation undergoing PCI.

Data Extraction and Synthesis

Patient-level data provided by each trial were synthesized into a pooled dataset and analyzed using a 1-step mixed-effects model. The study is reported following the Preferred Reporting Items for Systematic Review and Meta-Analyses of Individual Participant Data.

Main Outcomes and Measures

The primary objective was to determine noninferiority of ticagrelor or clopidogrel monotherapy vs DAPT on the composite of death, myocardial infarction (MI), or stroke in the per-protocol analysis with a 1.15 margin for the hazard ratio (HR). Key secondary end points were major bleeding and net adverse clinical events (NACE), including the primary end point and major bleeding.

Results

Analyses included 6 randomized trials including 25 960 patients undergoing PCI, of whom 24 394 patients (12 403 patients receiving DAPT; 8292 patients receiving ticagrelor monotherapy; 3654 patients receiving clopidogrel monotherapy; 45 patients receiving prasugrel monotherapy) were retained in the per-protocol analysis. Trials of ticagrelor monotherapy were conducted in Asia, Europe, and North America; trials of clopidogrel monotherapy were all conducted in Asia. Ticagrelor was noninferior to DAPT for the primary end point (HR, 0.89; 95% CI, 0.74-1.06; P for noninferiority = .004), but clopidogrel was not noninferior (HR, 1.37; 95% CI, 1.01-1.87; P for noninferiority > .99), with this finding driven by noncardiovascular death. The risk of major bleeding was lower with both ticagrelor (HR, 0.47; 95% CI, 0.36-0.62; P < .001) and clopidogrel monotherapy (HR, 0.49; 95% CI, 0.30-0.81; P = .006; P for interaction = 0.88). NACE were lower with ticagrelor (HR, 0.74; 95% CI, 0.64-0.86, P < .001) but not with clopidogrel monotherapy (HR, 1.00; 95% CI, 0.78-1.28; P = .99; P for interaction = .04).

Conclusions and Relevance

This systematic review and meta-analysis found that ticagrelor monotherapy was noninferior to DAPT for all-cause death, MI, or stroke and superior for major bleeding and NACE. Clopidogrel monotherapy was similarly associated with reduced bleeding but was not noninferior to DAPT for all-cause death, MI, or stroke, largely because of risk observed in 1 trial that exclusively included East Asian patients and a hazard that was driven by an excess of noncardiovascular death.

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.

P2Y12 Inhibitor or Aspirin Monotherapy for Secondary Prevention of Coronary Events

BACKGROUND

Aspirin is the only antiplatelet agent with a Class I recommendation for long-term prevention of cardiovascular events in patients with coronary artery disease (CAD). There is inconsistent evidence on how it compares with alternative antiplatelet agents.

OBJECTIVES

This study compared P2Y12 inhibitor monotherapy vs aspirin in patients with CAD.

METHODS

We conducted a patient-level meta-analysis of randomized trials comparing P2Y12 inhibitor monotherapy vs aspirin monotherapy for the prevention of cardiovascular events in patients with established CAD. The primary outcome was the composite of cardiovascular death, myocardial infarction, and stroke. Prespecified key secondary outcomes were major bleeding and net adverse clinical events (the composite of the primary outcome and major bleeding). Data were pooled in a 1-step meta-analysis.

RESULTS

Patient-level data were obtained from 7 trials. Overall, 24,325 participants were available for analysis, including 12,178 patients assigned to receive P2Y12 inhibitor monotherapy (clopidogrel in 7,545 [62.0%], ticagrelor in 4,633 [38.0%]) and 12,147 assigned to receive aspirin. Risk of the primary outcome was lower with P2Y12 inhibitor monotherapy compared with aspirin over 2 years (HR: 0.88; 95% CI: 0.79-0.97; P = 0.012), mainly owing to less myocardial infarction (HR: 0.77; 95% CI: 0.66-0.90; P < 0.001). Major bleeding was similar (HR: 0.87; 95% CI: 0.70-1.09; P = 0.23) and net adverse clinical events were lower (HR: 0.89; 95% CI: 0.81-0.98; P = 0.020) with P2Y12 inhibitors. The treatment effect was consistent across prespecified subgroups and types of P2Y12 inhibitors.

CONCLUSIONS

Given its superior efficacy and similar overall safety, P2Y12 inhibitor monotherapy might be preferred over aspirin monotherapy for long-term secondary prevention in patients with established CAD. (P2Y12 Inhibitor or Aspirin Monotherapy as Secondary Prevention in Patients With Coronary Artery Disease: An Individual Patient Data Meta-Analysis of Randomized Trials [PANTHER collaborative initiative]; CRD42021290774).

P2y12 inhibitor monotherapy after 1-3 months dual antiplatelet therapy in patients with coronary artery disease and chronic kidney disease undergoing percutaneous coronary intervention: a meta-analysis of randomized controlled trials

Introduction

In patients with coronary artery disease (CAD) and chronic kidney disease (CKD) undergoing percutaneous coronary intervention (PCI), whether short-term dual antiplatelet therapy (DAPT) followed by P2Y₁₂ inhibitors confers benefits compared with standard DAPT remains unclear. This study aimed to assess the efficacy and safety of 1-3 months of DAPT followed by P2Y₁₂ monotherapy in patients with CAD and CKD undergoing PCI.

Methods

PubMed, Embase, and the Cochrane Library were searched to identify randomized controlled trials (RCTs) comparing the P2Y₁₂ inhibitor monotherapy after a 1-3 months DAPT vs. DAPT in patients with CAD and CKD after PCI. The primary outcome was the incidence of major adverse cardiovascular events (MACEs), defined as a composite of all-cause mortality, myocardial infarction, stent thrombosis, target-vessel revascularization, and stroke. The safety outcome was the major bleeding events, defined as a composite of TIMI major bleeding or Bleeding Academic Research and Consortium (BARC) type 2, 3, or 5 bleeding. The pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated with a fixed- or random-effects model depending on the heterogeneity among studies.

Results

Four RCTs including 20,468 patients (2,833 patients with CKD and 17,635 without CKD) comparing P2Y₁₂ inhibitor monotherapy with DAPT were included in our meta-analysis. Patients with CAD and CKD had higher risk of ischemic and bleeding events. P2Y₁₂ inhibitor monotherapy after 1-3 months of DAPT significantly reduced the risk of major bleeding compared to DAPT in CKD patients (RR: 0.69, 95% CI: 0.51-0.95, P = 0.02) and non-CKD patients (RR: 0.66, 95% CI: 0.49-0.89, P = 0.01). No significant difference regarding MACEs between P2Y₁₂ inhibitor monotherapy and DAPT was found in CKD patients (RR: 0.88, 95% CI: 0.59-1.31, P = 0.53) and non-CKD (RR: 0.91, 95% CI: 0.79-1.04, P = 0.17).

Conclusion

P2Y₁₂ inhibitor monotherapy after 1-3 months of DAPT was an effective strategy for lowering major bleeding complications without increasing the risk of cardiovascular events in patients with CAD and CKD undergoing PCI as compared with DAPT.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, CRD42022355228.

Effectiveness of a structured pharmacist-delivered intervention for patients post-acute coronary syndromes on all-cause hospitalizations and cardiac-related hospital readmissions: a prospective quasi-experimental study

BACKGROUND

Acute coronary syndrome (ACS) is a leading cause of mortality and morbidity in Qatar and globally.

AIM

The primary objective of the study was to evaluate the effectiveness of a structured clinical pharmacist-delivered intervention on all-cause hospitalizations and cardiac-related readmissions in patients with ACS.

