Search

Background: US and European guidelines diverge on whether to vaccinate adults who are not at high risk for cardiovascular events against influenza. Here, we investigated the associations between influenza vaccination and risk for acute myocardial infarction, stroke and pulmonary embolism during the 2009 pandemic in Norway, when vaccination was recommended to all adults.Methods: Using national registers, we studied all vaccinated Norwegian individuals who suffered AMI, stroke, or pulmonary embolism from May 1, 2009 through September 30, 2010. We defined higher-risk individuals as those using anti-diabetic, anti-obesity, anti-thrombotic, pulmonary or cardiovascular medications (i.e. individuals to whom vaccination was routinely recommended); all other individuals were regarded as having lower-risk. We estimated incidence rate ratios with 95% CI using conditional Poisson regression in the pre-defined risk periods up to 180 days following vaccination compared to an unexposed time-period, with adjustment for season or daily temperature.Results: Overall, we observed lower risk for cardiovascular events following influenza vaccination. When stratified by baseline risk, we observed lower risk across all three outcomes in association with vaccination among higher-risk individuals. In this subgroup, relative risks were 0.72 (0.59-0.88) for AMI, 0.77 (0.59-0.99) for stroke, and 0.73 (0.45-1.19) for pulmonary embolism in the period 1-14 days following vaccination when compared to the background period. These associations remained essentially the same up to 180 days after vaccination. In contrast, the corresponding relative risks among subjects not using medications were 4.19 (2.69-6.52), 1.73 (0.91-3.31) and 2.35 (0.78-7.06).Conclusion: In this nationwide study, influenza vaccination was associated with overall cardiovascular benefit. This benefit was concentrated among those at higher cardiovascular risk as defined by medication use. In contrast, our results demonstrate no comparable inverse association with thrombosis-related cardiovascular events following vaccination among those free of cardiovascular medications at baseline. These results may inform the risk-benefit balance for universal influenza vaccination. [ABSTRACT FROM AUTHOR]

Aims: Health registers are used for administrative purposes, disease surveillance, quality assessment, and research. The value of the registers is entirely dependent on the quality of their data. The aim of this study was to investigate and compare the completeness and correctness of the acute myocardial infarction (AMI) diagnosis in the Norwegian Myocardial Infarction Register and in the Norwegian Patient Register. Methods : All Norwegian patients admitted directly to St Olavs hospital, Trondheim University Hospital, Trondheim University Hospital from 1 July to 31 December 2012 and who had plasma levels of cardiac troponin T measured during their hospitalization (n =4835 unique individuals, n =5882 hospitalizations) were identified in the hospital biochemical database. A gold standard for AMI was established by evaluation of maximum troponin T levels and by review of the information in the medical records. Cases of AMI in the registers were classified as true positive, false positive, true negative, and false negative according to the gold standard. We calculated sensitivity, positive predictive value (PPV), specificity, and negative predictive value (NPV). Results : The Norwegian Myocardial Infarction Register had a sensitivity of 86.0% (95% confidence interval (CI) 82.8–89.3%), PPV of 97.9% (96.4–99.3%), and specificity of 99.9% and NPV of 98.9% (98.6-99.2%) (99.8–100%). The corresponding figures for the Norwegian Patient Register were 85.8% (95% CI 82.5–89.1%), 95.1% (92.9–97.2%), and 99.7% (99.5–99.8%) and 98.9% (98.6-99.2%), respectively. Both registers had a sensitivity higher than 95% when compared to hospital discharge diagnoses. The results were similar for men and women and for cases below and above 80 years of age. Conclusions : The Norwegian Myocardial Infarction Register and the Norwegian Patient Register are adequately complete and correct for administrative purposes, disease surveillance, quality assessment, and research. [ABSTRACT FROM AUTHOR]

Aims: Health registers are essential sources of data used in a wide range of stroke research, including epidemiological, clinical and healthcare studies. Regardless of the type of register, the data must be of high quality to be useful. In this study, we investigated and compared the correctness and completeness of the Norwegian Patient Register (an administrative health register) and the Norwegian Stroke Register (a medical quality register for acute stroke). Methods: We reviewed the medical records for 5192 admissions to hospital in 2012 and defined cases of stroke in the two registers as true positive, false positive, true negative or false negative. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value with 95% confidence intervals assuming a normal approximation of the binomial distribution. Results: The Norwegian Stroke Register was highly correct and relatively complete (sensitivity 88.1%, specificity 100% and PPV 98.6%). The Norwegian Patient Register was more complete, but less correct, when we included both the main and secondary diagnoses of stroke (sensitivity 96.8%, specificity 99.6% and PPV 79.7%); restricting the analyses to the main diagnoses of stroke resulted in less complete and more correct registrations (sensitivity 86.1%, specificity 99.9% and PPV 93.5%). Conclusions: The Norwegian Stroke Register and the Norwegian Patient Register are adequately complete and correct to serve as valuable sources of data for epidemiological, clinical and healthcare studies, as well as for administrative purposes. [ABSTRACT FROM AUTHOR]

