Pharmacodynamic Effects of Switching From Ticagrelor to Clopidogrel in Patients With Coronary Artery Disease

Clopidogrel-Mediated P2Y12 Inhibition According to Renal Function in Patients With Diabetes Mellitus and CAD

This prospective ex vivo and in vitro pharmacodynamic (PD)/pharmacokinetic investigation was conducted in patients with diabetes mellitus with (n = 31) and without chronic kidney disease (n = 30). PD assessments included platelet reactivity index, maximum platelet aggregation, and P2Y12 reaction units. Ex vivo pharmacokinetic assessments included plasma levels of clopidogrel and its active metabolite. In vitro PD assessments were conducted on baseline samples incubated with escalating concentrations of clopidogrel and its active metabolite. Among patients with diabetes mellitus treated with clopidogrel, impaired renal function was associated with increased maximum platelet aggregation. This finding could be attributed partially to upregulation of the P2Y12 activity without differences in drug absorption or metabolism. (Impact of Chronic Kidney Disease on Clopidogrel Effects in Diabetes Mellitus; NCT03774394).

Impact of Close Surveillance on Dual-Antiplatelet Therapy Compliance in Myocardial Infarction Patients Post-Percutaneous Coronary Intervention

BACKGROUND

Dual-antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor is the mainstay regimen for acute coronary syndrome (ACS) patients after percutaneous coronary intervention (PCI). We aimed to investigate DAPT compliance and switching patterns in ACS patients prescribed ticagrelor and aspirin. Secondly, we evaluated the impact of a pilot strategy of close surveillance telephone calls.

METHODS

The study enrolled 150 consecutive ACS patients who underwent PCI and were prescribed DAPT (aspirin and ticagrelor). This cohort, the "close surveillance arm," then received telephone calls from a healthcare professional to inquire about DAPT for up to one year. These findings, and clinical outcomes, were then compared to a "historical arm" of ACS patients (n = 505) who received PCI and were prescribed DAPT before initiation of the program. Finally, healthcare providers were surveyed about their experience with prescribing DAPT.

RESULTS

The rate of ticagrelor cessation trended lower in the close surveillance arm (22.00 % versus 31.70 %, p = 0.0783). The most common reasons for ticagrelor cessation were adverse medication reaction (dyspnea), bleeding, and financial burden. Nevertheless, the adverse events were few and similar between the two groups during follow-up. Over 96 % of healthcare providers surveyed stated that they worry about their patients' DAPT compliance post-PCI.

CONCLUSION

Noncompliance and switching medications are still common for patients who undergo PCI for ACS. A close surveillance program identified patients at risk for medication cessation or switching and could potentially mitigate this phenomenon and improve quality of care.

Cangrelor in Patients With Coronary Artery Disease Pretreated With Ticagrelor: The Switching Antiplatelet (SWAP)-5 Study

BACKGROUND

There are no studies specifically designed to rule out a drug-drug interaction (DDI) when cangrelor is used among patients who have been pretreated with ticagrelor.

OBJECTIVES

This study sought to rule out a DDI among cangrelor-treated patients who have been pretreated with ticagrelor.

METHODS

In this prospective, randomized, double-blind, placebo-controlled, crossover, pharmacokinetic (PK) and pharmacodynamic (PD) study, patients with coronary artery disease (N = 20) were pretreated with a 180-mg ticagrelor loading dose and after 1 hour randomized to placebo or cangrelor (bolus and infusion for 2 hours). Patients crossed over after 1 to 4 weeks of washout. PK analysis included ticagrelor plasma levels and its active metabolite. PD assessments included VerifyNow P2Y₁₂ reaction units (PRU), light transmittance aggregometry, vasodilator-stimulated phosphoprotein, and Total Thrombus-Formation Analysis System. PK/PD assessments were performed at 7 time points.

RESULTS

Compared with placebo, adding cangrelor to patients pretreated with ticagrelor resulted in a significant reduction in PRU at 30 minutes and 1 hour after starting infusion. At 2 hours after stopping cangrelor/placebo infusion, PRU were low and similar in both groups (16.9 vs 12.6; mean difference: 4.3; 95% CI: -28.6 to 37.3), meeting the noninferiority primary endpoint (predefined noninferiority margin 45 PRU). Consistent findings were shown with all PD assays. PK tracked PD findings with no differences between groups in plasma levels of ticagrelor and its metabolite.

CONCLUSIONS

Compared with placebo, the use of cangrelor in patients pretreated with ticagrelor results in enhanced platelet inhibition with no differences in PK/PD profiles after discontinuation of drug infusion indicating the absence of a DDI. (PD and PK Profiles of Switching Between Cangrelor and Ticagrelor Following Ticagrelor Pre-treatment [SWAP-5]; NCT04634162).

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

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

De-escalation of antiplatelet therapy in acute coronary syndromes: Why, how and when?

The synergistic blockade of the key platelet signaling pathways of cyclooxygenase-1 blockade and P2Y12 signaling by combining aspirin plus a potent P2Y12 inhibitor (prasugrel or ticagrelor), the so called dual antiplatelet treatment (DAPT), has represented the antithrombotic regimen of choice in patients with acute coronary syndrome (ACS) for nearly a decade. Nevertheless, the use of such antiplatelet treatment regimen, while reduced the risk of thrombotic complications, it is inevitably associated with increased bleeding and this risk may outweigh the benefit of a reduction of ischemic events in specific subgroup of patients. In light of the adverse prognostic implications of a bleeding complication, there has been a great interest in the development of antiplatelet regimens aimed at reducing bleeding without any trade-off in ischemic events. The fact that the ischemic risk is highest in the early phase after an ACS while the risk of bleeding remains relatively stable over time has represented the rationale for the implementation of a more intense antithrombotic regimen early after an ACS, followed by a less intense antithrombotic regimen thereafter. This practice, known as a "de-escalation" strategy, represents one of the more promising approaches for personalization of antithrombotic therapy in ACS. In this review we discuss the rationale, appraise the evidence and provide practical recommendations on the use of a de-escalation strategy of antiplatelet therapy in patients with an ACS.

Precision medicine in interventional cardiology: implications for antiplatelet therapy in patients undergoing percutaneous coronary intervention

Precision medicine is a medical model that proposes the customization of medical treatments to the individual patient, as opposed to a one-drug-fits-all model. Such a "personalized medicine" approach has been widely adopted in several medical fields, such as cancer medicine, but the implementation of precision medicine in cardiovascular medicine has not been similarly straightforward. Because pharmacogenomics plays an important role in the safety and efficacy of cardiovascular drug therapy, there has been a great interest in the use of tools aiming at personalizing antiplatelet therapy. Moreover, antiplatelet therapy is essential for the treatment of cardiovascular patients to reduce the risk of thrombotic complications, particularly those undergoing percutaneous coronary intervention, but it is inevitably associated with increased bleeding risk. In this review, the authors discuss the rationale, summarize the evidence and discuss the current and future directions for the personalization of antiplatelet treatment regimens in patients undergoing percutaneous coronary intervention.

