Impact of Aspirin and Clopidogrel Hyporesponsiveness in Patients Treated With Drug-Eluting Stents: 2-Year Results of a Prospective, Multicenter Registry Study

Insights Into Platelet-Derived MicroRNAs in Cardiovascular and Oncologic Diseases: Potential Predictor and Therapeutic Target

Non-communicable diseases (NCDs), represented by cardiovascular diseases and cancer, have been the leading cause of death globally. Improvements in mortality from cardiovascular (CV) diseases (decrease of 14%/100,000, United States) or cancers (increase 7.5%/100,000, United States) seem unsatisfactory during the past two decades, and so the search for innovative and accurate biomarkers of early diagnosis and prevention, and novel treatment strategies is a valuable clinical and economic endeavor. Both tumors and cardiovascular system are rich in angiological systems that maintain material exchange, signal transduction and distant regulation. This pattern determines that they are strongly influenced by circulating substances, such as glycolipid metabolism, inflammatory homeostasis and cyclic non-coding RNA and so forth. Platelets, a group of small anucleated cells, inherit many mature proteins, mRNAs, and non-coding RNAs from their parent megakaryocytes during gradual formation and manifest important roles in inflammation, angiogenesis, atherosclerosis, stroke, myocardial infarction, diabetes, cancer, and many other diseases apart from its classical function in hemostasis. MicroRNAs (miRNAs) are a class of non-coding RNAs containing ∼22 nucleotides that participate in many key cellular processes by pairing with mRNAs at partially complementary binding sites for post-transcriptional regulation of gene expression. Platelets contain fully functional miRNA processors in their microvesicles and are able to transport their miRNAs to neighboring cells and regulate their gene expression. Therefore, the importance of platelet-derived miRNAs for the human health is of increasing interest. Here, we will elaborate systematically the roles of platelet-derived miRNAs in cardiovascular disease and cancer in the hope of providing clinicians with new ideas for early diagnosis and therapeutic strategies.

Ischemic and Bleeding Events After First Major Bleeding Event in Patients Undergoing Coronary Stent Implantation

There is a scarcity of data on ischemic and bleeding events in patients who experienced major bleeding after percutaneous coronary intervention (PCI). Moreover, there also is a shortage of data on comparative outcomes between patients with and without interruption of an antithrombotic drug after major bleeding. We evaluated the incidence and prognostic impacts of ischemic (myocardial infarction or ischemic stroke) and bleeding (Bleeding Academic Research Consortium type 3 or 5) events after major bleeding in 12,691 consecutive patients who underwent first PCI in the Coronary Revascularization Demonstrating Outcome Study in Kyoto PCI registry cohort-3. In the entire cohort, incidence of the first ischemic event and bleeding event was 2.3 per 100 person-years and 3.8 per 100 person-years, respectively. Major bleeding (Bleeding Academic Research Consortium type 3) occurred in 2,142 patients during a median follow-up of 5.7 years. In patients with major bleeding, cumulative 30-day, 1-year, and 5-year incidence of an ischemic event was 2.6%, 4.8%, and 13.2% (3.2 per 100 person-years), respectively, whereas that of a bleeding event was 6.3%, 16.1%, and 29.2% (8.5 per 100 person-years), respectively. Ischemic and bleeding events were independently associated with mortality (hazard ratio 2.36, 95% confidence interval 1.87 to 2.96, p <0.001, and hazard ratio 2.85, 95% confidence interval 2.42 to 3.37, p <0.001). The cumulative 180-day incidence of ischemic and bleeding events was not significantly different between patients with and without interruption of an antithrombotic drug in patients with major bleeding. In conclusion, the incidence of an ischemic event after the first major bleeding was approximately 1/3 of that of recurrent major bleeding, and the rates of ischemic and bleeding events after the first major bleeding were higher than the rates of first events in the general PCI population. Both ischemic events and bleeding events were strongly associated with subsequent mortality. The incidence of ischemic and recurrent bleeding events was not different between patients with and without interruption of an antithrombotic drug.

