Association of Dual Antiplatelet Therapy With Ticagrelor With Vein Graft Failure After Coronary Artery Bypass Graft Surgery: A Systematic Review and Meta-analysis.

Importance: The role of ticagrelor with or without aspirin after coronary artery bypass graft surgery remains unclear. Objective: To compare the risks of vein graft failure and bleeding associated with ticagrelor dual antiplatelet therapy (DAPT) or ticagrelor monotherapy vs aspirin among patients undergoing coronary artery bypass graft surgery. Data Sources: MEDLINE, Embase, and Cochrane Library databases from inception to June 1, 2022, without language restriction. Study Selection: Randomized clinical trials (RCTs) comparing the effects of ticagrelor DAPT or ticagrelor monotherapy vs aspirin on saphenous vein graft failure. Data Extraction and Synthesis: Individual patient data provided by each trial were synthesized into a combined data set for independent analysis. Multilevel logistic regression models were used. Main Outcomes and Measures: The primary analysis assessed the incidence of saphenous vein graft failure per graft (primary outcome) in RCTs comparing ticagrelor DAPT with aspirin. Secondary outcomes were saphenous vein graft failure per patient and Bleeding Academic Research Consortium (BARC) type 2, 3, or 5 bleeding events. A supplementary analysis included RCTs comparing ticagrelor monotherapy with aspirin. Results: A total of 4 RCTs were included in the meta-analysis, involving 1316 patients and 1668 saphenous vein grafts. Of the 871 patients in the primary analysis, 435 received ticagrelor DAPT (median age, 67 years [IQR, 60-72 years]; 65 women [14.9%]; 370 men [85.1%]) and 436 received aspirin (median age, 66 years [IQR, 61-73 years]; 63 women [14.5%]; 373 men [85.5%]). Ticagrelor DAPT was associated with a significantly lower incidence of saphenous vein graft failure (11.2%) per graft than was aspirin (20%; difference, -8.7% [95% CI, -13.5% to -3.9%]; OR, 0.51 [95% CI, 0.35 to 0.74]; P < .001) and was associated with a significantly lower incidence of saphenous vein graft failure per patient (13.2% vs 23.0%, difference, -9.7% [95% CI, -14.9% to -4.4%]; OR, 0.51 [95% CI, 0.35 to 0.74]; P < .001). Ticagrelor DAPT (22.1%) was associated with a significantly higher incidence of BARC type 2, 3, or 5 bleeding events than was aspirin (8.7%; difference, 13.3% [95% CI, 8.6% to 18.0%]; OR, 2.98 [95% CI, 1.99 to 4.47]; P < .001), but not BARC type 3 or 5 bleeding events (1.8% vs 1.8%, difference, 0% [95% CI, -1.8% to 1.8%]; OR, 1.00 [95% CI, 0.37 to 2.69]; P = .99). Compared with aspirin, ticagrelor monotherapy was not significantly associated with saphenous vein graft failure (19.3% vs 21.7%, difference, -2.6% [95% CI, -9.1% to 3.9%]; OR, 0.86 [95% CI, 0.58 to 1.27]; P = .44) or BARC type 2, 3, or 5 bleeding events (8.9% vs 7.3%, difference, 1.7% [95% CI, -2.8% to 6.1%]; OR, 1.25 [95% CI, 0.69 to 2.29]; P = .46). Conclusions and Relevance: Among patients undergoing coronary artery bypass graft surgery, adding ticagrelor to aspirin was associated with a significantly decreased risk of vein graft failure. However, this was accompanied by a significantly increased risk of clinically important bleeding.

Clopidogrel Versus Ticagrelor or Prasugrel After Primary Percutaneous Coronary Intervention According to CYP2C19 Genotype: A POPular Genetics Subanalysis.

[Figure: see text].

Blood loss after coronary artery bypass by aspirin responsiveness assessed with preoperative VerifyNow aspirin testing.

