Repeated measurements of carotid atherosclerosis and future risk of venous thromboembolism: the Tromsø Study.

Essentials The relationship between atherosclerosis and venous thromboembolism (VTE) is controversial. In total, 10 426 participants recruited from the general population were included. Carotid intima media thickness and total plaque area was not associated with VTE. There was no association between plaque initiation or plaque progression and subsequent VTE. SUMMARY: Background Whether a relationship between atherosclerosis and subsequent venous thromboembolism (VTE) exists is controversial. Objective To investigate the association between carotid atherosclerosis and VTE by using repeated measurements of intima media thickness (IMT) and total plaque area (TPA) in participants recruited from the general population. Methods Participants were recruited from the fourth (1994-1995), fifth (2001-2002) and sixth (2007-2008) surveys of the Tromsø Study. In total, 10 426 participants attended, for whom measurements of carotid IMT and TPA and potential confounders were updated at each available survey. Time-varying Cox regression models were used to calculate hazard ratios (HRs) of VTE across various levels of IMT and TPA adjusted for age, sex, and body mass index. Results There were 368 incident VTE events during a median follow-up of 10.8 years. Participants with increasing IMT were, on average, older and had a less favorable cardiovascular risk profile. There was no association between tertiles of increasing TPA and the risk of VTE in the time-varying model, and increasing IMT was not associated with an increased risk of VTE (HR 0.96, 95% confidence interval [CI] 0.86-1.07). Neither plaque formation nor plaque progression was associated with the risk of VTE (respectively: HR 1.00, 95% CI 0.98-1.02; and HR 0.96, 95% CI 0.84-1.11). Conclusion Carotid IMT and TPA were not associated with an increased risk of VTE in time-varying analyses. Furthermore, there was no association between plaque initiation or plaque progression and subsequent VTE.

Impact of incident myocardial infarction on the risk of venous thromboembolism: the Tromsø Study.

UNLABELLED: Essentials Registry-based studies indicate a link between arterial- and venous thromboembolism (VTE). We studied this association in a cohort with confounder information and validated outcomes. Myocardial infarction (MI) was associated with a 4.8-fold increased short-term risk of VTE. MI was associated with a transient increased risk of VTE, and pulmonary embolism in particular. SUMMARY: Background Recent studies have demonstrated an association between venous thromboembolism (VTE) and arterial thrombotic diseases. Objectives To study the association between incident myocardial infarction (MI) and VTE in a prospective population-based cohort. Methods Study participants (n = 29 506) were recruited from three surveys of the Tromsø Study (conducted in 1994-1995, 2001-2002, and 2007-2008) and followed up to 2010. All incident MI and VTE events during follow-up were recorded. Cox regression models with age as the time scale and MI as a time-dependent variable were used to calculate hazard ratios (HRs) of VTE adjusted for sex, body mass index, blood pressure, diabetes mellitus, HDL cholesterol, smoking, physical activity, and education level. Results During a median follow-up of 15.7 years, 1853 participants experienced an MI and 699 experienced a VTE. MI was associated with a 51% increased risk of VTE (HR 1.51; 95% confidence interval [CI] 1.08-2.10) and a 72% increased risk of pulmonary embolism (PE) (HR 1.72; 95% CI 1.07-2.75), but not significantly associated with the risk of deep vein thrombosis (DVT) (HR 1.36; 95% CI 0.86-2.15). The highest risk estimates for PE were observed during the first 6 months after the MI (HR 8.49; 95% CI 4.00-18.77). MI explained 6.2% of the PEs in the population (population attributable risk) and 78.5% of the PE risk in MI patients (attributable risk). Conclusions Our findings indicate that MI is associated with a transient increased VTE risk, independently of traditional atherosclerotic risk factors. The risk estimates were particularly high for PE.

Atrial fibrillation and future risk of venous thromboembolism:the Tromsø study.

