Platelet RNA Biomarker of Ticagrelor-Responsive Genes Is Associated With Platelet Function and Cardiovascular Events.

BACKGROUND: Identifying patients with the optimal risk:benefit for ticagrelor is challenging. The aim was to identify ticagrelor-responsive platelet transcripts as biomarkers of platelet function and cardiovascular risk. METHODS: Healthy volunteers (n=58, discovery; n=49, validation) were exposed to 4 weeks of ticagrelor with platelet RNA data, platelet function, and self-reported bleeding measured pre-/post-ticagrelor. RNA sequencing was used to discover platelet genes affected by ticagrelor, and a subset of the most informative was summarized into a composite score and tested for validation. This score was further analyzed (1) in CD34+ megakaryocytes exposed to an P2Y12 inhibitor in vitro, (2) with baseline platelet function in healthy controls, (3) in peripheral artery disease patients (n=139) versus patient controls (n=30) without atherosclerosis, and (4) in patients with peripheral artery disease for correlation with atherosclerosis severity and risk of incident major adverse cardiovascular and limb events. RESULTS: Ticagrelor exposure differentially expressed 3409 platelet transcripts. Of these, 111 were prioritized to calculate a Ticagrelor Exposure Signature score, which ticagrelor reproducibly increased in discovery and validation cohorts. Ticagrelor's effects on platelets transcripts positively correlated with effects of P2Y12 inhibition in primary megakaryocytes. In healthy controls, higher baseline scores correlated with lower baseline platelet function and with minor bleeding while receiving ticagrelor. In patients, lower scores independently associated with both the presence and extent of atherosclerosis and incident ischemic events. CONCLUSIONS: Ticagrelor-responsive platelet transcripts are a biomarker for platelet function and cardiovascular risk and may have clinical utility for selecting patients with optimal risk:benefit for ticagrelor use.

Coronary Atherosclerosis, Cardiac Troponin, and Interleukin-6 in Patients With Chest Pain: The PROMISE Trial Results.

BACKGROUND: Increased inflammation and myocardial injury can be observed in the absence of myocardial infarction or obstructive coronary artery disease (CAD). OBJECTIVES: The authors determined whether biomarkers of inflammation and myocardial injury-interleukin (IL)-6 and high-sensitivity cardiac troponin (hs-cTn)-were associated with the presence and extent of CAD and were independent predictors of major adverse cardiovascular events (MACEs) in stable chest pain. METHODS: Using participants from the PROMISE trial, the authors measured hs-cTn I and IL-6 concentrations and analyzed computed tomography angiography (CTA) images in the core laboratory for CAD characteristics: significant stenosis (≥70%), high-risk plaque (HRP), Coronary Artery Disease Reporting and Data System (CAD-RADS) categories, segment involvement score (SIS), and coronary artery calcium (CAC) score. The primary endpoint was a composite MACE (death, myocardial infarction, or unstable angina). RESULTS: The authors included 1,796 participants (age 60.2 ± 8.0 years; 47.5% men, median follow-up 25 months). In multivariable linear regression adjusted for atherosclerotic cardiovascular disease (ASCVD) risk, hs-cTn was associated with HRP, stenosis, CAD-RADS, and SIS. IL-6 was only associated with stenosis and CAD-RADS. hs-cTn above median (1.5 ng/L) was associated with MACEs in univariable analysis (HR: 2.1 [95% CI: 1.3-3.6]; P = 0.006), but not in multivariable analysis adjusted for ASCVD and CAD. IL-6 above median (1.8 ng/L) was associated with MACEs in multivariable analysis adjusted for ASCVD and HRP (HR: 1.9 [95% CI: 1.1-3.3]; P = 0.03), CAC (HR: 1.9 [95% CI: 1.0-3.4]; P = 0.04), and SIS (HR: 1.8 [95% CI: 1.0-3.2]; P = 0.04), but not for stenosis or CAD-RADS. In participants with nonobstructive CAD (stenosis 1%-69%), the presence of both hs-cTn and IL-6 above median was strongly associated with MACEs (HR: 2.5-2.7 after adjustment for CAD characteristics). CONCLUSIONS: Concentrations of hs-cTn and IL-6 were associated with CAD characteristics and MACEs, indicating that myocardial injury and inflammation may each contribute to pathways in CAD pathophysiology. This association was most pronounced among participants with nonobstructive CAD representing an opportunity to tailor treatment in this at-risk group. (PROspective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550).