BACKGROUND: Aspirin is important for preventing thrombotic events but also increases bleeding complications. Minimizing bleeding while preventing thrombotic events remains challenging in patients undergoing coronary artery bypass grafting (CABG). Establishing the patient's preoperative aspirin response could distinguish patients at risk for perioperative blood loss. OBJECTIVE: Aim was to compare 12-h blood loss after CABG between aspirin-sensitive and aspirin-resistant patients. PATIENTS/METHODS: The primary analysis of this substudy of the POPular CABG trial (NCT02352402) included patients that used aspirin monotherapy preoperatively. A preoperative platelet function test by the VerifyNow aspirin assay was performed before CABG and patients were classified as aspirin-sensitive or aspirin-resistant based on an aspirin reaction units cutoff value of 550. The primary end point was 12-hour blood loss after CABG. The secondary end point was, among others, clinical bleeding events after CABG. RESULTS: A total of 128 patients were included in the primary analysis. Of these, 116 patients were aspirin sensitive and 12 were aspirin resistant. Mean blood loss 12 hours after CABG was 555 ± 278 mL in aspirin-sensitive patients and 406±110 mL in aspirin-resistant patients (P = .04). All bleeding events (n = 15; 11.7%) occurred in aspirin-sensitive patients. CONCLUSIONS: In patients who are on aspirin preoperatively, aspirin sensitivity was associated with 12-hour blood loss after CABG, suggesting that preoperative VerifyNow aspirin testing could identify patients undergoing CABG at high risk for perioperative bleeding.

Effect of Adding Ticagrelor to Standard Aspirin on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting (POPular CABG): A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Approximately 15% of saphenous vein grafts (SVGs) occlude during the first year after coronary artery bypass graft surgery (CABG) despite aspirin use. The POPular CABG trial (The Effect of Ticagrelor on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting Surgery) investigated whether ticagrelor added to standard aspirin improves SVG patency at 1 year after CABG. METHODS: In this investigator-initiated, randomized, double-blind, placebo-controlled, multicenter trial, patients with ≥1 SVGs were randomly assigned (1:1) after CABG to ticagrelor or placebo added to standard aspirin (80 mg or 100 mg). The primary outcome was SVG occlusion at 1 year, assessed with coronary computed tomography angiography, in all patients that had primary outcome imaging available. A generalized estimating equation model was used to perform the primary analysis per SVG. The secondary outcome was 1-year SVG failure, which was a composite of SVG occlusion, SVG revascularization, myocardial infarction in myocardial territory supplied by a SVG, or sudden death. RESULTS: Among 499 randomly assigned patients, the mean age was 67.9±8.3 years, 87.1% were male, the indication for CABG was acute coronary syndrome in 31.3%, and 95.2% of procedures used cardiopulmonary bypass. Primary outcome imaging was available in 220 patients in the ticagrelor group and 223 patients in the placebo group. The SVG occlusion rate in the ticagrelor group was 10.5% (51 of 484 SVGs) versus 9.1% in the placebo group (43 of 470 SVGs), odds ratio, 1.29 [95% CI, 0.73-2.30]; P=0.38. SVG failure occurred in 35 (14.2%) patients in the ticagrelor group versus 29 (11.6%) patients in the placebo group (odds ratio, 1.22 [95% CI, 0.72-2.05]). CONCLUSIONS: In this randomized, placebo-controlled trial, the addition of ticagrelor to standard aspirin did not reduce SVG occlusion at 1 year after CABG. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02352402.

Effect of CYP3A4*22 and PPAR-α Genetic Variants on Platelet Reactivity in Patients Treated with Clopidogrel and Lipid-Lowering Drugs Undergoing Elective Percutaneous Coronary Intervention.