Multiparameter phenotyping of platelet reactivity for stratification of human cohorts

Accurate and comprehensive assessment of platelet function across cohorts of donors may be key to understanding the risk of thrombotic events associated with cardiovascular disease, and, hence, to help personalize the application of antiplatelet drugs. However, platelet function tests can be difficult to perform and analyze; they also can be unreliable or uninformative and poorly standardized across studies. The Platelet Phenomic Analysis (PPAnalysis) assay and associated open-source software platform were developed in response to these challenges. PPAnalysis utilizes preprepared freeze-dried microtiter plates to provide a detailed characterization of platelet function. The automated analysis of the high-dimensional data enables the identification of subpopulations of donors with distinct platelet function phenotypes. Using this approach, we identified that the sensitivity of a donor's platelets to an agonist and their capacity to generate a functional response are distinct independent metrics of platelet reactivity. Hierarchical clustering of these metrics identified 6 subgroups with distinct platelet phenotypes within healthy cohorts, indicating that platelet reactivity does not fit into the traditional simple categories of "high" and "low" responders. These platelet phenotypes were found to exist in 2 independent cohorts of healthy donors and were stable on recall. PPAnalysis is a powerful tool for stratification of cohorts on the basis of platelet reactivity that will enable investigation of the causes and consequences of differences in platelet function and drive progress toward precision medicine.

Intensified antiplatelet therapy in patients after percutaneous coronary intervention with high on-treatment platelet reactivity: the OPTImal Management of Antithrombotic Agents (OPTIMA)-2 Trial

High on-treatment platelet reactivity (HOPR) is associated with increased risk of cardiovascular events in patients undergoing percutaneous coronary intervention (PCI). We randomised post-PCI patients with HOPR after 5 days of standard dual antiplatelet therapy (DAPT) to intensified therapy with aspirin 100 mg once daily in combination with either clopidogrel 150 mg once daily, clopidogrel 75 mg once daily plus cilostazol 100 mg twice daily, ticagrelor 90 mg twice daily, or standard therapy with clopidogrel 75 mg once daily (STD) for 1 month, after which all patients were switched to standard DAPT for a further 11 months. The primary outcome was residual HOPR rate at 1 month. We screened 1724 patients with light transmission aggregation studies and randomised 434 with HOPR. At 1 month the proportion of patients with persistent HOPR was significantly lower in the intensified therapy groups compared with STD group. Compared to the group receiving STD therapy, those receiving intensified therapy had significantly lower rate of major adverse cardiovascular events (MACE) at both 1 month and 12 months with no significant increase in bleeding. In patients with post-PCI HOPR, 1 month of intensified antiplatelet therapy provides greater platelet inhibition and improves outcomes without increasing bleeding. Clinical Trial Registration URL: http://www.clinicaltrials.gov; Unique Identifier: NCT01955200.

Genome sequencing unveils a regulatory landscape of platelet reactivity

Platelet aggregation at the site of atherosclerotic vascular injury is the underlying pathophysiology of myocardial infarction and stroke. To build upon prior GWAS, here we report on 16 loci identified through a whole genome sequencing (WGS) approach in 3,855 NHLBI Trans-Omics for Precision Medicine (TOPMed) participants deeply phenotyped for platelet aggregation. We identify the RGS18 locus, which encodes a myeloerythroid lineage-specific regulator of G-protein signaling that co-localizes with expression quantitative trait loci (eQTL) signatures for RGS18 expression in platelets. Gene-based approaches implicate the SVEP1 gene, a known contributor of coronary artery disease risk. Sentinel variants at RGS18 and PEAR1 are associated with thrombosis risk and increased gastrointestinal bleeding risk, respectively. Our WGS findings add to previously identified GWAS loci, provide insights regarding the mechanism(s) by which genetics may influence cardiovascular disease risk, and underscore the importance of rare variant and regulatory approaches to identifying loci contributing to complex phenotypes.

