Guillaume Cayla

Cytochrome P450 2C19 polymorphism in young patients treated with clopidogrel after myocardial infarction: a cohort study.

BACKGROUND Clopidogrel and low-dose aspirin have become the mainstay oral antiplatelet regimen to prevent recurrent ischaemic events after acute coronary syndromes or stent placement. The frequent genetic functional variant 681 G>A (*2) of cytochrome P450 2C19 (CYP2C19) is an important contributor to the wide variability between individuals of the antiplatelet effect of clopidogrel. We assessed whether the CYP2C19*2 polymorphism affected long-term prognosis of patients who were chronically treated with clopidogrel. METHODS Between April 1, 1996, and April 1, 2008, 259 young patients (aged <45 years) who survived a first myocardial infarction and were exposed to clopidogrel treatment for at least a month, were enrolled in a multicentre registry and underwent CYP2C19*2 determination. The primary endpoint was a composite of death, myocardial infarction, and urgent coronary revascularisation occurring during exposure to clopidogrel. Follow-up was every 6 months. The key secondary endpoint was stent thrombosis proven by angiography. FINDINGS Median clopidogrel exposure time was 1.07 years (IQR 0.28-3.0). Baseline characteristics were balanced between carriers (heterozygous *1/*2, n=64; homozygous *2/*2, n=9) and non-carriers (n=186) of CYP2C19*2 variant. The primary endpoint occurred more frequently in carriers than in non-carriers (15 vs 11 events; hazard ratio [HR] 3.69 [95% CI 1.69-8.05], p=0.0005), as did stent thrombosis (eight vs four events; HR 6.02 [1.81-20.04], p=0.0009). The detrimental effect of the CYP2C19*2 genetic variant persisted from 6 months after clopidogrel initiation up to the end of follow-up (HR 3.00 [1.27-7.10], p=0.009). After multivariable analysis, the CYP2C19*2 genetic variant was the only independent predictor of cardiovascular events (HR 4.04 [1.81-9.02], p=0.0006). INTERPRETATION The CYP2C19*2 genetic variant is a major determinant of prognosis in young patients who are receiving clopidogrel treatment after myocardial infarction.

Cardiovascular risk in clopidogrel-treated patients according to cytochrome P450 2C19*2 loss-of-function allele or proton pump inhibitor coadministration: a systematic meta-analysis.

OBJECTIVES The aim of this study was to assess the association between the loss-of-function cytochrome P450 2C19 (CYP2C19)*2 variant (10 studies, 11,959 patients) or the use of proton pump inhibitors (PPIs) (13 studies, 48,674 patients) and ischemic outcomes (major adverse cardiovascular events [MACE]) in patients treated with clopidogrel. BACKGROUND In clopidogrel-treated patients, increased cardiovascular risk has been identified with the loss-of-function CYP2C19*2 allele or the use of PPIs, some of them CYP2C19 inhibitors. To further estimate the effect of a reduction in activity of this enzyme, the authors performed a meta-analysis of the studies available. METHODS The meta-analysis was performed on 23 studies using the odds ratio (OR) as the parameter of efficacy, with a fixed-effect model. The end points were MACE, mortality, or stent thrombosis. RESULTS Of the 11,959 patients, carriers of the loss-of-function CYP2C19*2 allele (28% [n = 3,418]) displayed a 30% increase in the risk for MACE compared with noncarriers (9.7% vs. 7.8%; OR: 1.29; 95% confidence interval [CI]: 1.12 to 1.49; p < 0.001). This single gene variant (CYP2C19*2) was also associated with an excess of mortality (1.8% vs. 1.0%; OR: 1.79; 95% CI: 1.10 to 2.91; p = 0.019; n = 6,225) and of stent thrombosis (2.9% vs. 0.9%; OR: 3.45; 95% CI: 2.14 to 5.57; p < 0.001; n = 4,905). This increased risk was apparent in both heterozygotes and homozygotes and was independent of the baseline cardiovascular risk. PPI users (42% [n = 19,614]) displayed increased risk for MACE (21.8% vs. 16.7%; OR: 1.41; 95% CI: 1.34 to 1.48; p < 0.001) and mortality (12.7% vs. 7.4%; OR: 1.18; 95% CI: 1.07 to 1.30; p < 0.001; n = 23,977) compared with nonusers. The impact of PPI use was, however, significantly influenced by baseline cardiovascular risk, being significant only in high-risk patients. CONCLUSIONS In this global meta-analysis, reduced CYP2C19 function appears to expose clopidogrel-treated patients to excess cardiovascular risk and mortality. Conflicting results among studies may be explained by differences in types and/or levels of risk of patients.