This study aims to determine whether genetic variants that influence CYP3A4 expression are associated with platelet reactivity in clopidogrel-treated patients undergoing elective percutaneous coronary intervention (PCI), and to evaluate the influence of statin/fibrate co-medication on these associations. A study cohort was used containing 1124 consecutive elective PCI patients in whom CYP3A4*22 and PPAR-α (G209A and A208G) SNPs were genotyped and the VerifyNow P2Y12 platelet reactivity test was performed. Minor allele frequencies were 0.4% for CYP3A4*22/*22, 6.8% for PPAR-α G209A AA, and 7.0% for PPAR-α A208G GG. CYP3A4*22 was not associated with platelet reactivity. The PPAR-α genetic variants were significantly associated with platelet reactivity (G209A AA: -24.6 PRU [-44.7, -4.6], p = 0.016; A208G GG: -24.6 PRU [-44.3, -4.8], p = 0.015). Validation of these PPAR-α results in two external cohorts, containing 716 and 882 patients, respectively, showed the same direction of effect, although not statistically significant. Subsequently, meta-analysis of all three cohorts showed statistical significance of both variants in statin/fibrate users (p = 0.04 for PPAR-a G209A and p = 0.03 for A208G), with no difference in statin/fibrate non-users. In conclusion, PPAR-α G209A and A208G were associated with lower platelet reactivity in patients undergoing elective PCI who were treated with clopidogrel and statin/fibrate co-medication. Further research is necessary to confirm these findings.

A randomized, double-blind, placebo-controlled trial investigating the effect of ticagrelor on saphenous vein graft patency in patients undergoing coronary artery bypass grafting surgery-Rationale and design of the POPular CABG trial.

RATIONALE: An estimated 15% of saphenous vein grafts (SVGs) occlude in the first year after coronary artery bypass grafting (CABG) despite aspirin therapy. Graft occlusion can result in symptoms, myocardial infarction, and death. SVG occlusion is primarily caused by atherothrombosis, in which platelet activation plays a pivotal role. Evidence regarding the effect of stronger platelet inhibition on SVG patency after CABG is limited. The main objective of the POPular CABG trial is to determine whether dual antiplatelet therapy with aspirin plus ticagrelor improves SVG patency when compared to aspirin alone. STUDY: The POPular CABG is a randomized, double-blind, placebo-controlled, multicenter trial investigating the effect of adding ticagrelor to standard aspirin therapy on the rate of SVG occlusion. A total of 500 patients undergoing CABG with ≥ 1 SVG are randomized to ticagrelor or placebo. The primary end point is SVG occlusion rate, assessed with coronary computed tomography angiography at 1 year. Secondary end points are stenoses and occlusions in both SVGs and arterial grafts and SVG failure at 1 year, defined as a composite of SVG occlusion on coronary computed tomography angiography or coronary angiography, SVG revascularization, myocardial infarction in the territory supplied by an SVG, or sudden death. Safety end points are bleeding events at 30 days and 1 year. CONCLUSION: The POPular CABG trial investigates whether adding ticagrelor to standard aspirin after CABG reduces the rate of SVG occlusion at 1 year.

A Genotype-Guided Strategy for Oral P2Y12 Inhibitors in Primary PCI.

BACKGROUND: It is unknown whether patients undergoing primary percutaneous coronary intervention (PCI) benefit from genotype-guided selection of oral P2Y12 inhibitors. METHODS: We conducted a randomized, open-label, assessor-blinded trial in which patients undergoing primary PCI with stent implantation were assigned in a 1:1 ratio to receive either a P2Y12 inhibitor on the basis of early CYP2C19 genetic testing (genotype-guided group) or standard treatment with either ticagrelor or prasugrel (standard-treatment group) for 12 months. In the genotype-guided group, carriers of CYP2C19*2 or CYP2C19*3 loss-of-function alleles received ticagrelor or prasugrel, and noncarriers received clopidogrel. The two primary outcomes were net adverse clinical events - defined as death from any cause, myocardial infarction, definite stent thrombosis, stroke, or major bleeding defined according to Platelet Inhibition and Patient Outcomes (PLATO) criteria - at 12 months (primary combined outcome; tested for noninferiority, with a noninferiority margin of 2 percentage points for the absolute difference) and PLATO major or minor bleeding at 12 months (primary bleeding outcome). RESULTS: For the primary analysis, 2488 patients were included: 1242 in the genotype-guided group and 1246 in the standard-treatment group. The primary combined outcome occurred in 63 patients (5.1%) in the genotype-guided group and in 73 patients (5.9%) in the standard-treatment group (absolute difference, -0.7 percentage points; 95% confidence interval [CI], -2.0 to 0.7; P<0.001 for noninferiority). The primary bleeding outcome occurred in 122 patients (9.8%) in the genotype-guided group and in 156 patients (12.5%) in the standard-treatment group (hazard ratio, 0.78; 95% CI, 0.61 to 0.98; P = 0.04). CONCLUSIONS: In patients undergoing primary PCI, a CYP2C19 genotype-guided strategy for selection of oral P2Y12 inhibitor therapy was noninferior to standard treatment with ticagrelor or prasugrel at 12 months with respect to thrombotic events and resulted in a lower incidence of bleeding. (Funded by the Netherlands Organization for Health Research and Development; POPular Genetics ClinicalTrials.gov number, NCT01761786; Netherlands Trial Register number, NL2872.).

