Clinical implementation of rapid CYP2C19 genotyping to guide antiplatelet therapy after percutaneous coronary intervention

© 2018 The Author(s). Background: The CYP2C19 nonfunctional genotype reduces clopidogrel effectiveness after percutaneous coronary intervention (PCI). Following clinical implementation of CYP2C19 genotyping at University Florida (UF) Health Shands Hospital in 2012, where genotype results are available approximately 3 days after PCI, testing was expanded to UF Health Jacksonville in 2016 utilizing a rapid genotyping approach. We describe metrics with this latter implementation. Methods: Patients at UF Health Jacksonville undergoing left heart catheterization with intent to undergo PCI were targeted for genotyping using the Spartan RX™ system. Testing metrics and provider acceptance of testing and response to genotype results were examined, as was antiplatelet therapy over the 6 months following genotyping. Results: In the first year, 931 patients, including 392/505 (78%) total patients undergoing PCI, were genotyped. The median genotype test turnaround time was 96 min. Genotype results were available for 388 (99%) PCI patients prior to discharge. Of 336 genotyped PCI patients alive at discharge and not enrolled in an antiplatelet therapy trial, 1/6 (17%) poor metabolizers (PMs, with two nonfunctional alleles), 38/93 (41%) intermediate metabolizers (IMs, with one nonfunctional allele), and 119/237 (50%) patients without a nonfunctional allele were prescribed clopidogrel (p = 0.110). Clopidogrel use was higher among non-ACS versus ACS patients (78.6% vs. 42.2%, p < 0.001). Six months later, among patients with follow-up data, clopidogrel was prescribed in 0/4 (0%) PMs, 33/65 (51%) IMs, and 115/182 (63%) patients without a nonfunctional allele (p = 0.008 across groups; p = 0.020 for PMs versus those without a nonfunctional allele). Conclusion: These data demonstrate that rapid genotyping is clinically feasible at a high volume cardiac catheterization facility and allows informed chronic antiplatelet prescribing, with lower clopidogrel use in PMs at 6 months

Baseline low-density lipoprotein cholesterol to predict the extent of cardiovascular benefit from lipid-lowering therapies: a review

Contains fulltext : 202705.pdf (Publisher’s version ) (Closed access) Contains fulltext : 202705pos.pdf (Author’s version postprint ) (Open Access)Lipid-lowering therapies have been shown to improve cardiovascular outcome in a wide range of patients. The current guidelines recommend a graded approach to reduction in low-density lipoprotein cholesterol (LDL-C) proportional to the patient's risk, with the goal of achieving either a certain magnitude of reduction or a specific threshold of final LDL-C. Recent findings from a meta-analysis of numerous randomized trials suggest that more attention should be given to the baseline LDL-C of an individual patient. In this review, we discuss how the baseline LDL-C level may provide a means to better understand the results of recent cardiovascular outcome trials and the expected benefits of lipid-lowering therapies. The exact quantification of the clinical benefit associate with an intensified lipid-lowering therapy depends on the baseline LDL-C. Mortality is reduced in a log-linear fashion only when LDL-C > 100 mg/dL

Clopidogrel metaboliser status based on point-of-care CYP2C19 genetic testing in patients with coronary artery disease.

We compared results obtained with the Nanosphere Verigene® System, a novel point-of-care (POC) genetic test capable of analysing 11 CYP2C19 variants within 3 hours, to an established, validated genotyping method (Affymetrix™ DMET+; reference assay) for identifying extensive and reduced metabolisers of clopidogrel. Based on genotyping, patients (N=82) with stable coronary artery disease on clopidogrel 75 mg daily were defined as extensive metabolisers (*1/*1, *1/*17, *17/*17), reduced metabolisers (*1/*2, *1/*8, *2/*2, *2/*3), or of indeterminate metaboliser status (*2/*17). Pharmacokinetic exposure to clopidogrel's active metabolite and pharmacodynamic measures with protein reaction units (PRU) (VerifyNow® P2Y12 assay) and VASP PRI (PRI) were also assessed. There was a 99.9% overall concordance of marker-level data between the Nanosphere Verigene and DMET+ systems in identifying the CYP2C19 variants and 100% agreement in classifying the patients as extensive (n=59) or reduced metabolisers (n=15). Extensive metabolisers had significantly higher active metabolite exposure than reduced metabolisers (LS means 12.6 ng*h/ml vs 7.7 ng*h/ml; p<0.001). Extensive metabolisers also had lower PRU (LS means 158 vs 212; p=0.003) and VASP PRI (LS means 48% vs 63%, p=0.01) compared to reduced metabolisers. Rates of high on-treatment platelet reactivity were higher in reduced metabolisers compared to extensive metabolisers (VASP PRI ≥50%: 79% vs 47%; PRU ≥ 235: 33% vs 16%). The Nanosphere Verigene CBS system identified 11 CYP2C19 alleles in less than 3 hours with a high degree of accuracy when compared to a conventional method, and was further validated against pharmacokinetic and pharmacodynamic phenotypes

Effects of Proprotein Convertase Subtilisin/Kexin Type 9 Antibodies in Adults With Hypercholesterolemia: A Systematic Review and Meta-analysis.

BACKGROUND: Guidelines recommend statins as first-line therapy for dyslipidemia. Monoclonal antibodies targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) are a new lipid-lowering approach. PURPOSE: To assess the efficacy and safety of PCSK9 antibodies in adults with hypercholesterolemia. DATA SOURCES: MEDLINE, PubMed Central, and Google Scholar; conference proceedings; and the ClinicalTrials.gov registry through 4 April 2015. STUDY SELECTION: Phase 2 or 3 randomized, controlled trials (RCTs) comparing treatment using PCSK9 antibodies with no anti-PCSK9 therapy in adults with hypercholesterolemia. DATA EXTRACTION: Two investigators independently extracted data on study characteristics and lipid and clinical outcomes, and rated risk of bias of trials. Prespecified primary end points were all-cause and cardiovascular mortality. DATA SYNTHESIS: Twenty-four RCTs comprising 10 159 patients were included. Compared with no antibody, treatment with PCSK9 antibodies led to marked reductions in low-density lipoprotein cholesterol levels (mean difference, -47.49% [95% CI, -69.64% to -25.35%]; P < 0.001] and other atherogenic lipid fractions, and it reduced all-cause mortality (odds ratio [OR], 0.45 [CI, 0.23 to 0.86]; P = 0.015; heterogeneity P = 0.63; I2 = 0%) and cardiovascular mortality (OR, 0.50 [CI, 0.23 to 1.10]; P = 0.084; heterogeneity P = 0.78; I2 = 0%). The rate of myocardial infarction was significantly reduced with use of PCSK9 antibodies (OR, 0.49 [CI, 0.26 to 0.93]; P = 0.030; heterogeneity P = 0.45; I2 = 0%), and increases in the serum creatine kinase level were reduced (OR, 0.72 [CI, 0.54 to 0.96]; P = 0.026; heterogeneity P = 0.65; I2 = 0%). Serious adverse events did not increase with administration of PCSK9 antibodies. LIMITATIONS: Results were derived from study-level data rather than patient-level data, and clinical outcome data are rare. CONCLUSION: PCSK9 antibodies seem to be safe and effective for adults with dyslipidemia