| 1. |
- Arinell, Karin, 1982-, et al.
(författare)
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Physical inactivity and platelet function in humans and brown bears : A comparative study
- 2018
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Ingår i: Platelets. - : Taylor & Francis. - 0953-7104 .- 1369-1635. ; 29:1, s. 87-90
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Tidskriftsartikel (refereegranskat)abstract
- Physical inactivity increases the risk of thromboembolism. However, good standardized human models on inactivity are in short supply and experimental models are few.Our objective was to investigate how standardized bed rest affects platelet aggregation in humans and to investigate if aggregation is altered in a translational model system - the hibernating brown bear (Ursus arctos). We collected blood from (1) healthy male volunteers participating in a 21-day bed rest study in head-down tilt position (-6°) 24 h a day; (2) free-ranging brown bears captured during winter hibernation and again during active state in summer. We analyzed platelet function using multiple electrode platelet aggregometry. In total, 9 healthy male volunteers (age 31.0 ± 6.4 years) and 13 brown bears (7 females and 6 males, age 2.8 ± 0.6 years) were included. In hibernating bears adenosine diphosphate, arachidonic acid, thrombin receptor activating peptide, and collagen impedance aggregometry tests were all halved compared to summer active state. In human volunteers no statistically significant changes were found between baseline and the end of bed rest. In human male volunteers 3 weeks of bed rest did not affect platelet function. In hibernating brown bears platelet aggregation was halved compared to summer and we hypothesize that this is a protective measure to avoid formation of thrombi under periods of low blood flow.
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| 2. |
- Stoen, Ole-Gunnar, et al.
(författare)
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Physiological evidence for a human-induced landscape of fear in brown bears (Ursus arctos)
- 2015
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Ingår i: Physiology and Behavior. - : Elsevier. - 0031-9384 .- 1873-507X. ; 152:A, s. 244-248
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Tidskriftsartikel (refereegranskat)abstract
- Human persecution is a major cause of mortality for large carnivores. Consequently, large carnivores avoid humans, but may use human-dominated landscapes by being nocturnal and elusive. Behavioral studies indicate that certain ecological systems are "landscapes of fear", driven by antipredator behavior. Because behavior and physiology are closely interrelated, physiological assessments may provide insight into the behavioral response of large carnivores to human activity. To elucidate changes in brown bears' (Ursus arctos) behavior associated with human activity, we evaluated stress as changes in heart rate (HR) and heart rate variability (HRV) in 12 GPS-collared, free-ranging bears, 7 males and 5 females, 3-11 years old, using cardiac-monitoring devices. We applied generalized linear regression models with HR and HRV as response variables and chest activity, time of day, season, distance traveled, and distance to human settlements from GPS positions recorded every 30 mm as potential explanatory variables. Bears exhibited lower HRV, an indication of stress, when they were close to human settlements and especially during the berry season, when humans were more often in the forest, picking berries and hunting. Our findings provide evidence of a human-induced landscape of fear in this hunted population of brown bears. (C) 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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| 3. |
- Andell, Pontus, et al.
(författare)
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Intravascular Ultrasound Guidance Is Associated With Better Outcome in Patients Undergoing Unprotected Left Main Coronary Artery Stenting Compared With Angiography Guidance Alone
- 2017
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Ingår i: Circulation. Cardiovascular Interventions. - : Lippincott Williams & Wilkins. - 1941-7640 .- 1941-7632. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: Small observational studies have indicated better outcome with intravascular ultrasound (IVUS) guidance when performing unprotected left main coronary artery (LMCA) percutaneous coronary intervention (PCI), but the overall picture remains inconclusive and warrants further investigation. We studied the impact of IVUS guidance on outcome in patients undergoing unprotected LMCA PCI in a Swedish nationwide observational study.Methods and Results: Patients who underwent unprotected LMCA PCI between 2005 and 2014 because of stable coronary artery disease or acute coronary syndrome were included from the nationwide SCAAR (Swedish Coronary Angiography and Angioplasty Registry). Of 2468 patients, IVUS guidance was used in 621 (25.2%). The IVUS group was younger (median age, 70 versus 75 years) and had fewer comorbidities but more complex lesions. IVUS was associated with larger stent diameters (median, 4 mm versus 3.5 mm). After adjusting for potential confounders, IVUS was associated with significantly lower occurrence of the primary composite end point of all-cause mortality, restenosis, or definite stent thrombosis (hazard ratio, 0.65; 95% confidence interval, 0.50-0.84) and all-cause mortality alone (hazard ratio, 0.62; 95% confidence interval, 0.47-0.82). In 340 propensity score-matched pairs, IVUS was also associated with significantly lower occurrence of the primary end point (hazard ratio, 0.54; 95% confidence interval, 0.37-0.80).Conclusions: IVUS was associated with an independent and significant outcome benefit when performing unprotected LMCA PCI. Potential mediators of this benefit include larger and more appropriately sized stents, perhaps translating into lower risk of subsequent stent thrombosis. Although residual confounding cannot be ruled out, our findings indicate a possible hazard when performing unprotected LMCA PCI without IVUS guidance.
