| 111. |
- Tricoci, Pierluigi, et al.
(författare)
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Effects of genetic variation in protease activated receptor 4 after an acute coronary syndrome : Analysis from the TRACER trial
- 2018
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Ingår i: Blood Cells, Molecules & Diseases. - : Elsevier BV. - 1079-9796 .- 1096-0961. ; 72, s. 37-43
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Tidskriftsartikel (refereegranskat)abstract
- Variation in platelet response to thrombin may affect the safety and efficacy of PAR antagonism. The Thr120 variant of the common single nucleotide polymorphism (SNP) rs773902 in the protease-activated receptor (PAR) 4 gene is associated with higher platelet aggregation compared to the Ala120 variant. We investigated the relationship between the rs773902 SNP with major bleeding and ischemic events, safety, and efficacy of PAR1 inhibition in 6177 NSTE ACS patients in the TRACER trial. There was a lower rate of GUSTO moderate/severe bleeding in patients with the Thr120 variant. The difference was driven by a lower rate in the smaller homozygous group (recessive model, HR 0.13 [0.02-0.92] P= 0.042). No significant differences were observed in the ischemic outcomes. The excess in bleeding observed with PAR1 inhibition was attenuated in patients with the Thr120 variant, but the interactions were not statistically significant. In summary, lower major bleeding rates were observed in the overall TRACER cohort with the hyperreactive PAR4 Thr120 variant. The increase in bleeding with vorapaxar was attenuated with the Thr120 variant, but we could not demonstrate an interaction with PAR1 inhibition. These findings warrant further exploration, including those of African ancestry where the A allele (Thr120) frequency is similar to 65%.
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| 112. |
- Tricoci, Pierluigi, et al.
(författare)
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Vorapaxar with or without clopidogrel after non-ST-segment elevation acute coronary syndromes : Results from the Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome trial
- 2014
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Ingår i: American Heart Journal. - : Elsevier BV. - 0002-8703 .- 1097-6744. ; 168:6, s. 869-877.e1
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Tidskriftsartikel (refereegranskat)abstract
- Background Protease-activated receptor 1 antagonism with vorapaxar represents a novel strategy for platelet inhibition. In TRACER, vorapaxar was compared with placebo plus standard of care among 12,944 patients with non-ST-segment elevation acute coronary syndromes. We anticipated that most patients would have received clopidogrel as part of standard care. We investigated the modification of vorapaxar's effect associated with clopidogrel use over time. Methods The marginal structural model method was used to estimate causal modification of vorapaxar effect by use of clopidogrel over time. The primary outcomes were the composite of cardiovascular death, myocardial infarction, or stroke and Global Use of Strategies to Open Occluded Coronary Arteries moderate or severe bleeding. The event accrual period excluded the time during which clopidogrel was clinically warranted. Results Among 12,887 patients who received study medication, 11,117 (86.3%) received clopidogrel before randomization, of whom 38.5% stopped later in the trial (median time to stoppage 200 days with placebo; interquartile range [IQR] 14-367) (186 days with vorapaxar; IQR 17-366). In total, 1,770 (13.7%) patients were not on clopidogrel at randomization, of whom 47.8% started afterward (median time to start 2 days; IQR 2-4). During the period of event accrual, vorapaxar was associated with a 26% reduction in the composite of cardiovascular death, myocardial infarction, or stroke when used with clopidogrel (hazard ratio [HR] 0.74; 95% CI 0.60-0.91) and a 24% reduction when used without clopidogrel (HR 0.76; 95% CI 0.56-1.02) (interaction; P = .89). The hazard of Global Use of Strategies to Open Occluded Coronary Arteries bleeding with vorapaxar was not significantly different without clopidogrel (HR 1.33; 95% CI 0.81-2.20) or with clopidogrel (HR 1.09; 95% CI 0.76-1.56) (interaction; P = .53). Conclusions We observed no interaction between vorapaxar and clopidogrel after non-ST-segment elevation acute coronary syndromes on efficacy or safety outcomes, supporting a complementary role of protease-activated receptor 1 and P2Y(12) antagonism.
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| 113. |
- Valgimigli, Marco, et al.