Background: Seasonal changes in cardiovascular disease (CVD) risk factors may be due to exposure to seasonal environmental variables like temperature and acute infections or seasonal behavioural patterns in physical activity and diet. Investigating the seasonal pattern of risk factors should help determine the causes of the seasonal pattern in CVD. Few studies have investigated the seasonal variation in risk factors using repeated measurements from the same individual, which is important as individual and population seasonal patterns may differ. Methods: The authors investigated the seasonal pattern in systolic and diastolic blood pressure, heart rate, body weight, total cholesterol, triglycerides, high-density lipoprotein cholesterol, C reactive protein and fibrinogen. Measurements came from 38 037 participants in the population-based cohort, the Tromsø Study, examined up to eight times from 1979 to 2008. Individual and population seasonal patterns were estimated using a cosinor in a mixed model. Results: All risk factors had a highly statistically significant seasonal pattern with a peak time in winter, except for triglycerides (peak in autumn), C reactive protein and fibrinogen (peak in spring). The sizes of the seasonal variations were clinically modest. Conclusions: Although the authors found highly statistically significant individual seasonal patterns for all risk factors, the sizes of the changes were modest, probably because this subarctic population is well adapted to a harsh climate. Better protection against seasonal risk factors like cold weather could help reduce the winter excess in CVD observed in milder climates. [ABSTRACT FROM AUTHOR]

Background: Meteorological factors like cold temperatures and heavy snowfalls have been reported to increase myocardial infarction (MI) incidence, but there are inconsistencies in results as well as in methodology in previous studies. The objective of this study was to examine the impact of meteorological factors on incidence of MI in a population-based study in Tromsø,Norway (698399N).Methods: A total of 32 110 participants from the Tromsø Study enrolled between 1974 and 2001 were followed throughout 2004. Each incident case of MI was validated by the review of medical records and death certificates.Meteorological data from the Tromsø Weather Station were collected from the Norwegian MeteorologicalInstitute database. Poisson regression models were applied to analyse the impact of meteorological factors on MI incidence. All analyses were stratified by sex and age.Results: A total of 1882 first-ever MIs were registered. The main finding was an increase in MI incidence among persons older than 65 years with decreasing temperatures (p=0.016) and increasing snowfall (p=0.030). When comparing the lowe and upper limits of the temperature distribution (−10°C with 20°C), the MI risk increased by 47% (RR=1.47, 95% CI 1.09 to 2.13). Comparing limits of the snowfall distribution (10 with 0 mm), the MI risk increased by 44% (rr=1.44, 95% CI 1.07 to 1.94).Conclusions: In this subarctic population, MI incidence was little affected by the weather, probably due to behavioural protection. However, cold weather and heavy snowfall may be associated with increased risk of MI among older people. [ABSTRACT FROM AUTHOR]

Background: Few studies have used individual person data to study whether contemporary trends in the incidence of coronary heart disease are associated with changes in modifiable coronary risk factors.Methods and Results: We identified 29 582 healthy men and women ≥25 years of age who participated in 3 population surveys conducted between 1994 and 2008 in Tromsø, Norway. Age- and sex-adjusted incidence rates were calculated for coronary heart disease overall, out-of-hospital sudden death, and hospitalized ST-segment-elevation and non-ST-segment-elevation myocardial infarction. We measured coronary risk factors at each survey and estimated the relationship between changes in risk factors and changes in incidence trends. A total of 1845 participants had an incident acute coronary heart disease event during 375 064 person-years of follow-up from 1994 to 2010. The age- and sex-adjusted incidence of total coronary heart disease decreased by 3% (95% confidence interval, 2.0-4.0; P<0.001) each year. This decline was driven by decreases in out-of-hospital sudden death and hospitalized ST-segment-elevation myocardial infarction. Changes in coronary risk factors accounted for 66% (95% confidence interval, 48-97; P<0.001) of the decline in total coronary heart disease. Favorable changes in cholesterol contributed 32% to the decline, whereas blood pressure, smoking, and physical activity each contributed 14%, 13%, and 9%, respectively.Conclusions: We observed a substantial decline in the incidence of coronary heart disease that was driven by reductions in out-of-hospital sudden death and hospitalized ST-segment-elevation myocardial infarction. Changes in modifiable coronary risk factors accounted for 66% of the decline in coronary heart disease events. [ABSTRACT FROM AUTHOR]

