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- Kondo, T., et al.
(författare)
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Predicting stroke in heart failure and reduced ejection fraction without atrial fibrillation
- 2022
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 43:42, s. 4469-4479
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Tidskriftsartikel (refereegranskat)abstract
- Aims Patients with heart failure with reduced ejection fraction (HFrEF) are at significant risk of stroke. Anticoagulation reduces this risk in patients with and without atrial fibrillation (AF), but the risk-to-benefit balance in the latter group, overall, is not favourable. Identification of patients with HFrEF, without AF, at the highest risk of stroke may allow targeted and safer use of prophylactic anticoagulant therapy. Methods and results In a pooled patient-level cohort of the PARADIGM-HF, ATMOSPHERE, and DAPA-HF trials, a previously derived simple risk model for stroke, consisting of three variables (history of prior stroke, insulin-treated diabetes, and plasma N-terminal pro-B-type natriuretic peptide level), was validated. Of the 20 159 patients included, 12 751 patients did not have AF at baseline. Among patients without AF, 346 (2.7%) experienced a stroke over a median follow up of 2.0 years (rate 11.7 per 1000 patient-years). The risk for stroke increased with increasing risk score: fourth quintile hazard ratio (HR) 2.35 [95% confidence interval (CI) 1.60-3.45]; fifth quintile HR 3.73 (95% CI 2.58-5.38), with the first quintile as reference. For patients in the top quintile, the rate of stroke was 21.2 per 1000 patient-years, similar to participants with AF not receiving anticoagulation (20.1 per 1000 patient-years). Model discrimination was good with a C-index of 0.84 (0.75-0.91). Conclusion It is possible to identify a subset of HFrEF patients without AF with a stroke-risk equivalent to that of patients with AF who are not anticoagulated. In these patients, the risk-to-benefit balance might justify the use of prophylactic anticoagulation, but this hypothesis needs to be tested prospectively.
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- McDowell, Kirsty, et al.
(författare)
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Prognostic Models for Mortality and Morbidity in Heart Failure with Preserved Ejection Fraction
- 2024
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Ingår i: JAMA Cardiology. - 2380-6583. ; 9:5, s. 457-465
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Tidskriftsartikel (refereegranskat)abstract
- Importance: Accurate risk prediction of morbidity and mortality in patients with heart failure with preserved ejection fraction (HFpEF) may help clinicians risk stratify and inform care decisions. Objective: To develop and validate a novel prediction model for clinical outcomes in patients with HFpEF using routinely collected variables and to compare it with a biomarker-driven approach. Design, Setting, and Participants: Data were used from the Dapagliflozin Evaluation to Improve the Lives of Patients With Preserved Ejection Fraction Heart Failure (DELIVER) trial to derive the prediction model, and data from the Angiotensin Receptor Neprilysin Inhibition in Heart Failure With Preserved Ejection Fraction (PARAGON-HF) and the Irbesartan in Heart Failure With Preserved Ejection Fraction Study (I-PRESERVE) trials were used to validate it. The outcomes were the composite of HF hospitalization (HFH) or cardiovascular death, cardiovascular death, and all-cause death. A total of 30 baseline candidate variables were selected in a stepwise fashion using multivariable analyses to create the models. Data were analyzed from January 2023 to June 2023. Exposures: Models to estimate the 1-year and 2-year risk of cardiovascular death or hospitalization for heart failure, cardiovascular death, and all-cause death. Results: Data from 6263 individuals in the DELIVER trial were used to derive the prediction model and data from 4796 individuals in the PARAGON-HF trial and 4128 individuals in the I-PRESERVE trial were used to validate it. The final prediction model for the composite outcome included 11 variables: N-terminal pro-brain natriuretic peptide (NT-proBNP) level, HFH within the past 6 months, creatinine level, diabetes, geographic region, HF duration, treatment with a sodium-glucose cotransporter 2 inhibitor, chronic obstructive pulmonary disease, transient ischemic attack/stroke, any previous HFH, and heart rate. This model showed good discrimination (C statistic at 1 year, 0.73; 95% CI, 0.71-0.75) in both validation cohorts (C statistic at 1 year, 0.71; 95% CI, 0.69-0.74 in PARAGON-HF and 0.75; 95% CI, 0.73-0.78 in I-PRESERVE) and calibration. The model showed similar discrimination to a biomarker-driven model including high-sensitivity cardiac troponin T and significantly better discrimination than the Meta-Analysis Global Group in Chronic (MAGGIC) risk score (C statistic at 1 year, 0.60; 95% CI, 0.58-0.63; delta C statistic, 0.13; 95% CI, 0.10-0.15; P <.001) and NT-proBNP level alone (C statistic at 1 year, 0.66; 95% CI, 0.64-0.68; delta C statistic, 0.07; 95% CI, 0.05-0.08; P <.001). Models derived for the prediction of all-cause and cardiovascular death also performed well. An online calculator was created to allow calculation of an individual's risk. Conclusions and Relevance: In this prognostic study, a robust prediction model for clinical outcomes in HFpEF was developed and validated using routinely collected variables. The model performed better than NT-proBNP level alone. The model may help clinicians to identify high-risk patients and guide treatment decisions in HFpEF..
