Effects of pantoprazole and esomeprazole on platelet inhibition by clopidogrel

An update on oral antiplatelet drug interactions with proton pump inhibitors: what are the risks?

INTRODUCTION

Aspirin and anti-P2Y12 are widely prescribed in cardiovascular patients, often in combination with proton pump inhibitors (PPIs) to limit the risk of upper gastrointestinal bleedings. The potential interaction between PPIs and antiplatelet agents has been widely discussed, but doubts remain as to whether PPIs may reduce the cardiovascular protection provided by aspirin, prasugrel, ticagrelor, and clopidogrel.

AREAS COVERED

Many pharmacokinetic (PK) and pharmacodynamic (PD) studies have confirmed the interaction, especially between PPIs and clopidogrel, but with uncertain consequences on clinical outcomes. Therefore, we aimed to summarize the evidence for the widespread combined use of oral antiplatelet drugs and PPIs, to outline the current evidence supporting or opposing drug-drug interaction, and to discuss the clinical implications of such interactions.

EXPERT OPINION

A large body of evidence describes the PK/PD interaction of antiplatelet drugs with PPIs and its potential role in increasing clinical cardiovascular adverse events, but no solid clinical data have confirmed these effects. In the light of the published studies, there seems to be no restriction on the choice of PPI with aspirin, prasugrel, and/or ticagrelor. The choice of a PPI with no (or minimal) interference with the hepatic cytochrome P450 2C19 is preferred in patients receiving clopidogrel.

Effects of treatment with clopidogrel with or without proton pump inhibitor omeprazole on the risk of ischemic stroke: a nationwide cohort study

Most proton pump inhibitors (PPIs) inhibit the bioactivation of clopidogrel to its active metabolite. There is controversy concerning whether PPIs alter the effectiveness of clopidogrel in reducing the risk of ischemic stroke (IS). We therefore aimed to examine the risk of IS associated with concomitant use of clopidogrel and omeprazole, a PPI commonly used in clinical settings. We conducted a retrospective cohort study using the National Health Insurance Research Database of Taiwan dated from 2000 to 2013. The study cohorts comprised 407 patients diagnosed with acute coronary syndrome (ACS) and with concomitant use of clopidogrel and omeprazole (the exposed cohort), 814 ACS patients with single use of clopidogrel (the comparison cohort), and 230 ACS patients with concurrent use of clopidogrel and pantoprazole (the reference cohort). The primary outcome was incident IS. The hazard ratios (HRs) and 95% confidence intervals (CIs) derived from the time-dependent Cox regression model were used to assess the association between concomitant use of clopidogrel and omeprazole and the risk of IS. The incidence rate of IS was significantly higher in the exposed cohort (81.67 per 1000 person-years) than in the comparison cohort (57.45 per 1000 person-years), resulting in an adjusted HR of 1.39 (95% CI 1.03-1.74). By contrast, there was no significant difference in the risk of IS between the exposed and reference cohorts (adjusted HR 1.11; 95% CI 0.81-1.52). The present study revealed that patients taking both clopidogrel and omeprazole was associated with an increased risk of IS.

Impact of Concomitant Use of Proton Pump Inhibitors and Clopidogrel on Recurrent Stroke and Myocardial Infarction

BACKGROUND/AIMS

Conflicting results have been reported regarding the interaction between proton pump inhibitors (PPIs) and clopidogrel. We investigated whether concomitant PPI use influenced the risk of recurrence in patients with stroke and myocardial infarction (MI).

METHODS

This study used two databases for two different designs, the Korean National Health Insurance Service (NHIS) database for a self-controlled case series design, and the national sample cohort of the NHIS data base converted to the Observational Medical Outcomes Partnership-Common Data Model version for a cohort study based on large-scale propensity score matching.

RESULTS

In the PPI co-prescription group, recurrent hospitalization with stroke occurred in 17.6% of the 8201 patients with history of stroke, and recurrent MI occurred in 17.1% of the 1216 patients with history of MI within1 year. According to the self-controlled case series, the overall relative risk (RR) of recurrent stroke was 2.09 (95% confidence interval (CI); 1.83-2.38); the RR showed an increasing trend parallel to the time from the beginning of PPI co-prescription. In the cohort study, there was a higher incidence of recurrent stroke in the PPI co-prescription group (Hazard ratio (HR): 1.34, 95% CI: 1.01-1.76, p = 0.04). The overall RR of recurrent MI was 1.47 (95% CI; 1.02-2.11) in the self-controlled case series; however, there was no statistically significant difference in recurrent MI in the cohort study (HR:1.42, 95% CI:0.79-2.49, p = 0.23). The impact of individual PPIs on stroke and MI showed different patterns.

CONCLUSIONS

A PPI co-prescription >4 weeks with clopidogrel was associated with hospitalization of recurrent stroke within 1 year of initial diagnosis; however, its association with recurrent MI remains inconclusive. The influence of individual PPIs should be clarified in the future.

Value of Autostrain LV in the study of left ventricular systolic function and synchronization in patients with systemic lupus erythematosus

BACKGROUND

There are relatively few studies investigating cardiac structural and functional abnormalities associated with systemic lupus erythematous (SLE). The long-term prognosis of SLE patients is closely related to the cardiovascular events caused by SLE. Accordingly, it is necessary to assess early myocardial systolic function and synchrony.

METHODS

Overall, 90 patients with SLE were randomly selected from our outpatient and inpatient clinics and divided according to SLE Disease Activity Index (SLE-DAI-2000) scores: group A, stable (scores 0-4); group B, mildly active stage (scores 5-9); and group C, moderately active stage (scores ≥10). Each group included 30 patients. Further, 30 sex- and age-matched healthy individuals who were referred for check-ups at the same period were selected as controls (group D). The minimum age for entry into the group was 17 years old. Autostrain LV and three-dimensional quantitative analysis (3DQA) were applied to obtain left ventricular systolic function parameters, information on strain parameters, and correlations between parameters. Simultaneity parameters measured by Autostrain LV and 3DQA were tested for reproducibility.

RESULTS

A two-by-two comparison of groups A-C showed that as the disease activity score increased, AP4LS%, AP2LS%, AP3LS%, and the LV mean overall longitudinal strain all gradually decreased, while LV longitudinal strain peak time standard deviation (Tls-SD) gradually increased, with all differences being statistically significant (p < .05). In groups A-C compared with controls, Tmsv-17-SD, Tmsv-17-Dif, Tmsv-17-SD%, and Tmsv-17-Dif% were all significantly prolonged (p < .05). Further, Tls-SD was positively correlated with Tmsv-17-SD and Tmsv-17-Dif, and there was good agreement between Autostrain and 3DQA for the measurement of left ventricular synchrony indexes, with Tmsv-17-Dif having the best repeatability (intraobserver interclass correlation coefficient (ICC) = .979; interobserver ICC = .848, p < .01).