METHOD

A prospective quasi-experimental study was conducted at Heart Hospital in Qatar. Discharged ACS patients were allocated to one of three study arms: (1) an intervention group (received a structured clinical pharmacist-delivered medication reconciliation and counselling at discharge, and two follow-up sessions at 4 weeks and 8 weeks post-discharge), (2) a usual care group (received the general usual care at discharge by clinical pharmacists) or, (3) a control group (discharged during weekends or after clinical pharmacists' working hours). Follow-up sessions for the intervention group were designed to re-educate and counsel patients about their medications, remind them about the importance of medication adherence, and answer any questions they may have. At the hospital, patients were allocated into one of the three groups based on intrinsic and natural allocation procedures. Recruitment of patients took place between March 2016 and December 2017. Data were analyzed based on intention-to-treat principles.

RESULTS

Three hundred seventy-three patients were enrolled in the study (intervention = 111, usual care = 120, control = 142). Unadjusted results showed that the odds of 6-month all-cause hospitalizations were significantly higher among the usual care (OR 2.034; 95% CI: 1.103-3.748, p = 0.023) and the control arms (OR 2.704; 95% CI: 1.456-5.022, p = 0.002) when compared to the intervention arm. Similarly, patients in the usual care arm (OR 2.304; 95% CI: 1.122-4.730, p = 0.023) and the control arm (OR 3.678; 95% CI: 1.802-7.506, p ≤ 0.001) had greater likelihood of cardiac-related readmissions at 6 months. After adjustment, these reductions were only significant for cardiac-related readmissions between control and intervention groups (OR 2.428; 95% CI: 1.116-5.282, p = 0.025).

CONCLUSION

This study demonstrated the impact of a structured intervention by clinical pharmacists on cardiac-related readmissions at 6 months post-discharge in patients post-ACS. The impact of the intervention on all-cause hospitalization was not significant after adjustment for potential confounders. Large cost-effective studies are required to determine the sustained impact of structured clinical pharmacist-provided interventions in ACS setting.

TRIAL REGISTRATION

Clinical Trials: NCT02648243 Registration date: January 7, 2016.

Escalation and De-Escalation of Antiplatelet Therapy after Acute Coronary Syndrome or PCI: Available Evidence and Implications for Practice

Dual antiplatelet therapy (DAPT) is the gold standard for the antithrombotic management of patients with an acute coronary syndrome (ACS) or undergoing percutaneous coronary intervention (PCI). Implementation of intensified or prolonged DAPT regimens has proven to lower the risk of ischemic events but at the expense of increased bleeding. Importantly, bleeding is a predictor of poor prognosis. Risk stratification and selection of tailored antiplatelet strategies to maximize the net clinical benefit in individual patients with ACS or undergoing PCI is therefore potentially beneficial. Recently, novel approaches including DAPT de-escalation or escalation have been proposed as possible alternatives to standard DAPT. These strategies, which are generally based on patient's risk profile, genetics, and/or platelet function have been proposed to offer more tailored treatments in patients with ACS or PCI, with the ultimate goal of providing adequate ischemic protection while mitigating the risk of bleeding. This review summarizes the available evidence on DAPT de-escalation or escalation (both guided and unguided) and discusses the practical implications of these strategies in the contemporary management of patients with ACS and/or undergoing PCI.

Opportunità cliniche e impatto sul sistema sanitario di un trattamento ottimale del paziente post-sindrome coronarica acuta

Despite the improvement of revascularization procedures, patients with acute coronary syndrome often develop recurrent ischemic events, suggesting a high residual cardiovascular risk in these patients, which requires a strict clinical monitoring as well as an optimal control of modifiable risk factors.

To this aim, an optimal management of index event and appropriate preventive measures are equally important. Hospital care by cardiologists should be followed by outpatient management by general practitioners, as established by specific diagnostic and therapeutic pathways, which should warrant an optimal support to the patient. A strict collaboration between hospital and primary care is crucial to monitor and adapt drug therapy after the acute event and improve adherence of the patients to prescribed treatments and implementation of life-style modifications, with benefits also in term of cost-effectiveness. In this context, individualized rehabilitation programs should also be offered to patients with acute coronary syndromes, in order to improve survival and quality of life.

Low-Dose Aspirin Augments the Anti-Inflammatory Effects of Low-Dose Lithium in Lipopolysaccharide-Treated Rats

Mounting evidence suggests that immune-system dysfunction and inflammation play a role in the pathophysiology and treatment of mood-disorders in general and of bipolar disorder in particular. The current study examined the effects of chronic low-dose aspirin and low-dose lithium (Li) treatment on plasma and brain interleukin-6 and tumor necrosis factor-α production in lipopolysaccharide (LPS)-treated rats. Rats were fed regular or Li-containing food (0.1%) for six weeks. Low-dose aspirin (1 mg/kg) was administered alone or together with Li. On days 21 and 42 rats were injected with 1 mg/kg LPS or saline. Two h later body temperature was measured and rats were sacrificed. Blood samples, the frontal-cortex, hippocampus, and the hypothalamus were extracted. To assess the therapeutic potential of the combined treatment, rats were administered the same Li + aspirin protocol without LPS. We found that the chronic combined treatment attenuated LPS-induced hypothermia and significantly reduced plasma and brain cytokine level elevation, implicating the potential neuroinflammatory diminution purportedly present among the mentally ill. The combined treatment also significantly decreased immobility time and increased struggling time in the forced swim test, suggestive of an antidepressant-like effect. This preclinical evidence provides a potential approach for treating inflammation-related mental illness.

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.

Appraising the contemporary role of aspirin for primary and secondary prevention of atherosclerotic cardiovascular events

INTRODUCTION

Although the role of aspirin for primary prevention of atherosclerotic cardiovascular disease (ASCVD) has been disputed, its use in secondary ASCVD prevention is well established. Recent trials of primary prevention do not suggest a significant net benefit with aspirin, whereas accruing evidence supports adopting aspirin-free strategies in the context of potent P2Y₁₂ inhibition for the secondary prevention of selected patients undergoing percutaneous coronary intervention.

AREAS COVERED

This updated review aims at summarizing and appraising the pharmacological characteristics and the contemporary role of aspirin for the primary and secondary prevention of ASCVD.

EXPERT OPINION

Recent trials and metanalyses in the context of primary prevention highlighted a modest reduction in ischemic events with aspirin use, counterbalanced by a significant increase in bleeding events. However, ongoing studies on cancer prevention could modify the current paradigm of the unfavorable benefit-risk ratio of aspirin in patients with no overt ASCVD. Conversely, aspirin use is crucial for secondary ASCVD prevention, both in chronic and acute coronary syndromes. Nevertheless, after a brief period of dual antiplatelet therapy, patients at high bleeding risk may benefit from discontinuation of aspirin if a P2Y₁₂ inhibitor is used, hence reducing the bleeding risk with no rebound in thrombotic events.

Safety and Efficacy of Combined Low-Dose Lithium and Low-Dose Aspirin: A Pharmacological and Behavioral Proof-of-Concept Study in Rats

Despite established efficacy in bipolar disorder patients, lithium (Li) therapy has serious side effects, particularly chronic kidney disease. We examined the safety and behavioral effects of combined chronic low-dose aspirin plus low-dose Li in rats to explore the toxicity and therapeutic potential of this treatment. Rats were fed regular or Li-containing food (0.1% [low-dose, LLD-Li] or 0.2% [standard-dose, STD-Li]) for six weeks. Low-dose aspirin (1 mg/kg) was administered alone or together with Li. Renal function and gastric mucosal integrity were assessed. The effects of the combination treatment were evaluated in depression-like and anxiety-like behavioral models. Co-treatment with aspirin did not alter plasma Li levels. Chronic STD-Li treatment resulted in significant polyuria and polydipsia, elevated blood levels of creatinine and cystatin C, and increased levels of kidney nephrin and podocin—all suggestive of impaired renal function. Aspirin co-treatment significantly damped STD-Li-induced impairments in kidney parameters. There were no gastric ulcers or blood loss in any treatment group. Combined aspirin and LLD-Li resulted in a significant increase in sucrose consumption, and in the time spent in the open arms of an elevated plus-maze compared with the LLD-Li only group, suggestive of antidepressant-like and anxiolytic-like effects, respectively. Thus, we demonstrate that low-dose aspirin mitigated the typical renal side effects of STD-Li dose and enhanced the beneficial behavioral effects of LLD-Li therapy without aggravating its toxicity.

