Variant recurrent risk among stroke patients with different CYP2C19 phenotypes and treated with clopidogrel

Polymorphisms of CYP2C19 have been associated with variant risk of subsequent cardiovascular events in survivors of myocardial infarction (MI) receiving clopidogrel. This study evaluated the impacts of CYP2C19 polymorphisms on stroke recurrence and other vascular events in a cohort of Chinese patients receiving clopidogrel. From Nanjing Stroke Registry Program, 625 consecutive patients with ischemic stroke were enrolled between May 2008 and April 2010. CYP2C19 variants (*2, *3, and *17) were genotyped. Clinical outcomes were determined with three monthly follow-up. The primary endpoint was a composite of vascular death, non-fatal ischemic stroke, and non-fatal MI. The second endpoint was bleeding events. The median exposure to clopidogrel was 13.2 (interquartile range, 8.9–18.0) months. Primary endpoint was observed in 85 (13.6%) patients and secondary endpoint in 13 (2.1%) patients. Frequencies of CYP2C19*1, *2, *3, and *17 alleles were 61.2, 34.0, 3.8, and 1.0%, respectively, in this patient cohort. CYP2C19 loss-of-function allele (*2 and *3, LOF) carriers were observed with higher risk of subsequent vascular events compared with non-carriers (17.2 versus 8.1%, HR?=?2.16, 95% CI: 1.31–3.56, p?=?0.003). After adjusted for age, sex, major cardiovascular risk factors, and drug agent, CYP2C19 LOF carrier was independently associated with primary endpoint (HR?=?2.31, 95% CI: 1.39–3.84, p?=?0.001). No significant association between CYP2C19 gain-of-function (*17, GOF) and clinical events was detected. In Chinese stroke survivors treated with clopidogrel, carriers of CYP2C19 LOF allele may have increased risk of recurrence.     

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.     

Near patient anti-platelet response testing over time and gene analysis in patients admitted with acute coronary syndromes

We sought to assess the relationships between platelet reactivity at different time points, CYP2C19*2 and ABCB1 status and clinical outcomes in patients with acute coronary syndromes (ACS). Anti-platelet response to clopidogrel was studied prospectively using the VerifyNow (VN) P2Y₁₂ assay at the time of angiography and at 30 days post procedure in 151 patients admitted with ACS who underwent percutaneous coronary intervention (PCI). Troponin T levels were measured at angiography and 16–24 hour following PCI. DNA was extracted and the presence of CYP2C19*2 allele and ABCB1 polymorphisms were determined. Adverse cardiovascular and cerebral events (ACCE) were assessed at 12 months. High VN P2Y12 response at angiography was associated with a greater peri-procedural rise in troponin T, but not ACCE. However, VN P2Y₁₂ response measured at 30 days was associated with ACCE (p?=?0.017). CYP2C19*2 status was associated with higher VN P2Y12 response at angiography (p?<?0.0001) and 30 days (p?=?0.006) but not ACCE. Near-patient testing for clopidogrel response was associated with subsequent ACCE when performed 30 days following PCI, but not at angiography.     

细胞色素P450 2C19*2基因多态性联合钙通道阻滞剂与冠状动脉支架内血栓形成的相关性

目的:探讨经皮冠状动脉介入术(PCI)后接受氯吡格雷治疗的患者中,细胞色素P450 2C19(CYP2C19)*2基因多态性(681A)与支架内血栓形成的相关性,以及服用钙通道阻滞剂(CCBs)与支架内血栓形成的相关性。方法:检测1 738例冠心病PCI术后患者的CYP2C19基因多态性,并将这些患者分为CCBs组和非CCBs组,采用比浊法检测二磷酸腺苷(ADP)途径诱导的血小板最大聚集率(MPAR),比较两组患者MPAR及支架内血栓形成率的差异。结果:19例(2.4%)CYP2C19*2基因型的患者(包括CYP2C19*2/*2或*1/*2)和7例(0.75%)基因型为CYP2C19*1/*1的患者发生了明确的支架内血栓形成;CYP2C19*2基因型患者支架内血栓形成的发生率明显高于CYP2C19野生型纯合子患者(CYP2C19*1/*1)(风险比为4.26,95%可信区间为1.28～9.22,P<0.05);基因型为CYP2C19*1/*1的患者发生支架内血栓形成的风险最低,而基因型为CYP2C19*2/*2的患者支架内血栓形成的风险最高(风险比为0.568,95%可信区间为0.308～2.070,P<0.01);CCBs组和非CCBs组MPAR及支架内血栓形成率差异无统计学意义。结论:PCI术后接受氯吡格雷治疗的冠心病患者中,CYP2C19*2基因型患者支架内血栓形成的风险增加,而服用CCBs不会导致氯吡格雷抗血小板聚集作用减弱以及支架内血栓形成事件增加。     