Tailored P2Y12 inhibitor treatment in patients undergoing non-urgent PCI-the POPular Risk Score study.

PURPOSE: The POPular Risk Score was developed for the selective intensification of P2Y12 inhibitor treatment with prasugrel instead of clopidogrel in patients undergoing non-urgent percutaneous coronary intervention (PCI) with stent implantation. This score is based on platelet reactivity (VerifyNow P2Y12 assay), CYP2C19 genotyping, and clinical risk factors. Our aim was to determine if the use of this score in clinical practice is associated with a reduction in thrombotic events without increasing bleeding events. METHODS: In a single-center prospective cohort study, patients with a high risk score were treated with prasugrel and patients with a low risk score with clopidogrel. The risk score-guided cohort was compared with a historic cohort of clopidogrel-treated patients. The endpoint consisted of all-cause death, myocardial infarction, stroke, or stent thrombosis during 1 year of follow-up. TIMI major and minor bleeding events were also analyzed. RESULTS: The guided cohort contained 1127 patients, 26.9% of whom were switched to prasugrel according to the POPular Risk Score. The historic cohort contained 893 patients. The incidence of the combined thrombotic endpoint was significantly lower in the guided cohort as compared with the historic cohort (8.4% versus 3.7%, p < 0.001). This strategy was safe with respect to bleeding (4.0% versus 1.3%, p < 0.001, for TIMI major or minor bleeding). Results were comparable after multivariate and propensity score matched and weighted analysis. CONCLUSION: Selective intensification of P2Y12 inhibitor treatment after non-urgent PCI based on the POPular Risk Score is associated with a reduction in thrombotic events without an increase in bleeding events.

Perioperative point of care platelet function testing and postoperative blood loss in high-risk cardiac surgery patients.

Postoperative coagulopathic bleeding is common in cardiac surgery and associated with increased morbidity and mortality. Platelet function is affected by multiple factors, including patient and procedural characteristics. Point-of-care (POC) multiple electrode aggregometry (MEA) can rapidly detect and quantify platelet dysfunction and could contribute to optimal patient blood management. In patients undergoing CABG and heart valve surgery platelet function was assessed using POC MEA at four different perioperative timepoints in response to stimulation with four specific receptor agonists (ADP, AA, COL, TRAP). Postoperative bleeding was recorded during 24 h after surgery. Regression analyses were performed to establish associations between perioperative platelet function and postoperative blood loss. Ninety-nine patients were included in the study. Fifty-nine patients (60%) were on antiplatelet therapy (APT) at time of surgery. ADP- and AA-induced platelet aggregation declined during CPB and after decannulation from CPB, with a maximum decrease of 55% for ADP (35 vs. 77 AU at baseline; P < 0.001) and 78% for ASPI (14 vs. 64 AU at baseline; P < 0.001). A linear relationship was present between ADP-induced platelet aggregometry at baseline and postoperative blood loss (r = -0.249; P = 0.015). In aspirin users, the maximum decline in platelet function between baseline and CPB decannulation was related to postoperative blood loss (r = 0.308; P = 0.037). In multivariate analysis, a reduced ADP platelet function prior to surgery remained associated with postoperative blood loss (r = -0.239; P = 0.012). Reduced ADP-induced platelet aggregation at baseline is associated with increased postoperative blood loss in high-risk cardiac surgery patients.

A clinical risk score to identify patients at high risk of very late stent thrombosis.