CONCLUSION

Autostrain LV can accurately detect changes in left ventricular myocardial strain in patients with SLE early in the disease, with simple operation. The 3DQA technique can quantitatively evaluate left ventricular systolic synchronization in patients with SLE, and Autostrain LV synchronization index measurements correlate significantly with 3DQA. Both methods are reproducible, but 3DQA is more sensitive to left ventricular synchronous motion changes.

Clinical pharmacology of antiplatelet drugs

INTRODUCTION

Platelets play a key role in arterial thrombosis and antiplatelet therapy is pivotal in the treatment of cardiovascular disease. Current antiplatelet drugs target different pathways of platelet activation and show specific pharmacodynamic and pharmacokinetic characteristics, implicating clinically relevant drug-drug interactions.

AREAS COVERED

This article reviews the role of platelets in hemostasis and cardiovascular thrombosis, and discusses the key pharmacodynamics, drug-drug interactions and reversal strategies of clinically used antiplatelet drugs.

EXPERT OPINION

Antiplatelet therapies target distinct pathways of platelet activation: thromboxane A₂ synthesis, adenosine diphosphate-mediated signaling, integrin α_IIbβ₃ (GPIIb/IIIa), thrombin-mediated platelet activation via the PAR1 receptor and phosphodiesterases. Key clinical drug-drug interactions of antiplatelet agents involve acetylsalicylic acid - ibuprofen, clopidogrel - omeprazole, and morphine - oral P2Y₁₂ inhibitors, all of which lead to an attenuated antiplatelet effect. Platelet function and genetic testing and the use of scores (ARC-HBR, PRECISE-DAPT, ESC ischemic risk definition) may contribute to a more tailored antiplatelet therapy. High on-treatment platelet reactivity presents a key problem in the acute management of ST-elevation myocardial infarction (STEMI). A treatment strategy involving early initiation of an intravenous antiplatelet agent may be able to bridge the gap of insufficient platelet inhibition in high ischemic risk patients with STEMI.

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

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

The efficacy and safety of the short-term combination therapy with ticagrelor and PPIs or H2RA in patients with acute STEMI who underwent emergency PCI

Combination therapy with platelet inhibitors and acid-suppressive agents is recommended for patients with acute ST-segment elevation myocardial infarction (STEMI) who underwent percutaneous coronary intervention (PCI), but there remains a paucity of data to evaluate both the efficacy and safety of these combinations. In this prospective study, a total of 170 patients with acute STEMI who underwent PCI were divided into four groups: pantoprazole + ticagrelor, omeprazole + ticagrelor, ranitidine + ticagrelor, and ticagrelor only. The risk of PCI, antithrombotic efficacy, cardiac function, and main end points were evaluated and compared. No significant differences were found in infarction-related artery perfusion indexes (thrombolysis in myocardial infarction [TIMI], corrected TIMI frame count), the incidence of stent thrombosis after PCI, platelet indicators (platelet count, mean platelet volume, and platelet distribution width), platelet activation (P-selectin and glycoprotein IIb/IIIa levels), platelet aggregation (thrombelastography indicators, such as ADP% and MA_ADP ), myocardial necrosis biomarker (creatine kinase isoenzyme-MB and cardiac troponin I) levels, brain natriuretic peptide levels, the incidence of ischemic end point events, and the incidence of other tissue and organ bleeding events among the four groups. The incidence of gastrointestinal (GI) bleeding events in the proton pump-inhibitor (PPI) group was significantly lower than that in the control group, whereas in the H2 receptor antagonist (H2RA) group it was not significantly different from the control group. The short-term combination therapy with ticagrelor and PPIs or H2RA is safe and effective in patients with acute STEMI after PCI. In addition, the PPIs combined with ticagrelor could reduce the incidence of GI bleeding events without increasing the incidence of ischemic events.

Is There an Optimal Antiplatelet Strategy after Gastrointestinal Bleeding in Patients with Coronary Artery Disease?

Gastrointestinal bleeding after percutaneous coronary intervention (PCI) is a not too uncommon clinical situation and is associated with high morbidity and mortality. After initial treatment, a number of clinical decisions must be made weighing the risks of ischemic events and future bleeding. In particular, healthcare providers must carefully balance the effectiveness of antiplatelet therapy in the secondary prevention of coronary events, primarily future spontaneous myocardial infarction and stent thrombosis, against the risk of major, most commonly gastrointestinal bleeding. The first question is whether a dual antiplatelet therapy strategy is required or if a single antiplatelet agent will suffice. Then, if a single antiplatelet agent is adequate, which agent should be continued. Although there is some guidance to answer some of these questions, there are inadequate evidence-based data for others. Below, we review the various considerations and summarize our approach and rationale to manage patients who had gastrointestinal bleeding after PCI.

Systematic Review and Meta-analysis: The Effects of Prophylactic Proton Pump Inhibitor Treatment in Patients With Coronary Heart Disease Receiving Dual Antiplatelet Therapy

Dual antiplatelet therapy (DAPT) and proton pump inhibitors (PPIs) are widely used in clinical treatment. However, the pharmacokinetic interaction between PPIs and DAPT is still unclear in patients with cardiovascular disease. This systematic review and meta-analysis aimed to evaluate the risks and benefits of the combination of PPI and DAPT in patients with coronary heart disease. The PubMed, EMBASE, Cochrane, and Web of Science databases were systematically searched from inception to April 1, 2020, for eligible studies. The outcomes investigated in this study included major adverse cardiovascular events, myocardial infarction, all-cause death, gastrointestinal complications, and platelet function testing. Studies were excluded from the review if other gastrointestinal medication or aspirin or P2Y12 receptor inhibitor monotherapy was administered. The review included 52 studies, and data from 40 studies were extracted for meta-analysis. No association was found between the risk of adverse clinical outcomes and the combination of PPI and DAPT based on the randomized controlled trial data (risk ratio: 0.98; 95% confidence interval: 0.87-1.09; P = 0.877; I2 = 0%). However, an increased risk of adverse clinical outcomes due to the use of PPIs was observed in patients treated with DAPT based on the data from observational studies (risk ratio: 1.259; 95% confidence interval: 1.079-1.468; P = 0.003; I2 = 67.8%), although the heterogeneity of these studies was high. In conclusion, this systematic review and meta-analysis demonstrated that pharmacokinetic interactions between PPI and DAPT do not lead to adverse clinical outcomes.

Multifactorial Background for a Low Biological Response to Antiplatelet Agents Used in Stroke Prevention

Effective platelet inhibition is the main goal of the antiplatelet therapy recommended as a standard treatment in the secondary prevention of non-embolic ischemic stroke. Acetylsalicylic acid (aspirin) and clopidogrel are commonly used for this purpose worldwide. A low biological response to antiplatelet agents is a phenomenon that significantly reduces the therapeutic and protective properties of the therapy. The mechanisms leading to high on-treatment platelet reactivity are still unclear and remain multifactorial. The aim of the current review is to establish the background of resistance to antiplatelet agents commonly used in the secondary prevention of ischemic stroke and to explain the possible mechanisms. The most important factors influencing the incidence of a low biological response were demonstrated. The similarities and the differences in resistance to both drugs are emphasized, which may facilitate the selection of the appropriate antiplatelet agent in relation to specific clinical conditions and comorbidities. Despite the lack of indications for the routine assessment of platelet reactivity in stroke subjects, this should be performed in selected patients from the high-risk group. Increasing the detectability of low antiaggregant responders, in light of its negative impact on the prognosis and clinical outcomes, can contribute to a more individualized approach and modification of the antiplatelet therapy to maximize the therapeutic effect in the secondary prevention of stroke.