Implementing a pragmatic clinical trial to tailor opioids for acute pain on behalf of the IGNITE ADOPT PGx investigators.

Opioid prescribing for postoperative pain management is challenging because of inter-patient variability in opioid response and concern about opioid addiction. Tramadol, hydrocodone, and codeine depend on the cytochrome P450 2D6 (CYP2D6) enzyme for formation of highly potent metabolites. Individuals with reduced or absent CYP2D6 activity (i.e., intermediate metabolizers [IMs] or poor metabolizers [PMs], respectively) have lower concentrations of potent opioid metabolites and potentially inadequate pain control. The primary objective of this prospective, multicenter, randomized pragmatic trial is to determine the effect of postoperative CYP2D6-guided opioid prescribing on pain control and opioid usage. Up to 2020 participants, age ≥8 years, scheduled to undergo a surgical procedure will be enrolled and randomized to immediate pharmacogenetic testing with clinical decision support (CDS) for CYP2D6 phenotype-guided postoperative pain management (intervention arm) or delayed testing without CDS (control arm). CDS is provided through medical record alerts and/or a pharmacist consult note. For IMs and PM in the intervention arm, CDS includes recommendations to avoid hydrocodone, tramadol, and codeine. Patient-reported pain-related outcomes are collected 10 days and 1, 3, and 6 months after surgery. The primary outcome, a composite of pain intensity and opioid usage at 10 days postsurgery, will be compared in the subgroup of IMs and PMs in the intervention (n = 152) versus the control (n = 152) arm. Secondary end points include prescription pain medication misuse scores and opioid persistence at 6 months. This trial will provide data on the clinical utility of CYP2D6 phenotype-guided opioid selection for improving postoperative pain control and reducing opioid-related risks.

Platelet inhibition by low-dose aspirin is not influenced by body mass or weight.

Aspirin's clinical efficacy may be influenced by body weight and mass. Although inadequate platelet inhibition by aspirin is suggested as responsible, evidence for this in non-diabetic patients is sparse. We investigated the influence of body weight and mass on aspirin's inhibition of platelet aggregation in healthy adults without diabetes. Cohort one (NYU, n = 84) had light transmission aggregometry (LTA) of platelet-rich plasma to submaximal adenosine diphosphate (ADP) and arachidonic acid (AA) before and following 1 week of daily 81 mg non-enteric coated aspirin. Subjects in the validation cohort (Duke, n = 66) were randomized to 81 mg or 325 mg non-enteric coated aspirin for 4 weeks, immediately followed by 4 weeks of the other dose, with LTA to submaximal collagen, ADP, and AA before and after each dosage period. Body mass index (BMI) range was 18.0-57.5 kg/m2 and 25% were obese. Inhibition of platelet aggregation was similar irrespective of BMI, body weight and aspirin dose. There was no correlation between platelet aggregation before or after aspirin with BMI or body weight. Our data demonstrate that aspirin produces potent inhibition of direct and indirect COX1-mediated platelet aggregation in healthy adults without diabetes regardless of body weight or mass - suggesting that other mechanisms explain lower preventive efficacy of low-dose aspirin with increasing body weight/mass.

Risk factors, transcriptomics, and outcomes of myocardial injury following lower extremity revascularization.

Myocardial injury after non-cardiac surgery (MINS) is common. We investigated the incidence and outcomes of MINS, and mechanistic underpinnings using pre-operative whole blood gene expression profiling in a prospective cohort study of individuals undergoing lower extremity revascularization (LER) for peripheral artery disease (PAD). Major adverse cardiovascular and limb events (MACLE) were defined as a composite of death, myocardial infarction, stroke, major lower extremity amputation or reoperation. Among 226 participants undergoing LER, MINS occurred in 53 (23.5%). Patients with MINS had a greater incidence of major adverse cardiovascular events (49.1% vs. 22.0%, adjusted HR 1.87, 95% CI 1.07-3.26) and MACLE (67.9% vs. 44.5%; adjusted HR 1.66, 95% CI 1.08-2.55) at median 20-month follow-up. Pre-operative whole blood transcriptome profiling of a nested matched MINS case-control cohort (n = 41) identified upregulation of pathways related to platelet alpha granules and coagulation in patients who subsequently developed MINS. Thrombospondin 1 (THBS1) mRNA expression was 60% higher at baseline in patients who later developed MINS, and was independently associated with long-term cardiovascular events in the Duke Catheterization Genetics biorepository cohort. In conclusion, pre-operative THBS1 mRNA expression is higher in patients who subsequently develop MINS and is associated with incident cardiovascular events. Pathways related to platelet activity and coagulation associated with MINS provide novel insights into mechanisms of myocardial injury.

