| 1. |
- Franchi, Francesco, et al.
(författare)
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Impact of Diabetes Mellitus and Chronic Kidney Disease on Cardiovascular Outcomes and Platelet P2Y12 Receptor Antagonist Effects in Patients With Acute Coronary Syndromes : Insights From the PLATO Trial
- 2019
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Ingår i: Journal of the American Heart Association. - 2047-9980 .- 2047-9980. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- Background-There are limited data on how the combination of diabetes mellitus (DM) and chronic kidney disease (CKD) affects cardiovascular outcomes as well as response to different P2Y(12) receptor antagonists, which represented the aim of the present investigation. Methods and Results-In this post hoc analysis of the PLATO (Platelet Inhibition and Patient Outcomes) trial, which randomized acute coronary syndrome patients to ticagrelor versus clopidogrel, patients (n=15 108) with available DM and CKD status were classified into 4 groups: DM+/CKD+ (n=1058), DM+/CKD- (n=2748), DM-/CKD+ (n=2160), and DM-/CKD- (n=9142). The primary efficacy end point was a composite of cardiovascular death, myocardial infarction, or stroke at 12 months. The primary safety end point was PLATO major bleeding. DM+/CKD+ patients had a higher incidence of the primary end point compared with DM-/CKD- patients (23.3% versus 7.1%; adjusted hazard ratio 2.22; 95% CI 1.88-2.63; P<0.001). Patients with DM+/CKD- and DM-/CKD+ had an intermediate risk profile. The same trend was shown for the individual components of the primary end point and for major bleeding. Compared with clopidogrel, ticagrelor reduced the incidence of the primary end point consistently across subgroups (P-interaction=0.264), but with an increased absolute risk reduction in DM+/CKD+. The effects on major bleeding were also consistent across subgroups (P-interaction=0.288). Conclusions-In acute coronary syndrome patients, a gradient of risk was observed according to the presence or absence of DM and CKD, with patients having both risk factors at the highest risk. Although the ischemic benefit of ticagrelor over clopidogrel was consistent in all subgroups, the absolute risk reduction was greatest in patients with both DM and CKD.
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| 2. |
- Jaldén, Joakim, et al.
(författare)
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On the diversity order of vector perturbation precoding with imperfect channel state information
- 2008
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Ingår i: 2008 IEEE 9TH WORKSHOP ON SIGNAL PROCESSING ADVANCES IN WIRELESS COMMUNICATIONS, VOLS 1 AND 2. - NEW YORK : IEEE. ; , s. 211-215
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Konferensbidrag (refereegranskat)abstract
- We consider vector perturbation precoding over a quasi-static MIMO channel under the assumption of imperfect channel state information (CSI). This is accomplished via a high SNR analysis, specifically targeting the overall system diversity order and the identification of typical errors. The effects of long-term and short-term power constraints, or power allocation policies, are investigated. Our results indicate that under realistic assumptions regarding the channel estimation error the system is mainly interference limited and as such, the particular power constraint does not significantly affect the asymptotic behavior of the error probability. This is in sharp contrast to the case of perfect CSI.
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| 3. |
- Kohli, Payal, et al.
(författare)
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Reduction in First and Recurrent Cardiovascular Events with Ticagrelor Compared with Clopidogrel in the PLATO Study
- 2013
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Ingår i: Circulation. - 0009-7322 .- 1524-4539. ; 127:6, s. 673-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:We sought to evaluate the effect of potent platelet inhibition following acute coronary syndrome on total (i.e. first and recurrent) occurrences of any of the primary outcome events (e.g. cardiovascular death, myocardial infarction, and stroke) as well as on other ischemic events, such as urgent revascularization, (severe) recurrent ischemia (SRI/RI), transient ischemic attacks (TIA) and arterial thrombotic events (ATE).METHODS AND RESULTS:In the PLATelet inhibition and patient Outcomes (PLATO) study, 18,624 patients presenting with acute coronary syndromes randomly received ticagrelor (N=9333) or clopidogrel (N=9291). Cox proportional hazard models were used to calculate time to first event and hazard ratios. Total events were compared using a Poisson regression model and time to second event or death was calculated with the Wei Lin Weissfeld method. Patients randomized to ticagrelor had 1057 total primary endpoint events vs. 1225 for patients on clopidogrel (rate ratio=0.86, 95% CI 0.79-0.93, p=0.003). The number of additional events was numerically lower for ticagrelor (189 vs. 205, p=0.40), resulting in a hazard for time to second event/death of 0.80 (95% CI 0.70-0.90, p<0.001) and a number needed to treat of 54. For CVD/MI/Stroke/SRI/RI/TIA/ATE, total events were fewer with ticagrelor (2030 vs. 2290, rate ratio 0.88, 95% CI 0.82-0.95, p<0.001), with fewer recurrent events with ticagrelor (740 vs. 834, p=0.01) and a highly significant concurrent reduction in hazard for time to second event or death of 0.83 (95% CI 0.75-0.91, p<0.001). Recurrent PLATO major or TIMI major non-CABG bleeding events were infrequent and not different between the two therapies (p=0.96 and 0.38, respectively).CONCLUSIONS: In PLATO, treatment with ticagrelor compared with clopidogrel resulted in a reduction in total events, including first and subsequent recurrent cardiovascular events, when compared to clopidogrel. These types of analyses demonstrate an even greater absolute benefit of ticagrelor over clopidogrel than previously reported.CLINICAL TRIAL REGISTRATION INFORMATION:http://www.clinicaltrials.gov. Identifier: NCT00391872.
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| 4. |
- Lindholm, Daniel P, 1982-, et al.
(författare)
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Growth Differentiation Factor 15 at 1 Month After an Acute Coronary Syndrome Is Associated With Increased Risk of Major Bleeding.