The Phenomenon of Clopidogrel High On-Treatment Platelet Reactivity in Ischemic Stroke Subjects: A Comprehensive Review

Clopidogrel is increasingly being used for the secondary prevention of ischemic stroke according to the updated guidelines on acute stroke management. Failure to achieve a drug response is referred to as clopidogrel resistance. Similarly, a higher activation of platelets during clopidogrel therapy—high on-treatment platelet reactivity—is equivalent to a reduced effectiveness of a therapy. Clopidogrel resistance is considered to be a common and multifactorial phenomenon that significantly limits the efficacy of antiplatelet agents. The aim of the current study is to review the latest literature data to identify the prevalance and predictors of clopidogrel high on-treatment platelet reactivity among stroke subjects and to establish the potential impact on clinical outcomes and prognosis. Clinical databases were searched by two independent researchers to select relevant papers on the topic, including all types of articles. Several important predictors contributing to clopidogrel resistance were identified, including genetic polymorphisms, the concomitant use of other drugs, or vascular risk factors, in particular nonsmoking and diabetes. Clopidogrel high on-treatment platelet reactivity has a negative impact on the clinical course of stroke, worsens the early- and long-term prognoses, and increases the risk of recurrent vascular events. Platelet function testing should be considered in selected stroke individuals, especially those predisposed to clopidogrel resistance, for whom an improvement in the efficacy of antiplatelet therapy is essential. This particular group may become the greatest beneficiaries of the modification of existing therapy based on platelet function monitoring.

Is empirical treatment a reasonable strategy for laryngopharyngeal reflux? A contemporary review

BACKGROUND

Diagnosis and treatment of presumed laryngopharyngeal reflux (LPR) remain controversial. Empiric medication trials remain widespread for suspected LPR despite emerging evidence against proton pump inhibitor (PPI) safety and for pepsin as a mediator of LPR symptoms. Ongoing concerns exist related to inaccurate diagnosis, the cost and morbidity of potentially unnecessary PPI prescriptions, and availability and interpretation of objective reflux testing.

OBJECTIVES

To review contemporary evidence that does and does not support empiric medication trials for presumed LPR.

METHODS

PubMed, Scopus and Cochrane Library were searched for literature about benefits, limitations and alternatives to empiric medication trial for LPR, in order to present both sides of this debate and identify best practices.

RESULTS

The majority of physicians perform prolonged empiric medication trial with PPIs for patients with suspected LPR. Because symptoms and signs of LPR are non-specific, empiric medication trials require exclusion of other conditions that can mimic LPR. Following a PPI empiric medication trial, over one-third of patients remain non-responders. The use of hypopharyngeal-oesophageal multichannel intraluminal impedance-pH monitoring (HEMII-pH) has benefits and limitations in objective diagnosis of LPR.

CONCLUSIONS

Use of PPIs for single-agent empiric medication trial does not account for possible non-responders with non-acid or mixed LPR. If LPR diagnosis remains uncertain, alginates can be added to PPI trials. HEMII-pH testing upfront is ideal for patients with suspected LPR, but not always practical; it is indicated when PPI and alginate empiric medication trials have failed or when comorbidities confuse the diagnosis. A more comprehensive, combination therapy empiric medication trial regimen may be needed.

The Clinician's Guide to Proton Pump Inhibitor Related Adverse Events

A substantial volume of literature exists linking proton pump inhibitor (PPI) use with a multitude of serious adverse events. There is uncertainty, however, over whether these associations are clinically important. Excessive concern about PPI-related adverse events may leave patients at risk of harm by leaving acid-related upper gastrointestinal disease untreated. Conversely, the risk of treatments may outweigh the benefits if any of the purported adverse events are directly caused by PPI use; this is of particular concern where indications for PPI use are not present. In this paper, we review the studies which have reported associations between adverse events and PPI use, discuss the proposed mechanisms of action, grade the confidence in whether these associations are truly causal, and provide advice regarding balancing the benefits of PPI use against their possible harms.

Different Clopidogrel Response Elicited by Lansoprazole or Esomeprazole in Patients Undergoing Neurointervention with Dual Antiplatelet Therapy

BACKGROUND

Aspirin-clopidogrel dual antiplatelet therapy and a proton-pump inhibitor are used worldwide to prevent thromboembolism and peptic ulceration in patients undergoing neurointervention. We performed VerifyNow assays (Accumetrics, San Diego, CA, USA) to retrospectively examine the relationship between the effectiveness of antiplatelet agents and different proton-pump inhibitor types.

METHODS

Sixty-four patients with unruptured intracranial aneurysm scheduled for neurointervention received aspirin-clopidogrel dual antiplatelet therapy plus the proton-pump inhibitor lansoprazole (n = 34) or esomeprazole (n = 30). A low response to aspirin and clopidogrel was defined in terms of aspirin reaction units > 550 and P2Y12 reaction units ≥ 230, respectively, by VerifyNow assay. The characteristics, response to antiplatelet therapy, and clinical outcomes were compared in patients treated with lansoprazole or esomeprazole.

RESULTS

The preoperative mean VerifyNow aspirin reaction units and P2Y12 reaction units were 466.0 ± 67.3 and 205.0 ± 67.6, respectively. The mean aspirin reaction unit value was 482.0 ± 64.1 in the lansoprazole group, and 461.5 ± 70.9 in the esomeprazole group (p = 0.77). The mean P2Y12 reaction unit was 220.0 ± 64.4 in the lansoprazole group, and 174.5 ± 65.0 in the esomeprazole group; there was a significant difference in the clopidogrel response of patient treated with lansoprazole or esomeprazole (p = 0.005).

CONCLUSIONS

Our VerifyNow assay results suggest that when on lansoprazole fewer patients achieved the therapeutic goal and required extra therapy before neurointervention.

Trends in concomitant clopidogrel and proton pump inhibitor treatment among ACS inpatients, 2000-2016

PURPOSE

The US Food and Drug Administration (FDA) issued three safety announcements between January 2009 and October 2010 warning against concomitant use of clopidogrel and proton pump inhibitors (PPIs) due to a potential drug-drug interaction that may attenuate clopidogrel's antiplatelet activity. This primary objective of this study was to examine trends in concomitant clopidogrel/PPI use among acute coronary syndrome (ACS) inpatients in the US between 2000 and 2016, in relation to the FDA safety communications.