(författare)
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Usefulness and Safety of Vorapaxar in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention (from the TRACER Trial)
- 2014
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Ingår i: American Journal of Cardiology. - : Elsevier BV. - 0002-9149 .- 1879-1913. ; 114:5, s. 665-673
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Tidskriftsartikel (refereegranskat)abstract
- The therapeutic potential of vorapaxar in patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention (PCI) is unknown. This prespecified analysis of a postrandomization subgroup evaluated the effects of vorapaxar compared with placebo among Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) participants undergoing PCI, focusing on the implanted stent type (drug-eluting stent [DES] vs bare-metal stent [BMS]). Among 12,944 recruited patients, 7,479 (57.8%) underwent PCI during index hospitalization, and 3,060 (40.9%) of those patients received exclusively BMS, whereas 4,015 (53.7%) received DES. The median (twenty-fifth, seventy-fifth percentiles) duration of thienopyridine therapy was 133 days (47, 246) with BMS and 221 days (88, 341) with DES. At 2 years among patients undergoing PCI, the primary (cardiovascular death, myocardial infarction, stroke, recurrent ischemia with rehospitalization, or urgent coronary revascularization) and secondary (cardiovascular death, myocardial infarction, or stroke) end points did not differ between vorapaxar and placebo groups, which was consistent with the treatment effect observed in the overall study population (p value for interaction = 0.540). However, the treatment effect trended greater (p value for interaction = 0.069) and the risk for bleeding in patients taking vorapaxar versus placebo appeared attenuated in BMS-only recipients. After adjustment for confounders, the interaction was no longer significant (p value = 0.301). The covariate that mostly explained the stent-type-by-treatment interaction was the duration of clopidogrel therapy. In conclusion, among patients with PCI, the effect of vorapaxar is consistent with the overall TRACER results. Patients who received a BMS underwent shorter courses of clopidogrel therapy and displayed trends toward greater ischemic benefit from vorapaxar and lesser bleeding risk, compared with patients who received a DES.
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| 114. |
- van Diepen, Sean, et al.
(författare)
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Efficacy and Safety of Vorapaxar in Non-ST-Segment Elevation Acute Coronary Syndrome Patients Undergoing Noncardiac Surgery
- 2015
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Ingår i: Journal of the American Heart Association. - 2047-9980 .- 2047-9980. ; 4:12
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Perioperative antiplatelet agents potentially increase bleeding after non-ST-segment elevation (NSTE) acute coronary syndromes (ACS). The protease-activated receptor 1 antagonist vorapaxar reduced cardiovascular events and was associated with increased bleeding versus placebo in NSTE ACS, but its efficacy and safety in noncardiac surgery (NCS) remain unknown. We aimed to evaluate ischemic, bleeding, and long-term outcomes of vorapaxar in NCS after NSTE ACS.METHODS AND RESULTS: In the TRACER trial, 2202 (17.0%) patients underwent major or minor NCS after NSTE ACS over 1.5 years (median); continuing study treatment perioperatively was recommended. The primary ischemic end point for this analysis was cardiovascular death, myocardial infarction, stent thrombosis, or urgent revascularization within 30 days of NCS. Safety outcomes included 30-day NCS bleeding and GUSTO moderate/severe bleeding. Overall, 1171 vorapaxar and 1031 placebo patients underwent NCS. Preoperative aspirin and thienopyridine use was 96.8% versus 97.7% (P=0.235) and 89.1% versus 86.1% (P=0.036) for vorapaxar versus placebo, respectively. Within 30 days of NCS, no differences were observed in the primary ischemic end point between vorapaxar and placebo groups (3.4% versus 3.9%; adjusted odds ratio 0.81, 95% CI 0.50 to 1.33, P=0.41). Similarly, no differences in NCS bleeding (3.9% versus 3.4%; adjusted odds ratio 1.41, 95% CI 0.87 to 2.31, P=0.17) or GUSTO moderate/severe bleeding (4.2% versus 3.7%; adjusted odds ratio 1.15, 95% CI, 0.72 to 1.83, P=0.55) were observed. In a 30-day landmarked analysis, NCS patients had a higher long-term risk of the ischemic end point (adjusted hazard ratio 1.62, 95% CI 1.33 to 1.97, P<0.001) and GUSTO moderate/severe bleeding (adjusted hazard ratio 5.63, 95% CI 3.98 to 7.97, P<0.001) versus patients who did not undergo NCS, independent of study treatment.CONCLUSION: NCS after NSTE ACS is common and associated with more ischemic outcomes and bleeding. Vorapaxar after NSTE ACS was not associated with increased perioperative ischemic or bleeding events in patients undergoing NCS.
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| 115. |
- Vranckx, Pascal, et al.