Pretreatment with prasugrel in non-ST-segment elevation acute coronary syndromes.

BACKGROUND Although P2Y12 antagonists are effective in patients with non-ST-segment elevation (NSTE) acute coronary syndromes, the effect of the timing of administration--before or after coronary angiography--is not known. We evaluated the effect of administering the P2Y12 antagonist prasugrel at the time of diagnosis versus administering it after the coronary angiography if percutaneous coronary intervention (PCI) was indicated. METHODS We enrolled 4033 patients with NSTE acute coronary syndromes and a positive troponin level who were scheduled to undergo coronary angiography within 2 to 48 hours after randomization. Patients were randomly assigned to receive prasugrel (a 30-mg loading dose) before the angiography (pretreatment group) or placebo (control group). When PCI was indicated, an additional 30 mg of prasugrel was given in the pretreatment group at the time of PCI and 60 mg of prasugrel was given in the control group. RESULTS The rate of the primary efficacy end point, a composite of death from cardiovascular causes, myocardial infarction, stroke, urgent revascularization, or glycoprotein IIb/IIIa inhibitor rescue therapy (glycoprotein IIb/IIIa bailout) through day 7, did not differ significantly between the two groups (hazard ratio with pretreatment, 1.02; 95% confidence interval [CI], 0.84 to 1.25; P=0.81). The rate of the key safety end point of all Thrombolysis in Myocardial Infarction (TIMI) major bleeding episodes, whether related or not related to coronary-artery bypass grafting (CABG), through day 7 was increased with pretreatment (hazard ratio, 1.90; 95% CI, 1.19 to 3.02; P=0.006). The rates of TIMI major bleeding and life-threatening bleeding not related to CABG were increased by a factor of 3 and 6, respectively. Pretreatment did not reduce the rate of the primary outcome among patients undergoing PCI (69% of the patients) but increased the rate of TIMI major bleeding at 7 days. All the results were confirmed at 30 days and in prespecified subgroups. CONCLUSIONS Among patients with NSTE acute coronary syndromes who were scheduled to undergo catheterization, pretreatment with prasugrel did not reduce the rate of major ischemic events up to 30 days but increased the rate of major bleeding complications. (Funded by Daiichi Sankyo and Eli Lilly; ACCOAST ClinicalTrials.gov number, NCT01015287.).

Clinical ResearchAntiplatelet TherapyCardiovascular Risk in Clopidogrel-Treated Patients According to Cytochrome P450 2C19*2 Loss-of-Function Allele or Proton Pump Inhibitor Coadministration: A Systematic Meta-Analysis