Efficacy and Safety of Aspirin for Primary Cardiovascular Risk Prevention in Younger and Older Age: An Updated Systematic Review and Meta-analysis of 178,310 Subjects from 21 Randomized Studies

AIMS

 The efficacy and safety of aspirin for primary cardiovascular disease (CVD) prevention is controversial. The aim of this study was to investigate the efficacy and safety of aspirin in subjects with no overt CVD, with a focus on age as a treatment modifier.

METHODS AND RESULTS

 Randomized trials comparing aspirin use versus no aspirin use or placebo were included. The primary efficacy outcome was all-cause death. The primary safety outcome was major bleeding. Secondary ischemic and bleeding outcomes were explored. Subgroup analyses were conducted to investigate the consistency of the effect sizes in studies including younger and older individuals, using a cut-off of 65 years. A total of 21 randomized trials including 173,810 individuals at a mean follow-up of 5.3 years were included. Compared with control, aspirin did not reduce significantly the risk of all-cause death (risk ratio: 0.96; 95% confidence interval: 0.92-1.00, p = 0.057). Major adverse cardiovascular events were significantly reduced by 11%, paralleled by significant reductions in myocardial infarction and transient ischemic attack. Major bleeding, intracranial hemorrhage, and gastrointestinal bleeding were significantly increased by aspirin. There was a significant age interaction for death (p for interaction = 0.007), with aspirin showing a statistically significant 7% relative benefit on all-cause death in studies including younger patients.

CONCLUSION

 The use of aspirin in subjects with no overt CVD was associated with a neutral effect on all-cause death and a modest lower risk of major cardiovascular events at the price of an increased risk in major bleeding. The benefit of aspirin might be more pronounced in younger individuals.

Ticagrelor Monotherapy Versus Dual-Antiplatelet Therapy After PCI: An Individual Patient-Level Meta-Analysis

OBJECTIVES

The aim of this study was to compare ticagrelor monotherapy with dual-antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with drug-eluting stents.

BACKGROUND

The role of abbreviated DAPT followed by an oral P2Y₁₂ inhibitor after PCI remains uncertain.

METHODS

Two randomized trials, including 14,628 patients undergoing PCI, comparing ticagrelor monotherapy with standard DAPT on centrally adjudicated endpoints were identified, and individual patient data were analyzed using 1-step fixed-effect models. The protocol was registered in PROSPERO (CRD42019143120). The primary outcomes were the composite of Bleeding Academic Research Consortium type 3 or 5 bleeding tested for superiority and, if met, the composite of all-cause death, myocardial infarction, or stroke at 1 year, tested for noninferiority against a margin of 1.25 on a hazard ratio (HR) scale.

RESULTS

Bleeding Academic Research Consortium type 3 or 5 bleeding occurred in fewer patients with ticagrelor than DAPT (0.9% vs. 1.7%, respectively; HR: 0.56; 95% confidence interval [CI]: 0.41 to 0.75; p < 0.001). The composite of all-cause death, myocardial infarction, or stroke occurred in 231 patients (3.2%) with ticagrelor and in 254 patients (3.5%) with DAPT (HR: 0.92; 95% CI: 0.76 to 1.10; p < 0.001 for noninferiority). Ticagrelor was associated with lower risk for all-cause (HR: 0.71; 95% CI: 0.52 to 0.96; p = 0.027) and cardiovascular (HR: 0.68; 95% CI: 0.47 to 0.99; p = 0.044) mortality. Rates of myocardial infarction (2.01% vs. 2.05%; p = 0.88), stent thrombosis (0.29% vs. 0.38%; p = 0.32), and stroke (0.47% vs. 0.36%; p = 0.30) were similar.

CONCLUSIONS

Ticagrelor monotherapy was associated with a lower risk for major bleeding compared with standard DAPT, without a concomitant increase in ischemic events.

Clinical Outcomes of Very Short Term Dual Antiplatelet Therapy in Patients With or Without Diabetes Undergoing Second-Generation Drug-Eluting Stents: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Background: Patients with diabetes represent 20-30% of the population considered for percutaneous coronary intervention (PCI) and associate with more deleterious clinical outcome, which requires the optimal strategy of dual antiplatelet therapy (DAPT). The meta-analysis aims to compare clinical outcomes between very short (1-3 months) and standard (12 months) DAPT after implanting the second-generation drug-eluting stents in patients with or without diabetes following PCI. Methods and Analysis: PubMed, Embase, Web of Science, Ovid, Cochrane Library, and ClinicalTrials.gov were searched for studies comparing the very short term and standard DAPT in patients with or without diabetes following PCI. Risk ratio with 95% confidence intervals was used to evaluate the pooled effect of discontinuous variables, and the pooled analyses were performed with RevMan 5.3 and Stata SE 14.0 software. Results: A total of 38,864 patients were randomized to the very short term DAPT (N = 19,423) vs. standard DAPT (N = 19,441). Among them, 11,476 patients were diabetes and 27,388 patients were non-diabetes. The primary outcome of the net adverse clinical event (NACE) was significantly lower in diabetic patients with very short term DAPT (risk ratio 0.72, 95% CI 0.60-0.88, p = 0.0009). The same result was also found in the major cardiac or cerebrovascular events (MACCEs) (0.87, 0.78-0.98, p = 0.03). The risk of major or minor bleeding was significantly reduced in very short term DAPT regardless of the diabetes statue (0.69, 0.52-0.93, p = 0.01 in the diabetic group, and 0.50, 0.39-0.63, p <0.0001 in the non-diabetic group). There was no statistical difference in the incidence of major bleeding, all-cause death, cardiac death, myocardial infarction, definite or probable stent thrombosis, and stroke between the very short term DAPT (1-3 months) and standard DAPT (12 months) in patients with or without diabetes. Conclusion: The very short term DAPT can significantly reduce the risk of the NACE and MACCE in patients with diabetes compared to standard DAPT. Meanwhile, the very short term DAPT can also reduce the incidence of major and minor bleeding without increasing the risk of ischemia in patients with or without diabetes (Registered by PROSPERO, CRD42020192133). Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, Identifier: CRD42020192133.

P2Y12 inhibitor monotherapy or dual antiplatelet therapy after coronary revascularisation: individual patient level meta-analysis of randomised controlled trials

OBJECTIVE

To assess the risks and benefits of P2Y₁₂ inhibitor monotherapy compared with dual antiplatelet therapy (DAPT) and whether these associations are modified by patients' characteristics.

DESIGN

Individual patient level meta-analysis of randomised controlled trials.

DATA SOURCES

Searches were conducted in Ovid Medline, Embase, and three websites (www.tctmd.com, www.escardio.org, www.acc.org/cardiosourceplus) from inception to 16 July 2020. The primary authors provided individual participant data.

ELIGIBILITY CRITERIA

Randomised controlled trials comparing effects of oral P2Y₁₂ monotherapy and DAPT on centrally adjudicated endpoints after coronary revascularisation in patients without an indication for oral anticoagulation.

MAIN OUTCOME MEASURES

The primary outcome was a composite of all cause death, myocardial infarction, and stroke, tested for non-inferiority against a margin of 1.15 for the hazard ratio. The key safety endpoint was Bleeding Academic Research Consortium (BARC) type 3 or type 5 bleeding.

