Age and outcomes following guided de-escalation of antiplatelet treatment in acute coronary syndrome patients undergoing percutaneous coronary intervention: results from the randomized TROPICAL-ACS trial

De-escalation or abbreviation of dual antiplatelet therapy in acute coronary syndromes and percutaneous coronary intervention: a Consensus Statement from an international expert panel on coronary thrombosis

Conventional dual antiplatelet therapy (DAPT) for patients with acute coronary syndromes undergoing percutaneous coronary intervention comprises aspirin with a potent P2Y purinoceptor 12 (P2Y12) inhibitor (prasugrel or ticagrelor) for 12 months. Although this approach reduces ischaemic risk, patients are exposed to a substantial risk of bleeding. Strategies to reduce bleeding include de-escalation of DAPT intensity (downgrading from potent P2Y12 inhibitor at conventional doses to either clopidogrel or reduced-dose prasugrel) or abbreviation of DAPT duration. Either strategy requires assessment of the ischaemic and bleeding risks of each individual. De-escalation of DAPT intensity can reduce bleeding without increasing ischaemic events and can be guided by platelet function testing or genotyping. Abbreviation of DAPT duration after 1-6 months, followed by monotherapy with aspirin or a P2Y12 inhibitor, reduces bleeding without an increase in ischaemic events in patients at high bleeding risk, particularly those without high ischaemic risk. However, these two strategies have not yet been compared in a head-to-head clinical trial. In this Consensus Statement, we summarize the evidence base for these treatment approaches, provide guidance on the assessment of ischaemic and bleeding risks, and provide consensus statements from an international panel of experts to help clinicians to optimize these DAPT approaches for individual patients to improve outcomes.

Net clinical benefit of dual antiplatelet therapy in elderly patients with acute coronary syndrome: A systematic review and meta-analysis

BACKGROUND

Contemporary dual antiplatelet therapy (DAPT) strategies, such as short-term DAPT or de-escalation of DAPT, have emerged as attractive strategies to treat patients with acute coronary syndrome (ACS). However, it remains uncertain whether they are suitable for elderly patients.

METHODS

PubMed, Embase, and Cochrane CENTRAL databases were searched in September 2022. Randomized controlled trials (RCTs) investigating DAPT strategies, including standard (12 months), short-term, uniform de-escalation, and guided-selection strategies for elderly patients with ACS (age ≥ 65 years) were identified, and a network meta-analysis was conducted. The primary endpoint was the net clinical benefit outcome, a composite of major adverse cardiovascular events (MACEs: cardiovascular death, myocardial infarction, or stroke) and clinically relevant bleeding (equivalent to bleeding of at least type 2 according to the Bleeding Academic Research Consortium). The secondary outcomes were MACE and major bleeding.

RESULTS

Sixteen RCTs with a combined total of 47,911 patients were included. The uniform de-escalation strategy was associated with an improved net clinical benefit compared with DAPT using potent P2Y12 inhibitors. The short-term DAPT strategy was associated with reduced risks of the primary outcome and major bleeding compared with DAPT using potent P2Y12 inhibitors, however, it was ranked as the least effective strategy for MACE compared with other DAPT strategies.

CONCLUSIONS

Uniform de-escalation and short-term DAPT strategies may be advantageous for elderly patients, but need to be tailored based on individual bleeding and ischemic risks. Further RCTs of contemporary DAPT strategies specifically designed for elderly patients are warranted to confirm the findings of the present study.

Acute, periprocedural and longterm antithrombotic therapy in older adults: 2022 Update by the ESC Working Group on Thrombosis

The first international guidance on antithrombotic therapy in the elderly came from the European Society of Cardiology Working Group on Thrombosis in 2015. This same group has updated its previous report on antiplatelet and anticoagulant drugs for older patients with acute or chronic coronary syndromes, atrial fibrillation, or undergoing surgery or procedures typical of the elderly (transcatheter aortic valve implantation and left atrial appendage closure). The aim is to provide a succinct but comprehensive tool for readers to understand the bases of antithrombotic therapy in older patients, despite the complexities of comorbidities, comedications and uncertain ischaemic- vs. bleeding-risk balance. Fourteen updated consensus statements integrate recent trial data and other evidence, with a focus on high bleeding risk. Guideline recommendations, when present, are highlighted, as well as gaps in evidence. Key consensus points include efforts to improve medical adherence through deprescribing and polypill use; adoption of universal risk definitions for bleeding, myocardial infarction, stroke and cause-specific death; multiple bleeding-avoidance strategies, ranging from gastroprotection with aspirin use to selection of antithrombotic-drug composition, dosing and duration tailored to multiple variables (setting, history, overall risk, age, weight, renal function, comedications, procedures) that need special consideration when managing older adults.