De-escalation of Dual Antiplatelet Therapy After Percutaneous Coronary Intervention in Patients With Acute Coronary Syndrome: An Updated Meta-analysis and Trial Sequential Analysis of 21 Studies and 38,741 Patients

ABSTRACT

Dual antiplatelet therapy (DAPT) is recommended among patients with established acute coronary syndrome. In this meta-analysis, we sought to compare the clinical outcomes between de-escalation versus unchanged DAPT based on both randomized controlled trials (RCTs) and observational studies. The primary outcomes were major adverse cardiovascular events for observational studies and net clinical events for RCTs. Four RCTs and 17 observational studies with a total of 38,741 patients were included. Net clinical events were more common with unchanged DAPT than with de-escalation in RCTs [odd ratio (OR): 1.71; 95% confidence interval (CI), 1.21-2.43; I2 = 69.4%], which was mainly due to higher risks of any bleeding (OR: 1.81; 95% CI, 1.14-2.88; I2 = 75.5%) and major bleeding (OR: 1.58; 95% CI, 1.02-2.46; I2 = 0), without significant differences in ischaemic events. However, trial sequential analysis revealed that sufficient information was obtained just for net clinical events, not for respective ischaemic or bleeding events in RCTs. In the analysis based on real-world observational studies, the risks of myocardial infarction (OR: 0.77; 95% CI, 0.61-0.98; I2 = 0) and stroke (OR: 0.42; 95% CI, 0.22-0.81; I2 = 0) were lower with the unchanged DAPT group. Therefore, de-escalation of DAPT led to a marked reduction in net clinical events compared with unchanged DAPT in RCTs, which was mainly due to reduced bleeding events. However, sufficient information for ischaemic events was not obtained. In the analysis based on real-world observational studies, myocardial infarction and stroke were more common with de-escalation, which should arise our attention.

Real-World Use and Outcomes of Oral Antiplatelets Among Patients with Acute Coronary Syndrome: A Retrospective Cohort Study

BACKGROUND

Acute coronary syndrome (ACS)-related readmission is an important hospital quality measure. Medication management therapy, especially adherence to antiplatelet agents post discharge, could play an important role in reducing readmission rates. Newer agents such as ticagrelor and prasugrel have been shown, in randomized control trials, to have superior effectiveness to cardiovascular outcomes compared to clopidogrel, but they are more expensive and have more common adverse events such as bleeding and dyspnea.

OBJECTIVE

We compared real-world readmission rates and adherence to antiplatelet agents among patients who initiated these agents post discharge.

METHODS

This was a retrospective cohortstudy of patients with an index ACS-related hospitalization between 1 July 2017 and 31 December 2018. Using integrated pharmacy and medical claims data from a large national pharmacy benefits manager for commercially insured adults aged ≥ 18 years, we compared ACS-related readmission and medication adherence (as medication possession ratio (MPR)) among the three agents. ANOVA and logistic regression, controlling for demographics such as age, gender, and Charlson Comorbidity Index, were used to estimate any association between the agents and 365-day readmission rates.

RESULTS

Of the 948 eligible patients, 86, 342, and 520 were initiated on prasugrel, ticagrelor, and clopidogrel (PTC), respectively. There were 4.7%, 5.3%, and 8.5% readmissions rates in the PTC cohorts, respectively, but these were not statistically significant in either the ANOVA or the logistic regression analyses. MPR was highest in the ticagrelor (88.1%) cohort, followed by the prasugrel (79.1%) and clopidogrel (76.4%) cohorts.

CONCLUSION

Ticagrelor cohort had the highest medication adherence. Clopidogrel cohort had the highest readmission rate but the difference with the other cohorts was statistically insignificant.

Prolonged ventricular pause associated with ticagrelor use: A case report

CASE

We report a case of a 76-year-old female who presented with non-ST elevation myocardial infarction and developed a 22-second ventricular pause with ticagrelor that did not recur after shifting to clopidogrel. Based on the Naranjo algorithm, the likelihood that our patient's prolonged ventricular pause was due to ticagrelor exposure was probable.

CONCLUSION

Ticagrelor use is associated with prolonged ventricular pauses, warranting close monitoring, particularly during the first week of therapy.

Coronary Heart Disease (CHD) in Elderly Patients: Which Drug to Choose, Ticagrelor and Clopidogrel? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: A new generation P2Y12 receptor inhibitor (ticagrelor) is recommended in current therapeutic guidelines to treat patients with coronary heart disease (CHD). However, it is unknown if ticagrelor is more effective than clopidogrel in elderly patients. Therefore, a systematic review was done to assess the effectiveness and safety of ticagrelor and clopidogrel in older patients with CHD to determine the appropriate antiplatelet treatment plan. Methodology: We performed a systematic review of randomized controlled trials (RCTs) to compare the effectiveness and safety of ticagrelor vs. clopidogrel in elderly patients with CHD. We selected eligible RCTs based on specified study criteria following a systematic search of PubMed and Scopus databases from January 2007 to May 2021. Primary efficacy outcomes assessed were major adverse cardiovascular events (MACEs), myocardial infarction (MI), stent thrombosis (ST), and all-cause death. The secondary outcome assessed was major bleeding events. We used RevMan 5.3 software to conduct a random-effects meta-analysis and estimated the pooled incidence and risk ratios (RRs) with 95% confidence intervals (CIs) for ticagrelor and clopidogrel. Results: Data from 6 RCTs comprising 21,827 elderly patients were extracted according to the eligibility criteria. There was no significant difference in the MACE outcome (incidence: 9.23% vs. 10.57%; RR = 0.95, 95% CI = 0.70–1.28, p = 0.72), MI (incidence: 5.40% vs. 6.23%; RR = 0.94, 95% CI= 0.69–1.27, p = 0.67), ST (incidence: 2.33% vs. 3.17%; RR = 0.61, 95% CI= 0.32–1.17, p = 0.13), and all-cause death (4.29% vs. 5.33%; RR = 0.86, 95% CI = 0.65–1.12, p = 0.25) for ticagrelor vs. clopidogrel, respectively. In addition, ticagrelor was not associated with a significant increase in the rate of major bleeding (incidence: 9.98% vs. 9.33%: RR = 1.37, 95% CI = 0.97–1.94, p = 0.07) vs. clopidogrel. Conclusions: This study did not find evidence that ticagrelor is significantly more effective or safer than clopidogrel in elderly patients with CHD.

Impact Of Chronic Kidney Disease On The Pharmacodynamic And Pharmacokinetic Effects Of Ticagrelor In Patients With Diabetes Mellitus And Coronary Artery Disease

AIMS

Patients with diabetes mellitus (DM) and chronic kidney disease (CKD) are at increased risk of atherothrombotic events. Ticagrelor reduces ischaemic events compared to clopidogrel, with the greatest risk reduction in patients with both DM and CKD. How CKD status affects the pharmacodynamic (PD) and pharmacokinetic (PK) profiles of different ticagrelor maintenance dose regimens in patients with DM is unknown.