- 2017
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Ingår i: Journal of the American Heart Association. - 2047-9980 .- 2047-9980. ; 6:4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Growth differentiation factor-15 (GDF-15) is related to major bleeding when measured at initial presentation in patients with acute coronary syndromes (ACSs) treated with dual antiplatelet therapy. It is unknown whether follow-up measurements provide additional information. The objective of this study was to investigate whether GDF-15 measured 1 month after an ACS provides additional information beyond the baseline levels with regard to the risk of major bleeding.METHODS AND RESULTS: GDF-15 was measured at baseline and at 1 month after an ACS in 4049 patients included in the PLATelet inhibition and patient Outcomes (PLATO) trial. The association between 1-month GDF-15 level and non-coronary artery bypass grafting surgery-related major bleeding was assessed by a multivariable Cox model, adjusting for baseline GDF-15, age, anemia, impaired renal function, history of gastrointestinal bleeding, and sex. Elevated GDF-15 (>1800 ng/L) at 1 month was associated with an increased risk of non-coronary artery bypass grafting-related major bleeding (3.9% versus 1.2%; hazard ratio, 3.38; 95% CI, 1.89-6.06), independent of baseline GDF-15. Patients who had elevated GDF-15 levels at baseline and subsequent nonelevated GDF-15 at 1 month had a similar risk as patients who had nonelevated levels at both measurements.CONCLUSIONS: GDF-15 at 1 month after an ACS is related to the risk of bleeding during DAPT and provides additional information on the bleeding risk beyond baseline GDF-15 levels. GDF-15 levels may therefore be useful as part of decision support concerning long-term antithrombotic treatment in patients post-ACS.CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00391872.
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| 5. |
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| 6. |
- Maurer, Johannes, et al.
(författare)
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Multi-threshold top - Full-diversity vector perturbation precodingwith finite-rate feedforward
- 2008
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Ingår i: 2008 42ND ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS. - 9781424429400 ; , s. 428-432
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Konferensbidrag (refereegranskat)abstract
- We consider vector perturbation (VP) precoding for a multiple antenna broadcast scenario with Multiple noncooperative users. Under an instantaneous transmit power constraint, VP precoding requires the feedforward of a power normalization factor to the users. Simple quantization of the power normalization factor is shown to result in an error floor. To overcome this problem, we propose a new precoding scheme that uses a finite set of power normalization factors and avoids transmission at all when the available power is not sufficient to perform channel equalization at the transmit side. With this scheme, full diversity can be achieved (even with imperfect channel state information) while simultaneously significant amounts of transmit power can be saved.
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| 7. |
- Maurer, Johannes, et al.
(författare)
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Transmit outage precoding with imperfect channel state information under an instantaneous power constraint
- 2008
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Ingår i: 2008 IEEE 9TH WORKSHOP ON SIGNAL PROCESSING ADVANCES IN WIRELESS COMMUNICATIONS, VOLS 1 AND 2. - NEW YORK : IEEE. - 9781424420452 ; , s. 66-70
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Konferensbidrag (refereegranskat)abstract
- In this paper, we consider a multiple antenna broadcast scenario with multiple non-cooperative users under the assumption of imperfect channel state information. Under an instantaneous transmit power constraint, vector perturbation precoding requires that the users be continuously informed about the adaptive power scaling factor used at the transmit side. To overcome this limitation, we propose a new precoding scheme that uses a fixed power scaling and avoids transmitting when the available power is not sufficient to perform channel equalization at the transmit side, an event referred to as outage. We present a performance analysis and optimization of this scheme and provide numerical comparisons with classical vector perturbation.
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| 8. |
- Maurer, Johannes, et al.
(författare)
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Vector perturbation precoding for receivers with limited dynamic range
- 2009
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Ingår i: 2009 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING. - 9781424423538 ; , s. 2709-2712
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Konferensbidrag (refereegranskat)abstract
- In this paper we consider the vector perturbation (VP) precoding scheme for the multiuser MISO broadcast channel proposed by Hochwald et al. under the practical assumption that the receivers have limited dynamic range. In this case, VP precoding is shown to suffer from an error floor at high signal-to-noise ratio (SNR). As an alternative, we propose precoding with restricted VP (RVP), which takes the limited dynamic range of the receivers explicitly into account by restricting to a finite set of possible perturbation vectors at the transmitter side. We derive the diversity order of this RVP scheme and show that no error floor occurs and that the performance is superior to VP for the entire range of SNRs.
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| 9. |
- Maurer, Johannes, et al.
(författare)
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Vector Perturbation Precoding Revisited
- 2011
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Ingår i: IEEE Transactions on Signal Processing. - 1053-587X .- 1941-0476. ; 59:1, s. 315-328
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Tidskriftsartikel (refereegranskat)abstract
- We consider the downlink of a multiuser system with multiple antennas at the base station. Vector perturbation (VP) precoding is a promising variant of transmit-side channel inversion allowing the users to detect their data in a simple, noncooperative manner. VP precoding has so far been developed and analyzed under the assumptions that the transmitter has perfect channel state information (CSI) and that the receivers know perfectly a channel-dependent transmit power normalization factor and have infinite dynamic range. We demonstrate that the violation of any of these idealizing assumptions degrades the performance of VP significantly and almost always results in an error floor. Motivated by this observation, we propose a novel scheme which we term transmit outage precoding (TOP). With TOP, the transmitter uses a prearranged power scaling known by the receivers and refrains from transmitting when channel conditions are poor. We further show how to augment TOP and conventional VP to deal with a finite dynamic range at the receiver. The performance of the proposed schemes under various levels of transmit CSI is studied in terms of a theoretical diversity analysis and illustrated by numerical results.
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| 10. |
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