De-escalation strategies of dual antiplatelet therapy in patients undergoing percutaneous coronary intervention for acute coronary syndrome

Antiplatelet therapy is important for reducing systemic and local thrombotic events in patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Antiplatelet treatment regimens, along with dual antiplatelet therapy consisting of aspirin and a P2Y12 inhibitor for patients receiving PCI, have frequently changed over the years. With improvements in the understanding of the prognostic relevance of bleeding events in patients with PCI, as well as the safety and efficacy of drug-eluting stents, several randomized controlled trials (RCTs) have been conducted on antiplatelet treatment strategies associated with a more favorable balance between ischemic and bleeding risks. Several key RCTs for appropriate antiplatelet therapy in patients receiving PCI for ACS have been reported, and practical guidelines have been updated. This manuscript presents the results of major RCTs on de-escalation strategies of dual antiplatelet treatment in patients receiving PCI for ACS.

Age-Dependent Effect of Ticagrelor Monotherapy Versus Ticagrelor With Aspirin on Major Bleeding and Cardiovascular Events: A Post Hoc Analysis of the TICO Randomized Trial

Background

We aimed to evaluate the age‐dependent effect of ticagrelor monotherapy after 3‐month dual‐antiplatelet therapy (DAPT) versus ticagrelor‐based 12‐month DAPT on major bleeding and cardiovascular events in patients with acute coronary syndrome.

Methods and Results

From the TICO trial (Ticagrelor Monotherapy After 3 Months in the Patients Treated With New Generation Sirolimus‐eluting Stent for Acute Coronary Syndrome), which randomized 3056 patients (median age, 61 years) to the ticagrelor monotherapy after 3‐month DAPT group or ticagrelor‐based 12‐month DAPT group, this post hoc analysis evaluated the age‐dependent effect of the treatment strategies on the primary end point (a composite of major bleeding, death, myocardial infarction, stent thrombosis, stroke, or target‐vessel revascularization) using the subpopulation treatment effect pattern plot. The cutoff age for distinguishing patients with greater benefit from this strategy was also determined. The risk reduction effect of ticagrelor monotherapy after 3‐month DAPT versus ticagrelor‐based 12‐month DAPT on the primary end point gradually increased with age and was more marked from the subpopulation of age 64 years with the change point. With this cutoff value of 64 years, the occurrence of the primary end point was significantly lower in the ticagrelor monotherapy after 3‐month DAPT group than in the ticagrelor‐based 12‐month DAPT group (4.4% versus 9.0%; P=0.002) in patients aged ≥64 years (n=1278), but it was not different in those aged <64 years (n=1778) with a significant interaction (P‐interaction=0.036).

Conclusions

The age‐dependent increase in the benefit of ticagrelor monotherapy after 3‐month DAPT versus ticagrelor‐based 12‐month DAPT was observed in the patients with acute coronary syndrome. In elderly patients with acute coronary syndrome, ticagrelor monotherapy after short‐term DAPT might be more optimal than ticagrelor‐based 12‐month DAPT.

Bleeding in the Elderly: Risk Factors and Impact on Clinical Outcomes After an Acute Coronary Syndrome, a Sub-study of the Randomized ANTARCTIC Trial

BACKGROUND

Elderly patients are at high-risk of bleeding, but are under-represented in clinical trials.

OBJECTIVES

The aims were to determine the incidence and the predictive factors of bleeding and to assess the impact of bleeding on further ischemic outcomes in elderly patients after acute coronary syndrome (ACS) treated with percutaneous coronary intervention.

METHODS

From the 877 patients aged ≥ 75 years included in the ANTARCTIC randomized trial, data on Bleeding Academic Research Consortium (BARC) bleeding complications and major adverse cardiovascular events (MACE), defined as the composite of cardiovascular death, myocardial infarction, and stroke, were collected over 1 year.

RESULTS

Clinically relevant bleeding events (BARC types 2, 3, or 5) were observed in 20.6% of patients (n = 181) at 1 year, of which, one third occurred in the first month. Anemia (adjusted hazard ratio [adj.HR] 3.98, 95% confidence interval [CI] 1.41-11.22; p = 0.009), severe chronic renal failure (adj.HR 1.83, 95% CI 1.12-2.98; p = 0.015), and femoral access (adj.HR 2.54, 95% CI 1.71-3.77; p < 0.001) were independently associated with clinically relevant bleeding events, while age > 85 years (adj.HR 2.22, 95% CI 1.14-4.30; p = 0.018) was independently associated with major bleeding events (BARC types 3 or 5). Patients with a clinically relevant bleeding event had a higher rate of MACE at 1 year (adj.HR 2.04, 95% CI 1.24-3.38; p = 0.005), with a particularly strong effect on stroke (adj.HR 5.55, 95% CI 2.04-15.06; p < 0.001).