OBJECTIVES The aim of this study was to assess the association between the loss-of-function cytochrome P450 2C19 (CYP2C19)*2 variant (10 studies, 11,959 patients) or the use of proton pump inhibitors (PPIs) (13 studies, 48,674 patients) and ischemic outcomes (major adverse cardiovascular events [MACE]) in patients treated with clopidogrel. BACKGROUND In clopidogrel-treated patients, increased cardiovascular risk has been identified with the loss-of-function CYP2C19*2 allele or the use of PPIs, some of them CYP2C19 inhibitors. To further estimate the effect of a reduction in activity of this enzyme, the authors performed a meta-analysis of the studies available. METHODS The meta-analysis was performed on 23 studies using the odds ratio (OR) as the parameter of efficacy, with a fixed-effect model. The end points were MACE, mortality, or stent thrombosis. RESULTS Of the 11,959 patients, carriers of the loss-of-function CYP2C19*2 allele (28% [n = 3,418]) displayed a 30% increase in the risk for MACE compared with noncarriers (9.7% vs. 7.8%; OR: 1.29; 95% confidence interval [CI]: 1.12 to 1.49; p < 0.001). This single gene variant (CYP2C19*2) was also associated with an excess of mortality (1.8% vs. 1.0%; OR: 1.79; 95% CI: 1.10 to 2.91; p = 0.019; n = 6,225) and of stent thrombosis (2.9% vs. 0.9%; OR: 3.45; 95% CI: 2.14 to 5.57; p < 0.001; n = 4,905). This increased risk was apparent in both heterozygotes and homozygotes and was independent of the baseline cardiovascular risk. PPI users (42% [n = 19,614]) displayed increased risk for MACE (21.8% vs. 16.7%; OR: 1.41; 95% CI: 1.34 to 1.48; p < 0.001) and mortality (12.7% vs. 7.4%; OR: 1.18; 95% CI: 1.07 to 1.30; p < 0.001; n = 23,977) compared with nonusers. The impact of PPI use was, however, significantly influenced by baseline cardiovascular risk, being significant only in high-risk patients. CONCLUSIONS In this global meta-analysis, reduced CYP2C19 function appears to expose clopidogrel-treated patients to excess cardiovascular risk and mortality. Conflicting results among studies may be explained by differences in types and/or levels of risk of patients.

Cyclosporine before PCI in Patients with Acute Myocardial Infarction

BACKGROUND Experimental and clinical evidence suggests that cyclosporine may attenuate reperfusion injury and reduce myocardial infarct size. We aimed to test whether cyclosporine would improve clinical outcomes and prevent adverse left ventricular remodeling. METHODS In a multicenter, double-blind, randomized trial, we assigned 970 patients with an acute anterior ST-segment elevation myocardial infarction (STEMI) who were undergoing percutaneous coronary intervention (PCI) within 12 hours after symptom onset and who had complete occlusion of the culprit coronary artery to receive a bolus injection of cyclosporine (administered intravenously at a dose of 2.5 mg per kilogram of body weight) or matching placebo before coronary recanalization. The primary outcome was a composite of death from any cause, worsening of heart failure during the initial hospitalization, rehospitalization for heart failure, or adverse left ventricular remodeling at 1 year. Adverse left ventricular remodeling was defined as an increase of 15% or more in the left ventricular end-diastolic volume. RESULTS A total of 395 patients in the cyclosporine group and 396 in the placebo group received the assigned study drug and had data that could be evaluated for the primary outcome at 1 year. The rate of the primary outcome was 59.0% in the cyclosporine group and 58.1% in the control group (odds ratio, 1.04; 95% confidence interval [CI], 0.78 to 1.39; P=0.77). Cyclosporine did not reduce the incidence of the separate clinical components of the primary outcome or other events, including recurrent infarction, unstable angina, and stroke. No significant difference in the safety profile was observed between the two treatment groups. CONCLUSIONS In patients with anterior STEMI who had been referred for primary PCI, intravenous cyclosporine did not result in better clinical outcomes than those with placebo and did not prevent adverse left ventricular remodeling at 1 year. (Funded by the French Ministry of Health and NeuroVive Pharmaceutical; CIRCUS ClinicalTrials.gov number, NCT01502774; EudraCT number, 2009-013713-99.).