Traditional clinical risk factors predict clopidogrel hypo-responsiveness in unselected patients undergoing non-emergent percutaneous coronary intervention

High and low platelet reactivity, HPR and LPR respectively, to clopidogrel and aspirin have previously been associated with adverse events following percutaneous coronary intervention (PCI). The aim is to test the ability of a previously developed clinical risk-score, the PREDICT score, to identify patients with HPR and LPR. Nine hundred and twenty-three consecutive patients undergoing non-emergent PCI were enrolled. Platelet reactivity (PR) was determined using Multiplate assays. Patients were grouped into quintiles based on their PR values. Upper and lower quintiles defined HPR and LPR, respectively, whereas quintiles 2–4 defined normal responders. All patients were assigned PREDICT score points in clinical categories (age?>?65, reduced left ventricular function, reduced kidney function, acute coronary syndrome (ACS) and diabetes). We found an association between the cumulative number of PREDICT score variables and the incidence of HPR for clopidogrel (HPR (ADP)) (p?p?=?0.007). In addition, the higher the PREDICT score, the higher the risk of HPR (ADP) (1–3 points, odds ratio (OR) 3.82 (95% CI 1.5–9.73, p?=?0.005); 4–6 points OR 4.11 (95% CI 1.61–10.52, p?=?0.003); 7–9 points OR 9.84 (95% CI 3.49–27.7, p?相似文献   

CYP2C19*2 and prognosis after an acute coronary syndrome: Insights from a Portuguese center

BackgroundClopidogrel requires oxidation dependent on the cytochrome P450 enzyme 2C19 (CYP2C19) to form its active metabolite. The importance of loss-of-function alleles (particularly CYP2C19*2, 681G>A) in poor platelet response to clopidogrel is well recognized.ObjectiveTo investigate the prevalence and prognostic impact of the CYP2C19*2 allele in a local acute coronary syndrome (ACS) population.MethodsWe performed a prospective, longitudinal study of 95 patients admitted for an ACS between March and October 2009 to a single coronary care unit. Patients aged under 75 who survived hospital stay and for whom clopidogrel was prescribed were included. At discharge, CYP2C19 was genotyped using a commercially available kit. Patients were divided into two groups: Group A (non-carriers, normal metabolizers, CYP2C19*1/*1), n = 69; and Group B (carriers, slow metabolizers, CYP2C19*2/*1 or *2/*2), n = 26. The primary endpoint was a combined outcome of cardiovascular death, non-fatal myocardial infarction or re-admission for unstable angina; median follow-up was 136.0 (79.0–188.0) days.ResultsThe median age of the population was 62.0 (51.0–68.0) years, and 83.2% were male. The CYP2C19*2 (A) allele had a frequency of 14.2%. There were no differences between the groups with respect to demographic data or history of cardiovascular disease. Coronary anatomy, left ventricular ejection fraction and renal function were also similar. The groups were also homogenous with respect to GRACE risk score (118.0 (95.0–136.5) vs. 115.0 (96.0–133.0), p = 0.68), medical treatment and percutaneous revascularization during hospital stay. Event-free survival was higher for Group A (94.0% vs. 75.0%, log-rank p = 0.010). Three readmissions for MI were documented, all in the slow metabolizers group.ConclusionIn our ACS population, the CYP2C19*2 allele was a medium-term prognostic marker.     