METHODS AND RESULTS

In this randomized, cross-over study, patients with DM on treatment with dual antiplatelet therapy (aspirin and clopidogrel) were stratified according to CKD status and randomized to ticagrelor 90 mg bid or 60 mg bid. PK/PD assessments were performed at baseline, after 7-10 days of ticagrelor (peak and trough), and after 7-10 days of alternative ticagrelor regimen (peak and trough). PK assessments included plasma concentrations of ticagrelor and its major metabolite. PD assessments included VASP-PRI, VerifyNow P2Y12, and LTA.A total of 92 patients with DM (CKD, n = 44; non-CKD, n = 48) were randomized. Levels of platelet reactivity were lower with the 90 mg compared with the 60 mg ticagrelor dose, which was statistically significant in non-CKD but not in CKD patients for most PD measures. There were no significant differences in the primary endpoint (trough levels of VASP-PRI following ticagrelor 90 mg dosing) between cohorts (31 ± 20 vs 25 ± 14; p = 0.105). VerifyNow and LTA provided similar findings. PK assessments tracked PD profiles showing increased plasma concentrations of ticagrelor and its major metabolite in CKD compared to non-CKD patients.

CONCLUSION

In patients with DM, although ticagrelor maintenance dose regimens (60 mg and 90 mg) yield potent P2Y12 inhibition, levels of platelet reactivity tended to be higher and subject to broader variability in non-CKD compared with CKD patients.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov Unique Identifier: NCT02539160.

Switching Ticagrelor to 600 mg or 300 mg Clopidogrel Loading Bridge in Patients with Unstable Angina

Ticagrelor is believed to be a more potent and faster antiplatelet agent compared with clopidogrel and may result in lower ischemic outcomes in patients with acute coronary syndrome. However, the best strategy of switching from ticagrelor to clopidogrel is unclear. Current guidelines advocate clopidogrel bridging with a 600 mg loading dose (LD). This study aimed to compare the safety and feasibility of switching protocols from ticagrelor to clopidogrel 600 mg or 300 mg LD in patients with unstable angina pectoris (USAP). One hundred and eighty patients with USAP undergoing adhoc percutaneous coronary intervention (PCI) received preprocedural ticagrelor 180 mg/daily. The decision to switch antiplatelet therapy to clopidogrel with either 300 mg LD or 600 mg LD at 12 h was left to the discretion of the treating physician. The primary outcome was a composite of an efficacy endpoint major adverse cardiac and cerebrovascular events (MACCEs) and a safety endpoint Bleeding Academic Research Consortium scale (BARC) (≥1). There were no differences in our composite clinical endpoint of MACCE between the two strategies, with one event occurring in each group. One patient in each group had myocardial infarction due to stent thrombosis, and the patient in the 300 mg switching group died due to stent thrombosis. No difference between the two arms was observed in terms of BARC bleeding criteria. This study showed that among USAP patients undergoing PCI, switching to clopidogrel with 300 mg LD showed no significant difference compared to 600 mg clopidogrel LD. Ticagrelor LD in ad hoc PCI and de-escalation to clopidogrel with 300 mg LD could translate to lower costs for patients with USAP without compromising safety and efficacy.

The effect of de-escalation of P2Y12 receptor inhibitor therapy after acute myocardial infarction in patients undergoing percutaneous coronary intervention: A nationwide cohort study

To examine the effect of de-escalation of P2Y₁₂ inhibitor in dual antiplatelet therapy (DAPT) on major adverse cardiovascular events (MACE) and bleeding complications after acute myocardial infarction (AMI) in Taiwanese patients undergoing percutaneous coronary intervention (PCI). Patients who had received PCI during hospitalization for AMI (between 2013 and 2016) and were initially treated with aspirin and ticagrelor and without adverse events after 3 months of treatment were retrospectively evaluated. In total, 1,901 and 8,199 patients were identified as “de-escalated DAPT” (switched to aspirin and clopidogrel) and “unchanged DAPT” (continued on aspirin and ticagrelor) cohorts, respectively. With a mean follow-up of 8 months, the incidence rates (per 100 person-year) of death, AMI readmission and MACE were 2.89, 3.68, and 4.91 in the de-escalated cohort and 2.42, 3.28, and 4.72 in the unchanged cohort, respectively, based on an inverse probability of treatment weighted approach that adjusting for baseline characteristics of the patients. Multivariate Cox regression analyses showed the two groups had no significant differences in the hazard risk of death, AMI admission, and MACE. Additionally, there was no observed difference in the risk of bleeding, including major or clinically relevant non-major bleeding. The real-world data revealed that de-escalation of P2Y₁₂ inhibitor in DAPT was not associated with a higher risk of death or AMI readmission in Taiwanese patients with AMI undergoing successful PCI.

Insights from In Vitro and Clinical Data to Guide Transition from the Novel P2Y12 Antagonist Selatogrel to Clopidogrel, Prasugrel, and Ticagrelor

Reduced pharmacodynamic (PD) effects of irreversible oral P2Y₁₂ receptor antagonists have been reported when administered during cangrelor infusion. Therefore, the PD interaction liability of the novel P2Y₁₂ receptor antagonist selatogrel with irreversible (i.e., clopidogrel, prasugrel) and reversible (i.e., ticagrelor) oral P2Y₁₂ receptor antagonists was investigated in vitro and in healthy subjects. In vitro, selatogrel reduced the effects of clopidogrel and prasugrel in a concentration-dependent manner, while additive effects were observed for the combination of selatogrel and ticagrelor. Accordingly, a single-center, randomized, double-blind, two-way crossover study was conducted consisting of six groups. In each group (N = 12), an open-label loading dose of 300 or 600 mg clopidogrel, 60 mg prasugrel, or 180 mg ticagrelor was administered 30 minutes (i.e., at t _max of selatogrel) or 12 hours after a single subcutaneous dose of 16 mg selatogrel or placebo. Inhibition of platelet aggregation (IPA) was assessed at various time points up to 48 hours. Reduced IPA was determined when clopidogrel or prasugrel was administered 30 minutes after selatogrel (∼40 and 70% lower IPA, respectively, at 24 hours postdosing). However, when administering prasugrel 12 hours after selatogrel, IPA was not impacted (>90% IPA) and in the case of clopidogrel reduced effects were partially mitigated. Similar IPA was determined for ticagrelor when administered 30 minutes after selatogrel or placebo. In conclusion, reduced IPA was observed for clopidogrel and prasugrel when administered after selatogrel, which can be mitigated by applying an appropriate time interval. No PD interaction with ticagrelor was observed.

Clopidogrel drug interactions: a review of the evidence and clinical implications

INTRODUCTION

Patients with cardiovascular disease are commonly affected by a number of comorbidities leading to a high prevalence of polypharmacy. Polypharmacy increases the probability of drug-drug interactions (DDIs). Amongst these, DDIs involving clopidogrel, the most commonly utilized platelet P2Y₁₂ inhibitor, is a topic of potential clinical concern.