METHODS

Adult inpatients with a primary diagnosis of ACS were identified from the Cerner Health Facts® database. The standardized (age, sex, race, and census region) prevalence of clopidogrel use with PPIs was calculated yearly and quarterly. Findings were stratified by PPIs' potential to inhibit clopidogrel's activity and by age.

RESULTS

A total of 204,533 inpatients were identified. In 2008, the prevalence of concomitant clopidogrel and PPI treatment was 34.9%, decreasing to 24.4 and 16.4% in 2009 and 2010, respectively, with the decline being similar across age groups. Treatment with inhibiting PPIs (omeprazole and esomeprazole) and clopidogrel has continued to decrease since 2010, with a prevalence of 0.8% in 2016. A similar reduction was not observed with clopidogrel and non-inhibiting PPIs (pantoprazole, lansoprazole, rabeprazole, and dexlansoprazole). During the FDA warning period, the combined treatment with clopidogrel and H₂ receptor antagonists, an alternative to PPIs suggested by the FDA, temporarily increased from 7.8% in 2008 to 12.8 and 14.5% in 2009 and 2010, respectively.

CONCLUSIONS

Findings suggest that clinical practice recommendations made by the FDA were followed. Further research is needed to determine how changes in drug labels and the availability of new drugs may have influenced the observed trends.

Consensus Document ANMCO/ANCE/ARCA/GICR-IACPR/GISE/SICOA: Long-term Antiplatelet Therapy in Patients with Coronary Artery Disease

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor is the cornerstone of pharmacologic management of patients with acute coronary syndrome (ACS) and/or those receiving coronary stents. Long-term (>1 year) DAPT may further reduce the risk of stent thrombosis after a percutaneous coronary intervention (PCI) and may decrease the occurrence of non-stent-related ischaemic events in patients with ACS. Nevertheless, compared with aspirin alone, extended use of aspirin plus a P2Y12 receptor inhibitor may increase the risk of bleeding events that have been strongly linked to adverse outcomes including recurrent ischaemia, repeat hospitalisation and death. In the past years, multiple randomised trials have been published comparing the duration of DAPT after PCI and in ACS patients, investigating either a shorter or prolonged DAPT regimen. Although the current European Society of Cardiology guidelines provide a backup to individualised treatment, it appears to be difficult to identify the ideal patient profile which could safely reduce or prolong the DAPT duration in daily clinical practice. The aim of this consensus document is to review contemporary literature on optimal DAPT duration, and to guide clinicians in tailoring antiplatelet strategies in patients undergoing PCI or presenting with ACS.

Pharmacogenomic Impact of CYP2C19 Variation on Clopidogrel Therapy in Precision Cardiovascular Medicine

Variability in response to antiplatelet therapy can be explained in part by pharmacogenomics, particularly of the CYP450 enzyme encoded by CYP2C19. Loss-of-function and gain-of-function variants help explain these interindividual differences. Individuals may carry multiple variants, with linkage disequilibrium noted among some alleles. In the current pharmacogenomics era, genomic variation in CYP2C19 has led to the definition of pharmacokinetic phenotypes for response to antiplatelet therapy, in particular, clopidogrel. Individuals may be classified as poor, intermediate, extensive, or ultrarapid metabolizers, based on whether they carry wild type or polymorphic CYP2C19 alleles. Variant alleles differentially impact platelet reactivity, concentration of plasma clopidogrel metabolites, and clinical outcomes. Interestingly, response to clopidogrel appears to be modulated by additional factors, such as sociodemographic characteristics, risk factors for ischemic heart disease, and drug-drug interactions. Furthermore, systems medicine studies suggest that a broader approach may be required to adequately assess, predict, preempt, and manage variation in antiplatelet response. Transcriptomics, epigenomics, exposomics, miRNAomics, proteomics, metabolomics, microbiomics, and mathematical, computational, and molecular modeling should be integrated with pharmacogenomics for enhanced prediction and individualized care. In this review of pharmacogenomic variation of CYP450, a systems medicine approach is described for tailoring antiplatelet therapy in clinical practice of precision cardiovascular medicine.

Platelet function variability and non-genetic causes

Dual antiplatelet therapy (DAPT) has been established for the treatment of coronary artery disease, especially in and after acute coronary syndromes, and after coronary interventions. Data suggest that a significant percentage of individuals treated with clopidogrel do not receive the expected therapeutic benefit because of a decreased responsiveness of their platelets, which is caused by several extrinsic and intrinsic mechanisms. The clinical consequence of clopidogrel non-responsiveness is severe cardiovascular complications. Besides genetic variability in response to antiplatelet therapy, non-genetic causes such as drug interactions (proton-pump inhibitors, statins, calcium-channel blockers, coumarine derivates, antibiotics, antimycotics) and co-morbidities (diabetes mellitus, renal failure, obesity) are responsible for this phenomenon. Large clinical trials with standardised laboratory methods and hard clinical endpoints are needed to identify these interactions with clopidogrel and predictors for its non-responsiveness.

Proton-pump inhibitors: understanding the complications and risks

Proton-pump inhibitors (PPIs) are the most effective therapy for the full spectrum of gastric-acid-related diseases. However, in the past decade, a steadily increasing list of complications following long-term use of PPIs has been reported. Their potent acid-suppressive action induces several structural and functional changes within the gastric mucosa, including fundic gland polyps, enterochromaffin-like cell hyperplasia and hypergastrinaemia, which can be exaggerated in the presence of Helicobacter pylori infection. As discussed in this Review, most associations of PPIs with severe adverse events are not based on sufficient evidence because of confounding factors and a lack of plausible mechanisms. Thus, a causal relationship remains unproven in most associations, and further studies are needed. Awareness of PPI-associated risks should not lead to anxiety in patients but rather should induce the physician to consider the appropriate dosing and duration of PPI therapy, including long-term monitoring strategies in selected groups of patients because of their individual comorbidities and risk factors.

How to improve the concept of individualised antiplatelet therapy with P2Y12 receptor inhibitors – is an algorithm the answer?

Within the past decade, high on-treatment platelet reactivity (HTPR) on clopidogrel and its clinical implications have been frequently discussed. Although it has been previously assumed that HTPR is a phenomenon occurring only in patients treated with clopidogrel, recent data show that HTPR might also occur during treatment with prasugrel or ticagrelor in the acute phase of ST-elevation myocardial infarction. Moreover, it has been postulated that there is a therapeutic window for P2Y12 receptor blockers, thus indicating that HTPR is associated with thrombotic events whereas low on-treatment platelet reactivity (LTPR) is associated with bleeding events. The current paper focuses on tools to identify risk factors for HTPR (pharmacogenomic testing, clinical scoring and drug-drug interactions) and on the use of platelet function testing in order to identify patients who might not respond adequately to clopidogrel. The majority of recent clinical randomised trials have not supported the hypothesis that platelet function testing and tailored antiplatelet therapy are providing a favourable clinical outcome. These trials, mainly performed in low-to-moderate risk patients, will be reviewed and discussed. Finally, an algorithm based on current knowledge is suggested, which might be of use for design of clinical trials.