(författare)
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Validation of BARC Bleeding Criteria in Patients With Acute Coronary Syndromes : The TRACER Trial
- 2016
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Ingår i: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097 .- 1558-3597. ; 67:18, s. 2135-2144
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND The Bleeding Academic Research Consortium (BARC) scale has been proposed to standardize bleeding endpoint definitions and reporting in cardiovascular trials. Validation in large cohorts of patients is needed.OBJECTIVES This study sought to investigate the relationship between BARC-classified bleeding and mortality and compared its prognostic value against 2 validated bleeding scales: TIMI (Thrombolysis In Myocardial Infarction) and GUSTO (Global Use of Strategies to Open Occluded Arteries).METHODS We analyzed bleeding in 12,944 patients with acute coronary syndromes without ST-segment elevation, with or without early invasive strategy. The main outcome measure was all-cause death.RESULTS During follow-up (median: 502 days), noncoronary artery bypass graft (CABG) bleeding occurred in 1,998 (15.4%) patients according to BARC (grades 2, 3, or 5), 484 (3.7%) patients according to TIMI minor/major, and 514 (4.0%) patients according to GUSTO moderate/severe criteria. CABG-related bleeding (BARC 4) occurred in 155 (1.2%) patients. Patients with BARC (2, 3, or 4) bleeding had a significant increase in risk of death versus patients without bleeding (BARC 0 or 1); the hazard was highest in the 30 days after bleeding (hazard ratio: 7.35; 95% confidence interval: 5.59 to 9.68; p < 0.0001) and remained significant up to 1 year. The hazard of mortality increased progressively with non-CABG BARC grades. BARC 4 bleeds were significantly associated with mortality within 30 days (hazard ratio: 10.05; 95% confidence interval: 5.41 to 18.69; p < 0.0001), but not thereafter. Inclusion of BARC (2, 3, or 4) bleeding in the 1-year mortality model with baseline characteristics improved it to an extent comparable to TIMI minor/major and GUSTO moderate/severe bleeding.CONCLUSIONS In patients with acute coronary syndromes without ST-segment elevation, bleeding assessed with the BARC scale was significantly associated with risk of subsequent death up to 1 year after the event and risk of mortality increased gradually with higher BARC grades. Our results support adoption of the BARC bleeding scale in ACS clinical trials. (Trial to Assess the Effects of Vorapaxar [SCH 530348; MK-5348] in Preventing Heart Attack and Stroke in Participants With Acute Coronary Syndrome [TRACER] [Study P04736]; NCT00527943)
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| 116. |
- Walker, Logan C, et al.
(författare)
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Evidence for SMAD3 as a modifier of breast cancer risk in BRCA2 mutation carriers.
- 2010
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Ingår i: Breast cancer research : BCR. - : Springer Science and Business Media LLC. - 1465-542X .- 1465-5411. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- Current attempts to identify genetic modifiers of BRCA1 and BRCA2 associated risk have focused on a candidate gene approach, based on knowledge of gene functions, or the development of large genome-wide association studies. In this study, we evaluated 24 SNPs tagged to 14 candidate genes derived through a novel approach that analysed gene expression differences to prioritise candidate modifier genes for association studies.
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| 117. |
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| 118. |
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| 119. |
- Xu, Zhilei, et al.
(författare)
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The Simons Observatory : metamaterial microwave absorber and its cryogenic applications
- 2021
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Ingår i: Applied Optics. - 1559-128X .- 2155-3165. ; 60:4, s. 864-874
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Tidskriftsartikel (refereegranskat)abstract
- Controlling stray light at millimeter wavelengths requires special optical design and selection of absorptive materials that should be compatible with cryogenic operating environments. While a wide selection of absorptive materials exists, these typically exhibit high indices of refraction and reflect/scatter a significant fraction of light before absorption. For many lower index materials such as commercial microwave absorbers, their applications in cryogenic environments are challenging. In this paper, we present a new tool to control stray light: metamaterial microwave absorber tiles. These tiles comprise an outer metamaterial layer that approximates a lossy gradient index anti-reflection coating. They are fabricated via injection molding commercially available carbon-loaded polyurethane (25% by mass). The injection molding technology enables mass production at low cost. The design of these tiles is presented, along with thermal tests to 1 K. Room temperature optical measurements verify their control of reflectance to less than 1% up to 65∘ angles of incidence, and control of wide angle scattering below 0.01%. The dielectric properties of the bulk carbon-loaded material used in the tiles is also measured at different temperatures, confirming that the material maintains similar dielectric properties down to 3 K.
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