RESULTS

The meta-analysis included data from six trials, including 24 096 patients. The primary outcome occurred in 283 (2.95%) patients with P2Y₁₂ inhibitor monotherapy and 315 (3.27%) with DAPT in the per protocol population (hazard ratio 0.93, 95% confidence interval 0.79 to 1.09; P=0.005 for non-inferiority; P=0.38 for superiority; τ²=0.00) and in 303 (2.94%) with P2Y₁₂ inhibitor monotherapy and 338 (3.36%) with DAPT in the intention to treat population (0.90, 0.77 to 1.05; P=0.18 for superiority; τ²=0.00). The treatment effect was consistent across all subgroups, except for sex (P for interaction=0.02), suggesting that P2Y₁₂ inhibitor monotherapy lowers the risk of the primary ischaemic endpoint in women (hazard ratio 0.64, 0.46 to 0.89) but not in men (1.00, 0.83 to 1.19). The risk of bleeding was lower with P2Y₁₂ inhibitor monotherapy than with DAPT (97 (0.89%) v 197 (1.83%); hazard ratio 0.49, 0.39 to 0.63; P<0.001; τ²=0.03), which was consistent across subgroups, except for type of P2Y₁₂ inhibitor (P for interaction=0.02), suggesting greater benefit when a newer P2Y₁₂ inhibitor rather than clopidogrel was part of the DAPT regimen.

CONCLUSIONS

P2Y₁₂ inhibitor monotherapy was associated with a similar risk of death, myocardial infarction, or stroke, with evidence that this association may be modified by sex, and a lower bleeding risk compared with DAPT.

REGISTRATION

PROSPERO CRD42020176853.

Short dual antiplatelet therapy followed by P2Y12 inhibitor monotherapy vs. prolonged dual antiplatelet therapy after percutaneous coronary intervention with second-generation drug-eluting stents: a systematic review and meta-analysis of randomized clinical trials

AIMS

After percutaneous coronary intervention (PCI) with second-generation drug-eluting stent (DES), whether short dual antiplatelet therapy (DAPT) followed by single antiplatelet therapy (SAPT) with a P2Y12 receptor inhibitor confers benefits compared with prolonged DAPT is unclear.

METHODS AND RESULTS

Multiple electronic databases, including PubMed, Scopus, Web of Sciences, Ovid, and ScienceDirect, were searched to identify randomized clinical trials comparing ≤3 months of DAPT followed by P2Y12 inhibitor SAPT vs. 12 months of DAPT after PCI with second-generation DES implantation. The primary and co-primary outcomes of interest were major bleeding and stent thrombosis 1 year after randomization. Summary hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by fixed-effect and random-effects models. Multiple sensitivity analyses including random-effects models 95% CI adjustment were applied. A sensitivity analysis comparing trials using P2Y12 inhibitor SAPT with those using aspirin SAPT was performed. A total of five randomized clinical trials (32 145 patients) were available. Major bleeding was significantly lower in the patients assigned to short DAPT followed by P2Y12 inhibitor SAPT compared with those assigned to 12-month DAPT (random-effects model: HR 0.63, 95% 0.45-0.86). No significant differences between groups were observed in terms of stent thrombosis (random-effects model: HR 1.19, 95% CI 0.86-1.65) and the secondary endpoints of all-cause death (random-effects model: HR 0.85, 95% CI 0.70-1.03), myocardial infarction (random-effects model: HR 1.05, 95% CI 0.89-1.23), and stroke (random-effects model: HR 1.08, 95% CI 0.68-1.74). Sensitivity analyses showed overall consistent results. By comparing trials testing ≤3 months of DAPT followed by P2Y12 inhibitor SAPT vs. 12 months of DAPT with trials testing ≤3 months of DAPT followed by aspirin SAPT vs. 12-month of DAPT, there was no treatment-by-subgroup interaction for each endpoint. By combining all these trials, regardless of the type of SAPT, short DAPT was associated with lower major bleeding (random-effects model: HR 0.63, 95% CI 0.48-0.83) and no differences in stent thrombosis, all-cause death, myocardial infarction, and stroke were observed between regimens.

CONCLUSION

After second-generation DES implantation, 1-3 months of DAPT followed by P2Y12 inhibitor SAPT is associated with lower major bleeding and similar stent thrombosis, all-cause death, myocardial infarction, and stroke compared with prolonged DAPT. Whether P2Y12 inhibitor SAPT is preferable to aspirin SAPT needs further investigation.

Inflamm-ageing: the role of inflammation in age-dependent cardiovascular disease

The ongoing worldwide increase in life expectancy portends a rising prevalence of age-related cardiovascular (CV) diseases in the coming decades that demands a deeper understanding of their molecular mechanisms. Inflammation has recently emerged as an important contributor for CV disease development. Indeed, a state of chronic sterile low-grade inflammation characterizes older organisms (also known as inflamm-ageing) and participates pivotally in the development of frailty, disability, and most chronic degenerative diseases including age-related CV and cerebrovascular afflictions. Due to chronic activation of inflammasomes and to reduced endogenous anti-inflammatory mechanisms, inflamm-ageing contributes to the activation of leucocytes, endothelial, and vascular smooth muscle cells, thus accelerating vascular ageing and atherosclerosis. Furthermore, inflamm-ageing promotes the development of catastrophic athero-thrombotic complications by enhancing platelet reactivity and predisposing to plaque rupture and erosion. Thus, inflamm-ageing and its contributors or molecular mediators might furnish targets for novel therapeutic strategies that could promote healthy ageing and conserve resources for health care systems worldwide. Here, we discuss recent findings in the pathophysiology of inflamm-ageing, the impact of these processes on the development of age-related CV diseases, results from clinical trials targeting its components and the potential implementation of these advances into daily clinical practice.

Effect of aspirin treatment duration on clinical outcomes in acute coronary syndrome patients with early aspirin discontinuation and received P2Y12 inhibitor monotherapy

Recent clinical trials showed that short aspirin duration (1 or 3 months) in dual antiplatelet therapy (DAPT) followed by P2Y12 inhibitor monotherapy reduced the risk of bleeding and did not increase the ischemic risk compared to 12-month DAPT in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). However, it is unclear about the optimal duration of aspirin in P2Y12 inhibitor monotherapy. The purpose of this study was to evaluate the influence of aspirin treatment duration on clinical outcomes in a cohort of ACS patients with early aspirin interruption and received P2Y12 inhibitor monotherapy. From January 1, 2014 to December 31, 2018, we included 498 ACS patients (age 70.18 ± 12.84 years, 71.3% men) with aspirin stopped for various reasons before 6 months after PCI and received P2Y12 inhibitor monotherapy. The clinical outcomes between those with aspirin treatment ≤ 1 month and > 1 month were compared in 12-month follow up after PCI. Inverse probability of treatment weighting was used to balance the covariates between groups. The mean duration of aspirin treatment was 7.52 ± 8.10 days vs. 98.05 ± 56.70 days in the 2 groups (p<0.001). The primary composite endpoint of all-cause mortality, recurrent ACS or unplanned revascularization and stroke occurred in 12.6% and 14.4% in the 2 groups (adjusted HR 1.19, 95% CI 0.85-1.68). The safety outcome of BARC 3 or 5 bleeding was also similar (adjusted HR 0.69, 95% CI 0.34-1.40) between the 2 groups. In conclusion, patients with ≤ 1 month aspirin treatment had similar clinical outcomes to those with treatment > 1 month. Our results indicated that ≤ 1-month aspirin may be enough in P2Y12 inhibitor monotherapy strategy for ACS patients undergoing PCI.

Aspirin at 120: Retiring, recombining, or repurposing?