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| 4. |
- Andell, Pontus, et al.
(författare)
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Reclassification of Treatment Strategy With Instantaneous Wave-Free Ratio and Fractional Flow Reserve : A Substudy From the iFR-SWEDEHEART Trial
- 2018
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Ingår i: JACC: Cardiovascular Interventions. - : Elsevier BV. - 1936-8798 .- 1876-7605. ; 11:20, s. 2084-2094
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The authors sought to compare reclassification of treatment strategy following instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR). Background: iFR was noninferior to FFR in 2 large randomized controlled trials in guiding coronary revascularization. Reclassification of treatment strategy by FFR is well-studied, but similar reports on iFR are lacking. Methods: The iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome Trial) study randomized 2,037 participants with stable angina or acute coronary syndrome to treatment guided by iFR or FFR. Interventionalists entered the preferred treatment (optimal medical therapy [OMT], percutaneous coronary intervention [PCI], or coronary artery bypass grafting [CABG]) on the basis of coronary angiograms, and the final treatment decision was mandated by the iFR/FFR measurements. Results: In the iFR/FFR (n = 1,009/n = 1,004) populations, angiogram-based treatment approaches were similar (p = 0.50) with respect to OMT (38%/35%), PCI of 1 (37%/39%), 2 (15%/16%), and 3 vessels (2%/2%) and CABG (8%/8%). iFR and FFR reclassified 40% and 41% of patients, respectively (p = 0.78). The majority of reclassifications were conversion of PCI to OMT in both the iFR/FFR groups (31.4%/29.0%). Reclassification increased with increasing number of lesions evaluated (odds ratio per evaluated lesion for FFR: 1.46 [95% confidence interval: 1.22 to 1.76] vs. iFR 1.37 [95% confidence interval: 1.18 to 1.59]). Reclassification rates for patients with 1, 2, and 3 assessed vessels were 36%, 52%, and 53% (p < 0.01). Conclusions: Reclassification of treatment strategy of intermediate lesions was common and occurred in 40% of patients with iFR or FFR. The most frequent reclassification was conversion from PCI to OMT regardless of physiology modality. Irrespective of the physiological index reclassification of angiogram-based treatment strategy increased with the number of lesions evaluated.
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| 5. |
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| 6. |
- Andersson, Tommy, 1970-
(författare)
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Atrial fibrillation and cause of death, sex differences in mortality, and anticoagulation treatment in low-risk patients
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Atrial fibrillation (AF) is the most common arrhythmia but information on cause of death in patients with AF is sparse, and whether individuals at low risk of cerebral infarction (CVL) should receive antico-agulant medication is controversial. Studies of sex differences with respect to mortality risk have shown conflicting results.Methods: Data were obtained from Swedish National Registers. In Study I, there were 272 186 AF patients and matched controls and in Studies II and III, 9519 AF patients and no other diagnosis and matched controls. Study IV compared treatment with warfarin to no treatment in 48 433 patients with AF. Hazard ratio (HR) was calculated with 95% confidence intervals and outcome rates as number per 1000 person-years.Results: Ischemic heart disease (IHD) was the most common underlying cause of death and was present in 40.2% of AF patients at a HR of 1.7 (1.4-2.1). CVL/stroke was a cause of death in 13.1%, HR 2.7 (1.8-4.0). Among underlying and contributing causes of death, the most common diagnoses were IHD in 43.5%, HR 1.7 (1.4-2.0) and heart failure in 33.1%, HR 2.9 (2.2-3.7). The HRs for mortality in females with AF in age categories ≤65, 65-74, and 75-85 were 2.15, 1.72, and 1.44, and for males 1.76, 1.36, and 1.24. The rates of mortality in females with AF in age categories 55-64, 65-74, and 75-85 were 6.2, 20.7, and 57.3, and for males 8.5, 27.3, and 64.5. In patients 65-74 years, females with a CHA2DS2-VASc score of 2, and males with a score of 1 receiving warfarin treatment showed a significantly reduced risk of cerebral infarc-tion/stroke, HR 0.46 (0.25-0.83) for females and for males, HR 0.39 (0.21-0.73).Conclusions: Most common causes of death in AF patients were CVL/stroke, heart failure, and IHD. HR of mortality in patients with AF was higher in females than in males but absolute risk was higher in males with AF compared to females with AF. Anticoagulant therapy was benefi-cial in patients ≥65 years, regardless of the CHA2DS2-VASc score.