AIMS: Whether atrial fibrillation is related to risk of venous thromboembolism (VTE) has not been extensively studied. Therefore, we investigated the association between atrial fibrillation and future risk of VTE in a population-based cohort. METHODS: In total, 29,975 subjects were recruited from three surveys of the Tromsø study and followed from enrollment (1994-1995, 2001-2002 and 2007-2008) up to 2010. Incident events of atrial fibrillation and VTE during follow-up were recorded. Information on potential confounders was obtained at baseline. Cox-regression models with atrial fibrillation as time-dependent variable were used to calculate hazard ratios (HRs) for VTE with 95% confidence intervals (CIs). RESULTS: During 16 years of median follow-up, 1604 subjects were diagnosed with atrial fibrillation and 614 with incident VTE. The risk of VTE was substantially increased during the first 6 months after diagnosis of atrial fibrillation (HR, 8.44; 95% CI, 5.61-12.69), and remained increased throughout the study period (HR, 1.43; 95% CI, 1.43-1.99) compared with those without atrial fibrillation. Atrial fibrillation displayed higher risk estimates for pulmonary embolism (HR, 11.84; 95% CI, 6.80-20.63) than for deep vein thrombosis (HR, 6.20; 95% CI, 3.37-11.39) during the first 6 months, and was still associated with pulmonary embolism (HR, 1.96; 95% CI, 1.24-3.10) but not with deep vein thrombosis (HR, 1.08; 95% CI, 0.66-1.75) more than 6 months after diagnosis. CONCLUSION: Atrial fibrillation was associated with increased risk of VTE, and pulmonary embolism in particular. Our findings support the concept that isolated pulmonary embolism may originate from right atrial thrombi due to atrial fibrillation.

Small crystals and small coils in variable-temperature single-crystal NMR.

Time savings by a factor of between 20 and 30 in the acquisition of multinuclear single-crystal (SC) NMR spectra have been obtained for submillimeter-size (0.01 to 0.03 mm(3)) single crystals when compared to recent results for (31)P and (87)Rb SC NMR. This gain in sensitivity is achieved by optimizing the filling factor using the smallest possible rf coil (2.0 mm inner diameter) for the specific SC probe design. Furthermore, this small coil is particularly useful for variable-temperature SC NMR studies. A probe design for such studies is presented and demonstrated experimentally.

Improved hardware and software for single-crystal NMR spectroscopy.

Design of state-of-the-art instrumentation and software for acquisition and analysis of single-crystal NMR spectra is presented. The design involves highly accurate rotation of a goniometer, and the acquisition of all the spectra for each rotation axis is automatically controlled by the host computer of the spectrometer using a homebuilt interface between the computer and the single-crystal probe. Moreover, a software package (ASICS) for fast and routine assignment/analysis of complex single-crystal spectra has been developed. Employing this equipment, the acquisition and complete analysis of single-crystal NMR spectra may be performed in about the same time as required for powder methods (spinning or static). The hardware and software are compared to recent alternative approaches within single-crystal NMR. Finally, it has been observed that single-crystal NMR techniques may provide the desired data for samples where powder methods fail.

A 4-mm probe for (13)C CP/MAS NMR of solids at 21.15 T.

The design of a broadband 4-mm magic-angle spinning (MAS) X-(1)H/(19)F double resonance probe for cross-polarization (CP)/MAS NMR studies at 21.15 T ((1)H at 900 MHz) is described. The high-frequency (1)H/(19)F channel employs a new and efficient transmission line tuning design. The first (13)C CP/MAS NMR spectra recorded at 21.15 T have been obtained with this probe and exhibit the best S/N per milligram sample of hexamethylbenzene achieved so far for a 4-mm rotor.

[Withdrawal of high estrogen containing oral contraceptives and the demand for medical service]. / Hljlstrogene p-pillers tilbagetraekning og eftersplrgsel på laegelig service

PIP: The results of a survey are presented conerning the effectiveness of mass media publicity with the public. After oral contraceptives containing high levels of estrogen were prohibited in Denmark, a telephone survey of 23 doctors was taken to determine the fluctuation in demand for medical information from patients, and the reason for the fluctuation. The reasons were divided into 3 groups: 1) resulting from mass media publicity, 2) resulting from the unavailability of a particular contraceptive, and 3) other. 3 surveys were conducted of the frequency of demand for information on the high estrogen contraceptives, 1 for each of the 2 weeks after the prohibition and withdrawal of the contraceptives took place, and 1 1 month after the prohibition. 2-3% of the inquiries received by the doctors concerned the prohibited contraceptives, and half of these could be attributed directly to the mass media publicity. The number of requests in categories 1 and 2 dropped sharply in the 2nd and 3rd surveys, indicating that the effect of the mass meida publicity and the withdrawal of the contraceptive from the market had only a very immediate effect. It is also shown that the telephone can be used successfully to ascertain the effects of a short-term social phenomenon on the public.^ieng