AREAS COVERED

This article reviews DDIs between clopidogrel and drugs which are widely used in clinical practice. In particular, drugs shown to interfere with the pharmacodynamic and pharmacokinetic effects of clopidogrel and the clinical implications of these findings are reviewed. These drugs include inhibitors of gastric acid secretion, statins, calcium channel blockers, antidiabetic agents, and antimicrobial agents. For the references, we searched PubMed, EMBASE, or the Cochrane Library.

EXPERT OPINION

Clopidogrel-drug interactions are common. Most of these DDIs are limited to laboratory findings showing an impact on clopidogrel-induced antiplatelet effects. While variability in clopidogrel-induced antiplatelet effects is known to affect clinical outcomes, with high platelet reactivity being associated with thrombotic complications among patients undergoing coronary stenting, most studies assessing the clinical implications of clopidogrel-drug interactions have not shown to significantly affect outcomes. However, awareness of these DDIs remains important for optimizing the selection of concomitant therapies.

An updated drug profile of ticagrelor with considerations on the treatment of patients with coronary artery disease and diabetes mellitus

INTRODUCTION

Ticagrelor is an antiplatelet agent acting through direct and reversible competitive inhibition of the platelet P2Y₁₂ receptor. While the clinical merits of ticagrelor in patients who experienced an acute coronary syndrome are widely accepted, its role in stable coronary artery disease is less established. Recently, large-scale trials of ticagrelor have been published in this setting, including a trial in patients with diabetes mellitus (DM).

AREAS COVERED

This review aims to inform about recent findings on ticagrelor, by appraising the current body of evidence on its use in different clinical scenarios, particularly in DM, ranging from pharmacology to clinical outcomes and future directions.

EXPERT OPINION

The results of the THEMIS trial, conducted in DM patients with stable coronary artery disease and no prior stroke or myocardial infarction, showed that although ticagrelor in addition to aspirin reduced the risk of ischemic events, this was associated with a parallel increase in bleeding complications. However, patients with history of percutaneous coronary intervention seemed to benefit more from adjunctive ticagrelor therapy. Careful bleeding and ischemic risk stratification remains crucial to define the best antithrombotic strategy for the individual patient.

Evaluation of a Novel Antiplatelet Therapy Strategy in Patients Undergoing Elective Percutaneous Coronary Intervention

BACKGROUND

Ticagrelor presents less thrombotic risk compared to clopidogrel in acute coronary syndromes. However, its role in dual antiplatelet therapy (DAPT)-naive patients with stable ischemic heart disease (SIHD) undergoing elective percutaneous intervention (PCI) remains unclear, including uncertainty in the method of conversion to clopidogrel for adequate coverage without increased bleeding risk.

OBJECTIVE

Determine the safety and efficacy of ticagrelor loading and transitioning to clopidogrel in patients with SIHD undergoing elective PCI.

METHODS

This is a retrospective cohort review of patients with SIHD who underwent elective PCI. The Switch Rx patients were treated with ticagrelor immediately before PCI, converted to clopidogrel 300 mg the day after, and discharged with clopidogrel 75 mg daily. Standard Rx patients, who received a clopidogrel load and received clopidogrel 75 mg daily after the procedure, were analyzed as a matched comparator cohort. The safety outcomes were any bleeding event at 24 hours and 30 days. The efficacy outcomes included major adverse cardiac events (MACE) at 24 hours and 30 days.

RESULTS

Five Switch Rx patients (n = 54) experienced bleeding academic research consortium type I bleeding within 24 hours, with no subsequent bleeding observed out to 30 days. When comparing the Switch Rx patients (n = 39) to their matched Standard Rx cohort (n = 39), no MACEs occurred within 30 days and there were no significant differences in safety and efficacy outcomes.

CONCLUSION

In DAPT-naive patients undergoing elective PCI for SIHD, a strategy of in-lab ticagrelor transitioning to clopidogrel with a 300-mg load was not associated with increased bleeding or other adverse events.

De-escalation therapy after acute coronary syndrome: is it reasonable to switch from prasugrel (or ticagrelor) to clopidogrel early?

Dual antiplatelet treatment (DAPT) is the treatment of choice to prevent atherothrombotic events in patients with acute coronary syndrome (ACS) treated with percutaneous interventions (PCIs). The availability of different P2Y12 inhibitors set the stage for costum made DAPT, as to achieve the highest profile of safety and efficacy. The de-escalation therapy for the newer and more powerful antiplatelet drugs, such as ticagrelor and prasugrel, to clopidogrel, is a strategy for patients with recent ACS, unfit for continuing DAPT for their high risk of bleeding, or side effects, or socio-economic reasons, but without a prohibitive ischaemic risk. There is a need for compelling clinical evidences able to provide the clinical cardiologist with the necessary information to decide the best antiplatelet strategy for each individual patient.

Prasugrel Versus Ticagrelor in Patients With CYP2C19 Loss-of-Function Genotypes: Results of a Randomized Pharmacodynamic Study in a Feasibility Investigation of Rapid Genetic Testing

The feasibility of rapid genetic testing in patients undergoing percutaneous coronary intervention (PCI) and the comparison of the pharmacodynamic effects of prasugrel versus ticagrelor among carriers of cytochrome P450 2C19 loss-of-function alleles treated with PCI has been poorly explored. Rapid genetic testing using the Spartan assay was shown to be feasible and provides results in a timely fashion in a real-world setting of patients undergoing coronary angiography (n = 781). Among patients (n = 223, 28.5%), carriers of at least 1 loss-of-function allele treated with PCI (n = 65), prasugrel, and ticagrelor achieve similar levels of platelet inhibition. (A Pharmacodynamic Study Comparing Prasugrel Versus Ticagrelor in Patients Undergoing PCI With CYP2C19 Loss-of-function [NCT02065479]).

Premature Ticagrelor Discontinuation in Secondary Prevention of Atherosclerotic CVD: JACC Review Topic of the Week

Ticagrelor is a cornerstone of modern antithrombotic therapy alongside aspirin in patients with acute coronary syndrome and after percutaneous coronary intervention. Adverse effects such as bleeding and dyspnea have been associated with premature ticagrelor discontinuation, which may limit any potential advantage of ticagrelor over clopidogrel. The randomized trials of ticagrelor captured adverse events, offering the opportunity to more precisely quantify these effects across studies. Therefore, a meta-analysis of 4 randomized clinical trials of ticagrelor conducted between January 2007 and June 2017 was performed to quantify the incidence and causes of premature ticagrelor discontinuation. Among 66,870 patients followed for a median 18 months, premature ticagrelor discontinuation was seen in 25%; bleeding was the most common cause of discontinuation followed by dyspnea. Versus the comparators, the relative risk of dyspnea-related discontinuation during follow-up was 6.4-fold higher, the relative risk of bleeding was 3.2-fold higher, and the relative risk of discontinuation due to any adverse event was 59% higher for patients receiving ticagrelor. Understanding these potential barriers to adherence to ticagrelor is crucial for informed patient-physician decision making and can inform future efforts to improve ticagrelor adherence. This review discusses the incidence, causes, and biological mechanisms of ticagrelor-related adverse effects and offers strategies to improve adherence to ticagrelor.