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| 9. |
- Lewis, Alistair T., et al.
(författare)
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Preliminary Research : Application of Non-Invasive Measure of Cytochrome c Oxidase Redox States and Mitochondrial Function in a Porcine Model of Carbon Monoxide Poisoning
- 2022
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Ingår i: Journal of Medical Toxicology. - : Springer Science and Business Media LLC. - 1556-9039 .- 1937-6995. ; 18:3, s. 214-222
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Carbon monoxide (CO) is a colorless and odorless gas that is a leading cause of environmental poisoning in the USA with substantial mortality and morbidity. The mechanism of CO poisoning is complex and includes hypoxia, inflammation, and leukocyte sequestration in brain microvessel segments leading to increased reactive oxygen species. Another important pathway is the effects of CO on the mitochondria, specifically at cytochrome c oxidase, also known as Complex IV (CIV). The purpose of this ongoing study is the preliminary development of a porcine model of CO poisoning for investigation of alterations in brain mitochondrial physiology. Methods: Four pigs (10 kg) were divided into two groups: Sham (n = 2) and CO (n = 2). Administration of a dose of CO at 2000 ppm to the CO group over 120 minutes followed by 30 minutes of re-oxygenation at room air. The control group received room air for 150 minutes. Non-invasive optical monitoring was used to measure CIV redox states. Cerebral microdialysis was performed to obtain semi real-time measurements of cerebral metabolic status. At the end of the exposure, fresh brain tissue (cortical and hippocampal) was immediately harvested to measure mitochondrial respiration. Snap frozen cortical tissue was also used for ATP concentrations and western blotting. Results: While a preliminary ongoing study, animals in the CO group showed possible early decreases in brain mitochondrial respiration, citrate synthase density, CIV redox changes measured with optics, and an increase in the lactate-to-pyruvate ratio. Conclusions: There is a possible observable phenotype highlighting the important role of mitochondrial function in the injury of CO poisoning.
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| 10. |
- Moradi, Ashkan, et al.
(författare)
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Distributed Kalman Filtering with Privacy against Honest-but-Curious Adversaries
- 2021
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Ingår i: 2021 55th Asilomar Conference on Signals, Systems, and Computers. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781665458290 - 9781665458283 ; , s. 790-794
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a privacy-preserving distributed Kalman filter (PP-DKF) to protect the private information of individual network agents from being acquired by honest-but-curious (HBC) adversaries. The proposed approach endows privacy by incorporating noise perturbation and state decomposition. In particular, the PP-DKF provides privacy by restricting the amount of information exchanged with decomposition and concealing private information from adversaries through perturbation. We characterize the performance and convergence of the proposed PP-DKF and demonstrate its robustness against perturbation. The resulting PP-DKF improves agent privacy, defined as the mean squared estimation error of private data at the HBC adversary, without significantly affecting the overall filtering performance. Several simulation examples corroborate the theoretical results.
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