The relation between CYP2C19 genotype and phenotype in stented patients on maintenance dual antiplatelet therapy

Both high platelet reactivity (HPR) and CYP2C19 genotyping have been proposed to stratify cardiovascular event risk and to personalize maintenance dual antiplatelet therapy (DAPT) in stented patients. However, how well CYP2C19 genotype correlates with HPR in patients on maintenance DAPT is less clear. We determined the association of CYP2C19 loss-of-function (*2) and gain-of-function (*17) allele status with platelet reactivity in 118 stented patients on DAPT ≥2 weeks and in 143 patients with stable coronary artery disease on aspirin therapy alone. Thirty-three percent and 39% carried at least 1 copy of *2 and *17 alleles, respectively. Neither allele was associated with platelet reactivity in patients on aspirin therapy alone. On DAPT, platelet aggregation was higher in those with *2 allele than noncarriers (P ≤ .01) but did not differ between those with the *17 allele and noncarriers. The prevalence of HPR using the 20 μM adenosine diphosphate-induced aggregation cutpoint was 34% in the total population: 26% in *1/*1 homozygotes, 49% in those with the *2 allele, and 20% in those with the *17 allele (P = .006). Determination of diplotype status enhanced identification of HPR. However, platelet function on DAPT is highly variable within diplotype groups. Therefore, CYP2C19 genotype and HPR are imperfect correlates of each other. Because both predict cardiovascular events with similar risk ratios, CYP2C19 genotyping and HPR may provide complementary information to stratify risk and personalized DAPT in stented patients than either alone.     

The efficacy and safety of CYP2C19 genotype-guided antiplatelet therapy compared with conventional antiplatelet therapy in patients with acute coronary syndrome or undergoing percutaneous coronary intervention: A meta-analysis of randomized controlled trials

Abstract

Cytochrome P450 (CYP) 2C19 genotype is closely associated with the metabolism and efficacy of clopidogrel, thereby having an important impact on clinical outcomes of patients with acute coronary syndrome (ACS) or undergoing percutaneous coronary intervention (PCI). This study aimed to evaluate the efficacy and safety of CYP2C19 genotype-guided antiplatelet therapy in patients with ACS or undergoing PCI. PubMed, EMBASE, the Cochrane Library and clinicaltrials.gov were searched to identify randomized controlled trials (RCTs) comparing CYP2C19 genotype-guided antiplatelet therapy with conventional therapy in patients with ACS or undergoing PCI. Eight RCTs involving 6708 patients were included in this meta-analysis. CYP2C19 genotype-guided antiplatelet therapy was slightly superior to the conventional antiplatelet therapy in reducing the risk of MACE [RR(95%CI): 0.71(0.51–0.98), p = .04]. Meanwhile, the genotype-guided therapy group had significantly lower incidence of myocardial infarction [RR(95%CI): 0.56(0.40–0.78), p < .01], but similar risk of all-cause mortality, cardiovascular mortality, stent thrombosis, urgent revascularization and stroke compared to the conventional therapy group. Incidences of major/minor bleeding and major bleeding were comparable between the two groups. In patients with ACS or undergoing PCI, CYP2C19 genotype-guided antiplatelet therapy displayed benefit over conventional antiplatelet therapy in reducing the risk of MACE and myocardial infarction, without increasing bleeding risk. Further RCTs are needed to provide more evidences for CYP2C19 genotype-guided antiplatelet therapy.     

Sulfonylureas and on-clopidogrel platelet reactivity in type 2 diabetes mellitus patients

Clopidogrel is a prodrug that needs to be converted in vivo by several cytochrome (CYP) P450 iso-enzymes to become active. Both clopidogrel and the oral hypoglycemic drug class sulfonylureas are metabolized by the iso-enzyme CYP2C9. The objective of the study was to evaluate the relationship of sulfonylureas and on-clopidogrel platelet reactivity in type 2 diabetes mellitus patients undergoing elective coronary stent implantation. In this prospective, observational study, on-clopidogrel platelet reactivity was quantified using adenosine diphosphate (ADP)-induced light transmittance aggregometry in 139 type 2 diabetes mellitus patients undergoing elective coronary stent implantation treated with clopidogrel and aspirin. High on-clopidogrel platelet reactivity was defined as >70.7% platelet reactivity to 20?µmol/L ADP. A total of 53 patients (38.1%) were on concomitant treatment with sulfonylureas. The remaining 86 patients were on other hypoglycemic drugs. On-clopidogrel platelet reactivity was significantly higher in patients with concomitant sulfonylurea treatment as compared to patients without concomitant sulfonylurea treatment (for 5?µmol/L ADP: 46.0%?±?11.8 vs. 40.6%?±?16.0; p?=?0.035, adjusted p?=?0.032 and for 20?µmol/L ADP: 64.6%?±?10.8 vs. 58.7%?±?15.5; p?=?0.019, adjusted p?=?0.017). The concomitant use of sulfonylureas was associated with a 2.2-fold increased risk of high on-clopidogrel platelet reactivity (OR 2.2, 95% CI 1.1–4.7, p?=?0.039 and after adjustment for confounders: OR_adj 2.0, 95% CI 1.0–5.7, p?=?0.048). Concomitant treatment with sulfonylureas might be associated with decreased platelet inhibition by clopidogrel in type 2 diabetes mellitus patients on dual antiplatelet therapy undergoing elective coronary stent implantation.     

