Search PubMed⌕ Search

Biomedical subjects

F R Rosendaal

Publications and source records attributed to F R Rosendaal.

At least 19 recordsLinked to original sources
PubMed2007

The quality of oral anticoagulant therapy and recurrent venous thrombotic events in the Leiden Thrombophilia Study.

BACKGROUND: The International Normalized Ratio (INR) target range is a relatively narrow range in which the efficacy of oral anticoagulant treatment, i.e. prevention of extension and recurrence of thrombosis, is balanced with the risk of hemorrhagic complications. Over the years, different INR target ranges have been implemented for individual indications, depending on their thrombotic potential. In most of the studies defining these INR targets, the treatment of the patients was aimed at a certain INR range, but in the analysis no account was taken of the time that the patients spent within this range in reality. METHODS: The Leiden Thrombophilia Study (LETS) is a population-based case-control study on risk factors for venous thrombosis, in which many genetic and acquired factors have been investigated. Our aim was to investigate the effect of the quality of the oral anticoagulant therapy for the initial venous thrombosis and its relationship with recurrence of thrombosis. Quality of anticoagulation was defined as the time spent at various INR levels during treatment, and we focused on the effect of sustained intensities above a certain INR in preventing recurrences later on. RESULTS: Two hundred and sixty-six patients with a total follow-up of 2495 patient-years were studied. The mean duration of the initial anticoagulant therapy was 194.5 days (range 48-4671). During follow-up, 58 recurrences were diagnosed (cumulative recurrence rate of 21.8% over 9 years). The mean INR during initial therapy was 2.90, with 90.3% [95% confidence interval (CI) 88.4-92.3%] of the time being spent above an INR of 2.0, and 39.1% (95% CI 35.5-42.7%) above an INR of 3.0. Patients who spent more time below the target range, or who had a shorter duration of anticoagulation, did not experience a higher risk of recurrence after the initial period of anticoagulation had passed. CONCLUSION: Provided that oral anticoagulant treatment is adequately managed, according to international guidelines, recurrent thrombosis cannot be ascribed to variation in the primary treatment. Further attempts to reduce the risk of recurrence should therefore be aimed at identifying other explanatory factors, and subsequently fine-tuning the target ranges.

Administration, Oral↗
PubMed2006

[Deep-vein thrombosis and pulmonary embolism due to air travel].

In recent years, the association between air travel and the incidence of deep-vein thrombosis or pulmonary embolism has become clearer. Epidemiologic studies reveal an increased relative risk of thromboembolism after flights of more than 8 hours and especially in subjects at higher risk for this disease, due, for example, to congenital thrombophilia or the use of oral contraceptives. However, the absolute risk of deep-vein thrombosis or pulmonary embolism after prolonged air travel is very small. Studies have shown that a combination of factors present during prolonged air travel may account for increased activation of coagulation. There is no definitive proof that elastic stockings are effective in reducing the incidence of clinically relevant thromboembolism during air travel. Acetylsalicylic acid is not effective in the prevention of thrombosis during air travel and may be dangerous. Prophylactic subcutaneous low molecular weight heparin may be effective to prevent air travel-associated thrombosis. However, pending more solid evidence, this strategy should only be used cautiously, e.g. only in patients with a high risk of thrombosis who are planning a long flight.

Aerospace Medicine↗
PubMed2006

von Willebrand factor and its propeptide: the influence of secretion and clearance on protein levels and the risk of venous thrombosis.

BACKGROUND AND OBJECTIVES: Elevated levels of factor (F)VIII are associated with an increased risk of thrombosis. FVIII levels are determined mainly by von Willebrand factor (VWF). We have investigated the contribution of secretion and clearance rates to the elevated VWF antigen (VWF:Ag) and to the risk of thrombosis. VWF is secreted in equimolar amounts with its propeptide, which has a shorter half-life. VWF propeptide can be used as a measure of VWF secretion and allows estimation of the VWF half-life. METHODS AND RESULTS: We have measured VWF propeptide, VWF:Ag, FVIII:Ag and FVIII activity (FVIII:C) in the Leiden Thrombophilia Study. In controls, high VWF propeptide was associated with high VWF:Ag, FVIII:Ag and FVIII:C. In contrast to mature VWF:Ag, VWF propeptide was not influenced by blood groups. Using an ELISA-based assay we have shown that VWF propeptide lacks ABO antigens. Levels were higher in men and increased with age. A long VWF half-life was also associated with high VWF:Ag, FVIII:Ag and FVIII:C. The VWF half-life was influenced by blood group (10 h in O vs. 12 h in non-O individuals), but not by sex, and only slightly by age. VWF propeptide was higher in thrombosis patients than in controls. The VWF half-life was similar in patients and controls (11.4 and 11.1 h, respectively). CONCLUSIONS: Both secretion and clearance rates are important determinants of VWF and FVIII levels. However, mainly high VWF and FVIII levels caused by increased secretion seem to be associated with thrombosis. ABO blood group influences the clearance rates of VWF rather than VWF secretion rates.