Cost-Effectiveness of Tumor Genomic Profiling to Guide First-Line Targeted Therapy Selection in Patients With Metastatic Lung Adenocarcinoma.

OBJECTIVES: A cost-effectiveness analysis comparing comprehensive genomic profiling (CGP) of 10 oncogenes, targeted gene panel testing (TGPT) of 4 oncogenes, and no tumor profiling over the lifetime for patients with metastatic lung adenocarcinoma from the Centers for Medicare and Medicaid Services' perspective was conducted. METHODS: A decision analytic model used 10 000 hypothetical Medicare beneficiaries with metastatic lung adenocarcinoma to simulate outcomes associated with CGP (ALK, BRAF, EGFR, ERBB2, MET, NTRK1, NTRK2, NTRK3, RET, ROS1), TGPT (ALK, BRAF, EGFR, ROS1), and no tumor profiling (no genes tested). First-line targeted cancer-directed therapies were assigned if actionable gene variants were detected; otherwise, nontargeted cancer-directed therapies were assigned. Model inputs were derived from randomized trials (progression-free survival, adverse events), the Veterans Health Administration and Medicare (drug costs), published studies (nondrug cancer-related management costs, health state utilities), and published databases (actionable variant prevalences). Costs (2019 US$) and quality-adjusted life-years (QALYs) were discounted at 3% per year. Probabilistic sensitivity analyses used 1000 Monte Carlo simulations. RESULTS: No tumor profiling was the least costly/person ($122 613 vs $184 063 for TGPT and $188 425 for CGP) and yielded the least QALYs/person (0.53 vs 0.73 for TGPT and 0.74 for CGP). The costs per QALY gained and corresponding 95% confidence interval were $310 735 ($278 323-$347 952) for TGPT vs no tumor profiling and $445 545 ($322 297-$572 084) for CGP vs TGPT. All probabilistic sensitivity analysis simulations for both comparisons surpassed the willingness-to-pay threshold ($150 000 per QALY gained). CONCLUSION: Compared with no tumor profiling in patients with metastatic lung adenocarcinoma, tumor profiling (TGPT, CGP) improves quality-adjusted survival but is not cost-effective.

The Clinical Pharmacogenetics Implementation Consortium Guideline for SLCO1B1, ABCG2, and CYP2C9 genotypes and Statin-Associated Musculoskeletal Symptoms.

Statins reduce cholesterol, prevent cardiovascular disease, and are among the most commonly prescribed medications in the world. Statin-associated musculoskeletal symptoms (SAMS) impact statin adherence and ultimately can impede the long-term effectiveness of statin therapy. There are several identified pharmacogenetic variants that impact statin disposition and adverse events during statin therapy. SLCO1B1 encodes a transporter (SLCO1B1; alternative names include OATP1B1 or OATP-C) that facilitates the hepatic uptake of all statins. ABCG2 encodes an efflux transporter (BCRP) that modulates the absorption and disposition of rosuvastatin. CYP2C9 encodes a phase I drug metabolizing enzyme responsible for the oxidation of some statins. Genetic variation in each of these genes alters systemic exposure to statins (i.e., simvastatin, rosuvastatin, pravastatin, pitavastatin, atorvastatin, fluvastatin, lovastatin), which can increase the risk for SAMS. We summarize the literature supporting these associations and provide therapeutic recommendations for statins based on SLCO1B1, ABCG2, and CYP2C9 genotype with the goal of improving the overall safety, adherence, and effectiveness of statin therapy. This document replaces the 2012 and 2014 Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines for SLCO1B1 and simvastatin-induced myopathy.

SLCO1B1*5 Allele Is Associated With Atorvastatin Discontinuation and Adverse Muscle Symptoms in the Context of Routine Care.