Increased bleeding events with the addition of apixaban to the dual anti-platelet regimen for the treatment of patients with acute coronary syndrome: A meta-analysis

BACKGROUND

Dual anti-platelet therapy (DAPT) with aspirin and clopidogrel has been the mainstay of treatment for patients with acute coronary syndrome (ACS). However, the recurrence of thrombotic events, potential aspirin and clopidogrel hypo-responsiveness, and other limitations of DAPT have led to the development of newer oral anti-thrombotic drugs. Apixaban, a new non-vitamin K antagonist, has been approved for use. In this meta-analysis, we aimed to compare the bleeding outcomes observed with the addition of apixaban to DAPT for the treatment of patients with ACS.

METHODS

Online databases including EMBASE, Cochrane Central, http://www.ClinicalTrials.gov, MEDLINE and Web of Science were searched for English based publications comparing the use of apixaban added to DAPT for the treatment of patients with ACS. Different categories of bleeding events and cardiovascular outcomes were assessed. The analysis was carried out by the RevMan software version 5.4. Odds ratios (OR) with 95% confidence intervals (CI) were used to represent the data following analysis.

RESULTS

This research analysis consisted of 4 trials with a total number of 9010 participants. Thrombolysis in myocardial infarction (TIMI) defined major bleeding (OR: 2.45, 95% CI: 1.45-4.12; P = .0008), TIMI defined minor bleeding (OR: 3.12, 95% CI: 1.71-5.70; P = .0002), International society of thrombosis and hemostasis (ISTH) major bleeding (OR: 2.49, 95% CI: 1.80-3.45; P = .00001) and Global Use of Strategies to Open Occluded Arteries (GUSTO) defined severe bleeding (OR: 3.00, 95% CI: 1.56-5.78; P = .01) were significantly increased with the addition of apixaban to DAPT versus DAPT alone in these patients with ACS. However fatal bleeding (OR: 10.96, 95% CI: 0.61-198.3; P = .11) was not significantly different.

CONCLUSIONS

Addition of the novel oral anticoagulant apixaban to the DAPT regimen significantly increased bleeding and therefore did not show any beneficial effect in these patients with ACS. However, due to the extremely limited data, we apparently have to rely on future larger studies to confirm this hypothesis.

Prasugrel for Japanese Patients With Ischemic Heart Disease in Long-Term Clinical Practice (PRASFIT-Practice II) - Final 2-Year Follow-up Results of a Postmarketing Observational Study

BACKGROUND

PRASFIT-Practice II is a postmarketing observational study conducted in 4,155 Japanese patients with ischemic heart disease (IHD) who received long-term prasugrel. The data were used to assess the utility of Academic Research Consortium for High Bleeding Risk (ARC-HBR) criteria.Methods and Results:Patients in PRASFIT-practice II were clinically followed for 2 years. The primary endpoint was the cumulative incidence of major adverse cardiovascular events (MACE) and Thrombolysis in Myocardial Infarction (TIMI) major/minor bleeding. Patients were divided into 2 groups based on ARC-HBR criteria (HBR (40.1% of patients) and non-HBR (59.9%)) and the effect of HBR on the primary endpoint was assessed. The median duration of dual antiplatelet therapy with prasugrel was 391.0 days. At 2 years, the cumulative incidence of MACE was 3.3%, and of TIMI major/minor bleeding was 2.7%. At 1 year, MACE and TIMI major/minor bleeding in the HBR group (4.0% and 3.4%, respectively) were higher than that in the non-HBR group (1.3% for both). Landmark analysis at 3 months and 1 year showed that the higher risk of MACE or TIMI major/minor bleeding in the HBR group persisted through 2 years.