ABO Blood-Group System↗
PubMed2006

The association of prothrombin A19911G polymorphism with plasma prothrombin activity and venous thrombosis: results of the MEGA study, a large population-based case-control study.

BACKGROUND: Prothrombin (FII) G20210A mutation and elevated plasma prothrombin activity are known risk factors for venous thrombosis. The risk of venous thrombosis among 19911G carriers of the prothrombin A19911G polymorphism has not been extensively investigated. OBJECTIVES AND METHODS: We assessed prothrombin activity, FIIG20210A, and FIIA19911G polymorphisms in a large population-based case-control study, the Multiple Environmental and Genetic Assessment (MEGA) study of risk factors for venous thrombosis. Four thousand three hundred and sixty-five consecutive patients with a first episode of deep vein thrombosis of the leg or pulmonary embolism were included. The control group (n = 4779) consisted of partners of patients or persons gathered using a random-digit dialing method. We studied the effect of FIIA19911G polymorphism on prothrombin activity and thrombosis risk, also in combination with factor V Leiden. RESULTS: Among FII20210-GG control subjects, FII19911-GG carriers had 7.1% [95% confidence interval (CI): 5.7-8.5] higher mean prothrombin activity than FII19911-AA carriers and the risk for GG carriers was 1.43-fold increased compared to AA carriers [odds ratio (OR) 1.43; 95% CI: 1.27-1.61]. Among FII20210-GA control carriers, the mean prothrombin activity in both FII19911-AA and -AG carriers was nearly equivalent [131.7% and 133.4%; mean difference (95% CI) = 1.7% (-7.2-10.7)]. Because of genetic linkage, FII19911-GG carriers were very rare on a FII20210-GA background, as only one FII20210A carrier had FII19911-GG. In FII20210-GA carriers, the OR increased from 3.05 (95% CI: 2.17-4.27) in subjects with FII19911-AA to 3.33 (2.28-4.85) in subjects with FII19911-AG, compared to those with FII20210-GG and FII19911-AA. CONCLUSIONS: The FIIA19911G polymorphism is associated with mildly elevated prothrombin activity and is a risk factor for venous thrombosis.

Adenine↗
PubMed2006

Use of preventive measures for air travel-related venous thrombosis in professionals who attend medical conferences.

BACKGROUND: Lack of guidelines for prevention of air travel-related venous thrombosis may lead to excessive use of potentially dangerous precautions. OBJECTIVES: To assess the use of preventive measures for air travel-related thrombosis in professionals employed in the field of thrombosis and hemostasis and in other fields. METHODS: A survey amongst delegates of the XXth ISTH Congress, the 15th ISDB Congress and the 13th Cochrane Colloquium, which all took place in Australia 2005. RESULTS: Two thousand and eighty-nine questionnaires were completed (response 53%). Overall, 80% of the respondents had used preventive measures. Low-molecular-weight heparin and vitamin K antagonists were mostly used by ISTH delegates (10% vs. 1% at the other conferences). Medical doctors used more pharmacological prophylaxis (31%) than research fellows (11%) and non-clinical scientists (22%). Dutch (64%) and Asian respondents (67%) least used any prevention, whereas Israeli used most (94%). Subjects with risk factors for thrombosis more often used prophylaxis (90%) than those without (77%). In a multivariate analysis, conference, nationality, age, presence of risk factors and profession were determinants of prophylaxis use. CONCLUSION: Major differences in the use of prophylactic measures for air travel-related thrombosis stress the need for studies of interventions and clear guidelines on prevention of air travel-related venous thrombosis.

Aircraft↗
PubMed2006

Activity limitations in the lower extremities in patients with osteoarthritis: the modifying effects of illness perceptions and mental health.