The effect of acenocoumarol on the antiplatelet effect of clopidogrel

Patients exhibiting high on-clopidogrel platelet reactivity (HPR) are at an increased risk of atherothrombotic events following percutaneous coronary interventions (PCI). The use of concomitant medication which is metabolised by the hepatic cytochrome P450 system, such as phenprocoumon, is associated with HPR. We assessed the level of platelet reactivity on clopidogrel in patients who received concomitant treatment with acenocoumarol (another coumarin derivative). Patients scheduled for PCI were included in a prospective, single centre, observational registry. Patients who were adequately pre-treated with clopidogrel were eligible for this analysis, which included 1,582 patients, of whom 104 patients (6.6 %) received concomitant acenocoumarol treatment. Platelet reactivity, as measured with the VerifyNow P2Y12 assay and expressed in P2Y12 Reaction Units (PRU), was significantly higher in patients on concomitant acenocoumarol treatment (mean PRU 229 ± 88 vs 187 ± 95; p< 0.001). In patients with concomitant acenocoumarol use, the proportion of patients with HPR was higher, defined as PRU > 208 (57.7 % vs 41.1 %; p=0.001) and PRU236 (49.0 % vs 31.4 %; p< 0.001). In multivariable analysis, concomitant acenocoumarol use was independently associated with a higher PRU and the occurrence of HPR defined as PRU236 (OR 2.00, [1.07–3.79]), but not with HPR defined as PRU > 208 (OR 1.37, [0.74–2.54]). PRU also was significantly increased after 1:1 propensity matching (+28.2; p< 0.001). As this was an observational study, confounding by indication cannot be excluded, although multivariable analyses and propensity matching were performed. The impact of the findings from this hypothesis-generating study on clinical outcome requires further investigation.

Third generation P2Y12 antagonists inhibit platelet aggregation more effectively than clopidogrel in a myocardial infarction registry

The current standard of antiplatelet therapy of patients after myocardial infarction includes the P2Y12 receptor antagonists clopidogrel, prasugrel or ticagrelor. This study aimed to compare the antiplatelet effect of clopidogrel, prasugrel and ticagrelor in patients after myocardial infarction. In a single-centre registry the antiplatelet effect of clopidogrel, prasugrel and ticagrelor was investigated by aggregometry in patients after myocardial infarction. To assess the overall capacity of platelet aggregation whole blood was induced with thrombin receptor activating peptide (TRAP; 32 μM). To specifically quantify the effect of P2Y12 antagonists, whole blood was stimulated with 6.4 μM adenosine diphophosphate (ADP). Relative ADP induced aggregation (r-ADP-agg) was defined as the ADP-TRAP ratio to reflect an individual degree of P2Y12-dependent platelet inhibition. Platelet function of 238 patients was analysed [clopidogrel (n=58), prasugrel (n=65), ticagrelor (n=115)]. The r-ADP-agg was 35 ± 14% for patients receiving clopidogrel, 28 ± 10% for patients receiving prasugrel and 26 ± 11% for patients receiving ticagrelor. The r-ADP-agg was significantly lower in patients treated with prasugrel (p=0.0024) or ticagrelor (p<0.0001) compared to clopidogrel. There was no significant difference between patients receiving prasugrel or ticagrelor (p=0.2559). In conclusion, prasugrel and ticagrelor provide a stronger platelet inhibition compared to clopidogrel in patients after myocardial infarction. No significant difference in platelet inhibition was detected between prasugrel and ticagrelor. (registry for patients after Myocardial Infarction Treated with AntiPlatelet agents; DRKS00003146).

Multiple electrode aggregometry and vasodilator stimulated phosphoprotein-phosphorylation assay in clinical routine for prediction of postprocedural major adverse cardiovascular events

Reduced antiplatelet effect of clopidogrel assessed with multiple electrode aggregometry (MEA) and vasodilator stimulated phosphoprotein-phosphorylation (VASP-P) assay has been proven to predict major adverse cardiovascular events (MACE) after coronary stenting. So far no consecutive registry has evaluated the usefulness of different adenosine diphosphate-based platelet function tests to predict outcome in unselected patients. Hence, our objective was to determine the feasibility of MEA and VASP-P for clinical routine and whether low-response to clopidogrel as determined by MEA and/or the VASP-P assays predicts MACE in a “real-life” population undergoing coronary stenting. Threehundred consecutive patients were included in this prospective registry. Blood was sampled 6–24 hours after stenting to measure MEA and VASP-P. The use of glycoprotein-IIb/IIIa-blockers limited MEA to 196 measurements. Concerning the VASP-P assay, 300 measurements were achieved. Receiver Operating Characteristics (ROC)-curves of sensitivity and specificity estimates for MACE were plotted for VASP-P assay. The area under the ROC-curve was 0.683 (p=0.014) for the platelet reactivity index (PRI) calculated from median fluorescence intensities (FI) with an optimal cut-off at 60.2% PRI. Patients above 60.2% had a significantly increased risk for MACE at six months follow-up (p=0.007). Estimating the cut-offs for the PRI from mean FI (52%) or from geometric mean FI (56.6%) led to clinically relevant differences. VASP-P assay is feasible for clinical routine to measure clopidogrel effects and to predict post-procedural MACE in unselected patients. With regard to differing cut-offs, exact standardisation of the VASP-P assay is mandatory. The use of GP-IIb/IIIa-blockers prevents MEA testing and limits its usability in unselected patients.

High platelet reactivity and clinical outcome – Fact and fiction

In patients suffering from acute coronary syndromes or undergoing percutaneous coronary intervention, oral antiplatelet treatment is routinely administered with the primary aim of inhibiting platelet-mediated thrombus formation and subsequent abrupt vessel occlusion. Simultaneous inhibition of blood platelet cyclooxygenase-1 by aspirin and of the P2Y12 receptor by clopidogrel or prasugrel is currently recommended in this setting. Inter-individual response variability to aspirin and especially to clopidogrel is the subject of much debate as evidence has grown over the years linking an attenuated response to treatment with the occurrence of ischaemic events. Consequently, the clinical entity of high (on-treatment) platelet reactivity (HPR) was born and subsequently characterised in numerous studies over the last decade. Until recently, alternative treatment options were limited in patients exhibiting HPR. At present the antiplatelet therapy landscape is changing with the advent of prasugrel and ticagrelor as alternative and more potent treatment options. Different tests for monitoring platelet function are available and are being increasingly employed in research projects and clinical routine. These tests may prove useful for achieving optimal platelet inhibition for the individual patient, and several centres now incorporate such testing in day-to-day practice. Widespread adoption of this practice and incorporation into clinical guidelines awaits the results of ongoing trials in which treatment is changed based on platelet function monitoring. This review aims to summarise available facts and fiction in relation to platelet function testing and reactivity with a particular focus on P2Y12 receptor inhibition in patients undergoing coronary stent placement.