OBJECTIVES: The aim of this study was to determine predictors of very late stent thrombosis (VLST; >1 year after stenting), and to evaluate whether addition of these predictors to the dual antiplatelet therapy (DAPT) score would improve the ability to identify patients at high risk of VLST who might benefit from DAPT. BACKGROUND: VLST is a severe complication of percutaneous coronary intervention (PCI). Extended knowledge about the predictors of VLST is needed to prevent this life-threatening complication. Recent data showed a reduction in VLST after treatment with prolonged DAPT. The DAPT study developed a prediction score to identify patients after PCI who might benefit from prolonged DAPT duration. METHODS: The Dutch stent thrombosis study is a multi-center case-control study. Consecutive patients with definite VLST were included between 2007 and 2014. Baseline characteristics from the index PCI were collected. Independent predictors of VLST were identified and added to the DAPT score to develop the VLST score. RESULTS: In total, 155 VLST cases and 155 matched controls were included. Suboptimal result of stenting, right coronary artery as target vessel, and diffuse coronary artery ectasia were independent predictors of VLST, and added to the DAPT score. The power of the VLST score to identify patients who experienced VLST was increased (AUC, 95%CI; DAPT score: 0.64, 0.57-0.70; VLST score: 0.70, 0.63-0.76, P = 0.010). CONCLUSIONS: Addition of newly identified independent predictors of VLST resulted in a prediction model with a higher ability to identify patients at high risk of VLST who might benefit from prolonged DAPT.

Safety of Ticagrelor Compared to Clopidogrel after Prehospital Initiation of Treatment.

Objectives The objective of this registry was to study the safety of prehospital initiation of ticagrelor compared with clopidogrel. Background Ticagrelor has replaced clopidogrel in many hospitals as the routinely used antiplatelet drug in patients with ST-segment elevation myocardial infarction (STEMI). Nevertheless, in the PLATelet inhibition and patient Outcomes (PLATO) trial, ticagrelor was associated with an increase in non-CABG (non-coronary artery bypass grafting)-related major bleeding. Data comparing the safety of ticagrelor and clopidogrel after prehospital initiation of treatment are not available. Methods A retrospective, multicenter registry was performed. Selection criteria were the administration of a prehospital loading dose of ticagrelor or clopidogrel according to the ambulance STEMI treatment protocol and the presentation to a percutaneous coronary intervention-capable hospital in our region between January 2011 and December 2012. Follow-up was performed using the electronic patient files for the time period between the antiplatelet loading dose and hospital discharge. The data were analyzed using a primary bleeding end point (any bleeding) and a secondary thrombotic end point (all-cause mortality, spontaneous myocardial infarction, definite stent thrombosis, stroke, or transient ischemic attack). Results Data of 304 clopidogrel-treated and 309 ticagrelor-treated patients were available for analysis. No significant difference in bleeding rate was observed between both groups, using univariate (17.8 vs. 20.1%; p = 0.47; odds ratio, 1.16 [95% confidence interval, 0.78-1.74]) and multivariate ( p = 0.42) analysis. Also for the secondary thrombotic end point (6.3 vs. 4.9%, p = 0.45), no significant differences were observed. Conclusion In this real-world registry, no significant differences in bleeding or thrombotic event rate were found between ticagrelor and clopidogrel after prehospital initiation of treatment.

Incidence and Causes for Early Ticagrelor Discontinuation: A "Real-World" Dutch Registry Experience.

OBJECTIVES: The PLATO trial revealed superiority of ticagrelor over clopidogrel for the prevention of atherothrombotic events in patients with acute coronary syndrome. However, adverse events such as bleeding, dyspnea, and bradycardia were frequently reported, potentially leading to excess early ticagrelor discontinuation (ETD), later confirmed in the PEGASUS trial. We here evaluated the incidence and causes for ETD in a real-world patient cohort in a high-volume nonacademic percutaneous coronary intervention center in the Netherlands. METHODS: In a retrospective single-center registry, all patients discharged from the hospital with a new ticagrelor prescription were screened for ETD. Follow-up data were obtained using the hospital electronic patient file records and confirmed by telephone contact with the patient and/or general practitioner, if necessary, to complement the data. RESULTS: Ticagrelor was prescribed in 354 patients between December 2011 and December 2012. The follow-up data were available in 301 patients with a mean follow-up duration of 330 days. ETD or switching to another antiplatelet agent occurred in 73 patients (24.3%), mostly due to dyspnea (11.6%), bleeding (3.7%), or planned major surgery (2.7%). CONCLUSIONS: Almost one quarter of ticagrelor patients were discontinued prematurely or switched to another antiplatelet agent within 1 year, mostly due to dyspnea or bleeding.