CONCLUSIONS

Clinically relevant bleeding events were observed in one out of five elderly patients undergoing stenting for an ACS and were strongly associated with further stroke occurrence. Rather than the antiplatelet therapy, comorbidities and an age > 85 years predicted bleeding outcomes in this elderly population.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT01538446. https://www.clinicaltrials.gov .

Safety considerations with the use of platelet inhibitors for elderly patients with non-ST- elevation acute coronary syndrome

Introduction: Dual antiplatelet therapy (DAPT) is standard treatment for patients with acute coronary syndrome (ACS). This includes lifelong aspirin combined with a P2Y₁₂ inhibitor for 1 year. The indication for one of the P2Y₁₂ inhibitors (clopidogrel, prasugrel, ticagrelor) is dependent on the treatment strategy; whether patients undergo coronary angiography or are treated medically only. Tailoring antiplatelet therapy to the risk profile of the individual patient is of specific importance to the older patient.Areas covered: In this review, we discuss dual antiplatelet therapy in elderly patients with ACS. We present the options to tailor antiplatelet therapy based on platelet function testing, CYP2C19 genotyping and patients' thrombotic and bleeding risk. Finally, we discuss alternatives for dual antiplatelet therapy.Expert opinion: DAPT in elderly patients with ACS should consist of aspirin with clopidogrel or ticagrelor. Weighing patients' thrombotic and bleeding risk, based on clinical judgment or with use of specific risk scores, is probably the most convenient method to individualize antiplatelet therapy; however, CYP2C19 genotyping can also be used. In elderly patients with an increased bleeding risk, clopidogrel is a safe and effective alternative to ticagrelor. An alternative to 12 months DAPT could be ticagrelor monotherapy after a short period of DAPT.

The Role of Genetic Polymorphism and Other Factors on Clopidogrel Resistance (CR) in an Asian Population with Coronary Heart Disease (CHD)

Clopidogrel is a widely-used antiplatelet drug. It is important for the treatment and prevention of coronary heart disease. Clopidogrel can effectively reduce platelet activity and therefore reduce stent thrombosis. However, some patients still have ischemic events despite taking the clopidogrel due to the alteration in clopidogrel metabolism attributable to various genetic and non-genetic factors. This review aims to summarise the mechanisms and causes of clopidogrel resistance (CR) and potential strategies to overcome it. This review summarised the possible effects of genetic polymorphism on CR among the Asian population, especially CYP2C19 *2 / *3 / *17, where the prevalence rate among Asians was 23.00%, 4.61%, 15.18%, respectively. The review also studied the effects of other factors and appropriate strategies used to overcome CR. Generally, CR among the Asian population was estimated at 17.2-81.6%. Therefore, our overview provides valuable insight into the causes of RC. In conclusion, understanding the prevalence of drug metabolism-related genetic polymorphism, especially CYP2C19 alleles, will enhance clinical understanding of racial differences in drug reactions, contributing to the development of personalised medicine in Asia.

Antithrombotic Management of Elderly Patients With Coronary Artery Disease

Antithrombotic therapy represents the mainstay of treatment in patients with coronary artery disease (CAD), including elderly patients who are at increased risk for ischemic recurrences. However, the elderly population is also more vulnerable to bleeding complications. Numerous mechanisms, including abnormalities in the vasculature, thrombogenicity, comorbidities, and altered drug response, contribute to both increased thrombotic and bleeding risk. Age-related organ changes and drug-drug interactions secondary to polypharmacy lead to distinct pharmacokinetic and pharmacodynamic profiles of antithrombotic drugs. Overall these factors contribute to the risk-benefit profiles of antithrombotic therapies in elderly subjects and underscore the need for treatment regimens that can reduce bleeding while preserving efficacy. Given that the prevalence of CAD, as well as concomitant diseases with thromboembolic potential, such as atrial fibrillation, increases with age and that the elderly population is in continuous growth, understanding the safety and efficacy of different antithrombotic regimens is pivotal for patient-centered care. In the present overview the authors appraise the available data on the use of antithrombotic therapy in older patients with CAD to assist with the management of this high-risk population and define knowledge gaps that can set the basis for future research.

