| 1. |
- Aulin, Julia
(författare)
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Biomarkers of inflammation in atrial fibrillation
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Atrial fibrillation (AF) is common and associated with increased risk of stroke, heart failure (HF) and mortality. Inflammation is linked to AF.The overall aim of this thesis was to investigate inflammatory activity and cardiovascular outcomes and mortality in patients with AF on effective oral anticoagulation. Levels of the inflammatory biomarkers interleukin 6 (IL-6), C-reactive protein (CRP) and fibrinogen at study entry and serial changes of IL-6 over time were investigated and related to stroke or systemic embolism, mortality and other cardiovascular events, including major bleeding. Associations between IL-6, CRP and biomarkers of cardiorenal dysfunction (NT-proBNP, troponin, GDF-15 and cystatin C) and HF hospitalisation, recurrent HF hospitalisations and mortality, were also investigated in patients with AF stratified for HF symptoms and reduced or preserved ejection fraction.The study populations consisted of patients with AF included in the biomarker substudies of the large multicentre randomised controlled trials RE-LY (n=6,187) and ARISTOTLE (n=14,954) with a median follow-up of 2.0 and 1.9 years, respectively. Repeated IL-6 measurements were available at study entry and at any postbaseline time point at 3, 6 and 12 months in RE-LY (n=2,559), and at study entry and at 2 months in ARISTOTLE (n=4,830). For HF stratification, patients in ARISTOTLE with information on HF symptoms and left ventricular function at study entry and with IL-6, CRP, NT-proBNP, troponin T, GDF-15 and cystatin C available at randomisation (n=11,818) were included.Higher level of IL-6, but not of CRP, was significantly associated with higher risk of mortality in Cox models adjusted for established clinical risk factors and other cardiovascular biomarkers. The level of any of the studied inflammatory biomarkers was not independently associated with any other cardiovascular outcome, including stroke or systemic embolism or major bleeding, in presence of other strong cardiovascular biomarkers. Levels of IL-6 were stable over time and persistent inflammatory activity was associated with increased risk of mortality, independent of clinical risk factors and other prognostic biomarkers. All biomarkers (IL-6, CRP, NT-proBNP, troponin T, GDF-15 and cystatin C) were associated with higher risk of HF hospitalisation and mortality regardless of HF symptoms and reduced or preserved ejection fraction.In conclusion, in anticoagulated patients with AF, higher level of IL-6, but not of CRP, was associated with higher risk of mortality, independent of clinical risk factors and other cardiovascular biomarkers. IL-6 levels were stable over time and provided incremental information on the risk of mortality irrespective of when measured. IL-6 may therefore serve as a risk marker for fatal outcomes. Biomarkers improved the identification of patients with AF at risk of HF in addition to clinical and echocardiography data.
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| 2. |
- Eriksson, Niclas, 1978-
(författare)
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On the Prediction of Warfarin Dose
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Warfarin is one of the most widely used anticoagulants in the world. Treatment is complicated by a large inter-individual variation in the dose needed to reach adequate levels of anticoagulation i.e. INR 2.0 – 3.0. The objective of this thesis was to evaluate which factors, mainly genetic but also non-genetic, that affect the response to warfarin in terms of required maintenance dose, efficacy and safety with special focus on warfarin dose prediction.Through candidate gene and genome-wide studies, we have shown that the genes CYP2C9 and VKORC1 are the major determinants of warfarin maintenance dose. By combining the SNPs CYP2C9 *2, CYP2C9 *3 and VKORC1 rs9923231 with the clinical factors age, height, weight, ethnicity, amiodarone and use of inducers (carbamazepine, phenytoin or rifampicin) into a prediction model (the IWPC model) we can explain 43 % to 51 % of the variation in warfarin maintenance dose. Patients requiring doses < 29 mg/week and doses ≥ 49 mg/week benefitted the most from pharmacogenetic dosing. Further, we have shown that the difference across ethnicities in percent variance explained by VKORC1 was largely accounted for by the allele frequency of rs9923231. Other novel genes affecting maintenance dose (NEDD4 and DDHD1), as well as the replicated CYP4F2 gene, have small effects on dose predictions and are not likely to be cost-effective, unless inexpensive genotyping is available.Three types of prediction models for warfarin dosing exist: maintenance dose models, loading dose models and dose revision models. The combination of these three models is currently being used in the warfarin treatment arm of the European Pharmacogenetics of Anticoagulant Therapy (EU-PACT) study. Other clinical trials aiming to prove the clinical validity and utility of pharmacogenetic dosing are also underway.The future of pharmacogenetic warfarin dosing relies on results from these ongoing studies, the availability of inexpensive genotyping and the cost-effectiveness of pharmacogenetic driven warfarin dosing compared with new oral anticoagulant drugs.
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| 3. |
- Åkerblom, Axel, 1977-
(författare)
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Biomarkers of Renal Function in Acute Coronary Syndromes
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis aimed to investigate cystatin C and creatinine-based estimates of glomerular filtration rate (eGFR), both at admission and during follow-up, on the combined endpoint of cardiovascular death and myocardial infarction in patients with acute coronary syndrome (ACS). We also evaluated two cystatin C assays and assessed genetic determinants of cystatin C concentrations.We used the PLATelet inhibition and Patient Outcomes study, where all types of ACS patients (n=18624) were randomized to ticagrelor or clopidogrel treatment. Multivariable Cox regression models, including clinical variables and biomarkers (troponin and NT-proBNP), and c-statistics were calculated.Cystatin C and the creatinine-based CKD-EPI equation exhibited similar significant prognostic impact on the combined endpoint, with Area Under Curves (AUC) 0.6923 and 0.6941, respectively. Follow-up samples of renal biomarkers did not improve risk prediction.Patients randomized to ticagrelor treatment were associated with a non-sustained larger increase in renal markers at discharge, but neither the change nor the difference between the randomized groups affected cardiovascular risk.Two different cystatin C assays exhibited good correlation 0.86 (95% confidence interval 0.85-0.86), however moderate level of agreement. Risk prediction with a combination of creatinine and cystatin C did not outperform the creatinine-based CKD-EPI equation, AUC: 0.6913 and 0.6924, respectively (n=13050).The genetic polymorphism rs6048952 independently affected the cystatin C concentration with mean levels of 0.85mg/L, 0.80mg/L and 0.73mg/L for the A/A, A/G, and G/G genotypes, respectively.The genetic polymorphism did not affect outcome overall, however in the non-ST-elevation ACS subgroup a signal that genetic polymorphism may be associated with cardiovascular death was observed (p=0.002).In conclusion: cystatin C or eGFR, irrespective of equation or assay, are important cardiovascular risk factors in ACS patients. Nonetheless, the incremental value of adding any renal variable, to a multivariable risk model, is small. Further research on the impact of cystatin C genetic polymorphism is warranted.
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