Genetic susceptibility to nonsteroidal anti-inflammatory drug-related gastroduodenal bleeding: role of cytochrome P450 2C9 polymorphisms

BACKGROUND AND AIMS: Several nonsteroidal anti-inflammatory drugs (NSAIDs) are metabolized by the cytochrome P450 2C9 (CYP2C9). Two common variants of the CYP2C9 gene (CYP2C9*2 and *3) were reported to significantly affect the activity of the CYP2C9 enzyme. The aim of this study was to evaluate the impact of CYP2C9 polymorphisms on the risk of gastroduodenal bleeding in acute NSAID users. METHODS: This case-control study included 26 patients with endoscopically documented NSAID-related gastroduodenal bleeding lesions and 52 age-, sex- and NSAID use-matched controls with no lesions at endoscopy. Both cases and controls were Helicobacter pylori negative and acute users of an NSAID or cycloxygenase-2 inhibitor that undergoes CYP2C9 metabolism (ie, celecoxib, diclofenac, ibuprofen, naproxen, or piroxicam). Two marker single nucleotide polymorphisms in the CYP2C9 gene, identifying the CYP2C9 *2 and *3 allele, were evaluated in all subjects. RESULTS: Setting the CYP2C9*1/*1 wild type as reference, significantly higher frequencies of CYP2C9*1/*3 (34.6% vs 5.8%; P < .001; odds ratio [OR], 12.9; 95% confidence interval [CI], 2.917-57.922) and CYP2C9*1/*2 (26.9% vs 15.4%; P = .036; OR, 3.8; 95% CI, 1.090-13.190) were identified in bleeding versus control patients, whereas no differences between bleeding and controls were observed in the distribution of CYP2C9*2/*3 heterozygotes. Considering allele carriers, the presence of CYP2C9*3 allele was associated with a significant high risk of bleeding (adjusted OR, 7.3; 95% CI, 2.058-26.004). CONCLUSIONS: CYP2C9 genotyping may identify subgroups of persons who potentially are at increased risk of gastroduodenal bleeding when treated with NSAIDs metabolized by CYP2C9. Further studies that evaluate the effectiveness of a strategy using CYP2C9 genotyping in NSAID users are needed before genotyping is introduced into clinical practice.     

Cytochrome P450 2C19 loss-of-function polymorphism is a major determinant of clopidogrel responsiveness in healthy subjects

The capacity of clopidogrel to inhibit ADP-induced platelet aggregation shows wide intersubject variability. To determine whether frequent functional variants of genes coding for candidate cytochrome P450 (CYP) isoenzymes involved in clopidogrel metabolic activation (CYP2C19*2, CYP2B6*5, CYP1A2*1F, and CYP3A5*3 variants) influence the platelet responsiveness to clopidogrel, we conducted a prospective pharmacogenetic study in 28 healthy white male volunteers treated for 7 days with clopidogrel 75 mg/d. We observed that pharmacodynamic response to clopidogrel was significantly associated with the CYP2C19 genotype. Twenty of the subjects were wild-type CYP2C19 (*1/*1) homozygotes, while the other 8 subjects were heterozygous for the loss-of-function polymorphism CYP2C19*2 (*1/*2). Baseline platelet activity was not influenced by the CYP2C19 genotype. In contrast, platelet aggregation in the presence of 10 muM ADP decreased gradually during treatment with clopidogrel 75 mg once daily in *1/*1 subjects, reaching 48.9% +/- 14.9% on day 7 (P < .001 vs baseline), whereas it did not change in *1/*2 subjects (71.8% +/- 14.6% on day 7, P = .22 vs baseline, and P < .003 vs *1/*1 subjects). Similar results were found with VASP phosphorylation. The CYP2C19*2 loss-of-function allele is associated with a marked decrease in platelet responsiveness to clopidogrel in young healthy male volunteers and may therefore be an important genetic contributor to clopidogrel resistance in the clinical setting.     