How Long Does It Take for Clopidogrel and Ticagrelor to Inhibit Platelets in Patients Undergoing Primary Percutaneous Coronary Intervention? A Detailed Pharmacodynamic Analysis: Time Course of Platelet Reactivity in STEMI (TOPS).

Antiplatelet therapy plays a pivotal role in patients with an ST-segment elevation myocardial infarction (STEMI) to prevent further atherothrombotic events, such as stent thrombosis. Although the risk of stent thrombosis is highest in the first hours after primary percutaneous coronary intervention (pPCI), little is known about when an adequate level of platelet inhibition is achieved following a clopidogrel or ticagrelor loading dose in STEMI patients. Patients presenting with STEMI in whom pPCI was performed and who were loaded with 600 mg clopidogrel or 180 mg ticagrelor were eligible for enrolment in this nonrandomized, open label, single-center study. Platelet reactivity was measured before PCI, 6 and 24 hours after loading dose and after 2, 7, and 14 days, using the VerifyNow P2Y12 assay as well as 20 µmol/L adenosine diphosphate stimulated light transmittance aggregometry (LTA). We analyzed the time until a VerifyNow result of < 236 P2Y12 reaction units or LTA maximum platelet aggregation of < 64.5% was reached. A total of 28 patients were participated in this study. Platelet reactivity dropped below the high platelet reactivity cutoff level after 11.4 (VerifyNow) and 5.7 (LTA) hours in patients who were loaded with clopidogrel, and after 2.4 (VerifyNow) and 3.9 (LTA) hours in patients who were loaded with ticagrelor. Despite the administration of a clopidogrel or ticagrelor loading dose, it still takes multiple hours (2-11) to reach adequate platelet inhibition in STEMI patients. This might indicate the need for additional antiplatelet therapy in the first hours after loading in patients undergoing pPCI with stenting.

The use of platelet reactivity testing in patients on antiplatelet therapy for prediction of bleeding events after cardiac surgery.

Many patients are treated with platelet inhibitors such as aspirin and clopidogrel for prevention of thrombotic cardiovascular events. However, the inhibitory effect of antiplatelet therapy is variable between patients; in some, the platelets are hardly inhibited, while in others, the platelets are excessively inhibited. The newer and more potent platelet inhibitors, prasugrel and ticagrelor, often lead to low platelet reactivity, which potentially leads to bleeding events. Preoperative measurement of platelet reactivity in patients receiving platelet inhibitors who undergo cardiac surgery, could be useful to identify those with low platelet reactivity and thus have an increased risk of bleeding during or after surgery. In this review, we discuss the most commonly used platelet inhibitors and platelet function tests. Furthermore, we will provide an overview of the evidence for the prediction of post-operative bleeding at the operation site with preoperative platelet reactivity testing in patients undergoing cardiac surgery.

Vascular risk levels affect the predictive value of platelet reactivity for the occurrence of MACE in patients on clopidogrel. Systematic review and meta-analysis of individual patient data.