CHADS2 and CHA2DS2-VASc scores as predictors of platelet reactivity in acute coronary syndrome

BACKGROUND

Platelet function testing (PFT) in patients treated with P2Y₁₂ inhibitors has been widely evaluated for the prediction of stent thrombosis, myocardial infarction, and bleeding events following percutaneous coronary intervention (PCI) in acute coronary syndrome (ACS). Thus, PFT-guided treatment could positively affect patient outcomes. Data regarding clinical parameters for predicting platelet reactivity in ACS patients are limited. Therefore, our study aims to evaluate CHADS2 and CHA2DS2-VASc scores as predictors for platelet reactivity in ACS patients.

METHODS

Two hundred and ninety-one consecutive patients who underwent PCI and were treated with aspirin and clopidogrel due to ACS were tested for their CHADS2, CHA2DS2-VASc scores and platelet reactivity using adenosine diphosphate (ADP)-induced aggregation (conventional aggregometry). Patients were classified into groups according to their CHADS2 and CHA2DS2-VASc scores. Low-risk group (0-1 score) for CHADS2 and CHA2DS2-VASc scores and high-risk group (2-6, 2-9) for CHADS2 and CHA2DS2-VASc scores, respectively. Furthermore, platelet reactivity in each group were compared (low CHADS2 group vs high CHADS2 group, and low CHA2DS2-VASc vs high CHA2DS2-VASc). Platelet reactivity was defined as low platelet reactivity (<19 U), optimal platelet reactivity [(OPR); 19-46 U], and high on-treatment platelet reactivity [(HPR); >46 U]. Thereafter receiver operating characteristic curve analysis was conducted to verify whether CHADS2 and CHA2DS2-VASc scores could predict platelet reactivity.

RESULTS

Low CHADS2 and CHA2DS2-VASc scores were significantly correlated with lower mean platelet ADP-induced aggregation as compared with high CHADS2 and CHA2DS2-VASc scores [45.5 U (± 16) vs. 54.8 U (±15) and 44.2 U (±16) vs. 51.0 U (±17), respectively, p = 0.01 for both].

CONCLUSION

In ACS patients treated with clopidogrel following PCI, high CHADS2 and CHA2DS2-VASc scores correlated with HPR and lower scores correlated with OPR. Further studies are needed to evaluate our findings' clinical implications.

De-Escalation of Antiplatelet Treatment in Patients with Myocardial Infarction Who Underwent Percutaneous Coronary Intervention: A Review of the Current Literature

In acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI), treatment with the P2Y₁₂ inhibitors ticagrelor or prasugrel is recommended over clopidogrel due to a better efficacy, albeit having more bleeding complication. These higher bleeding rates have provoked trials investigating de-escalation from ticagrelor or prasugrel to clopidogrel in the hope of reducing bleeding without increasing thrombotic event rates. In this review, we sought to present an overview of the major trials investigating several different options for de-escalation; unguided, platelet function testing- and genotype-guided. Based on these results, and on other established literature sources, such as guidelines and expert consensus papers, we provide an overview to help decide when and how to de-escalate antiplatelet therapy in ACS patients undergoing PCI.

Towards Personalized Antithrombotic Treatments: Focus on P2Y12 Inhibitors and Direct Oral Anticoagulants

Oral anticoagulants and antiplatelet drugs are commonly prescribed to lower the risk of cardiovascular diseases, such as venous and arterial thrombosis, which represent the leading causes of mortality worldwide. A significant percentage of patients taking antithrombotics will nevertheless experience bleeding or recurrent ischemic events, and this represents a major public health issue. Cardiovascular medicine is now questioning the one-size-fits-all policy, and more personalized approaches are increasingly being considered. However, the available tools are currently limited and they are only moderately able to predict clinical events or have a significant impact on clinical outcomes. Predicting concentrations of antithrombotics in blood could be an effective means of personalization as they have been associated with bleeding and recurrent ischemia. Target concentration interventions could take advantage of physiologically based pharmacokinetic (PBPK) and population-based pharmacokinetic (POPPK) models, which are increasingly used in clinical settings and have attracted the interest of governmental regulatory agencies, to propose dosages adapted to specific population characteristics. These models have the benefit of combining parameters from different sources, such as experimental in vitro data and patients' demographic, genetic, and physiological in vivo data, to characterize the dose-concentration relationships of compounds of interest. As such, they can be used to predict individual drug exposure. In the near future, these models could therefore be a valuable means of predicting personalized antithrombotic blood concentrations and, hopefully, of preventing clinical non-response or bleeding in a given patient. Existing approaches for personalization of antithrombotic prescriptions will be reviewed using practical examples for P2Y₁₂ inhibitors and direct oral anticoagulants. The review will additionally focus on the existing PBPK and POPPK models for these two categories of drugs. Lastly, we address potential scenarios for their implementation in clinics, along with the main limitations and challenges.