CONCLUSIONS

The results of this study confirmed the safety and effectiveness of long-term treatment with prasugrel, and demonstrated that the ARC-HBR criteria for bleeding risk are applicable in Japanese IHD patients treated with prasugrel.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prasugrel effectively reduces the platelet reactivity units in patients with genetically metabolic dysfunction of cytochrome P450 2C19 who are treated with long-term dual antiplatelet therapy after undergoing drug-eluting stent implantation

Dual antiplatelet therapy (DAPT) with aspirin and P2Y12 inhibitor is administered following percutaneous coronary intervention (PCI) with coronary stent implantation. Several studies have reported the effects of switching between P2Y12 inhibitors on platelet reactivity (P2Y12 reaction units: PRU), from acute to late phase after PCI. However, the effect of switching at very late phase is unknown. This study examined the effect on PRU in Japanese coronary heart disease patients with long-term DAPT (aspirin + clopidogrel) when switching from clopidogrel to prasugrel. Ninety-six patients were enrolled in this study. The median DAPT duration at enrollment was 1824.0 days. Twenty-three patients with PRU ≥ 208 at enrollment were randomly assigned into either continuing to receive clopidogrel (Continued Group; n = 11) or switching to prasugrel (Switched Group; n = 12). The primary endpoint was the rate of patients who achieved PRU < 208 at the end of 12 weeks of treatment, which was significantly higher in Switched Group relative to Continued Group (90.0% vs. 36.4%; P = 0.024). The secondary endpoint was the PRU at week 12 in groups subdivided according to cytochrome P450 (CYP) 2C19 genotypes. At week 12, extensive metabolizers (EM Group) had 202.3 ± 60.0 and 174.5 ± 22.3 in Continued Group and Switched Group (P = 0.591), respectively; intermediate and poor metabolizers (non-EM Group) had 229.4 ± 36.9 and 148.4 ± 48.4 in Continued Group and Switched Group (P = 0.002), respectively. The PRU for non-EM Group was significantly reduced in Switched Group. Thus, for patients with long-term DAPT (aspirin + clopidogrel) after PCI with coronary stent implantation, switching from clopidogrel to prasugrel resulted in a stable reduction in PRU, regardless of CYP2C19 polymorphism.

Omitting aspirin in PCI patients: Myth or reality?

In the current era of percutaneous coronary intervention (PCI), with the use of contemporary drug-eluting stents, refined techniques, and adjunctive pharmacotherapy, the role of aspirin peri-PCI remains undisputable. Beyond the initial period, dual antiplatelet therapy (DAPT) consisting of aspirin and a P2Y₁₂ receptor inhibitor for 6 months in stable coronary artery disease and 12 months in acute coronary syndromes is the standard of care. However, concerns regarding bleeding adverse events caused by aspirin have led to shortened DAPT duration or even omission of aspirin. Aspirin free-strategies have been increasingly encountered in several studies and showed a significant reduction in bleeding events, without any sign of increased ischemic risk. Individualization of DAPT duration particularly in high bleeding risk patients appears therefore mandatory, making aspirin not necessary in several cases. Moreover, recent randomized trials have shed light on how to treat PCI patients in the presence of concomitant anticoagulant treatment with P2Y₁₂ monotherapy and excluding aspirin. These aspirin-free strategies have been proved safer than the "older" standard triple antithrombotic treatment, without compromising safety. Ongoing studies may further dispel the myths and establish real facts regarding post-PCI-tailored treatment with or without aspirin.

Association Between Residual Platelet Reactivity on Clopidogrel Treatment and Severity of Coronary Atherosclerosis: Intrinsic Hypercoagulability as a Mediator

INTRODUCTION

High on-treatment residual platelet reactivity (HRPR) was associated with greater atherosclerosis burden. We examined whether intrinsic hypercoagulability (IHC) could be attributed to that association in patients treated by drug-eluting stents.

METHODS

This retrospective observation enrolled a total of 891 coronary artery disease (CAD) subjects. Platelet and coagulant reactivity was measured by thrombelastography. At least 24 h after a 300-mg dose of clopidogrel, adenosine diphosphate (ADP)-induced maximum amplitude of clot strength (MA_adp) > 47 mm represented HRPR. Thrombin-induced platelet-fibrin clot strength (MA_thrombin) and blood fibrinogen surrogated intrinsic coagulability. Using mediation analysis to evaluate the effect of IHC on the relationship between the number of narrowed coronaries and HRPR on clopidogrel.