The SLCO1B1 genotype is known to influence patient adherence to statin therapy, in part by increasing the risk for statin-associated musculoskeletal symptoms (SAMSs). The SLCO1B1*5 allele has previously been associated with simvastatin discontinuation and SAMSs. Prior analyses of the relationship between SLCO1B1*5 and atorvastatin muscle side effects have been inconclusive due to insufficient power. We now quantify the impact of SLCO1B1*5 on atorvastatin discontinuation and SAMSs in a large observational cohort using electronic medical record data from a single health care system. In our study cohort (n = 1,627 patients exposed to atorvastatin during the course of routine clinical care), 56% (n = 912 of 1,627 patients) discontinued atorvastatin and 18% (n = 303 of 1,627 patients) developed SAMSs. A univariate model revealed that SLCO1B1*5 increased the likelihood that patients would stop atorvastatin during routine care (odds ratio 1.2; 95% confidence interval (CI), 1.1-1.5; P = 0.04). A multivariate Cox proportional hazards model further demonstrated that this same variant was associated with time to atorvastatin discontinuation (hazard ratio 1.2; 95% CI, 1.1-1.4; P = 0.004). Additional time-to-event analyses also revealed that SCLO1B1*5 was associated with SAMSs (hazard ratio 1.4; 95% CI, 1.1-1.7; P = 0.02). Atorvastatin discontinuation was associated with SAMSs (odds ratio 1.67; P = 0.0001) in our cohort.

North Carolina's multi-institutional pharmacogenomics efforts with the North Carolina Precision Health Collaborative.

The North Carolina Precision Health Collaborative is an interdisciplinary, public-private consortium of precision health experts who strategically align statewide resources and strengths to elevate precision health in the state and beyond. Pharmacogenomics (PGx) is a key area of focus for the North Carolina Precision Health Collaborative. Experts from Atrium Health's Levine Cancer Institute, Duke University/Duke Health System, Mission Health and the University of North Carolina (UNC) at Chapel Hill/UNC Health System have collaborated since 2017 to implement strategic PGx initiatives, including basic sciences research, translational research and clinical implementation of germline testing into practice and policy. This institutional profile highlights major PGx programs and initiatives across these organizations and how the collaborative is working together to advance PGx science and implementation.

Platelet reactivity in response to aspirin and ticagrelor in African-Americans and European-Americans.

Platelet gene polymorphisms are associated with variable on-treatment platelet reactivity and vary by race. Whether differences in platelet reactivity and aspirin or ticagrelor exist between African-American and European-Americans remains poorly understood. Biological samples from three prior prospective antiplatelet challenge studies at the Duke Clinical Research Unit were used to compare platelet reactivity between African-American and European-American subjects. Platelet reactivity at baseline, on-aspirin, on-ticagrelor, and the treatment effect of aspirin or ticagrelor were compared between groups using an adjusted mixed effects model. Compared with European-Americans (n = 282; 50% female; mean ± standard deviation age, 50 ± 16), African-Americans (n = 209; 67% female; age 48 ± 12) had lower baseline platelet reactivity with platelet function analyzer-100 (PFA-100) (p < 0.01) and with light transmission aggregometry (LTA) in response to arachidonic acid (AA), adenosine diphosphate (ADP), and epinephrine agonists (p < 0.05). African-Americans had lower platelet reactivity on aspirin in response to ADP, epinephrine, and collagen (p < 0.05) and on ticagrelor in response to AA, ADP, and collagen (p < 0.05). The treatment effect of aspirin was greater in European-Americans with an AA agonist (p = 0.002). Between-race differences with in vitro aspirin mirrored those seen in vivo. The treatment effect of ticagrelor was greater in European-Americans in response to ADP (p < 0.05) but with collagen, the treatment effect was greater for African-Americans (p < 0.05). Platelet reactivity was overall lower in African-Americans off-treatment, on aspirin, and on ticagrelor. European-Americans experienced greater platelet suppression on aspirin and on ticagrelor. The aspirin response difference in vivo and in vitro suggests a mechanism intrinsic to the platelet. Whether the absolute level of platelet reactivity or the degree of platelet suppression after treatment is more important for clinical outcomes is uncertain.

Understanding the state of pharmacogenomic testing for thiopurine methyltransferase within a large health system.