Prior studies have shown an association between high on-clopidogrel platelet reactivity (PR) and the risk of major adverse cardiovascular events (MACE). However, large intervention trials on PR-tailored treatments have been neutral. The role and usefulness of PR with regard to levels of cardiovascular risk are unclear. We undertook a systematic review and meta-analysis of individual patient data on MACE outcomes (acute coronary syndromes (ACS), ischaemic strokes, and vascular deaths) in relation to PR and its interaction with cardiovascular risk levels. PR was determined using ADP-induced light transmission aggregometry with a primary concentration of 20 µM ADP. Thirteen prospective studies totaled 6,478 clopidogrel-treated patients who experienced 421 MACE (6.5 %) during a median follow-up of 12 months. The strength of the association between the risk of MACE and PR increased significantly (p=0.04) with the number of risk factors present (age> 75 years, ACS at inclusion, diabetes, and hypertension). No association was detected in patients with no risk factor (p=0.48). In patients presenting one risk factor, only high-PR was associated with an increased risk of MACE (HR 3.2, p=0.001). In patients presenting ≥ 2 risk factors, the increase of risk started from medium-PR (medium-PR: HR=2.9, p=0.0004; high-PR: HR=3.7, p=0.0003). PR allowed the reclassification of 44 % of the total population to a different risk level for the outcome of MACE, mostly in intermediate or high risk patients. In conclusion, the magnitude of the association between PR and MACE risk is strongly dependent on the level of cardiovascular risk faced by patients on clopidogrel.

Ticagrelor or prasugrel versus clopidogrel in elderly patients with an acute coronary syndrome: Optimization of antiplatelet treatment in patients 70 years and older--rationale and design of the POPular AGE study.

RATIONALE: Dual antiplatelet therapy with acetylsalicylic acid in combination with a more potent P2Y12- inhibitor (ticagrelor or prasugrel) is recommended in patients with acute coronary syndrome without ST-segment elevation (NSTE-ACS) to prevent atherothrombotic complications. The evidence on which this recommendation is based shows that ticagrelor and prasugrel reduce atherothrombotic events at the expense of an increase in bleeding events when compared with clopidogrel. However, it remains unclear whether ticagrelor or prasugrel has a better net clinical benefit in elderly patients with NSTE-ACS when compared with clopidogrel. The POPular AGE trial is designed to address the optimal antiplatelet strategy in elderly NSTE-ACS patients. STUDY DESIGN: POPular AGE is a multicenter, open-label, randomized controlled trial that aims to include 1000 patients ≥70years of age with NSTE-ACS. Patients are randomly assigned to receive either clopidogrel or a more potent P2Y12 inhibitor (ticagrelor or prasugrel). The first primary end point is any bleeding event requiring medical intervention. The second primary end point is the net clinical benefit, a composite of all-cause mortality, nonfatal myocardial infarction, nonfatal stroke, "PLATelet inhibition and patient Outcomes" major bleeding, or "PLATelet inhibition and patient Outcomes" minor bleeding. Patients will be followed for 1 year after randomization, and analyses will be performed on the basis of intention to treat. CONCLUSION: The POPular AGE is the first randomized controlled trial that will assess whether the treatment strategy with clopidogrel will result in fewer bleeding events without compromising the net clinical benefit in patients ≥70years of age with NSTE-ACS when compared with a treatment strategy with ticagrelor or prasugrel.

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 PRU ≥ 236 (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 PRU ≥ 236 (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.

Antithrombotic therapy in the anticoagulated patient undergoing percutaneous coronary intervention with coronary stenting.

PURPOSE OF REVIEW: Despite being the subject of extensive research, the optimal antithrombotic therapy for patients on chronic oral anticoagulation (OAC) undergoing percutaneous coronary intervention (PCI) with stent implantation is still unknown. This review presents the latest data regarding this much-debated topic. RECENT FINDINGS: Dual therapy, with clopidogrel (a P2Y12 inhibitor) and OAC, may be an alternative to triple therapy, which usually consists of aspirin and clopidogrel in addition to OAC, in terms of improving clinical outcomes in patients on chronic OAC following PCI with stent implantation. With the arrival of new, safer nonvitamin K antagonists oral anticoagulants (NOACs), the combination of NOAC and clopidogrel may also be an option for replacing triple therapy. In contrast to clopidogrel, combining the more potent P2Y12 inhibitors (prasugrel and ticagrelor) with OAC may only be considered in certain specific circumstances. SUMMARY: Patients on chronic OAC undergoing PCI with stent implantation require triple therapy. However, triple therapy is controversial, because it increases the risk of bleeding. With the introduction of prasugrel, ticagrelor and NOACs, the question arises which P2Y12 inhibitor to choose as part of the triple therapy regime and how NOACs combine with antiplatelet agents when treating patients undergoing PCI.