Evaluation of the INNOVANCE PFA P2Y assay and its association with CYP2C19 genotypes

The purpose of this study was to evaluate associations between INNOVANCE PFA P2Y (PFA P2Y) test results and CYP2C19 genotypes and provide baseline data for PFA P2Y testing to establish a therapeutic monitoring strategy for clopidogrel. A total of 75 new patients with acute coronary syndrome with planned percutaneous coronary intervention were enrolled between June 2012 and September 2012. All patients received clopidogrel at an initial loading dose of 600?mg followed by a 75-mg daily maintenance dose. Blood samples were obtained on the third morning after clopidogrel loading. PFA P2Y, VerifyNow P2Y12 and VASP assays were used to determine platelet inhibition due to clopidogrel, and the Verigene CYP2C19 test was used for CYP2C19 genotyping. The genotype frequency of 75 patients was as follows: CYP2C19 *1/*1 (wild type), 28 (37.3%); *1/*2, 31 (41.3%); *1/*3, 4 (5.3%); *2/*2, 5 (6.7%); *2/*3, 5 (6.7%); *1/*17, 1 (1.3%); and *2/*17, 1 (1.3%). Classified according to CYP2C19 genotypes, there were 29 (38.7%) extensive metabolizers (EM) or ultra rapid metabolizers (UM), 35 (46.7%) intermediate metabolizers (IM), and 10 (13.3%) poor metabolizers (PM). Median (interquartile range) PFA P2Y closure times (seconds) were 119 (101–260), 300 (130–300) and 300 (300–300) in the PM, IM and EM or UM groups, respectively (p?<?0.05). Median (interquartile range) VerifyNow PRUs were 294 (213–297), 215 (165–320) and 189 (118–279); and the VASP platelet reactivity index (%) was 52.7 (33.3–91.9), 59.9 (41.4–72.8) and 38.9 (26.8–62.2) in the PM, IM and EM or UM groups, respectively (p?>?0.05). Compared with non-carriers, carriers of reduced function CYP2C19 alleles tended to have higher platelet reactivity after clopidogrel treatment. The cut-off for PM versus other groups (IM and EM or UM) was ≤141 seconds (AUC 0.704, sensitivity 70%, specificity 76.6%) on the ROC curve. A statistically significant correlation between PFA P2Y (seconds) and VerifyNow (PRU) was found (ρ?=??0.47, p?<?0.0001). In conclusion, the PFA P2Y test showed a statistically significant association with CYP2C19 metabolizer phenotypes based on CYP2C19 genotyping and effectively determined the risk groups resistant to clopidogrel therapy, including PM.     

Predictors of high on-clopidogrel platelet reactivity in patients with acute coronary syndrome

High on-clopidogrel platelet reactivity (HPR) is a predictor of ischemic events after percutaneous coronary intervention. We conducted a prospective cohort study to identify variables related to HPR in acute coronary syndrome patients who are at high thrombotic risk. We enrolled 463 patients undergoing urgent coronary angiography. Platelet reactivity was measured 12–36 hours after 600?mg clopidogrel loading with multiple electrode aggregometry (Multiplate® analyzer, Roche, Basel, Switzerland, 6.4?µM ADP). HPR was defined by the consensus cut-off area under the curve >46?U. The rate of HPR was 16.0%. We analyzed simple clinical and laboratory parameters with backward multivariate logistic regression and identified the following predictors of HPR: platelet count (per G/L, OR: 1.0073, 95% CI: 1.0035–1.0112, p?=?0.0002), CRP level (per mg/L, OR: 1.0077, 95% CI: 1.0016–1.01372, p?=?0.01), and active smoking (OR: 0.51, 95% CI: 0.29–0.89, p?=?0.02). We developed and internally validated a risk prediction model demonstrating moderate discriminative capacity (area-under-the-receiver operating characteristic curve?=?0.67). In conclusion, we found a relatively low rate of high on-clopidogrel platelet reactivity (16.0%) even in an acute patient cohort. HPR measured by Multiplate was associated with high platelet count and CRP level on admission and was inversely related to active smoking. The model with rapidly available simple parameters might help to identify individuals at risk for HPR in the acute setting.     