Ticagrelor monotherapy beyond one month after PCI in ACS or stable CAD in elderly patients: a pre-specified analysis of the GLOBAL LEADERS trial

AIMS

Antiplatelet treatment in the elderly post percutaneous coronary interventions (PCI) remains a complex issue. Here we report the results of the pre-specified subgroup analysis of the GLOBAL LEADERS trial evaluating the long-term safety and cardiovascular efficacy of ticagrelor monotherapy among patients categorised according to the pre-specified cut-off value of 75 years of age.

METHODS AND RESULTS

This was a pre-specified analysis of the randomised GLOBAL LEADERS trial (n=15,991), comparing 23-month ticagrelor monotherapy (after one month of DAPT) with the reference treatment (12-month DAPT followed by 12 months of aspirin). Among elderly patients (>75 years; n=2,565), the primary endpoint (two-year all-cause mortality or new Q-wave core lab-adjudicated myocardial infarction [MI]) occurred in 7.2% and 9.4% of patients in the ticagrelor monotherapy and the reference group, respectively (hazard ratio [HR] 0.75, 95% confidence interval [CI]: 0.58-0.99, p=0.041; pint=0.23); BARC-defined bleeding type 3/5 occurred in 5.2% and 4.1%, respectively (HR 1.29, 95% CI: 0.89-1.86; p=0.180; pint=0.06). The elderly with stable CAD had a higher rate of BARC 3/5 type bleeding (HR 2.05, 95% CI: 1.18-3.55) with ticagrelor monotherapy versus the reference treatment (pint=0.02). Elderly patients had a lower rate of definite or probable stent thrombosis (ST) with ticagrelor monotherapy (0.4% vs 1.4%, p=0.015, pint=0.01), compared with the reference group.

CONCLUSIONS

In this pre-specified, exploratory analysis of the overall neutral trial, there was no differential treatment effect of ticagrelor monotherapy (after one-month dual therapy with aspirin) found in elderly patients undergoing PCI with respect to the rate of the primary endpoint of all-cause death or new Q-wave MI. The lower rate of ST in the elderly with ticagrelor monotherapy is hypothesis-generating. ClinicalTrials.gov identifier: NCT01813435.

Comparison of Age (<75 Years Vs ≥75 Years) and Platelet Reactivity to the Risk of Thrombotic and Bleeding Events After Successful Percutaneous Coronary Intervention With Drug-Eluting Stents (from the ADAPT-DES Study)

Elderly patients may have increased platelet reactivity and adverse events after percutaneous coronary intervention. Whether age is an independent predictor of worse outcomes after accounting for platelet reactivity is unknown. We sought to determine the relation between age and platelet reactivity on 2-year outcomes after percutaneous coronary intervention with drug-eluting stents (DES). ADAPT-DES was a prospective observational registry comprising 8,582 DES-treated patients. Patients were categorized with an age cutoff of 75 years. On-clopidogrel platelet reactivity was evaluated with VerifyNow P2Y12 testing. Multivariable Cox proportional hazards regression models were used to describe the relation between increasing age and 2-year clinical outcomes. Patients ≥75 old were more likely to be women and had more cardiovascular risk factors and more extensive coronary artery disease than younger patients. Residual platelet reactivity on-clopidogrel increased slightly with age (adjusted r = 0.05, p <0.0001). Age ≥75 years was associated with greater all-cause mortality (adjusted HR 1.64, 95% CI 1.25 to 2.15, p <0.001), myocardial infarction (adjusted HR 1.33, 95% CI 1.01 to 1.74, p = 0.04) and clinically relevant bleeding (adjusted HR 1.33, 95% CI 1.10 to 1.61 p = 0.003). In contrast, the risk of stent thrombosis was independent of age (adjusted HR 0.83, 95% CI 0.46 to 1.52, and p = 0.55). Considered as a continuous variable, age was directly related to clinically relevant bleeding, cardiac and all-cause mortality, was inversely related to stent thrombosis, and was not related to myocardial infarction. There was no significant interaction between age and on-treatment platelet reactivity for the risk of 2-year clinical outcomes. In conclusion, increasing age had a stronger association with the risk of death and bleeding than of thrombotic events. Despite being associated with older age, higher residual platelet reactivity did not modify the adjusted relative risks of ischemic and bleeding events associated with age.

Clinical Implications of "Tailored" Antiplatelet Therapy in Patients With Chronic Total Occlusion

Background

Clopidogrel nonresponsiveness is a prognostic marker after percutaneous coronary intervention. Prasugrel and ticagrelor provide a better platelet inhibition and represent the first‐line antiplatelet treatment in acute coronary syndrome. We sought to assess the prognostic impact of high platelet reactivity (HPR) and the potential clinical benefit of a “tailored” escalated or changed antiplatelet therapy in patients with chronic total occlusion.