During the past 20 years, we have witnessed the following trends in aspirin usage: (i) a "dropping" trend, characterized by the early discontinuation of low-dose aspirin from dual antiplatelet therapy or triple antithrombotic therapy (oral anticoagulation plus dual antiplatelet therapy in patients with atrial fibrillation) following an acute coronary syndrome or after percutaneous coronary intervention; (ii) a "combinatorial" trend, featuring the addition of a lower dose of a P2Y12 inhibitor or direct oral anticoagulant drug to low-dose aspirin for the long-term treatment of stable patients with atherosclerotic cardiovascular disease; and (iii) a "repurposing" trend, characterized by growing interest in the oncologic community to assess the chemopreventive effect of aspirin against certain types of cancers (particularly of the gastrointestinal tract), both as primary prevention and adjuvant therapy. The aim of this review is to present the mechanistic rationale underlying these trends, discuss the design and findings of trials testing novel treatments or new therapeutic applications of aspirin, and report on the ISTH Congress results on this topic.

Evolution of Clinical Thinking and Practice Regarding Aspirin: What Has Changed and Why?

Aspirin (ASA) is the original antiplatelet agent. Its routine use, long unquestioned for both primary and secondary prevention in cardiovascular disease, is under increasing scrutiny as the risk:benefit balance for ASA becomes less clear and other disease- and risk-modifying approaches are validated. It can be viewed as a significant advance in evidence-based medicine that the use of an inexpensive, readily available, long-validated therapy is being questioned in large, rigorous trials. In this overview we present the important questions surrounding a more informed approach to ASA therapy: duration of therapy, assessment of net clinical benefit, and timing of start and stop strategies. We also consider potential explanations for "breakthrough" thrombosis when patients are on ASA therapy. Other manuscripts in this Supplement address the specifics of primary prevention, secondary prevention, triple oral antithrombotic therapy, and the future of ASA in cardiovascular medicine.

Salicylic acid stabilizes Staphylococcus aureus biofilm by impairing the agr quorum-sensing system

Salicylic acid (SAL) has recently been shown to induce biofilm formation in Staphylococcus aureus and to affect the expression of virulence factors. This study was aimed to investigate the effect of SAL on the regulatory agr system and its impact on S. aureus biofilm formation. The agr quorum-sensing system, which is a central regulator in S. aureus pathogenicity, plays a pivotal role in the dispersal of S. aureus mature biofilms and contributes to the creation of new colonization sites. Here, we demonstrate that SAL impairs biofilm dispersal by interfering with agr expression. As revealed by our work, protease and surfactant molecule production is diminished, and bacterial cell autolysis is also negatively affected by SAL. Furthermore, as a consequence of SAL treatment, the S. aureus biofilm matrix revealed the lack of extracellular DNA. In silico docking and simulation of molecular dynamics provided evidence for a potential interaction of AgrA and SAL, resulting in reduced activity of the agr system. In conclusion, SAL stabilized the mature S. aureus biofilms, which may prevent bacterial cell dissemination. However, it may foster the establishment of infections locally and consequently increase bacterial persistence leading to therapeutic failure.

Safety and Efficacy of 1-Month Dual Antiplatelet Therapy (Ticagrelor + Aspirin) Followed by 23-Month Ticagrelor Monotherapy in Patients Undergoing Staged Percutaneous Coronary Intervention (A Sub-Study from GLOBAL LEADERS)

Patients undergoing staged percutaneous coronary intervention (SPCI) are exposed to extended duration of antiplatelet therapy, and a novel aspirin-free antiplatelet regimen after SPCI should be specifically evaluated among these patients. This is a prespecified substudy of the GLOBAL LEADERS which is a randomized, open-label trial, comparing an experimental regimen of 1-month dual antiplatelet therapy (DAPT; ticagrelor and aspirin) followed by 23-month ticagrelor monotherapy to a reference regimen of 12-month DAPT followed by 12-month aspirin monotherapy. Patients were stratified according to whether or not SPCI was performed. The impact of the timing of SPCI on clinical outcomes was also investigated. Of 15,968 randomized patients, 1,651 patients underwent SPCI within 3 months. These patients with SPCI had a significantly higher risk of bleeding and ischemic endpoints than those without SPCI. In patients undergoing SPCI, the primary endpoint (composite of all-cause death or new Q-wave myocardial infarction at 2 years) and secondary safety endpoint (Bleeding Academic Research Consortium [BARC]-defined bleeding 3 or 5) were similar in the 2 regimens. However, in patients presenting with acute coronary syndrome (ACS), the experimental regimen reduced a risk of BARC 3 or 5 bleeding (1.8% vs 4.5%; HR 0.387; 95% CI 0.179 to 0.836; p = 0.016). In patients undergoing SPCI later than 10 days after index procedure, this risk reduction was still prominent (0.8% vs 2.3%; HR 0.321; 95% CI 0.116 to 0.891; p = 0.029). In conclusion, patients undergoing SPCI are at high risk and may need special attention from clinicians. In ACS patients undergoing SPCI, a novel aspirin-free antiplatelet regimen appears to be associated with a lower bleeding risk than with standard DAPT.

Pharmacodynamic Comparison of Ticagrelor Monotherapy Versus Ticagrelor and Aspirin in Patients After Percutaneous Coronary Intervention: The TEMPLATE (Ticagrelor Monotherapy and Platelet Reactivity) Randomized Controlled Trial

Background

To assess differences in platelet inhibition during ticagrelor monotherapy (TIC) or dual therapy with ticagrelor and aspirin (TIC+ASP) in patients after percutaneous coronary intervention using a comprehensive panel of functional tests.

Methods and Results

In a single‐center parallel group, open label, randomized controlled trial, 110 participants were randomized to receive either TIC (n=55) or TIC+ASP (n=55) for 4 weeks. The primary outcome was the platelet aggregation response with 10 μmol/L thrombin receptor activation peptide‐6 (TRAP‐6). The secondary outcomes were platelet aggregation responses and binding of surface activation markers with a panel of other activators. The mean percentage aggregation for 10 μmol/L TRAP‐6 was similar for the TIC and TIC+ASP groups (mean difference+4.29; 95% CI, −0.87 to +9.46). Aggregation was higher in the TIC group compared with the TIC+ASP group with 1 μg/mL (+6.47; +2.04 to +10.90) and 0.5 μg/mL (+14.00; +7.63 to +20.39) collagen related peptide. Aggregation responses with 5 μmol/L TRAP‐6, 5 μmol/L or 2.5 μmol/L thromboxane A₂ receptor agonist and surface activation marker binding with 5 μmol/L TRAP‐6 or 0.5 μg/mL collagen related peptide were the same between the treatment groups.

Conclusions

Patients with PCI show similar levels of inhibition of most platelet activation pathways with TIC compared with dual therapy with TIC + ASP. However, the greater aggregation response with collagen related peptide during TIC indicates incomplete inhibition of glycoprotein VI (collagen) receptor‐mediated platelet activation. This difference in pharmacodynamic response to anti‐platelet medication may contribute to the lower bleeding rates observed with TIC compared with dual antiplatelet therapy in recent clinical trials.

Registration Information

URL: https://www.isrctn.com; Unique Identifier ISRCTN84335288.

Relation of High Lipoprotein (a) Concentrations to Platelet Reactivity in Individuals with and Without Coronary Artery Disease

INTRODUCTION

Lipoprotein (a) [Lp(a)] is a risk factor for coronary artery disease (CAD). To the best of our knowledge, this is the first study addressing the relationship between Lp(a) and platelet reactivity in primary and secondary prevention.