RESULTS

More HRPR on clopidogrel and higher intrinsic coagulability were observed in more severe coronary atherosclerosis, especially in the three-vessel disease. After adjustment for confounding factors, the number of narrowed coronaries (OR_adj = 1.343, 95% CI 1.063-1.695, p = 0.013), MA_thrombin (OR_adj = 1.106, 95% CI 1.058-1.157, p < 0.001), and fibrinogen (OR_adj = 1.003, 95% CI 1.001-1.005, p = 0.012) were all independent positive predictors for HRPR. MA_thrombin and fibrinogen were meaningful mediators for the significant positive association of the number of narrowed vessels and HRPR on clopidogrel, which were enhanced by around 30% and 43%, respectively, for this effect.

CONCLUSIONS

This is the first study to demonstrate that the positive correlation between the number of stenotic coronaries and HRPR on clopidogrel may be partly attributed to IHC, which may enhance the risk stratification, guide more precise coagulation in multi-vessel disease after drug-eluting stents, and therefore deserve further study.

Early and Late Stent Thrombosis in Patients with Versus Without Diabetes Mellitus Following Percutaneous Coronary Intervention with Drug-Eluting Stents: A Systematic Review and Meta-Analysis

BACKGROUND

Nowadays, drug-eluting stents (DES) are most commonly used compared with bare metal stents (BMS) since the former are associated with significantly lower rates of revascularization following percutaneous coronary intervention (PCI). However, unpredictable in-stent thrombosis is a major concern with DES, especially in patients with diabetes mellitus.

OBJECTIVE

In this analysis, we aimed to systematically compare early and late stent thrombosis in patients with versus without diabetes mellitus following PCI with DES.

METHODS

Studies were included if they were randomized controlled trials or observational studies comparing patients with diabetes mellitus versus those without it following PCI with DES and they reported acute and sub-acute/early and late stent thrombosis among their clinical outcomes. Early stent thrombosis was defined as stent thrombosis that occurred before 30 days and late stent thrombosis was defined as stent thrombosis that occurred after 30 days following PCI. The statistical analysis was carried out by the new version of the RevMan software (version 5.3), and odds ratios (ORs) and 95% confidence intervals (CIs) were considered as the statistical parameters.

RESULTS

A total number of 18,910 patients were included in this analysis comparing early and late stent thrombosis in patients with diabetes mellitus (5123 patients) and in patients without diabetes mellitus (13,787 patients). Both groups of patients had similar rates of early stent thrombosis, with an OR of 1.30 (95% CI 0.89-1.91; P = 0.18, I² = 9%) (4962 patients with diabetes mellitus were compared with 13,392 patients without diabetes mellitus). However, late stent thrombosis was significantly higher in patients with diabetes mellitus, with an OR of 1.95 (95% CI 1.35- 2.81; P = 0.0004, I² = 0%) (5113 patients with diabetes mellitus and 13,775 patients without diabetes mellitus were compared).

CONCLUSIONS

Both patients with and without diabetes mellitus had a similar rate of early stent thrombosis following PCI with DES. However, diabetes mellitus was associated with a significantly higher rate of late stent thrombosis.

Impact of high on-aspirin platelet reactivity on outcomes following successful percutaneous coronary intervention with drug-eluting stents

BACKGROUND

Whether high on-aspirin platelet reactivity (HAPR) confers an increased risk of adverse outcomes after percutaneous coronary intervention (PCI) remains unclear. We sought to examine the specific relationship between HAPR and clinical outcomes in ADAPT-DES.

METHODS

A total of 8,526 "all-comer" patients in the ADAPT-DES registry who underwent placement of drug-eluting stents (DES) and were treated with aspirin and clopidogrel were assessed to measure platelet reactivity. HAPR was characterized as ≥550 aspirin reaction units and high on-clopidogrel platelet reactivity as >208 P2Y12 reaction units. Univariable and propensity-adjusted multivariable analyses were used to assess the relationship between HAPR and clinical outcomes.

