| 1. |
- Alehagen, Urban, 1951-, et al.
(författare)
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Elevated D-dimer level is an independent risk factor for cardiovascular death in out-patients with symptoms compatible with heart failure
- 2004
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Ingår i: Thrombosis and Haemostasis. - 0340-6245 .- 2567-689X. ; 92:6, s. 1250-1258
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Tidskriftsartikel (refereegranskat)abstract
- D-dimer, a marker of fibrin turnover, exhibits many interesting properties as a biological marker of thrombosis. Some of the properties of D-dimer might also be used to provide additional information about patients with heart failure. In this study, we evaluate the prognostic information acquired from D-dimer concerning increased risk of cardiovascular mortality in an elderly population with symptoms associated with heart failure. A cardiologist examined 458 elderly patients, out of 548 invited, attending primary care for symptoms of dyspnoea, fatigue and/or peripheral oedema and assessed NYHA functional class and cardiac function. Abnormal systolic function was defined as EF <40% on Doppler echocardiography. Abnormal diastolic function was defined as reduced E/A ratio and/or an abnormal pattern of pulmonary venous flow. Blood samples were drawn, and BNP and D-dimer were analysed. D-dimer was analysed using an automated micro-latex assay. A statistical analysis was performed to identify the prognostic value of increased plasma concentration of D-dimer. Results showed that during a median follow-up period of 5.5 years, 68 (14%) patients died of cardiovascular disease. No gender difference was noted. A plasma concentration of D-dimer >0.25mg/L increased the risk almost 4-fold. In conclusion, D-dimer is an independent risk factor for cardiovascular mortality that may be used to risk-stratify patients with heart failure. © 2004 Schattauer GmbH, Stuttgart.
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| 2. |
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| 3. |
- Hansson, Kenny, 1972-, et al.
(författare)
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Comparative studies with surface plasmon resonance and free oscillation rheometry on the inhibition of platelets with cytochalasin E and monoclonal antibodies towards GPIIb/IIIa
- 2002
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Ingår i: Biosensors & bioelectronics. - 0956-5663 .- 1873-4235. ; 17:9, s. 761-771
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Tidskriftsartikel (refereegranskat)abstract
- In the haemostatic system a multitude of processes are intertwined in fine-tuned interactions that arrest bleeding, keep the circulatory system open, and the blood flowing. The occurrence of both surface and bulk interactions adds an additional dimension of complexity. These insights have led to the belief that global overall procedures can inform on the likely behaviour of the system in health and disease. Two sensing procedures: surface plasmon resonance (SPR), which senses surface interactions, and free oscillation rheometry (FOR), which senses interactions within the bulk, have been combined and evaluated. The contribution of blood cells, mainly platelets, to the SPR and FOR signals was explored by simultaneous SPR and FOR measurement during native whole blood coagulation, accelerated via the platelets through addition of SFLLRN peptide and inhibition of platelet aggregation with abciximab (ReoPro®) and of shape change with cytochalasin E. The SPR technique was found to be sensitive to inhibition of blood cell functions such as adhesion to and spreading on surfaces, as well as platelet aggregation. SPR seemed not to be directly sensitive to fibrin polymerisation in coagulating whole blood. The FOR technique detected the coagulation as a bulk phenomenon, i.e. the gelation of the blood due to fibrin formation was detected. The combination of SPR and FOR may therefore be suitable for studies on blood cell functions during coagulation.
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| 4. |
- Hansson, Kenny, 1972-, et al.
(författare)
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Surface plasmon resonance and free oscillation rheometry in combination : a useful approach for studies on haemostasis and interactions between whole blood and artificial surfaces
- 2002
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Ingår i: Biosensors & bioelectronics. - 0956-5663 .- 1873-4235. ; 17:9, s. 747-759
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Tidskriftsartikel (refereegranskat)abstract
- In haemostatic and biomaterial research biological processes at surfaces and in the bulk phase of the surface-contacting medium are important. The present work demonstrates the usefulness of the combination of surface plasmon resonance (SPR), sensitive to changes in refractive index at surfaces, and free oscillation rheometry (FOR), sensitive to rheological properties of the bulk, for simultaneous real-time measurements on coagulation and fibrinolysis of blood plasma and coagulation of whole blood. SFLLRN stimulated coagulation of native whole blood presented a higher SPR signal with different appearance than plasma coagulation, while the FOR signals corresponding to plasma and whole blood coagulation were similar. This indicated that the SPR technique was more sensitive to cell-surface interactions than to fibrin formation in whole blood during coagulation, while the FOR technique were equally sensitive to coagulation in whole blood and plasma. Spontaneous coagulation of native whole blood in contact with methyl- and hydroxyl-terminated self-assembled monolayers (SAM) on gold and gold surfaces regenerated after coagulation were also studied. The regenerated gold surfaces displayed the shortest coagulation times, although the contact-activation of blood coagulation for these surfaces was low. The methylated and hydroxylated surfaces were comparable in terms of coagulation activation, while the hydroxylated surfaces presented FOR signals that indicated detaching of the coagulum from the surface. The combination of SPR and FOR is well suited for studies of cell– and protein–surface interactions and simultaneous bulk processes. Possible applications are investigations of blood cell defects in patients and monitoring of native whole blood interactions with artificial surfaces.