Update on Antithrombotic Therapy after Percutaneous Coronary Intervention

Percutaneous coronary intervention (PCI) has become a standard-of-care procedure in the setting of angina or acute coronary syndrome. Antithrombotic therapy is the cornerstone of pharmacological treatment aimed at preventing ischemic events following PCI. Dual antiplatelet therapy as the combination of aspirin and P2Y12 inhibitor has been proven to decrease stent-related thrombotic risks. However, the optimal duration of dual antiplatelet therapy, an appropriate P2Y12 inhibitor, and the choice of aspirin versus P2Y12 inhibitor as single antiplatelet therapy remain controversial. Furthermore, the combined use of oral anticoagulation in addition to antiplatelet therapy is a complex issue in clinical practice, such as in patients with atrial fibrillation. The key challenge concerning the optimal antithrombotic regimen is ensuring a balance between protection against thrombotic events and against excessive increases in bleeding risk. In this review article, we summarize the current evidence concerning antithrombotic therapy in patients with coronary artery disease undergoing PCI.

Time Course of Ischemic and Bleeding Burden in Elderly Patients With Acute Coronary Syndromes Randomized to Low-Dose Prasugrel or Clopidogrel

Background Elderly patients have high ischemic and bleeding rates after acute coronary syndrome; however, the occurrence of these complications over time has never been studied. This study sought to characterize average daily ischemic rates ( ADIRs ) and average daily bleeding rates ( ADBRs ) over 1 year in patients aged >74 years with acute coronary syndrome undergoing percutaneous coronary intervention who were randomized in the Elderly ACS 2 trial, comparing low-dose prasugrel (5 mg daily) with clopidogrel (75 mg daily). Methods and Results ADIRs and ADBRs were calculated as the total number of events, including recurrent events, divided by the number of patient-days of follow-up and assessed within different clinical phases: acute (0-3 days), subacute (4-30 days), and late (31-365 days). Generalized estimating equations were used to test the least squares mean differences for the pairwise comparisons of ADIRs and ADBRs and the pairwise comparison of clopidogrel versus prasugrel effects. Globally, ADIRs were 2.6 times (95% CI, 2.4-2.9) higher than ADBRs . ADIRs were significantly higher in the clopidogrel arm than in the low-dose prasugrel arm in the subacute phase ( P_adj<0.001) without a difference in ADBRs ( P_adj=0.35). In the late phase, ADIRs remained significantly higher with clopidogrel ( P_adj<0.001), whereas ADBRs were significantly higher with low-dose prasugrel ( P_adj<0.001). Conclusions Ischemic burden was greater than bleeding burden in all clinical phases of 1-year follow-up of elderly patients with acute coronary syndrome treated with percutaneous coronary intervention. Low-dose prasugrel reduced ischemic events in the subacute and chronic phases compared with clopidogrel, whereas bleeding burden was lower with clopidogrel in the late phase. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 01777503.

Reasons for the Failure of Platelet Function Testing to Adjust Antiplatelet Therapy: Pharmacodynamic Insights From the ARCTIC Study

BACKGROUND

In the ARCTIC trial (Assessment by a Double Randomization of a Conventional Antiplatelet Strategy Versus a Monitoring-Guided Strategy for Drug-Eluting Stent Implantation and of Treatment Interruption Versus Continuation One Year After Stenting), treatment adjustment following platelet function testing failed to improve clinical outcomes. However, high-on-treatment platelet reactivity (HPR) is considered as a predictor of poor ischemic outcome. This prespecified substudy evaluated clinical outcomes according to the residual platelet reactivity status after antiplatelet therapy adjustment.

METHODS

We analyzed the 1213 patients assigned to the monitoring arm of the ARCTIC trial in whom platelet reactivity was evaluated by the VerifyNow P2Y₁₂ test before percutaneous coronary intervention and during the maintenance phase (at 14 days). HPR was defined as platelet reaction unit≥235U. The primary ischemic end point, a composite of death, myocardial infarction, stent thrombosis, stroke, or urgent revascularization and the safety end point of major bleeding were assessed according to the platelet reactivity status.

RESULTS

Before percutaneous coronary intervention, 35.7% of patients displayed HPR (n=419). During the acute phase, between percutaneous coronary intervention and the 14-day platelet function testing, ischemic (adjusted hazard ratio, 0.94 [95% CI, 0.74-1.18]; P=0.58) and safety outcomes (hazard ratio, 1.28 [95% CI, 0.22-7.59]; P=0.78) were similar in HPR and non-HPR patients. During the maintenance phase, the proportion of HPR patients (n=186, 17.4%) decreased by 56%. At 1-year, there was no difference for the ischemic end point (5.9% versus 6.0%; adjusted hazard ratio, 0.79 [95% CI, 0.40-1.58]; P=0.51) and a nonsignificant higher rate of major bleedings (2.7% versus 1.0%, hazard ratio, 2.83 [95% CI, 0.96-8.41]; P=0.06) in HPR versus non-HPR patients.

CONCLUSIONS

The proportion of HPR was halved after platelet function testing and treatment adjustment but without significant ischemic benefit at 1 year. HPR seems more as a modifiable risk marker than a risk factor of ischemic outcome.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00827411.

Optimal strategy of switching from clopidogrel to ticagrelor in Chinese acute coronary syndrome patients with complicated coronary artery disease: the switching from clopidogrel to ticagrelor (SHIFT-CACS) study

BACKGROUND

The dose and time point for switching from clopidogrel to ticagrelor remain controversial, especially for Chinese acute coronary syndrome (ACS) patients with complicated coronary artery disease (CAD). Hence, the purpose of this study was to further explore the optimal dose and time point for the switching strategy to balance the increase in platelet inhibition and the decrease in adverse events in Chinese ACS patients with complicated CAD managed by percutaneous coronary intervention (PCI).

METHODS

From July 2017 to December 2017, the prospective, randomized, open-label study (the SwitcHIng from clopidogrel to ticagrelor study) assigned the eligible Chinese ACS patients with complicated CAD managed by PCI (n = 102) for 90 mg of ticagrelor at 12 h (T-90 mg-12 h), 90 mg of ticagrelor at 24 h (T-90 mg-24h) or 180 mg ticagrelor at 24 h (T-180 mg-24 h) after the last dose of clopidogrel. The primary endpoint was the comparison of maximal platelet aggregation (MPA) values at 2 h after switching strategies among the three groups. In addition, the MPA values at baseline, 8 h and before discharge and the rates of high on-treatment platelet reactivity were evaluated, the incidences of bleeding episodes and dyspnea during hospitalization and at 30-day follow-up in our study were also recorded. The MPA was measured by light transmittance aggregometry in our study. A repeated-measures analysis of variance (ANOVA) model and one-way ANOVA were used to compare data for the primary endpoint.

RESULTS

The MPA values were significantly decreased in the T-180 mg-24 h group compared with the T-90 mg-12 h group (P = 0.017) and decreased numerically compared with the T-90 mg-24 h group (P = 0.072) at 2 h. In particular, the MPA values were markedly reduced in the T-90 mg-24 h group compared with the T-90 mg-12 h group at 8 h after switching treatment (P = 0.002). There was no significant difference among the three groups in all bleedings and dyspnea events.