Comparative Study of Effects of Vonoprazan and Esomeprazole on Antiplatelet Function of Clopidogrel or Prasugrel in Relation to CYP2C19 Genotype

Drug-drug interaction between antiacid and antiplatelet agents has not been fully elucidated. Vonoprazan, a new potassium competitive acid blocker, has been available in Japan. CYP2C19 and CYP3A4 are involved in the metabolism of clopidogrel, prasugrel, esomeprazole, and vonoprazan. Using a P2Y12 assay, we compared the effects of vonoprazan and esomeprazole on the antiplatelet functions of clopidogrel or prasugrel in 31 healthy Japanese volunteers (14 CYP2C19 homo-extensive (homo-EMs), nine hetero-extensive (hetero-EMs), and eight poor metabolizers (PMs)). Vonoprazan decreased the median inhibition of platelet aggregation (IPA) values of clopidogrel and prasugrel more potently than esomeprazole (P < 0.001 for clopidogrel and P = 0.011 for prasugrel). The same tendencies were observed when stratified by CYP2C19 genotype groups (P = 0.004 in homo-EMs, 0.033 in hetero-EMs, and 0.043 in PMs). Vonoprazan attenuated the antiplatelet function of clopidogrel more potently than esomeprazole. Esomeprazole did not affect that of prasugrel irrespective of CYP2C19 genotype.

Influence of low-dose proton pump inhibitors administered concomitantly or separately on the anti-platelet function of clopidogrel

Proton pump inhibitors (PPIs) at low doses can effectively prevent gastrointestinal bleeding due to aspirin and are widely used in Japan for gastroprotection in patients taking anti-platelet agents. We examined the influence of different PPIs at low doses administered concomitantly or separately on anti-platelet functions of clopidogrel. In 41 healthy Japanese volunteers with different CYP2C19 genotypes who took clopidogrel 75 mg in the morning alone, or with omeprazole 10 mg, esomeprazole 10 mg, lansoprazole 15 mg, or rabeprazole 10 mg, either concomitantly in the morning or separately in the evening, we measured the inhibition of platelet aggregation (IPA, %) using VerifyNow P2Y12 assay at 4 h after the last clopidogrel dose on Day 7 of each regimen. IPA by clopidogrel with rabeprazole administered at lunchtime, approximately 4 h after clopidogrel, was also measured. Mean IPAs in those concomitantly receiving omeprazole, esomeprazole, lansoprazole or rabeprazole (47.2 ± 21.1%, 43.2 ± 20.2%, 46.4 ± 18.8%, and 47.3 ± 19.2%, respectively) were significantly decreased compared with those receiving clopidogrel alone (56.0%) (all ps < 0.001). This decrease was observed when PPIs were administered separately in the evening. However, IPA by clopidogrel with rabeprazole administered at lunchtime was 51.6%, which was markedly similar to that of clopidogrel alone (p = 0.114). All tested PPIs reduce the efficacy of clopidogrel when administered concomitantly. Our preliminary data suggest that administration of rabeprazole 4 h following clopidogrel may minimize potential drug-drug interactions.

Thienopyridines in Acute Coronary Syndrome

OBJECTIVE:

To evaluate the safety and efficacy of the thienopyridines in order to identify their current place in therapy for the treatment of acute coronary syndrome (ACS).

DATA SOURCES:

Literature was accessed through MEDLINE (1966-October 2010 week 1), EMBASE (1980–2010 week 40), and a bibliographic review of published articles using the search terms acute coronary syndrome, clopidogrel, and prasugrel. Articles were limited to clinical trials conducted in humans and published in the English language.

STUDY SELECTION AND DATA EXTRACTION:

Head-to-head clinical trials evaluating the safety and efficacy of the thienopyridines in patients with ACS were critically reviewed. Trials evaluating ticlopidine were excluded due to its limited clinical use.

DATA SYNTHESIS:

Thienopyridines are an integral part of the treatment of ACS. Prior to the approval of prasugrel, clopidogrel was considered the agent of choice due to safety concerns associated with ticlopidine. A randomized controlled trial comparing prasugrel and clopidogrel has demonstrated superior efficacy with prasugrel, and post hoc analyses suggest additional benefit with prasugrel is derived in patients with ST-segment elevation myocardial infarction and patients with diabetes. However, safety concerns exist linking prasugrel with an increased risk of bleeding, which diminishes its advantage in elderly patients, underweight patients, and those with a history of stroke. Pharmacokinetic and pharmacodynamic studies discussing differences in response variability, platelet inhibition, interactions with proton pump inhibitors, and genetic factors between the thienopyridines are numerous, although more clinical data are needed to determine clinical implications.

CONCLUSIONS:

Clinical trial data have suggested prasugrel is superior to clopidogrel at preventing ischemic events in patients with ACS undergoing percutaneous coronary intervention. However, this coincides with an increased risk of bleeding. Clinicians must carefully interpret the current evidence, including limitations in study design and pharmacologic differences between agents, in order to balance the risks and benefits as new data become available.

The Personalization of Clopidogrel Antiplatelet Therapy: The Role of Integrative Pharmacogenetics and Pharmacometabolomics

Dual antiplatelet therapy of aspirin and clopidogrel is pivotal for patients undergoing percutaneous coronary intervention. However, the variable platelets reactivity response to clopidogrel may lead to outcome failure and recurrence of cardiovascular events. Although many genetic and nongenetic factors are known, great portion of clopidogrel variable platelets reactivity remain unexplained which challenges the personalization of clopidogrel therapy. Current methods for clopidogrel personalization include CYP2C19 genotyping, pharmacokinetics, and platelets function testing. However, these methods lack precise prediction of clopidogrel outcome, often leading to insufficient prediction. Pharmacometabolomics which is an approach to identify novel biomarkers of drug response or toxicity in biofluids has been investigated to predict drug response. The advantage of pharmacometabolomics is that it does not only predict the response but also provide extensive information on the metabolic pathways implicated with the response. Integrating pharmacogenetics with pharmacometabolomics can give insight on unknown genetic and nongenetic factors associated with the response. This review aimed to review the literature on factors associated with the variable platelets reactivity response to clopidogrel, as well as appraising current methods for the personalization of clopidogrel therapy. We also aimed to review the literature on using pharmacometabolomics approach to predict drug response, as well as discussing the plausibility of using it to predict clopidogrel outcome.

[Prevalence and prognosis of aspirin resistance in critical limb ischemia patients]

OBJECTIVES

To assess the prevalence and the association between aspirin resistance in critical limb ischemia patients using the VerifyNow^® bed-side platelet test, and occurrence of cardiovascular morbidity and/or death at one year.

MATERIALS AND METHODS

National multicenter prospective observational study related to COPART II centers. From 2010 through 2014, 64 subjects hospitalized for critical limb ischemia and already treated by aspirin before the VerifyNow^® test were included. A VerifyNow^® test>550 ARU was defined as aspirin resistance. Critical limb ischemia was defined according to the TASC I criteria. The primary outcome was a composite including death, acute coronary syndrome, stroke and major amputation during the one-year follow-up period.