Aim: To investigate the current state of TPMT testing at a single-academic medical center. Methods: Single-center, retrospective chart review for patients newly prescribed a thiopurine. Data collection and evaluation included the prevalence and timing of TPMT testing, correct dosage adjustment if applicable, and incidence of myelosuppression. Results: 121 patients (71%) received TPMT testing. Out of the tested patients, 110 (90.9%) were designated as wild-type with normal metabolism. Dosing modification was appropriate in applicable patients. In unadjusted analysis, there was a lower incidence of myelosuppression among patients who were tested versus those who were not (16.5 vs 36.7%). Conclusion: Based on the study results, TPMT testing opportunities exist for nearly 30% of patients. Testing may reduce the incidence of myelosuppression.

Cost-Effectiveness of Multigene Pharmacogenetic Testing in Patients With Acute Coronary Syndrome After Percutaneous Coronary Intervention.

OBJECTIVE: To evaluate the cost-effectiveness of multigene testing (CYP2C19, SLCO1B1, CYP2C9, VKORC1) compared with single-gene testing (CYP2C19) and standard of care (no genotyping) in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) from Medicare's perspective. METHODS: A hybrid decision tree/Markov model was developed to simulate patients post-PCI for ACS requiring antiplatelet therapy (CYP2C19 to guide antiplatelet selection), statin therapy (SLCO1B1 to guide statin selection), and anticoagulant therapy in those that develop atrial fibrillation (CYP2C9/VKORC1 to guide warfarin dose) over 12 months, 24 months, and lifetime. The primary outcome was cost (2016 US dollar) per quality-adjusted life years (QALYs) gained. Costs and QALYs were discounted at 3% per year. Probabilistic sensitivity analysis (PSA) varied input parameters (event probabilities, prescription costs, event costs, health-state utilities) to estimate changes in the cost per QALY gained. RESULTS: Base-case-discounted results indicated that the cost per QALY gained was $59 876, $33 512, and $3780 at 12 months, 24 months, and lifetime, respectively, for multigene testing compared with standard of care. Single-gene testing was dominated by multigene testing at all time horizons. PSA-discounted results indicated that, at the $50 000/QALY gained willingness-to-pay threshold, multigene testing had the highest probability of cost-effectiveness in the majority of simulations at 24 months (61%) and over the lifetime (81%). CONCLUSIONS: On the basis of projected simulations, multigene testing for Medicare patients post-PCI for ACS has a higher probability of being cost-effective over 24 months and the lifetime compared with single-gene testing and standard of care and could help optimize medication prescribing to improve patient outcomes.

Equilibrative nucleoside transporter 1 gene polymorphisms and clinical outcomes following acute coronary syndromes: findings from the PLATelet inhibition and patient Outcomes (PLATO) study.

In the PLATelet inhibition and patient Outcomes (PLATO) study, the P2Y12 inhibitors ticagrelor and clopidogrel were compared in the treatment of acute coronary syndromes (ACS). Ticagrelor was shown to reduce occurrence of the primary end point - a composite of death from vascular causes, myocardial infarction, or stroke - compared to clopidogrel. Ticagrelor's pleiotropic effects on reuptake of adenosine via inhibition of equilibrative nucleoside transporter 1 (ENT1) have been hypothesized to contribute to this. Several polymorphisms of ENT1 are known to exist. We explored the interaction between ENT1 polymorphisms and clinical outcomes in ACS patients participating in the PLATO genetic substudy. Using genotyping data obtained in a genome-wide association study, the gene region encoding ENT1 was assessed and 94 polymorphisms were identified. After quality control filtering, data from 9943 participants were included. Subjects were divided into discovery (phase 1, n = 3970) and replication (phase 2, n = 5973) cohorts. Cox-regression analysis of the relationship between variants and seven efficacy and safety outcomes was performed in discovery, replication, and combined cohorts. Treatment-marker interactions were also determined. Although 35 variants were found with associations to the investigated outcomes reaching p < 0.05 in the discovery cohort, only one of these was replicated in phase 2 of the analysis and also reached the predetermined level of statistical significance in the combined data, taking into account the number of tests performed: the rare polymorphism rs141034817, with a frequency of 0.2%, was significantly associated with bleeding. Thirty-three treatment-marker interactions were found with a significance level of p < 0.05 in phase 1, but none was replicated in phase 2. We found no significant interaction between ENT1 genotype and clinical outcomes in ACS patients treated with ticagrelor or clopidogrel, apart from the association between a rare polymorphism and bleeding that requires further study. If ticagrelor's pleiotropic effects on adenosine uptake are clinically relevant, these do not appear to be significantly affected by variation in the ENT1 gene.