Composition of Coronary Thrombus in Acute Myocardial Infarction

OBJECTIVES We sought to analyze the composition of coronary thrombus in vivo in ST-segment elevation myocardial infarction (STEMI) patients. BACKGROUND The dynamic process of intracoronary thrombus formation in STEMI patients is poorly understood. METHODS Intracoronary thrombi (n = 45) were obtained by thromboaspiration in 288 consecutive STEMI patients presenting for primary percutaneous intervention, and analyzed using high-definition pictures taken with a scanning electron microscope. Plasma biomarkers (TnI, CRPus, IL-6, PAI-1, sCD40 ligand, and TNF-α) and plasma fibrin clot viscoelastic properties were measured simultaneously on peripheral blood. RESULTS Thrombi were mainly composed of fibrin (55.9 ± 18%) with platelets (16.8 ± 18%), erythrocytes (11.5 ± 9%), cholesterol crystals (5.2 ± 8.4%), and leukocytes (1.3 ± 2.0%). The median ischemic time was 175 min (interquartile range: 140 to 297). Ischemic time impacted thrombi composition, resulting in a positive correlation with intracoronary thrombus fibrin content, r = 0.38, p = 0.01, and a negative correlation with platelet content, r = -0.34, p = 0.02. Thus, fibrin content increased with ischemic time, ranging from 48.4 ± 21% (<3 h) up to 66.9 ± 9% (>6 h) (p = 0.02), whereas platelet content decreased from 24.9 ± 23% (<3 h) to 9.1 ± 6% (>6 h) (p = 0.07). Soluble CD40 ligand was positively correlated to platelet content in the thrombus (r = 0.40, p = 0.02) and negatively correlated with fibrin content (r = -0.36; p = 0.04). Multivariate analysis indicated that ischemic time was the only predictor of thrombus composition, with a 2-fold increase of fibrin content per ischemic hour (adjusted odds ratio: 2.00 [95% confidence interval: 1.03 to 3.7]; p = 0.01). CONCLUSIONS In acute STEMI, platelet and fibrin contents of the occlusive thrombus are highly dependent on ischemia time, which may have a direct impact on the efficacy of drugs or devices used for coronary reperfusion.

Intravenous enoxaparin or unfractionated heparin in primary percutaneous coronary intervention for ST-elevation myocardial infarction: the international randomised open-label ATOLL trial

BACKGROUND Primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction has traditionally been supported by unfractionated heparin, which has never been directly compared with a new anticoagulant using consistent anticoagulation and similar antiplatelet strategies in both groups. We compared traditional heparin treatment with intravenous enoxaparin in primary PCI. METHODS In a randomised open-label trial, patients presenting with ST-elevation myocardial infarction were randomly assigned (1:1) to receive an intravenous bolus of 0·5 mg/kg of enoxaparin or unfractionated heparin before primary PCI. Wherever possible, medical teams travelling in mobile intensive care units (ambulances) selected, randomly assigned (using an interactive voice response system at the central randomisation centre), and treated patients. Patients who had received any anticoagulant before randomisation were excluded. Patients and caregivers were not masked to treatment allocation. The primary endpoint was 30-day incidence of death, complication of myocardial infarction, procedure failure, or major bleeding. The main secondary endpoint was the composite of death, recurrent acute coronary syndrome, or urgent revascularisation. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, number NCT00718471. FINDINGS 910 patients were assigned to treatment with enoxaparin (n=450) or unfractionated heparin (n=460). The primary endpoint occurred in 126 (28%) patients after anticoagulation with enoxaparin versus 155 (34%) patients on unfractionated heparin (relative risk [RR] 0·83, 95% CI 0·68-1·01, p=0·06). The incidence of death (enoxaparin, 17 [4%] vs heparin, 29 [6%] patients; p=0·08), complication of myocardial infarction (20 [4%] vs 29 [6%]; p=0·21), procedure failure (100 [26%] vs 109 [28%]; p=0·61), and major bleeding (20 [5%] vs 22 [5%]; p=0·79) did not differ between groups. Enoxaparin resulted in a significantly reduced rate of the main secondary endpoint (30 [7%] vs 52 [11%] patients; RR 0·59, 95% CI 0·38-0·91, p=0·015). Death, complication of myocardial infarction, or major bleeding (46 [10%] vs 69 [15%] patients; p=0·03), death or complication of myocardial infarction (35 [8%] vs 57 [12%]; p=0·02), and death, recurrent myocardial infarction, or urgent revascularisation (23 [5%] vs 39 [8%]; p=0·04) were all reduced with enoxaparin. INTERPRETATION Intravenous enoxaparin compared with unfractionated heparin significantly reduced clinical ischaemic outcomes without differences in bleeding and procedural success. Therefore, enoxaparin provided an improvement in net clinical benefit in patients undergoing primary PCI. FUNDING Direction de la Recherche Clinique, Assistance Publique-Hôpitaux de Paris; Sanofi-Aventis.