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| 7. |
- Andersson, Tommy, 1970-, et al.
(författare)
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Patients with atrial fibrillation and outcomes of cerebral infarction in those with treatment of warfarin versus no warfarin with references to CHA(2)DS(2)-VASc score, age and sex - A Swedish nationwide observational study with 48 433 patients
- 2017
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:5
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Tidskriftsartikel (refereegranskat)abstract
- Aims There is controversy in the guidelines as to whether patients with atrial fibrillation and a low risk of stroke should be treated with anticoagulation, especially those with a CHA(2)DS(2)-VASc score of 1 point. In a retrospective, nationwide cohort study, we used the Swedish National Patient Registry, the National Prescribed Drugs Registry, the Swedish Registry of Education and the Population and Housing Census Registry. 48 433 patients were identified between 1 January 2006 and 31 December 2008 with incident atrial fibrillation who were divided in age categories, sex and a CHA(2)DS(2)-VASc score of 0, 1, 2 and >= 3 and they were included in a time-varying analysis of warfarin treatment versus no treatment. The primary end-point was cerebral infarction and stroke, and patients were followed until 31 December 2009. Patients with 1 point from the CHA(2)DS(2)-VASc score showed the following adjusted hazard ratios (HR) with a 95% confidence interval: men 65-74 years 0.46 (0.25-0.83), men < 65 years 1.11 (0.56-2.23) and women < 65 years 2.13 (0.94-4.82), where HR < 1 indicates protection with warfarin. In patients < 65 years and 2 points, HR in men was 0.35 (0.18-0.69) and in women 1.84 (0.86-3.94) while, in women with at least 3 points, HR was 0.31 (0.16-0.59). In patients 65-74 years and 2 points, HR in men was 0.37 (0.23-0.59) and in women 0.39 ( 0.21-0.73). Categories including age >= 65 years or >= 3 points showed a statistically significant protection from warfarin. Our results support that treatment with anticoagulation may be considered in all patients with an incident atrial fibrillation diagnosis and an age of 65 years and older, i.e. also when the CHA(2)DS(2)-VASc score is 1.
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| 8. |
- Andersson, Tommy, 1970-, et al.
(författare)
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Patients without comorbidities at the time of diagnosis of atrial fibrillation : causes of death during long-term follow-up compared to matched controls
- 2017
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Ingår i: Clinical Cardiology. - : John Wiley & Sons. - 0160-9289 .- 1932-8737. ; 40:11, s. 1076-1082
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Little is known about the long-term, cause-specific mortality risk in patients without comorbidities at the time of diagnosis of atrial fibrillation (AF).METHODS: From a nation-wide registry of patients hospitalized with incident AF between 1995 and 2008 we identified 9 519 patients with a first diagnosed AF and no comorbidities at the time of AF diagnosis. They were matched with 12 468 controls. The follow-up continued until December 2008. Causes of death were classified according to the ICD-10 codes.RESULTS: During follow-up, 11.1% of patients with AF and 8.3% of controls died. Cardiovascular diseases were the most common causes of death and the only diagnoses which showed significantly higher relative risk in patients with AF than controls (HR 2.0, 95% CI 1.8-2.3), and the relative risk was significantly higher in women than in men. Stroke was a more common cause among patients with AF, 13.1% versus 9.7% (HR 2.7, 95% CI 1.8-4.0), while cerebral hemorrhage was more common among controls, 4.7% versus 10.2% (HR 0.9, 95% CI 0.6-1.5). The time from AF diagnosis to death was 6.0 ± 3.1 years.CONCLUSIONS: In patients with incident AF and no known comorbidities at the time of AF diagnosis, only cardiovascular diseases were more often causes of death as compared to controls. Women carried a significantly higher relative risk than men.