METHODS

Lp(a) was evaluated in 396 individuals with (82.3%) and without (17.7%) obstructive CAD. The population was divided into two groups according to Lp(a) concentrations with a cutoff value of 50 mg/dL. The primary objective was to evaluate the association between Lp(a) and adenosine diphosphate (ADP)-induced platelet reactivity using the VerifyNow™ P2Y₁₂ assay. Platelet reactivity was also induced by arachidonic acid and collagen-epinephrine (C-EPI) and assessed by Multiplate™, platelet function analyzer™ 100 (PFA-100), and light transmission aggregometry (LTA) assays. Secondary objectives included the assessment of the primary endpoint in individuals with or without CAD.

RESULTS

Overall, 294 (74.2%) individuals had Lp(a) < 50 mg/dL [median (IQR) 13.2 (5.8-27.9) mg/dL] and 102 (25.8%) had Lp(a) ≥ 50 mg/dL [82.5 (67.6-114.5) mg/dL], P < 0.001. Univariate analysis in the entire population revealed no differences in ADP-induced platelet reactivity between individuals with Lp(a) ≥ 50 mg/dL (249.4 ± 43.8 PRU) versus Lp(a) < 50 mg/dL (243.1 ± 52.2 PRU), P = 0.277. Similar findings were present in individuals with (P = 0.228) and without (P = 0.669) CAD, and regardless of the agonist used or method of analysis (all P > 0.05). Finally, multivariable analysis did not show a significant association between ADP-induced platelet reactivity and Lp(a) ≥ 50 mg/dL [adjusted OR = 1.00 [(95% CI 0.99-1.01), P = 0.590].

CONCLUSION

In individuals with or without CAD, Lp(a) ≥ 50 mg/dL was not associated with higher platelet reactivity.

Safety and efficacy of double vs. triple antithrombotic therapy in patients with atrial fibrillation with or without acute coronary syndrome undergoing percutaneous coronary intervention: a collaborative meta-analysis of non-vitamin K antagonist oral anticoagulant-based randomized clinical trials

Aims

Safety and efficacy of antithrombotic regimens in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) may differ based on clinical presentation. We sought to compare double vs. triple antithrombotic therapy (DAT vs. TAT) in AF patients with or without acute coronary syndrome (ACS) undergoing PCI.

Methods and results

A systematic review and meta-analysis was performed using PubMed to search for non-vitamin K antagonist oral anticoagulant (NOAC)-based randomized clinical trials. Data on subgroups of ACS or elective PCI were obtained by published reports or trial investigators. A total of 10 193 patients from four NOAC trials were analysed, of whom 5675 presenting with ACS (DAT = 3063 vs. TAT = 2612) and 4518 with stable coronary artery disease (SCAD; DAT = 2421 vs. TAT = 2097). The primary safety endpoint of ISTH major bleeding or clinically relevant non-major bleeding was reduced with DAT compared with TAT in both ACS (12.2% vs. 19.4%; RR 0.63, 95% CI 0.56–0.71; P < 0.0001; I² = 0%) and SCAD (14.6% vs. 22.0%; RR 0.68, 95% CI 0.55–0.85; P = 0.0008; I² = 66%), without interaction (P-int = 0.54). Findings were consistent for secondary bleeding endpoints, including intra-cranial haemorrhage. In both subgroups, there was no difference between DAT and TAT for all-cause death, major adverse cardiovascular events, or stroke. Myocardial infarction and stent thrombosis were numerically higher with DAT vs. TAT consistently in ACS and SCAD (P-int = 0.60 and 0.86, respectively). Findings were confirmed by multiple sensitivity analyses, including a separate analysis on dabigatran regimens and a restriction to PCI population.

Conclusions

DAT, compared with TAT, is associated with lower bleeding risks, including intra-cranial haemorrhage, and a small non-significant excess of cardiac ischaemic events in both patients with or without ACS.

Safety and efficacy outcomes of double vs. triple antithrombotic therapy in patients with atrial fibrillation following percutaneous coronary intervention: a systematic review and meta-analysis of non-vitamin K antagonist oral anticoagulant-based randomized clinical trials

AIMS

To investigate the safety and efficacy of double vs. triple antithrombotic therapy (DAT vs. TAT) in patients with atrial fibrillation (AF) and acute coronary syndrome or who underwent percutaneous coronary intervention (PCI).

METHODS AND RESULTS

A systematic review and meta-analysis was performed using PubMed to search for non-vitamin K antagonist oral anticoagulant (NOAC)-based randomized clinical trials comparing DAT vs. TAT in AF patients undergoing PCI. Four trials encompassing 10 234 patients (DAT = 5496 vs. TAT = 4738) were included. The primary safety endpoint (ISTH major or clinically relevant non-major bleeding) was significantly lower with DAT compared with TAT [risk ratio (RR) 0.66, 95% confidence interval (CI) 0.56-0.78; P < 0.0001; I2 = 69%], which was consistent across all available bleeding definitions. This benefit was counterbalanced by a significant increase of stent thrombosis (RR 1.59, 95% CI 1.01-2.50; P = 0.04; I2 = 0%) and a trend towards higher risk of myocardial infarction with DAT. There were no significant differences in all-cause and cardiovascular death, stroke and major adverse cardiovascular events. The comparison of NOAC-based DAT vs. vitamin K antagonist (VKA)-TAT yielded consistent results and a significant reduction of intracranial haemorrhage (RR 0.33, 95% CI 0.17-0.65; P = 0.001; I2 = 0%).

CONCLUSION

Double antithrombotic therapy, particularly if consisting of a NOAC instead of VKA and a P2Y12 inhibitor, is associated with a reduction of bleeding, including major and intracranial haemorrhages. This benefit is however counterbalanced by a higher risk of cardiac-mainly stent-related-but not cerebrovascular ischaemic occurrences.

Relationship between aspirin use and subarachnoid hemorrhage: A systematic Review and meta-analysis

BACKGROUND

Aspirin has been associated with a decreasing risk of subarachnoid hemorrhage due to its anti-inflammatory mechanism of action and potential protective properties against aneurysm growth.

OBJECTIVE

To determine the association between aneurysmal subarachnoid hemorrhage and aspirin use.

METHODS

A systematic review of the literature and a meta-analysis were performed across the PubMed database. The following keywords were used: "aspirin, acetylsalicylic acid, 2-acetyloxy-benzoic acid, ruptured intracranial aneurysm, aneurysmal subarachnoid hemorrhage, spontaneous subarachnoid hemorrhage, intracerebral hemorrhage, spontaneous aneurysmal hemorrhage, spontaneous intracerebral bleeding". Studies that were performed with animals or analyzed patients with traumatic brain injury were excluded. A total of five studies were included in our meta-analysis, with a total of 19,222 patients evaluated. Statistical analysis was performed to determine the association between the use of aspirin and the risk of subarachnoid hemorrhage.

RESULTS

Aspirin use reduce the risk of subarachnoid hemorrhage (odds ratio [OR] 0.51, 95 % confidence interval [CI] 0.34-0.76).

CONCLUSION

Although some previous studies suggested that aspirin may potentially reduce the risk of subarachnoid hemorrhage, our meta-analysis found an association between the reduction of risk of aneurysmal subarachnoid hemorrhage.

Lifelong Aspirin for All in the Secondary Prevention of Chronic Coronary Syndrome: Still Sacrosanct or Is Reappraisal Warranted?