Methods and Results

From Florence CTO‐PCI (chronic total occlusion‐percutaneous coronary intervention) registry, platelet function assessed by light transmission aggregometry, was available for 1101 patients. HPR was defined by adenosine diphosphate test ≥70% and optimal platelet reactivity by adenosine diphosphate test <70%. The endpoint of the study was long‐term cardiac survival. Patients were stratified according to light transmission aggregometry results: optimal platelet reactivity (82%) and HPR (18%). Means for the adenosine diphosphate test were 44±16% versus 77±6%, respectively. Three‐year survival was significantly higher in the optimal platelet reactivity group compared with HPR patients (95.3±0.8% versus 86.2±2.8%; P<0.001). With the availability of new P2Y₁₂ inhibitors, a deeper platelet inhibition (46±17%) and similar survival to the optimal platelet reactivity group were achieved in patients with HPR on clopidogrel therapy after escalation. Conversely, HPR on clopidogrel therapy “not switched” was associated with cardiac mortality (hazard ratio 2.37; P=0.003) after multivariable adjustment.

Conclusions

HPR on treatment could be a modifiable prognostic marker by new antiaggregants providing a deeper platelet inhibition associated with clinical outcome improvement in complex chronic total occlusion patients. A “tailored” antiplatelet therapy, also driven by the entity of platelet inhibition, could be useful in these high risk setting patients.

Assessing platelet reactivity after drug eluting stent implantation: state of the art

Introduction: Platelets play a pivotal role in the occurrence of recurrent ischemic events in coronary artery disease patients who are treated with drug-eluting stents and are on dual antiplatelet therapy (DAPT).Areas covered: High platelet reactivity (HPR) to adenosine diphosphate during clopidogrel therapy is a strong predictor of post-stenting ischemic event occurrences. However, uniform use of potent P2Y₁₂ receptors blockers to overcome HPR is associated with elevated bleeding risk. Selective de-escalation of P2Y₁₂ receptor blocker therapy based on PFT in patients with acute coronary syndrome treated with stenting has been shown to be associated with a similar risk of ischemic event occurrence but with a reduced risk of bleeding. This review aims to discuss the role of PFT in guiding DAPT in patients treated with DES. We searched electronic databases from January 2000 to December 2019 for literatures evaluating the role of platelet function assessment after drug eluting stents.Expert opinion: Platelet function guided therapy improves patient outcomes by lessening bleeding and limiting the overuse of highly potent P2Y₁₂ inhibitors. Interest in this area of de-escalation of therapy will likely grow as the consequences of bleeding are better recognized and the cost of healthcare gains greater focus.

Smoking and outcomes following guided de-escalation of antiplatelet treatment in acute coronary syndrome patients: a substudy from the randomized TROPICAL-ACS trial

Aims

Prior analyses disclosed variations in antiplatelet drug response and clinical outcomes between smokers and non-smokers, thus the safety and efficacy of any dual antiplatelet therapy (DAPT) de-escalation strategy may differ in relation to smoking status. Hence, we assessed the impact of smoking on clinical outcomes and adenosine diphosphate-induced platelet aggregation following guided de-escalation of DAPT in invasively managed acute coronary syndrome (ACS) patients.

Methods and results

The multicentre TROPICAL-ACS trial randomized 2610 biomarker-positive ACS patients 1:1 to standard treatment with prasugrel for 12 months (control group) or a platelet function testing guided de-escalation of DAPT. Current smokers (n = 1182) showed comparable event rates between study groups [6.6% vs. 6.6%; hazard ratio (HR) 1.0, 95% confidence interval (CI) 0.64–1.56, P &gt; 0.99]. In non-smokers (n = 1428), a guided DAPT de-escalation was associated with a lower 1-year incidence of the primary endpoint [cardiovascular death, myocardial infarction, stroke, or bleeding ≥ Grade 2 according to Bleeding Academic Research Consortium (BARC) criteria] compared with control group patients (7.9% vs. 11.0%; HR 0.71, 95% CI 0.50–0.99, P = 0.048). This reduction was mainly driven by a lower rate of BARC ≥ Grade 2 bleedings (5.2% vs. 7.7%; HR 0.68, 95% CI 0.45–1.03, P = 0.066). There was no significant interaction of smoking status with treatment effects of guided DAPT de-escalation (Pint = 0.23). Adenosine diphosphate-induced platelet aggregation values were higher in current smokers [median 28 U, interquartile range (IQR: 20–40)] vs. non-smoker [median 24 U (16–25), P &lt; 0.0001] in the control group and in current smokers [median 42 U, IQR (27–68)] vs. non-smoker [median 37 U, IQR (25–55), P &lt; 0.001] in the monitoring group.