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| 5. |
- Hillarp, Andreas, et al.
(författare)
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Local INR calibration of the Owren type prothrombin assay greatly improves the intra- and interlaboratory variation
- 2004
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Ingår i: Thrombosis and Haemostasis. - 0340-6245 .- 2567-689X. ; 91:2, s. 300-307
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Tidskriftsartikel (refereegranskat)abstract
- In 1999, a simplified procedure for calibration of the Owren prothrombin time (Owren PT) assay was introduced by a working group of the organisation for national quality assurance in laboratory medicine in Sweden. The new protocol allowed local calibration by means of only two lyophilised national plasma calibrators and expression of results as an international normalized ratio (INR). This is our report of a three-year follow-up involving the analysis of data from all laboratories, in hospitals (n=88 in 2002) and primary health care units (n=246 in 2002) that perform the Owren PT assay in Sweden. The interlaboratory variation was significantly improved after the introduction of the new calibration procedure. For the larger hospital-based laboratories, the mean coefficient of variation (CV) was reduced from 7.9% to 5.2% (p<0.0001) when analysing test materials with INR range 2-4. In the higher INR range (>4), the CV was reduced even further, from 10.4% to 6.8% (p<0.0001). The corresponding results from smaller laboratories in the primary health care units showed a similar decrease in CV from 8.2% to 5.7% in the INR range 2-4 (p<0.0001). At the INR range >4, the CV was reduced from 9.5% to 7.8%. The intralaboratory variation was also improved for both types of laboratory categories. This study shows an improved precision, with CV less than 6% at the therapeutic INR range, for both hospital-based laboratories and smaller laboratories in the primary health care system. The results indicate that the Owren PT assay is well suited for local INR calibration employing only two calibrant plasmas in a simplified procedure.
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| 7. |
- Jackson, Craig M, et al.
(författare)
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A critical evaluation of the prothrombin time for monitoring oral anticoagulant therapy
- 2003
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Ingår i: Pathophysiology of Haemostasis and Thrombosis. - : S. Karger AG. - 1424-8832 .- 1424-8840. ; 33:1, s. 43-51
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Tidskriftsartikel (refereegranskat)abstract
- The Quick prothrombin time is the most common clotting test performed, principally for monitoring oral anticoagulant therapy. The International Normalized Ratio (INR) for comparing patient results from prothrombin time measurements and the International Standardized Index (ISI) for achieving greater consistency of results using different thromboplastins have made it possible to compare the results of vitamin K antagonist drug therapy that was impossible before the introduction of the INR and ISI. However, INR values obtained from the same patient plasma sample using different thromboplastins are significantly different. This is so even when the thromboplastins have nearly the same ISI values. We suggest that investigation of patient-specific differences can provide a means by which the INR discrepancies can be identified and understood and thus lead to better methods for monitoring oral anticoagulant therapy.
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| 8. |
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| 9. |
- Johanson, Per, 1963, et al.
(författare)
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Prognostic value of ST-segment resolution-when and what to measure.
- 2003
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Ingår i: European heart journal. - 0195-668X. ; 24:4, s. 337-45
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Tidskriftsartikel (refereegranskat)abstract
- Analyses of ST-segment resolution during acute myocardial infarction has, during recent years, challenged coronary angiography as gold-standard for predicting myocardial reflow and future risk. We have previously reported that continuous ST-monitoring can be done accurately in the clinical setting. We now set out to compare the prognostic value of previously suggested cut-offs for ST-segment resolution, and determine the times to measure these.
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| 10. |
- Järemo, Petter, et al.
(författare)
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Individual variations of platelet inhibition after loading doses of clopidogrel
- 2002
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 252:3, s. 233-238
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To investigate individual variations of platelet inhibition after clopidogrel-loading doses.Setting. Department of Cardiology, Linköping University Hospital, Linköping, Sweden.Subjects. Individuals with stable angina pectoris (n = 18) subject to percutaneous coronary interventions (PCI) and subsequent stenting were investigated.Methods and experimental protocol. A 300-mg clopidogrel loading dose was administrated immediately after stenting (day 1) followed by an additional 75 mg clopidogrel after 24 h (day 2). The ADP-evoked platelet fibrinogen binding was analysed to estimate platelet reactivity immediately before angiography and on day 2. A flow cytometry technique was used with two ADP solutions (final concentrations 0.6 and 1.7 μmol L−1) employed as platelet activating agents. Soluble P-selectin was used as a marker of platelet activity.Results. When using 1.7 μmol L−1 ADP to activate platelets four individuals had a strong inhibition (i.e. platelet reactivity <10% of the day 1-value day 2). In contrast, five patients demonstrated a weak inhibition (i.e. platelet reactivity >60% of the day 1-value day 2). Similar results were obtained when using 0.6 μmol L−1 ADP as a platelet-activating agent. Clopidogrel, however, fails to suppress platelet activity as estimated from soluble P-selectin.Conclusions. Clopidogrel evoked platelet inhibition exhibits a considerable individual heterogeneity. Some individuals only had weak responses whereas others displayed strong platelet inhibition. The present flow cytometry technique appears suitable for identifying patients with abnormal reactions after clopidogrel exposure.
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