Background: Cardiovascular disease and cancer have been described as possible risk factors for COVID-19 mortality. The purpose of this study was to investigate whether a history of cardiovascular disease or cancer affects the risk of dying after a COVID-19 diagnosis in Norway., Material and Method: Data were compiled from the Norwegian Surveillance System for Communicable Diseases, the Norwegian Cardiovascular Disease Registry and the Cancer Registry of Norway. Univariable and multivariable regression models were used to calculate both relative and absolute risk., Results: In the first half of 2020, 8 809 people tested positive for SARS-CoV-2 and 260 COVID-19-associated deaths were registered. Increasing age, male sex (relative risk (RR): 1.5; confidence interval (CI): 1.2-2.0), prior stroke (RR: 1.5; CI: 1.0-2.1) and cancer with distant metastasis at the time of diagnosis (RR: 3.0; CI: 1.1-8.2) were independent risk factors for death after a diagnosis of COVID-19. After adjusting for age and sex, myocardial infarction, atrial fibrillation, heart failure, hypertension, and non-metastatic cancer were no longer statistically significant risk factors for death., Interpretation: The leading risk factor for death among individuals who tested positive for SARS-CoV-2 was age. Male sex, and a previous diagnosis of stroke or cancer with distant metastasis were also associated with an increased risk of death after a COVID-19 diagnosis.

Background: ST-elevation myocardial infarction is treated with reperfusion, either in the form of primary percutaneous coronary intervention (PCI) or thrombolytic therapy. The choice of treatment depends on transport time to the nearest PCI centre. Norway's geography means that thrombolytic therapy will be appropriate for many patients. Irrespective of treatment choice, it is important to avoid delays. We wished to compare the outcomes of primary PCI and thrombolytic therapy in our healthcare region and to examine whether reperfusion therapy was administered within the recommended time window., Material and Method: Using registry data and patient medical records, we compared the outcomes of primary PCI and thrombolytic therapy in cases of ST-elevation myocardial infarction in the Central Norway Regional Health Authority in the period 2015-16. The outcomes analysed were 30-day mortality, ejection fraction measured by echocardiography during the hospital stay, incidence of bleeding complications, and time from diagnosis to start of treatment., Results: The study population comprised 648 patients with ST-elevation myocardial infarction. Of these, 382 were treated with primary PCI and 266 received thrombolytic therapy. The 30-day mortality was 5.5 % in the primary PCI group and 5.6 % in the thrombolysis group (p = 1.0). There were no significant differences in ejection fraction and no cases of serious bleeding. In 45 % of the total population, reperfusion therapy was started later than recommended in guidelines., Interpretation: There was no statistically significant difference in mortality or ejection fraction when comparing primary PCI and thrombolytic therapy in an unselected population with ST-elevation myocardial infarction. Many patients experienced delayed start of treatment . It is important to take action to reduce delays at all stages of the therapeutic chain. Thrombolytic therapy should be considered when it is unclear whether transport time to a PCI centre will exceed that recommended in guidelines.

Background: Identification of individuals with high risk for first-ever myocardial infarction (MI) can be improved. The objectives of the study were to survey multiple protein biomarkers for association with the 10-year risk of incident MI and identify a clinically significant risk model that adds information to current common risk models., Methods and Results: We used an immunoassay platform that uses a sensitive, sample-efficient molecular counting technology to measure 51 proteins in samples from the fourth survey (1994) in the Tromsø Study, a longitudinal study of men and women in Tromsø, Norway. A case control design was used with 419 first-ever MI cases (169 females/250 males) and 398 controls (244 females/154 males). Of the proteins measured, 17 were predictors of MI when considered individually after adjustment for traditional risk factors either in men, women, or both. The 6 biomarkers adjusted for traditional risk factors that were selected in a multivariable model (odds ratios [OR] per standard deviation) using a stepwise procedure were apolipoprotein B/apolipoprotein A1 ratio (1.40), kallikrein (0.73), lipoprotein a (1.29), matrix metalloproteinase 9 (1.30), the interaction term IP-10/CXCL10×women (0.69), and the interaction term thrombospondin 4×men (1.38). The composite risk of these biomarkers added significantly to the traditional risk factor model with a net reclassification improvement of 14% (P=0.0002), whereas the receiver operating characteristic area increased from 0.757 to 0.791, P=0.0004., Conclusions: Novel protein biomarker models improve identification of 10-year MI risk above and beyond traditional risk factors with 14% better allocation to either high or low risk group., (© 2015 American Heart Association, Inc.)