Conclusion

Guided DAPT de-escalation appears to be equally safe and effective in smokers and non-smokers. Regardless of smoking status and especially for those patients deemed unsuitable for 1 year of potent platelet inhibition this DAPT strategy might be used as an alternative antiplatelet treatment regimen.

Diabetes and outcomes following guided de-escalation of antiplatelet treatment in acute coronary syndrome patients undergoing percutaneous coronary intervention: a pre-specified analysis from the randomised TROPICAL-ACS trial

AIMS

A guided de-escalation of P2Y12 inhibitor treatment is considered an alternative treatment strategy in ACS patients undergoing PCI. However, the safety and efficacy of this strategy may differ in diabetic vs non-diabetic patients. The aim of this study was to compare the outcomes of platelet function testing (PFT)-guided de-escalation of dual antiplatelet therapy (DAPT) in ACS patients with and without diabetes mellitus.

METHODS AND RESULTS

The TROPICAL-ACS trial randomised 2,610 biomarker-positive ACS patients 1:1 to either standard treatment with prasugrel for 12 months (control group) or PFT-guided DAPT de-escalation. The association and interaction of diabetes on clinical endpoints across treatment groups and on platelet reactivity was investigated. In diabetic patients (n=527, 20.2%), the overall event rates were high and the one-year incidence of the primary endpoint (cardiovascular death, myocardial infarction, stroke or bleeding ≥grade 2) did not differ between guided de-escalation and control group patients (12.5% vs 10.8%; HR 1.17, 95% CI: 0.71-1.93, p=0.55). In non-diabetic patients (n=2,083, 79.8%), the one-year incidence of the primary endpoint was lower in the guided de-escalation vs control group (6.1% vs 8.5%; HR 0.71, 95% CI: 0.52-0.99, p=0.04, pint=0.10). Diabetic patients showed higher platelet reactivity levels in both control (=on prasugrel, p=0.01) and guided de-escalation group (=on clopidogrel, p=0.005) patients.

CONCLUSIONS

Although diabetic status did not significantly interfere with the treatment effects of guided DAPT de-escalation, our results suggest that this approach might be safe and effective in non-diabetic patients. Further investigation is definitely warranted in diabetic patients.

Guided de-escalation of DAPT in acute coronary syndrome patients undergoing percutaneous coronary intervention with BVS implantation: a post-hoc analysis from the randomized TROPICAL-ACS trial

To investigate the safety and efficacy of an early platelet function testing (PFT)-guided de-escalation of dual antiplatelet treatment (DAPT) in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) with bioresorbable vascular scaffolds (BVS). Early DAPT de-escalation is a new non-inferior alternative to 12-months DAPT in patients with biomarker positive ACS treated with stent implantation. In this post-hoc analysis of the TROPICAL-ACS trial, which randomized 2610 ACS patients to a PFT-guided DAPT de-escalation (switch from prasugrel to clopidogrel) or to control group (uniform prasugrel), we compared clinical outcomes of patients (n = 151) who received a BVS during the index PCI. The frequency of the primary endpoint (cardiovascular death, myocardial infarction, stroke or BARC ≥ 2 bleeding) was 8.8% (n = 6) in the de-escalation group vs. 12.0% (n = 10) in the control group (HR 0.72, 95% CI 0.26–1.98, p = 0.52) at 12 months. One early definite stent thrombosis (ST) occurred in the control group (day 19) and 1 possible ST (sudden cardiovascular death) in the de-escalation group (day 86), both despite prasugrel treatment and in a background of high on-treatment platelet reactivity assessed at day 14 after randomization (ADP-induced platelet aggregation values of 108 U and 59 U, respectively). A PFT-guided DAPT de-escalation strategy could potentially be a safe and effective strategy in ACS patients with BVS implantation but the level of platelet inhibition may be of particular importance. This hypothesis-generating post-hoc analysis requires verification in larger studies with upcoming BVS platforms.

Platelet reactivity and clinical outcomes in acute coronary syndrome patients treated with prasugrel and clopidogrel: a pre-specified exploratory analysis from the TROPICAL-ACS trial

Aims

The value of platelet function testing (PFT) in predicting clinical outcomes and guiding P2Y12-inhibitor treatment is uncertain. In a pre-specified sub-study of the TROPICAL-ACS trial, we assessed ischaemic and bleeding risks according to high platelet reactivity (HPR) and low platelet reactivity (LPR) to ADP in patients receiving uniform prasugrel vs. PFT-guided clopidogrel or prasugrel.