The dawn of aspirin free strategy after short term dual antiplatelet for percutaneous coronary intervention: meta-analysis of randomized controlled trials

There is still a debate about the safety and efficacy of an aspirin free strategy after percutaneous coronary intervention (PCI). Hence, we performed a meta-analysis comparing aspirin free strategy to dual antiplatlets therapy (DAPT). Randomized trials (RCTs) comparing aspirin free strategy to DAPT in patients who received PCI were included. The primary outcome of interest was bleeding, defined per the Bleeding Academic Research Consortium (BARC). Secondary outcomes included major adverse cardiovascular and cerebrovascular events (MACE); defined as all-cause mortality, myocardial infarction or stroke, the individual component of MACE and stent thrombosis. A total of 4 RCTs with 29,089 patients were included. There was significant reduction in BARC 2,3 or 5 bleeding events in patients who were treated with aspirin free strategy versus DAPT (HR 0.61, 95% CI 0.39?, p?=?0.03, I²?=?89%). Moreover, although there was a trend of reduced major bleeding (BARC 3 or 5) outcomes in the aspirin free strategy group compared to the DAPT group, this did not achieve statistical significance (HR 0.63, 95% CI 0.37–1.06, p?=?0.08, I²?=?795). Additionally, there was no difference between the aspirin free strategy and DAPT in term of MACE (HR 0.92, 95% CI 0.82–1.03, p?=?0.13, I²?=?0%), all-cause mortality (HR 0.89, 95% CI 0.77–1.04, p?=?0.15, I²?=?0%), MI (HR 0.89, 95% CI 0.74–1.08, p?=?0.24, I²?=?0%), stroke (HR 1.13, 95% CI 0.65–1.99, p?=?0.66, I²?=?60%) or stent thrombosis (HR 0.1.01, 95% CI 0.83–1.22, p?=?0.93, I²?=?0%). Aspirin free strategy is as effective as DAPT in reducing MACE with better safety profile in term of bleeding.

     

Pharmacogenetics of acenocoumarol: cytochrome P450 CYP2C9 polymorphisms influence dose requirements and stability of anticoagulation

BACKGROUND AND OBJECTIVES: Cytochrome P4502C9 (CYP2C9) is the main enzyme implicated in coumarinic metabolism. Variant alleles, CYP2C9*2 and CYP2C9*3, have been related to decreased enzymatic activity, but their clinical relevance in acenocoumarol metabolism has not been established. We investigated CYP2C9 polymorphisms in relation to acenocoumarol dose requirement, stability of anticoagulation and bleeding. DESIGN AND METHODS: CYP2C9 genotyping was performed in 325 acenocoumarol-treated patients (INR target between 2.0 and 3.0) and in an additional group of 84 patients with repeated bleeding. RESULTS: Patients with the wild-type CYP2C9*1/*1 genotype (n=169) required a higher maintenance dose of acenocoumarol (17.1 8.7 mg/week) than did patients with the CYP2C9*2 (14.6 6.4 mg/week, p<0.05, N=97) or the CYP2C9*3 allele (11.2 6.2 mg/week, p<0.001, n=59). Out of 170 patients requiring a low-dose of acenocoumarol (70 years (OR=3.73, 95%CI=2.29-6.08, p<0.001), and the CYP2C9*3 allele (OR=4.75, 95%CI=2.36-9.55, p <0.001). Carriers of CYP2C9*3 spent less time within the therapeutic range (64.7 23.1%) than did patients with the CYP2C9*1/*1 genotype (75.1 22.0%, p<0.01), and more frequently had an INR >4.5 at the initiation of treatment (43.9% vs.11.6%, p<0.001), but did not show repeated bleeding more frequently (19.0% vs.15.5%, p=NS). INTERPRETATION AND CONCLUSIONS: CYP2C9*3 is related to lower acenocoumarol dose requirements, a higher frequency of over-anticoagulation at the initiation of therapy and an unstable anticoagulant response.     