CONCLUSIONS

The optimal treatment strategy recommended in this study for Chinese ACS patients with complicated CAD managed by PCI is 180 or 90 mg of ticagrelor at 24 h after the last dose of clopidogrel. In addition, a negative interaction was detected in this study between the overlap for clopidogrel and ticagrelor at 12 h after the last dose of clopidogrel.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03577652; http://clinicaltrials.gov/ct2/show/NCT03577652.

Therapeutic Window of Clopidogrel and Ticagrelor in Patients With Critical Limb-Threatening Ischemia

BACKGROUND

Critical limb-threatening ischemia (CLTI) is associated with an increased risk of major adverse limb events and mortality. High on-treatment platelet reactivity (HPR) is associated with an increased risk of ischemic events, while low on-treatment platelet reactivity (LPR) is associated with an increased risk of bleeding. This study investigates the frequency with which patients with CLTI on clopidogrel or ticagrelor achieve a "therapeutic window" (TW) of platelet inhibition.

METHODS

Data from the "Switch To Ticagrelor in Critical Limb Ischemia Anti-Platelet Study" were assessed retrospectively to determine the incidence of TW of on-treatment platelet reactivity in 50 consecutive patients with CLTI (mean age: 65.2 ± 10.5 years, 54% male). The data included 4 measurements of patients' platelet reactivity using the VerifyNow P2Y12 Assay: baseline and steady state platelet reactivity on clopidogrel 75 mg daily and on ticagrelor 90 mg twice daily.

RESULTS

At baseline, 46% of patients on clopidogrel were within TW of on-treatment platelet reactivity compared to 10% of patients on ticagrelor (P < .0001). At steady state, 42% of patients on clopidogrel were within the TW compared to 10% of patients on ticagrelor (P < .0001). Patients on ticagrelor exhibited higher rates of LPR compared to those on clopidogrel at baseline as well as at steady state (baseline 88% vs 18%, steady state 88% vs 28%; P < .0001).

CONCLUSION

Although ticagrelor has been proposed as an alternative for patients with HPR on clopidogrel, the current study observes an excess of platelet inhibition with ticagrelor in most patients with CLTI at a dose of 90 mg twice daily.

Pharmacodynamics During Transition Between Platelet P2Y12 Inhibiting Therapies

Several platelet P2Y₁₂ inhibiting agents, both oral and intravenous, are available for clinical use. The oral P2Y₁₂ inhibitors comprise clopidogrel, prasugrel, and ticagrelor. Cangrelor is the only intravenous P2Y₁₂ inhibitor. Numerous pharmacodynamic studies have been performed to assess the impact of P2Y₁₂ inhibitor switching on platelet reactivity profiles and to define the optimal strategy if switching is needed, with the goal of minimizing the risk of having inadequate platelet inhibition due to potential drug-drug interactions occurring during the drug overlap phase. This article provides an overview of pharmacodynamic studies assessing switching between P2Y₁₂ inhibitors and recommendations on switching modalities based on these findings.

Effects of Methylnaltrexone on Ticagrelor-Induced Antiplatelet Effects in Coronary Artery Disease Patients Treated With Morphine

OBJECTIVES

The aim of this study was to assess if intravenous methylnaltrexone can counteract the effects of morphine on the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of ticagrelor.

BACKGROUND

Morphine delays the onset of action of oral P2Y₁₂ receptor inhibitors, including ticagrelor, by inhibiting gastric emptying and leading to delayed drug absorption. Methylnaltrexone is a peripheral opioid receptor antagonist that has the potential to prevent opioid-induced peripherally mediated side effects (e.g., gastric emptying inhibition) without affecting analgesia.

METHODS

In this prospective, randomized, double-blind, placebo-controlled, crossover study, aspirin-treated patients with stable coronary artery disease (n = 30) were randomized to receive methylnaltrexone (0.3 mg/kg intravenous) or matching placebo. After methylnaltrexone or placebo administration, all patients received morphine (5 mg intravenous). This was followed 15 min later by a 180-mg loading dose of ticagrelor. Patients crossed over to the alternative study treatment after 7 ± 2 days of washout. PK and PD assessments were performed at 12 time points (6 pre- and 6 post-crossover). PK analysis included measurement of plasma levels of ticagrelor and its major active metabolite (AR-C124910XX). PD assessments included VerifyNow P2Y₁₂, light transmittance aggregometry, and vasodilator-stimulated phosphoprotein.

RESULTS

Only marginal changes in plasma levels of ticagrelor (and its major active metabolite) were observed with ticagrelor: maximum plasma concentration and area under the plasma concentration versus time curve from time 0 to the last measurable concentration were 38% and 30% higher, respectively, in patients receiving methylnaltrexone compared with those receiving placebo, but no differences in time to maximum plasma concentration were observed. There were no differences in P2Y₁₂ reaction units by VerifyNow P2Y₁₂ between groups at each time point, including 2 h (the primary endpoint; p = 0.261). Similarly, there were no differences in PD markers assessed by light transmittance aggregometry and vasodilator-stimulated phosphoprotein.

CONCLUSIONS

In patients with coronary artery disease receiving morphine, intravenous administration of the peripheral opioid receptor antagonist methylnaltrexone leads to only marginal changes in plasma levels of ticagrelor and its major metabolite, without affecting levels of platelet reactivity. (Effect of Methylnaltrexone on the PK/PD Profiles of Ticagrelor in Patients Treated With Morphine; NCT02403830).

De-escalation from ticagrelor to clopidogrel in acute coronary syndrome patients: a systematic review and meta-analysis

De-escalation from ticagrelor to clopidogrel in acute coronary syndrome (ACS) may occur for a variety of reasons, including side effects (bleeding and non-bleeding) and costs. This study sought to assess the prevalence of de-escalation from ticagrelor to clopidogrel and the occurrence of adverse clinical outcomes following de-escalation. We conducted a systematic review of clinical trials and real-world studies in ACS patients treated with ticagrelor. Real-world data on the prevalence of de-escalation during hospitalization or at discharge, after hospital discharge, and during the whole study period were included for meta-analysis. Major adverse cardiovascular events (MACE) and bleeding events occurring after de-escalation were also assessed. A total of 12 studies were eligible for meta-analysis of the prevalence of de-escalation. De-escalation from ticagrelor to clopidogrel therapy occurred with a mean prevalence of 19.8% [95% confidence interval (CI) 11.2-28.4%]. De-escalation occurred more frequently in-hospital or at discharge than after hospital discharge (23.7% vs. 15.8%). For assessment of clinical outcomes, a total of six studies were eligible for meta-analysis. Mean rate of MACE for patients with de-escalation was 2.1% (95% CI 1.1-4.1%) and the rate of major bleeding events was 1.3% (95% CI 0.4-4.5%). In conclusion, de-escalation commonly occurs in real-world practice. Although rates of major cardiovascular and bleeding events in this analysis were generally low, the profile of patients suitable for de-escalation, the impact of de-escalation on adverse clinical outcomes and how this is affected by the timing after index ACS warrants further large-scale investigation.