RESULTS

HAPR was present in 478 (5.6%) patients. Patients with HAPR were older and had more comorbid illnesses and more complex coronary anatomy. During 2-year follow-up, HAPR was not associated with increased rates of major adverse cardiac events (MACE), stent thrombosis, myocardial infarction, or all-cause mortality. In propensity-adjusted multivariable analyses, HAPR was not an independent predictor of MACE after successful PCI (multivariable adjusted hazard ratio: 1.04; 95% CI 0.64-1.69, P = .87). Nor was HAPR associated with reduced bleeding. Even among patients with concomitant high on-clopidogrel platelet reactivity, HAPR was not associated with worse ischemic outcomes (adjusted hazard ratio for 2-year MACE: 1.06; 95% CI 0.55-2.00, P = .87).

CONCLUSIONS

HAPR was infrequently present in a large registry of patients undergoing PCI. There was no clear relationship between HAPR and 2-year clinical outcomes. Investigations of antiplatelet regimens without aspirin after DES implantation are ongoing and should inform future management of patients undergoing PCI.

Monitoring platelet function: what have we learned from randomized clinical trials?

Dual antiplatelet therapy, with aspirin plus a P2Y12 inhibitor agent, remains the cornerstone treatment after percutaneous coronary intervention. However, significant proportion of patients did experience recurrent ischemic events on aspirin plus clopidogrel and the concept of non-response to P2Y12 inhibitor emerged. Evaluation of platelet reactivity has known a promising era aiming to improve platelet inhibition conferred by clopidogrel. Then, the development of more potent antiplatelet agents (i.e., prasugrel and ticagrelor) shifted the concern to excessive platelet inhibition and increased risk of bleeding. Therefore, personalized antiplatelet therapy according to platelet function testing has been tested in several randomized trials for both escalation and de-escalation of antiplatelet regimen. This review aims to report the evidence from randomized trials in this field and upcoming roles for platelet function testing.

Clopidogrel utilization in patients with coronary artery disease and diabetes mellitus: should we determine CYP2C19*2 genotype?

PURPOSE

Clopidogrel non-responsiveness is multifactorial; several genetic and non-genetic factors may contribute to impaired platelet inhibition. The goal of this study is to determine the effect of the cytochrome P450 CYP2C19*2 polymorphism on the platelet response to clopidogrel in patients with and without diabetes mellitus (DM).

METHODS

We conducted an observational study in patients with coronary artery disease and consequent exposure to clopidogrel therapy (75 mg/day for at least 7 consecutive days). We have analyzed two groups of patients: group I (DM patients) and group II (non-diabetes mellitus patients). Platelet reactivity was assessed by the VerifyNow P2Y12 assay and high on clopidogrel platelet reactivity (HPR) was defined as P2Y12 reaction units (PRU) ≥ 208. Genotyping for CYP2C19*2 polymorphism was performed by PCR-RFLP.

RESULTS

We have included 150 subjects (76 DM and 74 non-diabetes mellitus patients). The carriage of CYP2C19*2 allele, in DM patients, was significantly associated to HPR (odds ratio (OR) 4.437, 95% confidence interval (CI) 1.134 to 17.359; p = 0.032). Furthermore, 8.4% of the variability in percent inhibition by clopidogrel could be attributed to CYP2C19*2 carrier status. However, in non-diabetes mellitus patients, there was no significant difference in platelet response to clopidogrel according to the presence or absence of CYP2C19*2 allele carriage (OR 1.260, 95% CI 0.288 to 5.522; p = 0.759).

CONCLUSIONS

Our study suggests that the carriage of CYP2C19*2 polymorphism, in DM patients, might be a potential predictor of persisting HPR in these high-risk individuals.

TRIAL REGISTRATION

Clinical Trials.gov NCT03373552 (Registered 13 December 2017).

Relationship between high platelet reactivity on clopidogrel and long-term clinical outcomes after drug-eluting stents implantation (PAINT-DES): a prospective, propensity score-matched cohort study

Background

The relationship between platelet reactivity and long-term clinical outcomes remains controversial. The present prospective study was designed to explore the association between high platelet reactivity (HPR) on clopidogrel and long-term clinical outcomes following implantation of drug eluting stents (DES).