OBJECTIVES: Using the International Classification of Functioning, Disability and Health as framework, we evaluated modifying effects of illness perceptions and mental health on the association between impairments in body structures and functions due to osteoarthritis (OA) and limitation in activities in the lower extremities. METHODS: Self-reported limitation in activities was assessed by the Western Ontario and McMaster Universities OA index (WOMAC) function subscale in 316 patients with knee or hip pain or evidence of OA on knee or hip radiographs. Body structures and functions were evaluated during clinical and radiological assessments. Illness perceptions and mental health were assessed with the revised Illness Perception Questionnaire (IPQ-R) and the mental component summary score of the RAND 36-item Health Survey, respectively. For each patient an expected WOMAC function score was calculated, using an equation based on a multivariate model of the association of body structures and functions with limitation in activities. RESULTS: The median (interquartile) self-reported WOMAC function score was 22.2 (9.6-43.5). Ninety-one patients reported more and 120 patients reported less limitation in activities than expected. Patients with lumbar spine degeneration, physical or exercise therapy and high IPQ-R identity, consequences and chronic timeline scores had an increased risk to report more limitation in activities than the expected range. Low IPQ-R identity, consequences and emotional representation scores and better mental health were associated with reporting less limitation in activities than the expected range. CONCLUSION: Illness perceptions and mental health modify the association between self-reported limitation in activities and calculated limitation in activities based on impairments in body structures and functions due to OA.

Adult↗
PubMed2006

Activation of coagulation system during air travel: a crossover study.

BACKGROUND: There is an increased risk of venous thrombosis after air travel, but the underlying mechanism is unclear. Our aim was to ascertain whether flying leads to a hypercoagulable state. METHODS: We did a crossover study in 71 healthy volunteers (15 men, 56 women), in whom we measured markers of activation of coagulation and fibrinolysis before, during, and after an 8-h flight. The same individuals participated in two control exposure situations (8-h movie marathon and daily life) to separate the effect of air travel on the coagulation system from those of immobilisation and circadian rhythm. To study the effect of risk factors for thrombosis, we included participants with the factor V Leiden mutation (n=11), those who took oral contraceptives (n=15), or both (n=15), as well as 30 individuals with no specific risk factors. FINDINGS: After the flight, median concentrations of thrombin-antithrombin (TAT) complex increased by 30.1% (95% CI 11.2-63.2), but decreased by 2.1% (-11.2 to 14) after the cinema and by 7.9% (-16.2 to -1.2) after the daily life situation. We recorded a high response in TAT levels in 17% (11 of 66) of individuals after air travel (3% [2 of 68] for movie marathon; 1% [1 of 70] in daily life). These findings were most evident in the group with the factor V Leiden mutation who used oral contraceptives. We noted a high response in all variables (prothrombin fragment 1 and 2, TAT, and D-dimer) in four of 63 (6.3%) volunteers after the flight, but in no-one after either of the control situations. INTERPRETATION: Activation of coagulation occurs in some individuals after an 8-h flight, indicating an additional mechanism to immobilisation underlying air travel related thrombosis.

Adult↗
PubMed2006

Membrane sweeping and prevention of post-term pregnancy in low-risk pregnancies: a randomised controlled trial.

OBJECTIVE: To evaluate the effectiveness of membrane sweeping at 41 weeks for the prevention of post-term pregnancy. DESIGN: A multicentre randomised controlled trial. SETTING: Fifty-one primary care midwifery practices in the Netherlands. POPULATION: A total of 742 low-risk pregnant women at 41 weeks of gestation. METHODS: Participants were randomly assigned to serial sweeping of the membranes (every 48 hours until labour commenced up to 42 weeks of gestation) or no intervention. MAIN OUTCOME MEASURES: Post-term pregnancy (>or=42 weeks). Subgroup analyses were performed on nulliparous and parous women. Secondary outcomes included adverse effects. RESULTS: Serial sweeping of the membranes at 41 weeks decreased the risk of post-term pregnancy (87/375 [23%] versus 149/367 [41%]; relative risk [RR] 0.57, 95% CI 0.46-0.71; number needed to treat [NNT] 6 [95% CI 4-9]). Benefits were also seen in both subgroups (nulliparous: 57/198 [29%] versus 89/192 [46%]; RR 0.62 [95% CI 0.48-0.81]; NNT 6 [95% CI 4-12] and parous: 30/177 [17%] versus 60/175 [34%]; RR 0.49 [95% CI 0.34-0.73]; NNT 6 [95% CI 4-6]). Adverse effects were similar in both the groups except for uncomplicated bleeding, which was reported more frequently in the sweeping group. Other obstetric outcomes and indicators of neonatal morbidity were similar in both groups. There were two perinatal deaths in each group. CONCLUSIONS: Membrane sweeping at 41 weeks can substantially reduce the proportion of women with post-term pregnancy.