Complete versus incomplete revascularization for treatment of multivessel coronary artery disease in the drug-eluting stent era

Limited data exist regarding the impact of complete revascularization (CR) versus incomplete revascularization (IR) on the long-term outcomes of patients with multivessel coronary artery disease (MVD) who underwent percutaneous coronary intervention with drug-eluting stents. We compared major adverse cardiac events [MACE: death, myocardial infarction (MI), or any revascularization] in 873 patients and in 255 pairs generated by propensity-score matching. CR was performed in 427 patients (48.9%) and IR in 446 (51.1%). While the amount of myocardium at risk by the APPROACH score was similar between two groups (56.0?±?14.4 vs. 56.7?±?16.1, p?=?0.49), the SYNTAX score was lower in the CR group than in the IR group (20.7?±?9.4 vs. 23.3?±?10.7, p?<?0.01). MACE occurred in 203 patients (23.3%) during a median follow-up of 35?months. CR was associated with a lower incidence of MACE (HR 0.64; 95% CI 0.46–0.88; p?<?0.01) and revascularization (HR 0.61; 95% CI 0.42–0.90; p?=?0.01), but not of death (HR 0.87; 95% CI 0.48–1.57; p?=?0.64) and MI (HR 0.62; 95% CI 0.23–1.67; p?=?0.35). The incidence of periprocedural MI and stent thrombosis was similar in two groups (4.7% in the CR group vs. 3.6% in the IR group, p?=?0.42; 1.6 vs. 1.3%, p?=?0.72, respectively). After propensity-score matching, patients with CR had fewer MACE and revascularization than those with IR. In patients with MVD, CR strategy using drug-eluting stents could reduce repeat revascularization with similar death, MI, and stent thrombosis risk compared with IR strategy.     

Pharmacogenetics of cyclophosphamide and CYP2C19 polymorphism in Thai systemic lupus erythematosus

To assess whether the CYP2C19 polymorphism modified the effect of cyclophosphamide on ovarian toxicity in Thai patients with SLE. We performed a case–control study of female patients with SLE who were treated with cyclophosphamide at Ramathibodi Hospital, Bangkok, Thailand. Cases were patient who had ovarian toxicity (sustained amenorrhoea >12 months or lack of menstruation for >4 months). CYP2C19 polymorphism was genotyped using PCR–RFLP method. Logistic regression was applied to assess CYP2C19 polymorphism as an effect modifier of cyclophosphamide. Seventy-one patients with SLE were enrolled, of which 36 (59.7%) had ovarian toxicity. CYP2C19*2 allele frequencies were 27.8 and 21.4% in the ovarian and non-ovarian toxicity groups. Patients with CYP2C19*1/*1 genotype and higher cumulative dose of cyclophosphamide (>23.75 g) had the highest odds of ovarian toxicity, i.e. 11.0 (95% CI: 1.2–99.1) times higher than patients with the CYP2C19*1/*2 or *2/*2 genotypes who received less cyclophosphamide (<23.75 g). After adjusting for age at start of treatment, this risk increased to 13.6 (95% CI: 1.1–162.2). Our results suggest that a cumulative cyclophosphamide dose of 23.75 g or higher carries a twofold higher risk of ovarian toxicity and the CYP2C19*1/*1 genotype increases the risk of toxicity a further fivefold.     

CYP2C19*2/ABCB1-C3435T polymorphism and risk of cardiovascular events in coronary artery disease patients on clopidogrel: Is clinical testing helpful?