Four decades have passed since the first trial suggesting the efficacy of aspirin in the secondary prevention of myocardial infarction. Further trials, collectively summarized by the Antithrombotic Trialists' Collaboration, solidified the historical role of aspirin in secondary prevention. Although the benefit of aspirin in the immediate phase after a myocardial infarction remains incontrovertible, a number of emerging lines of evidence, discussed in this narrative review, raise some uncertainty as to the primacy of aspirin for the lifelong management of all patients with chronic coronary syndrome (CCS). For example, data challenging the previously unquestioned role of aspirin in CCS have come from recent trials where aspirin was discontinued in specific clinical scenarios, including early discontinuation of the aspirin component of dual antiplatelet therapy after percutaneous coronary intervention and the withholding of aspirin among patients with both CCS and atrial fibrillation who require anticoagulation. Recent primary prevention trials have also failed to consistently demonstrate net benefit for aspirin in patients treated to optimal contemporary cardiovascular risk factor targets, indicating that the efficacy of aspirin for secondary prevention of CCS may similarly have changed with the addition of more modern secondary prevention therapies. The totality of recent evidence supports further study of the universal need for lifelong aspirin in secondary prevention for all adults with CCS, particularly in stable older patients who are at highest risk for aspirin-induced bleeding.

Novel Perspective for Antithrombotic Therapy in TAVI

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While surgical aortic valve replacement (SAVR) was for years the only available treatment for symptomatic aortic stenosis, the introduction of transcatheter aortic valve implantation (TAVI) in 2002 and the improvement of its technical aspects in the following years, has holistically changed the synchronous therapeutic approach of aortic valve stenosis. Recent evidence has expanded the indication of TAVI from high to lower surgical risk populations with symptomatic aortic stenosis. The administration of antithrombotic therapy periprocedurally and its maintenance after a successful TAVI is crucial for the prevention of complications and affects postprocedural survival. Randomized controlled trials investigating the appropriate combination and the duration of antithrombotic treatment after TAVI are for the moment scarce. This review article sheds light on the underlying pathogenetic mechanisms contributing in periprocedural TAVI thrombotic complications and discuss the efficacy of current antithrombotic policies as evaluated in randomized trials.

Profiling the eicosanoid networks that underlie the anti- and pro-thrombotic effects of aspirin

Aspirin prevents thrombosis by inhibiting platelet cyclooxygenase (COX)-1 activity and the production of thromboxane (Tx)A₂, a pro-thrombotic eicosanoid. However, the non-platelet actions of aspirin limit its antithrombotic effects. Here, we used platelet-COX-1-ko mice to define the platelet and non-platelet eicosanoids affected by aspirin. Mass-spectrometry analysis demonstrated blood from platelet-COX-1-ko and global-COX-1-ko mice produced similar eicosanoid profiles in vitro: for example, formation of TxA₂, prostaglandin (PG) F_2α, 11-hydroxyeicosatraenoic acid (HETE), and 15-HETE was absent in both platelet- and global-COX-1-ko mice. Conversely, in vivo, platelet-COX-1-ko mice had a distinctly different profile from global-COX-1-ko or aspirin-treated control mice, notably significantly higher levels of PGI₂ metabolite. Ingenuity Pathway Analysis (IPA) predicted that platelet-COX-1-ko mice would be protected from thrombosis, forming less pro-thrombotic TxA₂ and PGE₂. Conversely, aspirin or lack of systemic COX-1 activity decreased the synthesis of anti-aggregatory PGI₂ and PGD₂ at non-platelet sites leading to predicted thrombosis increase. In vitro and in vivo thrombosis studies proved these predictions. Overall, we have established the eicosanoid profiles linked to inhibition of COX-1 in platelets and in the remainder of the cardiovascular system and linked them to anti- and pro-thrombotic effects of aspirin. These results explain why increasing aspirin dosage or aspirin addition to other drugs may lessen antithrombotic protection.

Who needs acetylsalicylic acid? Some order after many studies

The role of acetylsalicylic acid (ASA) in cardiovascular prevention is essentially consequence of its ability to inhibit platelet aggregation, thus reducing the impact of atherosclerotic disease. The preventive power of this drug is clear when used in patients with previous cardiovascular event (myocardial infarction, stroke, etc.), but the data are less dependable when considering patients who did not experienced a cardiovascular event or in the diabetic population, in whom recent studies reported neutral results in term of efficacy, in face of an increase in the risk of bleeding. Furthermore, the interpretation of the efficacy results of ASA should be reconsidered in light of the increasing clinical complexity, not addressed in the clinical studies on which current evidences are based. Accordingly the rationale for ASA use in cardiovascular prevention is ever more of current interest, and requires a particular attention, considering the crucial role of antithrombotic therapy in the foreseeable future. What could be learned on the use of ASA in cardiovascular prevention after a century since its chemical synthesis? In secondary prevention, supporting evidences have now a couple of decades of history, and the use of the drug appears to be firmly established: in this setting, the benefits clearly surpass the risks. On the other hand, in primary prevention, where age and diabetes are among the main risk factors, the risk/benefit ratio for prophylactic therapy with ASA does not support its widespread use. Deciding when this treatment should be implemented should require a case-by-case evaluation, considering, first, the correction of each risk factor, whose control has led to a reduction of global cardiovascular mortality. The other fundamental aspect is the compliance to the treatment, particularly in patients subjected to multiple drugs regimens, in whom the physician should take into account the specific needs of the patient, as not to provide a mere prescription service.

Monotherapy with a P2Y12 inhibitor or aspirin for secondary prevention in patients with established atherosclerosis: a systematic review and meta-analysis

BACKGROUND

Antiplatelet therapy is recommended among patients with established atherosclerosis. We compared monotherapy with a P2Y₁₂ inhibitor versus aspirin for secondary prevention.

METHODS

In this systematic review and meta-analysis, all randomised trials comparing P2Y₁₂ inhibitor with aspirin monotherapy for secondary prevention in patients with cerebrovascular, coronary, or peripheral artery disease were evaluated for inclusion. On Dec 18, 2019, we searched PubMed, Embase, BioMedCentral, Google Scholar, and the Cochrane Central Register of Controlled Trials. Additionally, we reviewed references from identified articles and searched abstracts from 2017 to 2019 presented at relevant scientific meetings. Data about year of publication, inclusion and exclusion criteria, sample size, baseline patients' features including the baseline condition determining study inclusion (ie, cerebrovascular, coronary, or peripheral artery disease), P2Y₁₂ inhibitor type and dosage, aspirin dosage, endpoint definitions, effect estimates, follow-up duration, and percentage of patients lost to follow-up were collected. Odds ratios (ORs) and 95% CIs were used as metric of choice for treatment effects with random-effects models. Co-primary endpoints were myocardial infarction and stroke. Key secondary endpoints were all-cause death and vascular death. Heterogeneity was assessed with the I² index. This study is registered with PROSPERO (CRD42018115037).

FINDINGS

A total of nine randomised trials were identified and included in this study, and 42 108 patients randomly allocated to a P2Y₁₂ inhibitor (n=21 043) or aspirin (n=21 065) were included in our analyses. Patients who received a P2Y₁₂ inhibitor had a borderline reduction for the risk of myocardial infarction compared with those who received aspirin (OR 0·81 [95% CI 0·66-0·99]; I²=10·9%). Risks of stroke (OR 0·93 [0·82-1·06]; I²=34·5%), all-cause death (OR 0·98 [0·89-1·08]; I²=0%), and vascular death (OR 0·97 [0·86-1·09]; I²=0%) did not differ between patients who received a P2Y₁₂ inhibitor and those who received aspirin. Similarly, the risk of major bleeding (OR 0·90 [0·74-1·10]; I²=3·9%) did not differ between patients who received a P2Y₁₂ inhibitor and those who received aspirin. The number needed to treat to prevent one myocardial infarction with P2Y₁₂ inhibitor monotherapy was 244 patients. Findings were consistent regardless of the type of P2Y₁₂ inhibitor used.

INTERPRETATION

Compared with aspirin monotherapy, P2Y₁₂ inhibitor monotherapy is associated with a risk reduction for myocardial infarction and a comparable risk of stroke in the setting of secondary prevention. The benefit of P2Y₁₂ inhibitor monotherapy is of debatable clinical relevance, in view of the high number needed to treat to prevent a myocardial infarction and the absence of any effect on all-cause and vascular mortality.