Methods

A total of 1769 consecutive patients assessed by Aggrestar (PL-11) were enrolled at our center from February 2011 to December 2017. The primary end point was major adverse cardiovascular and cerebrovascular events (MACCE), defined as definite or probable stent thrombosis, spontaneous myocardial infarction, all cause death, clinically driven target vessel revascularization (TVR), or ischemic stroke. Bleeding served as the safety endpoint. Propensity score matching (PSM) analysis was performed to adjust for baseline differences in the overall cohort.

Results

Finally, 409 patients (23.1%) were identified with HPR on clopidogrel. At a median follow-up of 4.1 years (interquartile range, 1.8 years), the occurrence of MACCE was significantly higher in HPR on clopidogrel group than normal platelet reactivity (NPR) on clopidogrel group (15.6% vs. 5.4%, p < 0.001). After PSM, 395 paired patients were matched, and the difference in MACCE between HPR (15.7%) versus NPR (9.4%) on clopidogrel groups remained significant (P < 0.001), mainly driven by increased all cause death (5.3% vs. 1.8%, p < 0.001), and clinically driven TVR (8.1% vs. 6.3%, p = 0.019) in the HPR group. The risk of bleeding between two groups was similar.

Conclusions

This prospective study confirms the relationship between HPR on clopidogrel and long-term adverse cardiovascular events after coronary stenting.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0841-1) contains supplementary material, which is available to authorized users.

Impact of hepatitis B virus (HBV) infection on platelet response to clopidogrel in patients undergoing coronary stent implantation

BACKGROUND

Hepatitis B virus (HBV) infection has been reported to down-regulate the expression of CYP2C19 gene, which may decrease the bioactivation of clopidogrel into active metabolites. We aimed to evaluate the impact of HBV infection on platelet response to clopidogrel in patients undergoing coronary stent implantation.

METHODS

A total of 1805 patients who had received coronary stent implantation and taken aspirin 100 mg in combination with clopidogrel 75 mg daily ≥5 days were consecutively recruited. The serologic identifications for HBV, platelet aggregations in response to arachidonic acid (PL_AA) and adenosine diphosphate (PL_ADP), as well as ABCB1, CYP2C19, CYP3A5, PON1 and P2RY12 genotypes were determined. Clopidogrel low response (CLR) was defined as PL_ADP > 40%.

RESULTS

Among the recruited subjects, 102 patients showed hepatitis B surface antigen (HBsAg) positive and 1703 patients negative. PL_ADP was significantly higher in HBsAg positive group than that in HBsAg negative group [38 (24-48) % vs. 29 (20-39) %, p < 0.001] while the difference of PL_AA was not statistically significant (p = 0.329). The incidence of CLR was significantly higher in HBsAg positive group compared with that in HBsAg negative group (43.1% vs. 23.4%, p < 0.001). After adjusted for CYP2C19 genotype and known risk factors, HBsAg positive patients exhibited a significantly higher risk of CLR (adjusted odds ratio: 2.81, 95% confidence interval: 1.73 to 4.58, p < 0.001).

CONCLUSIONS

HBV infection is an independent risk factor of CLR, in addition to CYP2C19 gene mutations. (Pharmacogenetic and Pharmacokinetic Study of Clopidogrel; NCT01968499).

ADP Platelet Hyperreactivity Predicts Cardiovascular Disease in the FHS (Framingham Heart Study)

BACKGROUND

Platelet function is associated with adverse events in patients with cardiovascular disease (CVD).