RESULTS

In all, 9/64 patients were aspirin resistant, the status was confirmed in one case. The prevalence of aspirin resistance was 14.06%. There was no significant difference between aspirin resistant and aspirin non-resistant groups in terms of cardiovascular history and glycemia status. Neither was there significant difference between the two groups in terms of survival.

CONCLUSION

Aspirin resistance was not predictive of poorer survival in critical limb ischemia patients. However, our population was limited. Considering that a clear definition of aspirin resistance and standardized diagnostic tests are lacking, complementary studies might be useful.

Effect of long-term adherence to clopidogrel on the VASP-PRI after elective coronary stent implantation: a randomized controlled study

AIMS

The biological response to clopidogrel is highly variable and a poor responsiveness is associated with major adverse cardiac events. Adherence to therapy is a major cause of poor responsiveness but its impact on long-term platelet inhibition is unknown. The objective of the present study was to evaluate the effect of different programmes monitoring adherence to clopidogrel on platelet reactivity.

METHODS

The study took the form of a monocentric, parallel group, randomized controlled trial. Adults treated with clopidogrel 75 mg after elective coronary stenting were randomized into one of three groups: (i) a standard of care group; (ii) a standard of care + adherence electronic monitoring group, in which drug intake was recorded but kept blinded until the study end; or (iii) an integrated care group, with regular feedback on recorded adherence. Clopidogrel response was assessed with the vasodilator-stimulated phosphoprotein-platelet reactivity index (VASP-PRI) at randomization, 3 months and 6 months.

RESULTS

A total of 123 adults were enrolled and randomized. Baseline VASP-PRI was highly variable, with a mean of 48 ± 18.8%. No difference between groups in VASP-PRI was found at 6 months (P = 0.761), despite better adherence to clopidogrel in the integrated care group. However, adherence (P = 0.035) and baseline VASP-PRI (P = 0.015) were associated with VASP-PRI at 3 months and 6 months. The association between adherence and VASP-PRI was lost in patients with baseline VASP-PRI > 50%. Diabetes, CYP2C19*2 carrier status and body mass index were significant predictors of VASP-PRI.

CONCLUSIONS

The platelet response to clopidogrel during chronic therapy remained highly variable, despite high adherence. Different adherence monitoring programmes did not affect VASP-PRI at 6 months. Poor adherence is associated with lower VASP-PRI only in initial good responders to clopidogrel.

The effects of clopidogrel and omeprazole on platelet function in normal dogs

Omeprazole is used concurrently with clopidogrel to reduce gastrointestinal adverse effects. In humans, the concurrent use of these two drugs can reduce the antiplatelet efficacy of clopidogrel. Our objective was to determine the effects of omeprazole and clopidogrel on platelet function in healthy dogs. A crossover study utilized turbidimetric aggregometry (ADP and collagen) and the PFA-100^® with the collagen/ADP cartridge to evaluate platelet function in eight healthy dogs during the administration of clopidogrel (1 mg/kg/24 h p.o.), omeprazole (1 mg/kg/24 h p.o.), and a combination of clopidogrel and omeprazole. Drug metabolite concentrations were also measured. Compared to pretreatment, on Days 3 and 5, with ADP as the agonist, there was a significant decrease in maximum amplitude on aggregometry for both clopidogrel and clopidogrel/omeprazole groups. The following revealed no significant differences between clopidogrel and clopidogrel/omeprazole groups when compared on Days 3 and 5: maximum amplitude on aggregometry with ADP or collagen agonists, and PFA-100^® closure times. When compared to the clopidogrel group, clopidogrel metabolite concentrations in the clopidogrel/omeprazole group were significantly higher on Days 3 and 5. The concurrent administration of omeprazole and clopidogrel in healthy dogs was associated with an increase in the plasma concentration of an inactive metabolite of clopidogrel, but does not significantly alter the antiplatelet effects of clopidogrel.

Non-Carriers of Reduced-Function CYP2C19 Alleles are Most Susceptible to Impairment of the Anti-Platelet Effect of Clopidogrel by Proton-Pump Inhibitors: A Pilot Study

BACKGROUND

The phenomenon of CYP2C19 polymorphism affects the metabolism of both clopidogrel and proton-pump inhibitors (PPI). However, concomitant use of both drugs may reduce the desired therapeutic effects. In this study, we evaluated whether individuals with different numbers of reduced-function CYP2C19 alleles were equally affected and whether PPIs with different dependencies on CYP2C19 metabolism were equally involved.

METHODS

Thirty healthy volunteers were recruited to a six-week regimen of clopidogrel. Three PPIs with different metabolic dependencies on CYP2C19 were included and separately administered in this order. Each PPI was given for a week, followed by a one-week washout period before the intervention of the next PPI. The anti-platelet effect was examined by Thromboelastography Platelet Mapping(TM) (TEG®) and vasodilator-stimulated phosphoprotein (VASP) assays.

RESULTS

Both TEG® and VASP tests showed the same general qualitative trend, but TEG® detected a statistically significant fluctuation of platelet aggregation in response to different drug interventions. The TEG® results also demonstrated that non-carriers experienced the most significant impairment of anti-platelet effect of clopidogrel after concomitant use of PPIs. This impairment was closely related to the metabolic dependence on CYP2C19 of PPI.

CONCLUSIONS

Our study indicated that non-carriers of reduced-function CYP2C19 alleles are most susceptible to impairment of the anti-platelet effect of clopidogrel after concomitant PPI use. Individual subjects are not equally affected, and PPIs are not equally involved. However, large-scale randomized clinical trials are needed to evaluate the clinical outcome.

KEY WORDS

Clopidogrel • CYP2C19 polymorphism • Platelet aggregation • Proton pump inhibitors • TEG • VASP.

In Vitro Effects of Pantoprazole on Platelet Aggregation in Blood Samples From Clopidogrel and Aspirin-treated Patients

Platelet inhibition during treatment with the antiplatelet drug clopidogrel is prone to great interindividual variability and is believed to be affected by several factors such as genetics and drug-drug interactions. Proton pump inhibitors have been shown to interfere with the liver metabolism of clopidogrel. However, there are limited data on any direct effects proton pump inhibitors may have on clopidogrel. The aim of the study was to evaluate whether the in vitro addition of pantoprazole affects platelet aggregation in blood samples from clopidogrel and aspirin-treated patients. Blood samples were drawn from 66 patients on clopidogrel and aspirin who underwent coronary angiography. Platelet aggregation was analyzed using the bed-side Plateletworks assay before and after the addition of 2 different amounts of pantoprazole. The addition of 2.5 μL (4 mg/mL) pantoprazole, final concentration 0.01 mg/mL, was followed by a significant reduction (26%, P ≤ 0.001) of platelet aggregation, which was further reduced (39%, P ≤ 0.001) when a higher dose, 10 μL (4 mg/mL), final concentration 0.04 mg/mL, was added. In conclusion, platelet aggregation was significantly decreased by in vitro addition of pantoprazole. To explore the clinical relevance of this, future studies are needed.