Dual-antiplatelet treatment beyond 1 year after drug-eluting stent implantation (ARCTIC-Interruption): a randomised trial.

BACKGROUND Optimum duration of dual antiplatelet treatment (DAPT) after coronary stenting remains uncertain, with an unknown efficacy to safety ratio of extended treatment leading to discrepancies between international guidelines and clinical practice. We assessed whether DAPT continuation beyond 1 year after coronary stenting is beneficial. METHODS This analysis was a planned extension of the previously published ARCTIC-Monitoring trial, in which we randomly allocated 2440 patients to a strategy of platelet function testing with antiplatelet treatment adjustment or a conventional strategy after coronary stenting with drug-eluting stent (DES). We recruited patients (aged 18 years or older) scheduled for planned DES implantation at 38 centres in France. After 1 year of follow-up, patients without contraindication to interruption of DAPT were eligible for a second randomisation to this second phase of the study (ARCTIC-Interruption). Using a computer-generated randomisation sequence (1:1; stratified by centre), we allocated patients to a strategy of interruption of DAPT where the thienopyridine was interrupted and single aspirin antiplatelet treatment was maintained (interruption group) or a strategy of DAPT continuation for 6-18 months (continuation group). The primary endpoint was the composite of death, myocardial infarction, stent thrombosis, stroke, or urgent revascularisation, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00827411. FINDINGS Between Jan 4, 2011, and March 3, 2012, 1259 eligible patients were randomly allocated to treatment in ARCTIC-Interruption: 624 to the interruption group and 635 to the continuation group. After a median follow-up of 17 months (IQR 15-18), the primary endpoint occurred in 27 (4%) patients in the interruption group and 24 (4%) patients in the continuation group (hazard ratio [HR] 1·17 [95% CI 0·68-2·03]; p=0·58). STEEPLE major bleeding events occurred more often in the continuation group (seven [1%] patients) compared with the interruption group (one [<0·5%] patient; HR 0·15 [0·02-1·20]; p=0·073). Major or minor bleedings were also more common in the continuation group compared with the interruption group (12 [2%] patients vs three [1%] patients; HR 0·26 [0·07-0·91]; p=0·04). INTERPRETATION Our finding suggests no apparent benefit but instead harm with extension of DAPT beyond 1 year after stenting with DES when no event has occurred within the first year after stenting. No conclusion can be drawn for high-risk patients who could not be randomised. The consistency between findings from all trials of such interruption suggests the need for a reappraisal of guidelines for DAPT after coronary stenting towards shorter duration of treatment. FUNDING Allies in Cardiovascular Trials Initiatives and Organized Networks (ACTION Study Group), Fondation de France, Sanofi-Aventis, Cordis, Medtronic, Boston Scientific, Fondation SGAM.