Methods and results

Acute coronary syndrome patients with PFT done 14 days after hospital discharge were included with prior randomization to uniform prasugrel for 12 months (control group, no treatment modification) vs. early de-escalation from prasugrel to clopidogrel and PFT-guided maintenance treatment (HPR: switch-back to prasugrel, non-HPR: clopidogrel). The composite ischaemic endpoint included cardiovascular death, myocardial infarction, or stroke, while key safety outcome was Bleeding Academic Research Consortium (BARC) 2–5 bleeding, from PFT until 12 months. We identified 2527 patients with PFT results available: 1266 were randomized to the guided and 1261 to the control group. Before treatment adjustment, HPR was more prevalent in the guided group (40% vs. 15%), while LPR was more common in control patients (27% vs. 11%). Compared to control patients without HPR on prasugrel (n = 1073), similar outcomes were observed in guided patients kept on clopidogrel [n = 755, hazard ratio (HR): 1.06 (0.57–1.95), P = 0.86] and also in patients with HPR on clopidogrel switched to prasugrel [n = 511, HR: 0.96 (0.47–1.96), P = 0.91]. In contrast, HPR on prasugrel was associated with a higher risk for ischaemic events in control patients [n = 188, HR: 2.16 (1.01–4.65), P = 0.049]. Low platelet reactivity was an independent predictor of bleeding [HR: 1.74 (1.18–2.56), P = 0.005], without interaction (Pint = 0.76) between study groups.

Conclusion

Based on this substudy of a randomized trial, selecting prasugrel or clopidogrel based on PFT resulted in similar ischaemic outcomes as uniform prasugrel therapy without HPR. Although infrequent, HPR on prasugrel was associated with increased risk of ischaemic events. Low platelet reactivity was a strong and independent predictor of bleeding both on prasugrel and clopidogrel.

De-Escalation of P2Y12 Receptor Inhibitor Therapy after Acute Coronary Syndromes in Patients Undergoing Percutaneous Coronary Intervention

Dual antiplatelet therapy (DAPT) - a combination of a P2Y₁₂ receptor inhibitor and aspirin - has revolutionized antithrombotic treatment. Potent P2Y₁₂ inhibitors such as prasugrel and ticagrelor exhibit a strong and more consistent platelet inhibition when compared to clopidogrel. Therefore, ticagrelor and prasugrel significantly reduce ischemic events, but at an expense of an increased bleeding risk in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). These observations have engaged intensive clinical research in alternative DAPT regimens to achieve sufficient platelet inhibition with an acceptable bleeding risk. Our review focusses on P2Y₁₂ receptor therapy de-escalation defined as a switch from a potent antiplatelet agent (ticagrelor or prasugrel) to clopidogrel. Recently, both unguided (platelet function testing independent) and guided (platelet function testing dependent) DAPT de-escalation strategies have been investigated in different clinical studies and both switching strategies could be possible options to prevent bleeding complications without increasing ischemic risk. In light of the still limited data currently available, future large-scale trials should accumulate more data on various DAPT de-escalation regimens with both ticagrelor and prasugrel in unguided and guided de-escalation approaches. In the current review we aim at summarizing and discussing the current evidence on this still emerging topic in the field of antiplatelet treatment.

LMU Munich: platelet inhibition novel aspects on platelet inhibition and function

A core research area in the Department of Cardiology at Ludwig-Maximilians-University (LMU) Munich focuses on antiplatelet therapy, its translational aspects, and its underlying mechanism with respect to platelet physiology. We are conducting a broad range of investigator-initiated clinical trials (phase II-IV) and preclinical studies on the topic of antithrombotic therapy for percutaneous coronary intervention patients, platelet activation, and reactivity as well as on novel inhibitors of platelet adhesion. Just recently, we completed the large multi-centre investigator-initiated TROPICAL-ACS trial on guided early de-escalation of antiplatelet treatment in acute coronary syndrome (ACS) patients (Sibbing et al. in Lancet 390:1747-1757, 2017; Sibbing et al. in Thromb Haemost 117:1240-1248), done at 33 sites in Europe. Furthermore, besides other ongoing clinical studies, we initiated and are currently recruiting patients for the multi-centre randomized APixaban versus PhenpRocoumon in Patients With ACS and AF: APPROACH-ACS-AF study as well as for the multi-centre phase II randomized, double-blind, placebo-controlled study of revacept in Patients With Stable Coronary Artery Disease (Revacept/CAD/02) trial.