Effects of Delivering SLCO1B1 Pharmacogenetic Information in Randomized Trial and Observational Settings.

BACKGROUND: Outcomes of tailoring statin-type based on solute carrier organic anion transporterfamily member 1B1 ( SLCO1B1)pharmacogenetic toxicity information on patient, provider, and pharmacological outcomes are unknown. METHODS: The trial randomized 159 patients not taking statins because of prior statin myalgia 1:1 to receiving SLCO1B1 GIST (Genotype Informed Statin Therapy) versus usual care (UC) and followed for up to 8 months. The UC arm received their SLCO1B1 results post-trial. The primary outcome was statin adherence using the Morisky Medication Adherence Scale, which was assessed in those patients who reinitiated statins. Secondary outcomes assessed in all participants included statin reinitiation and LDLc (low-density lipoprotein cholesterol), within and post-trial. Using commercial laboratory data, serial LDLc were compared between 1907 patients receiving SLCO1B1 testing and propensity-matched, untested controls. RESULTS: Trial participants were 25% SLCO1B1*5 carriers. Statin adherence was similar between arms (Morisky Medication Adherence Scale in GIST versus UC, 6.8±1.5 versus 6.9±1.6, P=0.96). GIST led to more new statin prescriptions (55.4% versus 38.0%, P=0.04) and lower LDLc at 3 months (131.9±42.0 versus 144.4±43.0 mg/dL; P=0.048) with similar magnitude at 8 months (128.6±37.9 versus 141.0±44.4; P=0.12). SLCO1B1*5 carriers exhibited a greater drop in LDLc with GIST versus UC (interaction P=0.048). Post-trial, LDLc decreased in UC participants who crossed over to GIST compared with those allocated to GIST (-14.9±37.8 versus +9.0±37.3 mg/dL, P=0.03). Patients tested for SLCO1B1 though a commercial laboratory had a greater LDLc decrease ( P=0.04) compared with controls. CONCLUSIONS: Delivery of SLCO1B1 pharmacogenetic testing that addresses statin myalgia improved statin reinitiation and LDLc but did not improve self-reported statin adherence. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01894230.

Peripheral blood gene expression signatures which reflect smoking and aspirin exposure are associated with cardiovascular events.

BACKGROUND: Cardiovascular disease and its sequelae are major causes of global mortality, and better methods are needed to identify patients at risk for future cardiovascular events. Gene expression analysis can inform on the molecular underpinnings of risk factors for cardiovascular events. Smoking and aspirin have known opposing effects on platelet reactivity and MACE, however their effects on each other and on MACE are not well described. METHODS: We measured peripheral blood gene expression levels of ITGA2B, which is upregulated by aspirin and correlates with platelet reactivity on aspirin, and a 5 gene validated smoking gene expression score (sGES) where higher expression correlates with smoking status, in participants from the previously reported PREDICT trial (NCT 00500617). The primary outcome was a composite of death, myocardial infarction, and stroke/TIA (MACE). We tested whether selected genes were associated with MACE risk using logistic regression. RESULTS: Gene expression levels were determined in 1581 subjects (50.5% female, mean age 60.66 +/-11.46, 18% self-reported smokers); 3.5% of subjects experienced MACE over 12 months follow-up. Elevated sGES and ITGA2B expression were each associated with MACE (odds ratios [OR] =1.16 [95% CI 1.10-1.31] and 1.42 [95% CI 1.00-1.97], respectively; p < 0.05). ITGA2B expression was inversely associated with self-reported smoking status and the sGES (p < 0.001). A logistic regression model combining sGES and ITGA2B showed better performance (AIC = 474.9) in classifying MACE subjects than either alone (AIC = 479.1, 478.2 respectively). CONCLUSION: Gene expression levels associated with smoking and aspirin are independently predictive of an increased risk of cardiovascular events.

Transcription Factor RUNX1 Regulates Platelet PCTP (Phosphatidylcholine Transfer Protein): Implications for Cardiovascular Events: Differential Effects of RUNX1 Variants.