METHODS AND RESULTS

We examined associations of baseline platelet function with incident CVD events in the community-based FHS (Framingham Heart Study). Participants free of prevalent CVD and without recent aspirin treatment with available data in the Framingham Offspring cohort (1991-1995) and Omni cohort (1994-1998) were included. Platelet function was measured with light transmission aggregometry using collagen (1.9 μg/mL), ADP (0.05-15 μmol/L), and epinephrine (0.01-15 μmol/L). We used proportional hazards models to analyze incident outcomes (myocardial infarction/stroke, CVD, and CVD mortality) with respect to platelet measures. The study sample included 2831 participants (average age, 54.3 years; 57% women). During follow-up (median, 20.4 years), we observed 191 composite incident myocardial infarction or stroke events, 432 incident CVD cases, and 117 CVD deaths. Hyperreactivity to ADP and platelet aggregation at ADP concentration of 1.0 μmol/L were significantly associated with incident myocardial infarction/stroke in a multivariable model (hazard ratio, 1.68 [95% confidence interval, 1.13-2.50] [P=0.011] for hyperreactivity across ADP doses; and hazard ratio, 1.16 [95% confidence interval, 1.02-1.33] [P=0.029] for highest quartile of ADP response at 1.0 μmol/L versus others). No association was observed for collagen lag time or any epinephrine measures with incident myocardial infarction or stroke.

CONCLUSIONS

Intrinsic hyperreactivity to low-dose ADP in our community-based sample, who were free of CVD and any antiplatelet therapy, is associated with future arterial thrombosis during a 20-year follow-up. These findings reinforce ADP activation inhibition as a critical treatment paradigm and encourage further study of ADP inhibitor-refractive populations.

CYP2C19 genotype and adverse cardiovascular outcomes after stent implantation in clopidogrel-treated Asian populations: A systematic review and meta-analysis

The effect of CYP2C19 gene polymorphism on clinical outcomes of patients with coronary artery disease (CAD) treated with clopidogrel remains controversial. Ethnicity has been proposed to influence clopidogrel response following stent implantation in CAD patients with different CYP2C19 genotypes. Furthermore, Asian populations are reported to have a relatively greater prevalence of CYP2C19 loss-of-function (LOF) alleles. We aimed to evaluate the impact of CYP2C19 gene polymorphism on clinical outcomes in Asian populations who underwent percutaneous coronary interventions (PCI) and received clopidogrel therapy. We conducted a comprehensive search in PubMed, EMBASE, and Cochrane Library from their inceptions to January 20, 2017. Studies that reported clopidogrel therapy information, clinically relevant outcomes (adverse cardiovascular events, stent thrombosis and bleeding), and CYP2C19 genotypes among Asian populations were included. The primary endpoint was major adverse cardiovascular events (MACE), defined as a composite of cardiovascular death and myocardial infarction. The safety endpoint was any kind of bleeding. We retrieved 20 studies of 15056 patients reporting 1301 cardiovascular events. The primary analysis showed at least one CYP2C19 LOF allele (*2 and/or *3) carriers were at an increased risk of MACE compared with non-carriers (10.58% vs. 6.07%, OR: 1.99, 95% CI: 1.64 to 2.42, p < .001). Stent thrombosis (ST) was also more frequent in LOF allele carriers (2.22% vs. 0.44%, OR: 4.77, 95% CI: 2.84 to 8.01, p < .001). Inversely, the risk of bleeding was lower in LOF allele carriers (OR: 0.66, 95% CI: 0.46 to 0.96, p < .001). Subgroup analysis was performed to assess differences by high (600 mg) or routine (300 mg) loading dose of clopidogrel and by different nationalities. The risk of MACE in LOF allele carriers remained significantly higher even in high loading dose group (high loading dose: OR 1.72, 95% CI: 1.37 to 2.16, and routine loading dose: OR 2.22, 95% CI: 1.68 to 2.94, p for subgroup heterogeneity = 0.16). Subgroup analysis between three nationalities of China, Korea, and Japan demonstrated that the risk of MACE among Chinese LOF allele carriers was the greatest (OR: 2.28; 95% CI:1.91 to 2.73). In conclusion, among Asian populations with CAD undergoing stent implantation, CYP2C19 LOF allele carriers are at greater risk of adverse cardiovascular events and lower risk of bleeding compared with non-carriers. Genetic testing may be helpful for clinicians to personalize antiplatelet therapy especially in Asian population.