Adult↗
PubMed2006

High risk of venous thrombosis in patients with pancreatic cancer: a cohort study of 202 patients.

To estimate the risk of venous thrombosis associated with pancreatic malignancies we followed a cohort of patients with pancreatic cancer (n = 202). We calculated incidence rates of venous thrombosis and compared this with population rates using a Standardised Morbidity Ratio (SMR). The effects of location, histology and treatment were assessed by Cox-modelling. The incidence of venous thrombosis was 108.3/1000 patient-years (95% confidence interval (CI) 64.4-163.8), 58.6-fold increased (SMR 58.6, 95% CI 36.9-92.9). Patients with a tumour of the corpus/cauda had a 2-fold increased risk compared with those with a tumour of the caput. Patients treated with chemotherapy had a 4.8-fold increased risk (HR(adj) 4.8, 95% CI 1.1-20.8), whereas radiotherapy did not increase the risk. In a postoperative period of 30 d, patients had a 4.5-fold increased risk of venous thrombosis (HR(adj) 4.5, 95% CI 0.5-40.9). The risk was 1.9-fold increased in the presence of distant metastases (HR(adj) 1.9, 95% CI 0.7-5.1). Anti-thrombotic prophylaxis seems warranted in the first month after surgery, during and after treatment with chemotherapy, and when distant metastases have been diagnosed.

Antimetabolites, Antineoplastic↗
PubMed2006

The effect of genetic variants in the thrombin activatable fibrinolysis inhibitor (TAFI) gene on TAFI-antigen levels, clot lysis time and the risk of venous thrombosis.

Thrombin activatable fibrinolysis inhibitor (TAFI) is an important inhibitor of fibrinolysis. High TAFI antigen levels are associated with an increased risk of deep venous thrombosis (DVT). Because TAFI levels are partly determined genetically, we assessed the association between three TAFI gene polymorphisms (-438 G/A, 505 A/G and 1040 C/T), TAFI antigen levels and clot lysis times and the risk of DVT. Carriers of the 505G allele, which is associated with lower TAFI antigen levels than the 505A allele, showed an increased risk of DVT. This indicates that the relationship between TAFI and venous thrombosis is more complex than previously suggested.

Adolescent↗
PubMed2006

Chronic frequent headache in the general population: prevalence and associated factors.

We studied the prevalence and short-term natural course of chronic frequent headache (CFH) in the general population and identified risk factors. In the Netherlands everyone is registered at a single general practice. We sent questionnaires to all persons (n = 21 440) aged 25-55 years, registered at 16 general practices. We compared the characteristics of 177 participants with CFH (>14 headache days/month for >3 months) with 141 participants with infrequent headache (1-4 days/month) and 526 without headache (<1 day/month). The prevalence of CFH was 3.7% [95% confidence interval (CI) 3.4, 4.0]. In 5 months, 12% showed a clinically relevant decrease to <7 days/month. In both headache groups 70% were women vs. 41% in the group without headache. Compared with the group with infrequent headache, the CFH group had more subjects with low educational level [35% vs. 11%; odds ratio (OR) 4.3, 95% CI 2.3, 7.8], medication overuse (62% vs. 3%; OR 38.4, 95% CI 13.8, 106.9), sleeping problems (44% vs. 8%; OR 8.1, 95% CI 3.6, 18.1), a history of head/neck trauma (36% vs. 14%; OR 4.0, 95% CI 2.2, 7.1), high scores on the General Health Questionnaire (62% vs. 34%; OR 2.7, 95% CI 1.3, 3.6) and more smokers (45% vs. 19%; OR 3.1, 95% CI 1.9, 5.3). We conclude that headache frequency fluctuates. CFH is common and associated with overuse of analgesics, psychopathology, smoking, sleeping problems, a history of head/neck trauma and low educational level. Female sex is a risk factor for headache, not for chronification of headache.