BACKGROUND: PCTP (phosphatidylcholine transfer protein) regulates the intermembrane transfer of phosphatidylcholine. Higher platelet PCTP expression is associated with increased platelet responses on activation of protease-activated receptor 4 thrombin receptors noted in black subjects compared with white subjects. Little is known about the regulation of platelet PCTP. Haplodeficiency of RUNX1, a major hematopoietic transcription factor, is associated with thrombocytopenia and impaired platelet responses on activation. Platelet expression profiling of a patient with a RUNX1 loss-of-function mutation revealed a 10-fold downregulation of the PCTP gene compared with healthy controls. METHODS: We pursued the hypothesis that PCTP is regulated by RUNX1 and that PCTP expression is correlated with cardiovascular events. We studied RUNX1 binding to the PCTP promoter using DNA-protein binding studies and human erythroleukemia cells and promoter activity using luciferase reporter studies. We assessed the relationship between RUNX1 and PCTP in peripheral blood RNA and PCTP and death or myocardial infarction in 2 separate patient cohorts (587 total patients) with cardiovascular disease. RESULTS: Platelet PCTP protein in the patient was reduced by ≈50%. DNA-protein binding studies showed RUNX1 binding to consensus sites in ≈1 kB of PCTP promoter. PCTP expression was increased with RUNX1 overexpression and reduced with RUNX1 knockdown in human erythroleukemia cells, indicating that PCTP is regulated by RUNX1. Studies in 2 cohorts of patients showed that RUNX1 expression in blood correlated with PCTP gene expression; PCTP expression was higher in black compared with white subjects and was associated with future death/myocardial infarction after adjustment for age, sex, and race (odds ratio, 2.05; 95% confidence interval 1.6-2.7; P<0.0001). RUNX1 expression is known to initiate at 2 alternative promoters, a distal P1 and a proximal P2 promoter. In patient cohorts, there were differential effects of RUNX1 isoforms on PCTP expression with a negative correlation in blood between RUNX1 expressed from the P1 promoter and PCTP expression. CONCLUSIONS: PCTP is a direct transcriptional target of RUNX1. PCTP expression is associated with death/myocardial infarction in patients with cardiovascular disease. RUNX1 regulation of PCTP may play a role in the pathogenesis of platelet-mediated cardiovascular events.

Systems Pharmacogenomics Finds RUNX1 Is an Aspirin-Responsive Transcription Factor Linked to Cardiovascular Disease and Colon Cancer.

Aspirin prevents cardiovascular disease and colon cancer; however aspirin's inhibition of platelet COX-1 only partially explains its diverse effects. We previously identified an aspirin response signature (ARS) in blood consisting of 62 co-expressed transcripts that correlated with aspirin's effects on platelets and myocardial infarction (MI). Here we report that 60% of ARS transcripts are regulated by RUNX1 - a hematopoietic transcription factor - and 48% of ARS gene promoters contain a RUNX1 binding site. Megakaryocytic cells exposed to aspirin and its metabolite (salicylic acid, a weak COX-1 inhibitor) showed up regulation in the RUNX1 P1 isoform and MYL9, which is transcriptionally regulated by RUNX1. In human subjects, RUNX1 P1 expression in blood and RUNX1-regulated platelet proteins, including MYL9, were aspirin-responsive and associated with platelet function. In cardiovascular disease patients RUNX1 P1 expression was associated with death or MI. RUNX1 acts as a tumor suppressor gene in gastrointestinal malignancies. We show that RUNX1 P1 expression is associated with colon cancer free survival suggesting a role for RUNX1 in aspirin's protective effect in colon cancer. Our studies reveal an effect of aspirin on RUNX1 and gene expression that may additionally explain aspirin's effects in cardiovascular disease and cancer.

Effect of genetic variations on ticagrelor plasma levels and clinical outcomes.