BackgroundStudies evaluating CYP2C19*2 and ABCB1-C3435T polymorphisms have shown conflicting results. We performed this meta-analysis to evaluate role of clinical testing for these polymorphisms in CAD patients on clopidogrel.Methods19,601 patients from 14 trials were analyzed. The endpoints were major adverse cardiovascular events (MACE), cardiovascular (CV) death, stent thrombosis (ST), myocardial infarction (MI), stroke and major bleeding. Combined relative risks (RR) with 95% confidence intervals (CI) were computed for each outcome by using standard methods of meta-analysis and test parameters were computed.ResultsCYP2C19*2 polymorphism was associated with higher risk of MACE [RR: 1.28, CI: 1.06–1.54; p = 0.009], CV death [RR: 3.21, CI: 1.65–6.23; p = 0.001], MI [RR: 1.36, CI: 1.12–1.65; p = 0.002], ST [RR: 2.41, CI: 1.69–3.41; p < 0.001]. No difference was seen in major bleeding events [RR: 1.02, CI: 0.86–1.20; p = 0.83]. Subgroup analysis showed similar results for elective PCI [RR: 1.34, CI: 1.01–1.76; p = 0.03], and PCI with DES [RR: 1.53, CI: 1.029–1.269; p = 0.03]. CYP2C19*2 polymorphism has very low sensitivity (28–58%), specificity (71–73%), positive predictive value (3–10%) but good negative predictive value (92–99%). ABCB1-C3435T polymorphism analysis revealed similar MACE [RR: 1.13, CI: 0.99–1.29; p = 0.06], ST [RR: 0.88, CI: 0.52–1.47; p = 0.63] and major bleeding [RR: 1.04, CI: 0.87–1.25; p = 0.62] in both groups.ConclusionIn CAD patients on clopidogrel therapy, CYP2C19*2 polymorphism is associated with significantly increased adverse cardiovascular events. However, due to the low positive predictive value, routine genetic testing cannot be recommended at present.     

Defining predictive values using three different platelet function tests for CYP2C19 phenotype status on maintenance dual antiplatelet therapy after PCI

Abstract

Published data suggests that the presence of CYP2C19*2 or *3 loss of function (LOF) alleles is indicative of increased platelet aggregation and a higher risk of adverse cardiovascular events after clopidogrel administration. We sought to determine cut-off values using three different assays for prediction of the CYP2C19 phenotype in Korean percutaneous coronary intervention (PCI) patients. We enrolled 244 patients with drug-eluting stent implantation who were receiving clopidogrel and aspirin maintenance therapy for one month or more. Platelet reactivity was assessed with light transmittance aggregometry (LTA), multiple electrode aggregometry (MEA) and the VerifyNow P2Y12 assay (VN). The CYP2C19 genotype was analyzed by polymerase chain reaction (PCR) and snapshot method. The frequency of CYP2C19 LOF allele carriers was 58.6%. The cut-off values from LTA, MEA and VerifyNow for the identification of LOF allele carriers were as follows: 10?µM ADP-induced LTA?≥?48 %, VN?>?242 PRU and MEA?≥?37?U. Between the three tests, correlation was higher between LTA vs. VN assays (r?=?0.69) and LTA vs. MEA (r?=?0.56), with moderate agreement (κ?=?0.46 and κ?=?0.46), but between VN assay and MEA, both devices using whole blood showed a lower correlation (r?=?0.42) and agreement (κ?=?0.3). Our results provide guidance regarding cut-off levels for LTA, VerifyNow and MEA assays to detect the CYP2C19 LOF allele in patients during dual antiplatelet maintenance therapy.     

CYP4A11 gene T8590C polymorphism is associated with essential hypertension in the male western Chinese Han population

Background: CYP4A11 is a member of the cytochrome P450 enzymes and is responsible for metabolizing arachidonic acid to 20-hydroxyeicosatetraenoic acid, a metabolite involved in the regulation of blood pressure. This study aimed to evaluate whether or not the CYP4A11 gene polymorphism T8590C (rs1126742) is involved in essential hypertension in the western Chinese Han population.

Methods: In a case-control study, the participants included 864 (523 males and 341 females) patients with essential hypertension and 661 (422 males and 239 females) healthy subjects. The T8590C polymorphism of the CYP4A11 gene was analyzed by using the TaqMan® SNP Genotyping Assay.

Results: For men, the frequencies of the CC genotype and the C allele were higher in essential hypertension than in the control group (p?=?0.022 and p?=?0.016, respectively). After adjustment of confounding factor such as diabetes, smoking, BMI, TG and TC, the significant difference was observed in CC genotype (OR?=?1.897, 95% confidence interval [CI] 1.026–3.508; p?=?0.041). No difference was found in all participants and females.

Conclusions: The CC genotype and C allele were associated with essential hypertension in the male western Chinese Han population.