Adult↗
PubMed2006

A prospective study of anticardiolipin antibodies as a risk factor for venous thrombosis in a general population (the HUNT study).

We prospectively examined whether there is an association between elevated anticardiolipin antibody levels and the risk for a future first venous thrombosis (VT) in a general population. We studied this in a large population-based nested case-cohort study of 508 VT cases and 1464 matched control subjects from a cohort of 66,140 participants in the Health Study of Nord-Trøndelag in Norway. Venous thrombosis was validated using standardized criteria for venous thrombosis and pulmonary embolism. Prethrombotic serum anticardiolipin antibodies were measured by an enzyme-linked immunoassay. There was no association between elevated anticardiolipin antibody levels and subsequent venous thrombosis, overall or after stratification by sex, different age groups or idiopathic vs. secondary thrombosis. The overall odds ratio was 1.11 (95% CI: 0.71-1.74) for greater than vs. less than the 95th percentile of anticardiolipin antibody levels. In conclusion, in this general population sample elevated anticardiolipin antibody levels was not a risk factor for subsequent venous thrombosis.

Adult↗
PubMed2006

Incidence of venous thrombosis in a large cohort of 66,329 cancer patients: results of a record linkage study.

BACKGROUND: The incidence of venous thrombosis (VT) for cancer patients is increased compared with patients without cancer, but estimations of the incidence for different types of cancer have rarely been made because of the low incidence of various types of cancer. Large registries offer an opportunity to study the risk of VT in large cohorts of cancer patients, which is essential in decisions on prophylactic anti-coagulant treatment. METHODS: This cohort study estimates the incidence of VT in cancer patients by using record linkage of a Cancer Registry and an Anticoagulation Clinic database in the Netherlands. Cumulative incidences in patients with different types of malignancies were estimated. We calculated relative risks (RRs) in relation to the presence of distant metastases and treatment. RESULTS: Tumors of the bone, ovary, brain, and pancreas are associated with the highest incidence of VT (37.7, 32.6, 32.1, and 22.7/1000/0.5 year). Patients with distant metastases had a 1.9-fold increased risk [RRadj: 1.9; 95% confidence interval (CI): 1.6-2.3]. Chemotherapy leads to a 2.2-fold increased risk (RR(adj): 2.2; 95% CI: 1.8-2.7) and hormonal therapy leads to a 1.6-fold increased risk (RRadj: 1.6; 95% CI: 1.3-2.1) compared with patients not using these treatment modalities. Patients with radiotherapy or surgery did not have an increased risk. CONCLUSIONS: We compared the overall incidences of VT in the first half year in our study to the risk of major bleeding as described in the literature. For patients with distant metastases, for several types of cancer, prophylactic anti-thrombotic treatment could be beneficial.

Aged↗
PubMed2006

Mortality and causes of death in patients with hemophilia, 1992-2001: a prospective cohort study.

BACKGROUND: Clotting factor products have been safe for HIV since 1985, and for hepatitis C since 1992. Few studies have reported on mortality in the total population of hemophilia patients after the period of risk of viral infection transmission. OBJECTIVES: We studied the mortality, causes of death, and life expectancy of hemophilia patients between 1992 and 2001. We compared these findings with those of previous cohorts, together spanning the periods before, during, and after the use of potentially contaminated clotting products. PATIENTS AND METHODS: We performed a prospective cohort study among 967 patients with hemophilia A and B. Death rates, overall and cause-specific, were compared with national mortality figures for males adjusted for age and calendar period as standardized mortality ratio (SMRs). RESULTS: Between 1992 and 2001, 94 (9.7%) patients had died and two patients were lost to follow-up (0.2%). Mortality was 2.3-times higher in hemophilia patients than in the general male population (SMR 2.3 95% confidence interval 1.9-2.8). In patients with severe hemophilia, life expectancy decreased from 63 (1972-1985) to 59 years (1992-2001). Exclusion of virus-related deaths resulted in a life expectancy at birth of 72 years. CONCLUSIONS: AIDS was the main cause of death (26%) and 22% of deaths were because of hepatitis C. In patients not affected by viral infections, there still appeared to be a trend toward a moderately increased mortality compared with the Dutch male population. Thus, mortality of patients with hemophilia is still increased; this is largely because of the consequences of viral infections.

Adolescent↗