Background: Although the mortality of coronary heart disease (CHD) has declined in Western countries during the last decades, studies have suggested that the prevention and treatment of CHD may not have been as effective in women as in men. We examined gender- and age-specific trends in incidence, case fatality and the severity of first myocardial infarction (MI) in a large Norwegian population-based study., Design: Prospective population-based cohort study., Methods: A total of 31,323 participants enrolled between 1974 and 2001 were followed throughout 2004 for a total of 400,572 person-years. Suspected coronary events were adjudicated by a review of hospital records and death certificates. A total of 1669 events fulfilled standardized criteria of first-ever fatal or non-fatal MI., Results: In the age group 35-79 years, the age-adjusted incidence of MI declined significantly in men, whereas an increase was observed in women. For men and women ≥ 80 years the incidence rates remained unchanged. The severity of MI and the 28-day and 1-year case fatality rates declined significantly and similarly in men and women., Conclusion: Trends in MI incidence differed by sex and age; in the age group 35-79 years a marked decrease was observed among men but an increase was observed among women, while no change was observed among older patients. MI severity and case fatality were clearly reduced for both sexes. These data suggest that the burden of CHD is shifting from middle-aged men toward middle-aged women and elderly patients.

Background: A seasonal pattern with higher winter morbidity and mortality has been reported for acute myocardial infarction (MI). The magnitude of the difference between peak and nadir season has been associated with latitude, but results are inconsistent. Studies of seasonal variation of MI in population-based cohorts, based on adjudicated MI cases,are few.We investigated the monthly and seasonal variation in first-ever nonfatal and fatal MI in the population of Tromsø in northern Norway, a region with a harsh climate and extreme seasonal variation in daylight exposure., Design: Prospective population-based cohort study., Methods: A total of 37 392 participants from the Tromsø Study enrolled between 1974 and 2001 were followed throughout 2004. Each incident case of MI was validated by the review of medical records and death certificates. MI incidence rates for months and seasons were analyzed for seasonal patterns with Poisson regression and the Cosinor procedure. All analyses were stratified by sex, age and smoking status., Results: A total of 1893 first-ever MIs were registered, of which 592 were fatal. There was an 11 % (95% confidence interval: 1.00-1.23, P=0.04) increased risk of incident MI during winter (November-January) compared with non-winter seasons, with no statistically significant interaction with sex, age, smoking or calendar year. Other seasonal modelling gave similar but not statistically significant results., Conclusion: We found a small increase in risk of incident MI during the darkest winter months. Populations living in sub-Arctic areas may be adapted to face climate exposure during winter through behavioural protection.

Context: Recently, concern has been raised about the safety of folic acid, particularly in relation to cancer risk., Objective: To evaluate effects of treatment with B vitamins on cancer outcomes and all-cause mortality in 2 randomized controlled trials., Design, Setting, and Participants: Combined analysis and extended follow-up of participants from 2 randomized, double-blind, placebo-controlled clinical trials (Norwegian Vitamin Trial and Western Norway B Vitamin Intervention Trial). A total of 6837 patients with ischemic heart disease were treated with B vitamins or placebo between 1998 and 2005, and were followed up through December 31, 2007., Interventions: Oral treatment with folic acid (0.8 mg/d) plus vitamin B(12) (0.4 mg/d) and vitamin B(6) (40 mg/d) (n = 1708); folic acid (0.8 mg/d) plus vitamin B(12) (0.4 mg/d) (n = 1703); vitamin B(6) alone (40 mg/d) (n = 1705); or placebo (n = 1721)., Main Outcome Measures: Cancer incidence, cancer mortality, and all-cause mortality., Results: During study treatment, median serum folate concentration increased more than 6-fold among participants given folic acid. After a median 39 months of treatment and an additional 38 months of posttrial observational follow-up, 341 participants (10.0%) who received folic acid plus vitamin B(12) vs 288 participants (8.4%) who did not receive such treatment were diagnosed with cancer (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.03-1.41; P = .02). A total of 136 (4.0%) who received folic acid plus vitamin B(12) vs 100 (2.9%) who did not receive such treatment died from cancer (HR, 1.38; 95% CI, 1.07-1.79; P = .01). A total of 548 patients (16.1%) who received folic acid plus vitamin B(12) vs 473 (13.8%) who did not receive such treatment died from any cause (HR, 1.18; 95% CI, 1.04-1.33; P = .01). Results were mainly driven by increased lung cancer incidence in participants who received folic acid plus vitamin B(12). Vitamin B(6) treatment was not associated with any significant effects., Conclusion: Treatment with folic acid plus vitamin B(12) was associated with increased cancer outcomes and all-cause mortality in patients with ischemic heart disease in Norway, where there is no folic acid fortification of foods., Trial Registration: clinicaltrials.gov Identifier: NCT00671346.