Clinician's Guide to the Updated ABCs of Cardiovascular Disease Prevention: A Review Part 1

Efforts to better control risk factors for cardiovascular disease and prevent the development of subsequent events are crucial to maintaining healthy populations. In today's busy practice environment and with the overwhelming pace of new research findings, ensuring appropriate emphasis and implementation of evidence-based preventive cardiovascular care can be challenging. The ABCDEF approach to cardiovascular disease prevention is intended to improve dissemination of contemporary best practices and facilitate the implementation of comprehensive preventive strategies for clinicians. This review serves as a succinct yet authoritative overview for internists and subspecialty cardiologists not otherwise focused on cardiovascular prevention. The goal of this 2-part series is to compile a state-of-the-art list of elements central to both primary and secondary prevention of cardiovascular disease, using an ABCDEF checklist, with particular focus on recent society guideline updates. In Part 1 we highlight developments in cardiovascular risk assessment tools, summarize important recent aspirin trials, discuss prevention considerations in atrial fibrillation, and review guidelines for blood pressure categorization, goals, and therapy.

De-escalation of anti-platelet therapy in patients with acute coronary syndromes undergoing percutaneous coronary intervention: a narrative review

Objective:

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y₁₂ receptor inhibitor is the cornerstone of treatment in patients with acute coronary syndromes (ACS) and in those undergoing percutaneous coronary intervention (PCI). In current clinical situation, availability of different oral P2Y₁₂ inhibitors (clopidogrel, prasugrel, and ticagrelor) has enabled physicians to switch among therapies owing to specific clinical scenarios. Although optimum time, loading dose and interval of transition between P2Y₁₂ inhibitors is still controversial and needs further evidence, switching between oral inhibitors frequently occurs in clinical practice for several reasons.

Data sources:

This review was based on data in articles published in PubMed up to June 2018, with the following keywords “antiplatelet therapy”, “ACS”, “PCI”, “ticagrelor”, and “clopidogrel”.

Study selection:

Original articles and critical reviews on de-escalation strategy in ACS patients after PCI were selected. References of the retrieved articles were also screened to search for potentially relevant papers.

Results:

Safety concerns associated with switching between antiplatelet agents, has prompted the use of clopidogrel for patients with ACS especially after PCI as a de-escalation strategy. Practical considerations for de-escalating therapies in patients with ACS such as reducing dose of P2Y₁₂ inhibitors or shortening duration of DAPT (followed by aspirin or P2Y₁₂ receptor inhibitor monotherapy) as potential options are yet to be standardized and validated.

Conclusions:

Current review will provide an overview of the pharmacology of common P2Y₁₂ inhibitors, definitions of de-escalation and different de-escalating strategies and its outcomes, along with possible direction to be explored in de-escalation.

Switching of Oral P2Y12 Inhibitor Treatment in Patients with Acute Coronary Syndrome: Prevalence, Predictors, and Prognosis

BACKGROUND AND OBJECTIVE

Dual antiplatelet therapy is one of the main treatments in acute coronary syndrome (ACS). Switching antiplatelet agents may be necessary in some patients to improve efficacy or safety. The objective of this study was to determine the prevalence, predictors, and implications of clinical switching in patients during hospital admission and 1-year follow-up at discharge.

METHODS

Observational, prospective, multicenter registry study in patients discharged following an admission for ACS and followed up for 1 year. We analyzed ischemic and bleeding events as well as treatment changes.

RESULTS

We recruited 1717 patients; in-hospital switching occurred in 425 (24.8%): 15.1% to clopidogrel and 84.9% to newer antiplatelet drugs (prasugrel or ticagrelor). Those switched to newer antiplatelets were younger, with lower scores on the GRACE and CRUSADE scales, admitted more frequently for ST-elevation myocardial infarction and underwent more invasive management and percutaneous revascularization. The clinical cardiologist was responsible for most in-hospital switching to newer antiplatelets (79.6%). The loading dose of the second antiplatelet did not affect incidence of bleeding events. Post-discharge switching was infrequent (2%) and depended mainly on clinical indications; only 30% was related to a new ACS.

CONCLUSIONS

In a contemporary registry with ACS, in-hospital switching of antiplatelet drugs was frequent. Those switched to newer antiplatelets were younger and admitted more frequently for ST-elevation myocardial infarction. Post-discharge switching was infrequent.

Switching between P2Y12 inhibitors: Rationale, methods, and expected consequences

The pharmacological and clinical differences of the three recommended oral P2Y₁₂ inhibitors (clopidogrel, prasugrel, ticagrelor) enable physicians to switch from one agent to another that it is considered more appropriate in the specific clinical setting. Moreover, the recent availability of cangrelor, the only intravenous P2Y₁₂ inhibitor with a rapid onset and offset of its antiplatelet action, makes it necessary to switch from this agent to an oral P2Y₁₂ inhibitor for a continued platelet inhibition after percutaneous coronary intervention. Several pharmacodynamic studies have provided information on how to change drug, in terms of timing and dosage, without running the risk of a temporary impairment of platelet inhibition. In addition, several studies have assessed the impact of the switching between P2Y₁₂ inhibitors on clinical outcomes. Overall, these evidences have prompted the development of an extensive expert consensus document, have set the basis for recent practice guidelines recommendations, and have stimulated several systematic overviews. The present article provides a brief and schematic summary on the topic of switching between P2Y₁₂ inhibitors, focusing on three main practical issues: why and how to switch therapies and what are the clinical consequences of such strategy.

De-Escalation of Antiplatelet Therapy in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: A Meta-Analysis of Randomized Clinical Trials

AIMS

Patients with acute coronary syndrome undergoing percutaneous coronary intervention (PCI) are recommended to be placed on potent P2Y12 blockade. However, the long-term bleeding risk is high. Therefore, despite no definitive evidence, switching to clopidogrel beyond the acute phase is common. We aimed to evaluate the clinical outcomes of antiplatelet de-escalation compared with continuation in patients treated with PCI.

METHODS

We searched databases for randomized clinical trials (RCTs) that evaluated the safety and efficacy of antiplatelet de-escalation compared with continuation in patients treated with PCI. Pooled summary estimates were calculated.

RESULTS

We included 3 RCTs with 3391 patients (median follow-up: 12 months). Compared with the continued group, the net clinical outcome (composite of bleeding or thrombotic events) was significantly reduced in the group switched to clopidogrel (8.7% vs 12.1%; risk ratio [RR]: 0.64; 95% confidence interval [CI]: 0.43-0.97; P = .03). However, there were similar clinical outcomes between groups for major adverse cardiovascular events (MACE; RR: 0.78; 95% CI: 0.55-1.11; P = .17), all Bleeding Academic Research Consortium (BARC) types bleeding (RR: 0.61; 95% CI: 0.33-1.11; P = .10), or BARC types ≥2 bleeding (RR: 0.49; 95% CI: 0.19-1.26; P = .14).

