MD Conference Express TCT 2011 - (Page 9)
point-of-care (POC) genetic test. After 1 hour, nurses were able to determine a patient’s CYP2C19*2 carrier status and whether the patient was heterozygous or homozygous by utilizing the new technology. The primary objective of the Reassessment of Antiplatelet Therapy using an Individualized Strategy Based on Genetic Evaluation (NCT01184300; RAPID GENE) study, presented by Derek So, MD, University of Ottawa Heart Institute, Ottawa, Ontario, Canada, was to evaluate the feasibility and test characteristics of a nurse-operated POC genetic test to determine CYP2C19*2 carrier status. PCI patients with non-ST elevation acute coronary syndrome (ACS) or stable coronary artery disease (CAD) were pretreated with a minimum of 600 mg clopidogrel. Following baseline platelet function testing, the patients were randomized 1:1 to rapid genotyping (RG; n=102) using the new POC technology or to no POC testing and standard therapy (ST; n=98) with clopidogrel 75 mg daily. In the RG group, CYP2C19*2 carriers were treated with prasugrel 10 mg daily, and noncarriers were treated with clopidogrel 75 mg daily. At 1 week, all patients underwent platelet function testing and DNA sequencing. Patients in the ST arm also underwent POC rapid genotyping after 1 week. The primary endpoint was the proportion of CYP2C19*2 carriers with a P2Y12 reaction unit (PRU) >234 (consistent with high on-treatment platelet reactivity) after 1 week of dual antiplatelet therapy. In the RG arm, POC genotyping identified 25.3% (n=23) of patients as CYP2C19*2 carriers, with 20.9% heterozygous and 4.4% homozygous. In the ST group after 1 week, POC genotyping identified a similar proportion of patients as CYP2C19*2 carriers (24.0%; n=23), with 20.8% heterozygous and 3.1% homozygous. Compared with direct DNA sequencing, POC genotyping had a sensitivity of 100%, specificity of 99.4%, and a conclusive rate of 93.6%. The proportion of CYP2C19*2 carriers with high ontreatment platelet reactivity (PRU >234) was significantly lower in the RG group (prasugrel-treated) compared with the ST group (clopidogrel-treated; 0% vs 30.4%; p=0.009). CYP2C19*2 carriers who were treated with prasugrel as compared with clopidogrel had a significantly lower PRU at 7 days (75.6 vs 207.3 PRU; p<0.001) and greater platelet inhibition after 7 days (73.3 vs 27.0 PRU; p<0.001), demonstrating the superior antiplatelet efficacy of prasugrel in this population. No MACE occurred in either group at 7 and 30 days. POC genetic testing at the bedside, performed by nurses, is feasible and can accurately identify CYP2C19*2
carriers. This novel, rapid genetic test facilitates rapid personalization of antiplatelet therapy. Administration of prasugrel to CYP2C19*2 carriers decreased the rate of high on-treatment platelet reactivity relative to standard therapy with clopidogrel. These findings represent the validation and proof-of-concept of the first POC genetic test in clinical medicine. The results of the RAPID GENE trial will hopefully lead to larger-scale studies that can establish the role of pharmacogenomic tailored antiplatelet therapy after PCI.
Bioabsorbable Polymer Stent Noninferior to Permanent Polymer Stent
Durable polymer coatings on drug-eluting stents are associated with chronic inflammation and impaired healing. The reduced polymer load and short-term polymer exposure of bioabsorbable polymer stents may reduce duration of dual antiplatelet therapy (DAPT), reduce risk with DAPT interruption, and decrease stent thrombosis. The SYNERGY stent has a PLGA bioabsorbable polymer coating plus everolimus that is applied only to the abluminal surface of a thin-strut platinum chromium stent. Once implanted, the polymer coating completely resorbs within 4 months. The Randomized Evaluation of a Novel Bioabsorbable Polymer-Coated, EverolimusEluting Coronary Stent (EVOLVE) trial, presented by Ian Meredith, MBBS, PhD, Monash Medical Centre and Southern Health, Melbourne, Australia, compared the bioabsorbable polymer SYNERGY Everolimus-Eluting Coronary Stent System with the permanent polymer PROMUS Element Stent for the treatment of de novo atherosclerotic lesions. Two SYNERGY bioabsorbable stents were compared with the PROMUS Element permanent polymer stent. One SYNERGY stent had an everolimus dose and release profile that was similar to that of the PROMUS Element. The SYNERGY ½ Dose had half the dose of everolimus and a similar release profile to the PROMUS Element. Patients with de novo native coronary lesions (≤28 mm in length, reference vessel diameter ≥2.5 mm and ≤3.5 mm, %DS >50) were randomized to receive the PROMUS Element (n=98), SYNERGY (n=94), or SYNERGY ½ Dose (n=99). The primary clinical endpoint was target lesion failure (TLF) at 30 days, defined as target vessel cardiac death, target vessel myocardial infarction (MI), or target lesion revascularization. The primary angiographic
Highlights from TCT 2011
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Table of Contents for the Digital Edition of MD Conference Express TCT 2011
MD Conference Express TCT 2011
Contents
TAVI Improves QoL in Patients Suitable for Transfemoral TAVI: PARTNER Cohort A
Results from the PARTNER Trial (Cohort A): Transfemoral TAVI Economically Attractive but Transapical TAVI More Costly
PARTNER Cohort B: TAVI Superior to Standard Therapy at Two Years
Transapical TAVI Inferior to SAVR in Operable Elderly Patients
Primary Results from ADVISE: Validation of a Vasodilator Independent Measure of Coronary FFR
Point-of-Care Genetic Testing Facilitates Rapid Personalization of Antiplatelet Therapy
Bioabsorbable Polymer Stent Noninferior to Permanent Polymer Stent
BRIDGE Study Demonstrates Feasibility and Safety of Cangrelor
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