Impact of concomitant use of proton pump inhibitors and clopidogrel or ticagrelor on clinical outcomes in patients with acute coronary syndrome

Background

There is great debate on the possible adverse interaction between proton pump inhibitors (PPIs) and clopidogrel. In addition, whether the use of PPIs affects the clinical efficacy of ticagrelor remains less known. We aimed to determine the impact of concomitant administration of PPIs and clopidogrel or ticagrelor on clinical outcomes in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI).

Methods

We retrospectively analyzed data from a “real world”, international, multi-center registry between 2003 and 2014 (n = 15,401) and assessed the impact of concomitant administration of PPIs and clopidogrel or ticagrelor on 1-year composite primary endpoint (all-cause death, re-infarction, or severe bleeding) in patients with ACS after PCI.

Results

Of 9429 patients in the final cohort, 54.8% (n = 5165) was prescribed a PPI at discharge. Patients receiving a PPI were older, more often female, and were more likely to have comorbidities. No association was observed between PPI use and the primary endpoint for patients receiving clopidogrel (adjusted HR: 1.036; 95% CI: 0.903–1.189) or ticagrelor (adjusted HR: 2.320; 95% CI: 0.875–6.151) (P_interaction = 0.2004). Similarly, use of a PPI was not associated with increased risk of all-cause death, re-infarction, or a decreased risk of severe bleeding for patients treated with either clopidogrel or ticagrelor.

Conclusions

In patients with ACS following PCI, concomitant use of PPIs was not associated with increased risk of adverse outcomes in patients receiving either clopidogrel or ticagrelor. Our findings indicate it is reasonable to use a PPI in combination with clopidogrel or ticagrelor, especially in patients with a higher risk of gastrointestinal bleeding.

Proton pump inhibitors and other disease-based factors in the recurrence of adverse cardiovascular events following percutaneous coronary angiography: A long-term cohort

BACKGROUND

Dual aspirin-clopidogrel antiplatelet therapy (DAPT) has been shown to decrease the risk of adverse cardiac events after percutaneous coronary intervention (PCI). Proton pump inhibitors (PPIs) are used in these patients to decrease the risk of gastrointestinal bleeding and several studies have reported potential interaction and conflicting clinical outcomes with their use. We aim to assess the effect of different PPIs and other factors on the recurrence of cardiovascular (CV) events in patients following PCI.

METHODS

We performed a retrospective cohort on patients who underwent PCI in the last 5 years and were discharged with or without PPIs. Strict inclusion criteria were adopted, outcome measures were defined, and patient follow up up to 2 years was collected.

RESULTS

Out of 740 patients, 453 (61.2 %) had received PPIs and 287 (38.8 %) were discharged without PPIs. Ninety-five (12.8 %) patients were readmitted due to adverse CV events. Statistically, there was no significant difference in the recurrence of CV events with the use of different PPIs (p = 0.384) and PPI use had an overall protective effect (p = 0.009, HR 0.58 (CI 0.39-0.88). Patients with history of diabetes mellitus (p = 0.048) had an increased risk of adverse CV events.

CONCLUSION

We conclude that pharmacokinetic interaction between PPIs and antiplatelet therapy is not associated with adverse CV events. A comprehensive, multicenter, open-label trial including all PPI subclasses and patient and disease-based factors is warranted for a fair evaluation.

Effects of omeprazole or pantoprazole on platelet function in non-ST-segment elevation acute coronary syndrome patients receiving clopidogrel

BACKGROUND

This study evaluated the effect of omeprazole or pantoprazole on platelet reactivity in non-ST-segment elevation acute coronary syndrome (NSTE-ACS) patients receiving clopidogrel.

METHODS

Consecutive patients with NSTE-ACS (n = 620) from general hospital of Shenyang Military Command were randomized to the omeprazole or pantoprazole (20 mg/d) group (1:1), and received routine dual antiplatelet treatment. Patients' reversion rate of adenosine diphosphate-induced platelet aggregation (ADP-PA) was assessed at baseline, 12 to 24 h after administration of medication, and after 72 h of percutaneous coronary intervention (PCI). The primary endpoint of the study was platelet reactivity assessed with ADP-PA at 30 days after PCI. Adverse events (AEs) were recorded for 30-day and 180-day follow-up periods.

RESULTS

There were no significant differences between both the groups in platelet response to clopidogrel at 12-24 h after drug administration (54.09% ± 18.90% vs 51.62% ± 19.85%, P = 0.12), 72 h after PCI (52.15% ± 19.45% vs 49.66% ± 20.05%, P = 0.18), and 30 days after PCI (50.44% ± 14.54% vs 48.52% ± 15.08%, P = 0.17). The rate of AEs did not differ significantly between groups during the 30-day (15.2% vs 14.8%, P = 0.91) and 180-day (16.5% vs 14.5%, P = 0.50) follow-up periods after PCI.

CONCLUSIONS

The addition of omeprazole or pantoprazole to clopidogrel did not restrict the effect of platelet aggregation by reducing the conversion of clopidogrel. Compared with clopidogrel alone, pantoprazole-clopidogrel and omeprazole-clopidogrel combinations did not increase the incidence of adverse clinical events during 30-day and 180-day follow-up periods after PCI.

TRIAL REGISTRATION

The study is registered in the National Institutes of Health website with identifier NCT01735227. Registered 14 November 2012.

Proton Pump Inhibitors in Cardiovascular Disease: Drug Interactions with Antiplatelet Drugs

Aspirin and P2Y₁₂ receptor antagonists are widely used across the spectrum of cardiovascular diseases. Upper gastrointestinal complications, including ulcer and bleeding, are relatively common during antiplatelet treatment and, therefore, concomitant proton pump inhibitor (PPI) treatment is often prescribed.PPIs provide gastroprotection by changing the intragastric milieu, essentially by raising intragastric pH. In recent years, it has been heavily discussed whether PPIs may reduce the cardiovascular protection by aspirin and, even more so, clopidogrel. Pharmacodynamic and pharmacokinetic studies suggested an interaction between PPIs and clopidogrel, and subsequent clinical studies were conducted to evaluate the clinical impact of this interaction. More recently, it was reported that PPIs may also attenuate the antiplatelet effect of aspirin. This may be clinically important, because a fixed combination of aspirin and a PPI (esomeprazole) has recently been approved and because aspirin is the most widely used drug in patients with cardiovascular disease. The antiplatelet effect of the new P2Y₁₂ receptor antagonists, ticagrelor and prasugrel, seems less influenced by PPI co-treatment.Given the large number of patients treated with antithrombotic drugs and PPIs, even a minor reduction of platelet inhibition potentially carries considerable clinical impact. The present book chapter summarizes the evidence regarding the widespread use of platelet inhibitors and PPIs in combination. Moreover, it outlines current evidence supporting or opposing drug interactions between these drugs and discusses clinical implications.