AIMS: Ticagrelor, a direct-acting P2Y12-receptor antagonist, is rapidly absorbed and partly metabolized to the major metabolite AR-C124910XX (ARC). To identify single-nucleotide polymorphisms (SNPs) associated with pharmacokinetics of ticagrelor and clinical outcomes, we performed a genome-wide association study (GWAS) in patients treated with ticagrelor in the PLATO trial. METHODS AND RESULTS: A two-stage design was used for the GWAS with discovery (discovery phase: n = 1812) and replication cohorts (replication phase: n = 1941). The steady-state area under the curve (AUCss) values, estimated by the population pharmacokinetic (PK) models, were log transformed and analysed on a genome-wide scale using linear regression. SNPs were analysed against clinical events using Cox-regression in 4990 patients. An SNP (rs113681054) in SLCO1B1 was associated with levels of ticagrelor (P = 1.1 × 10(-6)) and ARC (P = 4.6 × 10(-13)). This SNP is in linkage disequilibrium with a functional variant (rs4149056) that results in decreased OATP1B1 transporter activity. Ticagrelor levels were also associated with two independent SNPs (rs62471956, P = 7.7 × 10(-15) and rs56324128, P = 9.7 × 10(-12)) in the CYP3A4 region. Further, ARC levels were associated with rs61361928 (P = 3.0 × 10(-14)) in UGT2B7. At all loci, the effects were small. None of the identified SNPs that affected ticagrelor PK were associated with the primary composite outcome (cardiovascular death myocardial infarction, and stroke), non-CABG-related bleeds or investigator-reported dyspnoea. CONCLUSION: In patients with ACS, ticagrelor pharmacokinetics is influenced by three genetic loci (SLCO1B1, UGT2B7, and CYP3A4). However, the modest genetic effects on ticagrelor plasma levels did not translate into any detectable effect on efficacy or safety during ticagrelor treatment. CLINICAL TRIAL REGISTRATION: NCT00391872.

SLCO1B1 genetic variants, long-term low-density lipoprotein cholesterol levels and clinical events in patients following cardiac catheterization.

AIM: SLCO1B1 variants are associated with intermediate outcomes that may increase risk of death/myocardial infarction (MI) in statin-treated patients. PATIENTS & METHODS: In high-risk Caucasians undergoing cardiac catheterization, we tested the association between rs4149056/625T>C and rs2306283/492A>G with low-density lipoprotein cholesterol (LDL-c) over 3 years (n = 1402) and death/MI over 6 years (n = 2994), accounting for statin use or type during follow-up. RESULTS: Carriers of the rs4149056 C allele had 6.2 ± 1.7 mg/dl higher LDL-c per C allele (p < 0.001) but were not at higher risk for death/MI (p = 0.9). We found no associations between rs2306283 and LDL-c or death/MI (p > 0.6). CONCLUSION: Functional SLCO1B1 variants are not associated with death/MI in patients commonly treated with statins, despite higher LDL-c in carriers of the rs4149056 C allele.

Preoperative CYP2D6 metabolism-dependent ß-blocker use and mortality after coronary artery bypass grafting surgery.

OBJECTIVE: Recently, the role of ß-blockers (BBs) in reducing perioperative mortality has been challenged. The conflicting results might have resulted from the extent of BB metabolism by the cytochrome P-450 (CYP2D6) isoenzyme. The purpose of the present study was to assess the association between the preoperative use of BBs dependent on metabolism of the CYP2D6 isoenzyme with operative mortality after coronary artery bypass grafting surgery. METHODS: We performed a retrospective study of 5248 patients who had undergone coronary bypass grafting surgery from January 1, 2001 to November 30, 2009 at Duke University Medical Center. The cohorts were defined by the preoperative use of BBs and BB type (non-CYP2D6_BBs, CYP2D6_BBs, or no BBs). Operative mortality was analyzed using inverse probability-weighted estimators with propensity score adjustment. RESULTS: Of the 5248 patients, 14% received non-CYP2D6_BBs, 43%, CYP2D6_BBs, and 43%, no BBs. The incidence of operative mortality was 0.8%, 2.1%, and 3.7% in the non-CYP2D6_BB, CYP2D6_BB, and no BB groups, respectively. Multivariable inverse probability-weighted-adjusted analyses showed that non-CYP2D6_BBs were associated with a lower incidence of operative mortality (odds ratio, 0.33; 95% confidence interval, 0.13-0.83; P = .02) compared with no BB use and a trend toward lower operative mortality (odds ratio, 0.44; 95% confidence interval, 0.16-1.07; P = .06) compared with CYP2D6_BBs. No significant decrease occurred in the risk of operative mortality between the CYP2D6_BB and no BB groups (odds ratio, 0.85; 95% confidence interval, 0.54-1.34; P = .48). CONCLUSIONS: Among these patients, preoperative non-CYP2D6_BB use, but not CYP2D6_BB use, was associated with a decreased risk of operative mortality.