Clinical, Angiographic, and Genetic Factors Associated With Early Coronary Stent Thrombosis

CONTEXT Despite dual antiplatelet therapy, stent thrombosis remains a devastating and unpredictable complication of percutaneous coronary intervention (PCI). OBJECTIVE To perform a sequential analysis of clinical and genetic factors associated with definite early stent thrombosis. DESIGN, SETTING, AND PARTICIPANTS Case-control study conducted in 10 centers in France between January 2007 and May 2010 among 123 patients undergoing PCI who had definite early stent thrombosis and DNA samples available, matched on age and sex with 246 stent thrombosis-free controls. MAIN OUTCOME MEASURE Accuracy of early stent thrombosis prediction by 23 genetic variants. RESULTS Among the 23 genetic variants investigated in 15 different genes, the significant determinants of early stent thrombosis were CYP2C19 metabolic status (adjusted odds ratio [OR], 1.99; 95% CI, 1.47-2.69), ABCB1 3435 TT genotype (adjusted OR, 2.16; 95% CI, 1.21-3.88), and ITGB3 PLA2 carriage (adjusted OR, 0.52; 95% CI, 0.28-0.95). Nongenetic independent correlates were acuteness of PCI (adjusted OR, 3.05; 95% CI, 1.54-6.07), complex lesions (American College of Cardiology/American Heart Association type C) (adjusted OR, 2.33; 95% CI, 1.40-3.89), left ventricular function less than 40% (adjusted OR, 2.25; 95% CI, 1.09-4.70), diabetes mellitus (adjusted OR, 1.82; 95% CI, 1.02-3.24), use of proton pump inhibitors (adjusted OR, 2.19; 95% CI, 1.29-3.75), and higher clopidogrel loading doses (adjusted OR, 0.73; 95% CI, 0.57-0.93). The discriminative accuracy of the clinical-only model was similar to that of a genetic-only model (area under the curve, 0.73 [95% CI, 0.67-0.78] vs 0.68 [95% CI, 0.62-0.74], respectively; P = .34). A combined clinical and genetic model led to a statistically significant increase in the discriminatory power of the model compared with the clinical-only model (area under the curve, 0.78 [95% CI, 0.73-0.83] vs 0.73 [95% CI, 0.67-0.78]; P = .004). CONCLUSIONS This case-control study identified 3 genes (CYP2C19, ABCB1, and ITGB3) and 2 clopidogrel-related factors (loading dose and proton pump inhibitors) that were independently associated with early stent thrombosis. Future studies are needed to validate the prognostic accuracy of these risk factors in prospective cohorts.

Predictive value of post-treatment platelet reactivity for occurrence of post-discharge bleeding after non-ST elevation acute coronary syndrome. Shifting from antiplatelet resistance to bleeding risk assessment?

AIMS We assessed prospectively the association between occurrence of post-discharge non-CABG-related TIMI major and minor bleeding and post-treatment platelet reactivity in patients with non-ST elevation acute coronary syndrome (NSTE ACS). METHODS AND RESULTS Five hundred and ninety-seven consecutive patients admitted with NSTE ACS were prospectively included. Between hospital discharge and one month follow-up, we observed 16 (2.7%) non-CABG-related TIMI haemorrhagic complications including five (0.84%) major and 11 (1.8%) minor bleeds. Patients with bleeding had significantly lower post-treatment values of ADP-induced aggregation (43+/-14% versus. 56+/-19%, p=0.002) and platelet reactivity index VASP (43+/-14% versus 54+/-23%; p=0.04) and a trend for lower values of arachidonic acid-induced aggregation (2.4+/-5.4 versus 13+/-21; p=0.27). After stratification by quartiles based on post-treatment ADP-induced platelet aggregation, we identified patients in the first quartile as hyper-responders with very low post-treatment platelet reactivity, below <40%. The risk of TIMI major and minor bleeding was significantly higher in the first quartile of hyper-responders than in the others quartiles: 10 (6.6%) versus six (1.4%), p=0.001. CONCLUSIONS Our results suggest that assessment of post-treatment platelet reactivity might be used to detect hyper-responders to antiplatelet therapy with higher risk of non-CABG related bleeding and tailor antiplatelet therapy according to both ischaemic and bleeding risk.