CONCLUSIONS

Our results suggest a net clinical benefit of de-escalation therapy shortly after PCI, without increased risk of MACE. Larger randomized trials will be necessary to confirm these findings.

Switching from ticagrelor to clopidogrel in patients with ST-segment elevation myocardial infarction undergoing successful percutaneous coronary intervention in real-world China: Occurrences, reasons, and long-term clinical outcomes

BACKGROUND

Although switching between ticagrelor and clopidogrel is common in clinical practice, the efficacy and safety of this de-escalation remain controversial.

HYPOTHESIS

We assessed the occurrences, reasons, and outcomes of switching from ticagrelor to clopidogrel in patients with ST-segment elevation myocardial infarction (STEMI) undergoing successful primary percutaneous coronary intervention (PCI).

METHODS

A total of 653 patients with STEMI were randomly assigned to receive loading dose of ticagrelor or clopidogrel before PCI and then received maintenance dose, respectively, for 12 months follow-up. The primary outcome was major adverse cardiac events (MACE), including cardiovascular death, nonfatal myocardial infarction, and stroke. The secondary outcome included unexpected rehospitalization for angina, coronary revascularization, and stent thrombosis. The safety outcome was bleeding described by the Bleeding Academic Research Consortium (BARC) criteria.

RESULTS

A total of 602 participants completed the study. The rate of switching from ticagrelor to clopidogrel was 48.6% and the main reason was financial burden. The rate of secondary ischemic events in the de-escalation group was higher than that in the ticagrelor group (15.1% vs 5.6%, P = 0.008), but lower than that in the clopidogrel group (15.1% vs 24.6%, P = 0.03), while there were no significant differences in MACE among the three groups (P = 0.16). De-escalation, ticagrelor, and clopidogrel did not cause significant differences in the rates of major bleeding among the three groups (BARC ≥ 2, P = 0.34).

CONCLUSION

Switching from ticagrelor to clopidogrel is very common in patients with STEMI in China. De-escalation might be safe but associated with high risk of ischemic events as compared to ticagrelor.

Effects of switching ticagrelor to clopidogrel on cardiovascular outcomes in patients with acute coronary syndrome

Present study was to evaluate whether switching ticagrelor to clopidogrel would impact platelet reactivity and cardiovascular outcomes in acute coronary syndrome (ACS) patients after percutaneous coronary intervention (PCI).A total of 202 ACS patients after PCI were enrolled and prescribed ticagrelor. Before discharge, 138 (68%) patients were switched to clopidogrel. Peripheral blood was obtained before switching and at 48 hours after switching to measure platelet reactivity. Patients were followed for 30 days to evaluate cardiovascular events.Compared to ticagrelor group, patients in clopidogrel group were more likely to be male (69.6% vs 65.6%), smokers (34.1% vs 31.3%) and had higher prevalence of hypertension (75.4% vs 71.9%). The frequency of right coronary artery lesion was significantly higher in ticagrelor group (34.4% vs 30.4%). There were no significant differences in baseline platelet reactivity (37.6 ± 5.2% vs 38.4 ± 4.9%). Forty-eight hours after switching to clopidogrel, platelet reactivity in clopidogrel group was significantly higher (46.3 ± 5.6% vs 38.1 ± 5.0%, P <.05). Patients in clopidogrel group had significantly higher incidence of cardiovascular events (3.6% vs 1.6%, P <.05). However, after further adjusted for platelet reactivity at 48 hours of switching, clopidogrel switching was not significantly associated with composite outcomes, with hazard ratio 1.08 (95% confidence interval 0.98-1.21, P = .063), indicating that platelet reactivity was a critical mediator between antiplatelet drug switching and cardiovascular outcomes.ACS patients after PCI treatment, early switching ticagrelor to clopidogrel results in increased platelet reactivity and higher incidence of short-term cardiovascular events.

Study of Two Dose Regimens of Ticagrelor Compared With Clopidogrel in Patients Undergoing Percutaneous Coronary Intervention for Stable Coronary Artery Disease

BACKGROUND

Ticagrelor has superior efficacy to clopidogrel in the management of acute coronary syndromes but has not been assessed in patients undergoing percutaneous coronary intervention for stable coronary artery disease. We compared the pharmacodynamic effects of ticagrelor and clopidogrel in this stable population.

METHODS

One hundred eighty aspirin-treated stable coronary artery disease patients, who were planned to undergo elective percutaneous coronary intervention in a single center, were randomized 1:1:1 to either a standard clopidogrel regimen or 1 of 2 regimens of ticagrelor, either 90 mg (T90) or 60 mg twice daily (T60), both with a 180 mg loading dose. Cellular adenosine uptake was assessed, at the time of the procedure and pre- and postdose at 1 month, by adding adenosine 1 µmol/L to aliquots of anticoagulated whole blood and mixing with a stop solution at 0, 15, 30, and 60 seconds, then measuring residual plasma adenosine concentration by high-performance liquid chromatography. Systemic plasma adenosine concentration and platelet reactivity were assessed at the same timepoints. High-sensitivity troponin T was measured pre- and 18 to 24 hours postpercutaneous coronary intervention.

RESULTS

One hundred seventy-four patients underwent an invasive procedure, of whom 162 received percutaneous coronary intervention (mean age 65 years, 18% female, 21% with diabetes mellitus). No effect on in vitro adenosine uptake was seen postdose at 1 month for either ticagrelor dose compared with clopidogrel (residual adenosine at 15 seconds, mean±SD: clopidogrel 0.274±0.101 µmol/L; T90 0.278±0.134 µmol/L; T60 0.288±0.149 µmol/L; P=0.37). Similarly, no effect of ticagrelor on in vitro adenosine uptake was seen at other timepoints, nor was plasma adenosine concentration affected (all P>0.1). Both maintenance doses of ticagrelor achieved more potent and consistent platelet inhibition than clopidogrel (VerifyNow P2Y12 reaction units, 1 month, mean±SD: predose, T60: 62±47, T90: 40±38, clopidogrel 181±44; postdose, T60: 34±30, T90: 24±21, clopidogrel 159±57; all P<0.0001 for ticagrelor versus clopidogrel). High platelet reactivity was markedly less with both T60 and T90 compared with clopidogrel (VerifyNow P2Y12 reaction units>208, 1 month postdose: 0%, 0%, and 21%, respectively). Median (interquartile range) high-sensitivity troponin T increased 16.9 (6.5-46.9) ng/L for clopidogrel, 22.4 (5.5-53.8) ng/L for T60, and 17.7 (8.1-43.5) ng/L for T90 (P=0.95). There was a trend toward less dyspnea with T60 versus T90 (7.1% versus 19.0%; P=0.09).

CONCLUSIONS

Maintenance therapy with T60 or T90 had no detectable effect on cellular adenosine uptake at 1 month, nor was there any effect on systemic plasma adenosine levels. Both regimens of ticagrelor achieved greater and more consistent platelet inhibition than clopidogrel but did not appear to affect troponin release after percutaneous coronary intervention.

CLINICAL TRIAL REGISTRATION

URL: https://www.

CLINICALTRIALS

gov. Unique identifier: NCT02327624.