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| 9. |
- Andersson, T., et al.
(författare)
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What do patients with incident atrial fibrillation and no comorbidities at the time of diagnosis die of?
- 2017
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Konferensbidrag (refereegranskat)abstract
- Introduction: Little is known about the long-term mortality risk and the causes of death in patients without comorbidities at the time of diagnosis of atrial fibrillation (AF).Purposes: To identify the causes of death in patients with AF and without comorbidities at the time of AF diagnosis.Methods: We identified 9 519 patients with first diagnosed AF and no co-morbidities at the time of AF diagnosis in a nation-wide registry of patients hospitalized between 1995 and 2008. They represented 3.5% of the original cohort of 271186 patients hospitalized with incident AF. Patients with any diagnosis from ICD9 and ICD10 at the time of AF diagnosis wereexcluded. They were matched for age, sex and calendar year of AF diagnosis with 12 468 controls. The follow-up continued until December 2008. Causes of death were classified according to the ICD-10 codes.Results: During follow-up, 11.1% and 8.3% of patients with AF and controls died, HR 1.3, 95% CI 1.2–1.4. Most of the difference was explained by deaths of cardiovascular causes, 8.3% versus 3.9%, (HR 2.0, 95% CI 1.8–2.3). The cause of death pattern was the same in controls although at much lower rates. The age adjusted relative risk was higher in women than in men, HR 2.3, 95% CI 1.9–2.8 versus HR 1.7, 95% CI 1.4–2.0. Myocardial infarction was the most common cardiovascular cause of death but was less common among patients with AF than in controls, 20.5% versus 32.0%. Stroke was a more common cause among patients with AF, 13.1% versus 9.7% (HR 2.7, 95% CI 1.8–4.0), while cerebral hemorrhage was more common among controls, 4.7% versus 10.2% (HR 0.9, 95% CI 0.6–1.5). The time from AF diagnosis to death was 6.0±3.1 years, as compared to the time from inclusion to death, 5.8±3.1 years, in controls.Conclusions: Only cardiovascular diseases were more often causes of death than in controls. Women carried a significantly higher relative risk than men. The duration between AF diagnosis and death suggests that there is often time enough for early intervention with antithrombotic therapy, rhythm and/or rate control and treatment of risk factors as they appear. Interestingly, controls had the same cause of death pattern although at much lower rates.
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| 10. |
- Angerås, Oskar, 1976, et al.
(författare)
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Impact of Thrombus Aspiration on Mortality, Stent Thrombosis, and Stroke in Patients with ST-Segment-Elevation Myocardial Infarction: A Report From the Swedish Coronary Angiography and Angioplasty Registry
- 2018
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Ingår i: Journal of the American Heart Association. - : John Wiley & Sons. - 2047-9980. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Background-Thrombus aspiration is still being used in a substantial number of patients despite 2 large randomized clinical trials showing no favorable effect of routine thrombus aspiration during primary percutaneous coronary intervention in patients with STsegment- elevation myocardial infarction. The aim of this observational study was to evaluate the impact of thrombus aspiration on mortality, stent thrombosis, and stroke using all available data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR). Methods and Results--We identified 42 829 consecutive patients registered in SCAAR between January 2005 and September 2014 who underwent percutaneous coronary intervention for ST-segment-elevation myocardial infarction. Thrombus aspiration was used in 25% of the procedures. We used instrumental variable analysis with administrative healthcare region as the treatmentpreference instrumental variable to evaluate the effect of thrombus aspiration on mortality, stent thrombosis, and stroke. Thrombus aspiration was not associated with mortality at 30 days (risk reduction: -1.2; 95% confidence interval [CI] , -5.4 to 3.0; P=0.57) and 1 year (risk reduction: -2.4; 95% CI, -7.6 to 3.0; P=0.37). Thrombus aspiration was associated with a lower risk of stent thrombosis both at 30 days (risk reduction: -2.7; 95% CI, -4.1 to -1.4; P < 0.001) and 1 year (risk reduction: -3.5; 95% CI, -5.3 to -1.7; P < 0.001). In-hospital stroke and neurologic complications did not differ between groups (risk reduction: 0.1; 95% CI, -0.8 to 1.1; P=0.76). Conclusions--Mortality was not different between the groups. Thrombus aspiration was associated with decreased risk of stent thrombosis. Our study provides important evidence for the external validity of previous randomized studies regarding mortality.
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