FUNDING

Italian Ministry of Education.

Indications and Evidence for Dual Antiplatelet Therapy After Acute Ischemic Stroke

The antiplatelet landscape for the secondary prevention of ischemic stroke has changed significantly over the past decade. Poststroke dual antiplatelet regimens are becoming increasingly routine as supported by recent literature and guideline recommendations. Dual antiplatelet therapy after stroke generally consists of aspirin and clopidogrel and is considered in the short term after stroke in select populations including those with mild stroke or transient ischemic attack and in patients with severe intracranial atherosclerosis. When initiating dual antiplatelet therapy, factors that may increase a patient's risk of bleeding must be weighed against the patient's risk of future ischemic events. This review focuses on antiplatelet medications available in the United States with the aim to provide a summary of the available literature on poststroke dual antiplatelet therapy, pharmacological nuances of the agents, and reversal of antiplatelets in the setting of intracerebral hemorrhage.

Platelet count, aspirin use, and characteristics of host inflammatory responses in colorectal cancer

Background

Platelets not only contribute to hemostasis but also to the regulation of inflammatory reactions and cancer pathogenesis. We hypothesized that blood platelet count would be associated with systemic inflammation, the densities of tumor infiltrating immune cells, and survival in colorectal cancer (CRC), and these relationships could be altered by aspirin use.

Methods

We measured blood platelet count in a cohort of 356 CRC patients and analyzed its relationships with tumor and patient characteristics including aspirin use, markers of systemic inflammation (modified Glasgow Prognostic Score, mGPS; serum levels of CRP, albumin, and 13 cytokines), blood hemoglobin levels, five types of tumor infiltrating immune cells (CD3, CD8, FoxP3, Neutrophil elastase, mast cell tryptase), and survival.

Results

Platelet count inversely correlated with blood hemoglobin levels (p < 0.001) and positively correlated with serum levels of CRP and multiple cytokines including IL-1RA, IL-4, IL-6, IL-7, IL-8, IL-12, IFNγ, and PDGF-BB (p < 0.001 for all), while aspirin use was not associated with the levels of systemic inflammatory markers. High platelet count was also associated with high mGPS (p < 0.001) but did not show statistically significant multivariable adjusted associations with the densities of tumor infiltrating immune cells. Higher platelet counts were observed in higher tumor stage (p < 0.001), but platelet count or aspirin use were not associated with patient survival.

Conclusions

High platelet count is associated with systemic inflammation in CRC. This study could not demonstrate statistically significant associations between platelet count, aspirin use, and the densities of tumor infiltrating immune cells.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1950-z) contains supplementary material, which is available to authorized users.

Rationale and design of a prospective substudy of clinical endpoint adjudication processes within an investigator-reported randomised controlled trial in patients with coronary artery disease: the GLOBAL LEADERS Adjudication Sub-StudY (GLASSY)

INTRODUCTION

The GLOBAL LEADERS is an open-label, pragmatic and superiority randomised controlled trial designed to challenge the current treatment paradigm of dual antiplatelet therapy (DAPT) for 12 months followed by aspirin monotherapy among patients undergoing percutaneous coronary intervention. By design, all study endpoints are investigator reported (IR) and not subject to formal adjudication by an independent Clinical Event Committee (CEC), which may introduce detection, reporting or ascertainment bias.

METHODS AND ANALYSIS

We designed the GLOBAL LEADERS Adjudication Sub-StudY (GLASSY) to prospectively implement, in a large sample of patients enrolled within the GLOBAL LEADERS trial (7585 of 15 991, 47.5%), an independent adjudication process of reported and unreported potential endpoints, using standardised CEC procedures, in order to assess whether 23-month ticagrelor monotherapy (90 mg twice daily) after 1-month DAPT is non-inferior to a standard regimen of DAPT for 12 months followed by aspirin monotherapy for the primary efficacy endpoint of death, non-fatal myocardial infarction, non-fatal stroke or urgent target vessel revascularisation and superior for the primary safety endpoint of type 3 or 5 bleeding according to the Bleeding Academic Research Consortium criteria.This study will comprehensively assess the comparative safety and efficacy of the two tested antithrombotic strategies on CEC-adjudicated ischaemic and bleeding endpoints and will provide insights into the role of a standardised CEC adjudication process on the interpretation of study findings by quantifying the level of concordance between IR-reported and CEC-adjudicated events.

ETHICS AND DISSEMINATION

GLASSY has been approved by local ethics committee of all study sites and/or by the central ethics committee for the country depending on country-specific regulations. In all cases, they deemed that it was not necessary to obtain further informed consent from individual subjects.

TRIAL REGISTRATION NUMBER

NCT01813435.

Thromboembolic and Bleeding Complications in Transcatheter Aortic Valve Implantation: Insights on Mechanisms, Prophylaxis and Therapy

Transcatheter aortic valve implantation (TAVI) has emerged as an important alternative to surgical aortic valve repair (SAVR) for patients with severe aortic stenosis. This rapidly advancing field has produced new-generation devices being delivered with small delivery sheaths, embolic protection devices and improved retrieval features. Despite efforts to reduce the rate of thrombotic complications associated with TAVI, valve thrombosis and cerebral ischaemic events post-TAVI continue to be a significant issue. However, the antithrombotic treatments utilised to prevent these dreaded complications are based on weak evidence and are associated with high rates of bleeding, which in itself is associated with adverse clinical outcomes. Recently, experimental data has shed light on the unique mechanisms, particularly the complex haemodynamic changes at sites of TAVI, that underpin the development of post-TAVI thrombosis. These new insights regarding the drivers of TAVI-associated thrombosis, coupled with the ongoing development of novel antithrombotics which do not cause bleeding, hold the potential to deliver newer, safer therapeutic paradigms to prevent post-TAVI thrombotic and bleeding complications. This review highlights the major challenge of post-TAVI thrombosis and bleeding, and the significant issues surrounding current antithrombotic approaches. Moreover, a detailed discussion regarding the mechanisms of post-TAVI thrombosis is provided, in addition to an appraisal of current antithrombotic guidelines, past and ongoing clinical trials, and how novel therapeutics offer the hope of optimizing antithrombotic strategies and ultimately improving patient outcomes.

Using Ticagrelor to Prevent Recurrent Type 1 and Type 2 Myocardial Infarctions: Boon or Bane?

See Editorial by Bonaca et al.

Dual Antiplatelet Therapy Duration: Reconciling the Inconsistencies

Dual antiplatelet therapy (DAPT) prevents recurrent ischemic events after an acute coronary syndrome (ACS) as well as stent thrombosis (ST) in patients with prior stent implantation. Nevertheless, these benefits are counterbalanced by a significant bleeding hazard, which is directly related to the treatment duration. Although DAPT has been extensively studied in numerous clinical trials, optimal treatment duration is still debated, mostly because of apparent inconsistencies among studies. Shortened treatment duration of 6 or 3 months was shown to mitigate bleeding risk compared with consensus-grounded 12-month standard duration, without any apparent excess of ischemic events. However, recent trials showed that a >12-month course of treatment reduces ischemic events but increases bleeding compared with 12 months. The inconsistent benefit of a longer DAPT course compared with shorter treatment durations is puzzling, and requires a careful appraisal of between-studies differences. We sought to summarize the existing evidence aiming at reconciling apparent inconsistencies among these studies, as well as thoroughly discuss the possible increased risk of fatal events associated with long-term DAPT. Benefits and risks of prolonging or shortening DAPT duration will be discussed, with a focus on treatment individualization. Finally, we will provide an outlook for possible future directions in the field.