Roderik A. Kraaijenhagen

Travel and risk of venous thrombosis.

Summary In 1998 the term economy class syndrome was coined to describe the association between travel and thrombosis. A fair risk estimate, however, has not been done. We report the results of a prospective study, in which we kept the effect of bias to a minimum. We compared travel history in 788 patients with venous thrombosis with that of controls with similar symptoms but in whom the disease had been excluded. For air travel alone, the odds ratio was 1·0 (95% CI 0·3–3·0); also, no association was recorded for other methods of transportation. We have shown that, there is no increased risk of deep vein thrombosis among travellers.

Systematic Review of Guidelines on Cardiovascular Risk Assessment: Which Recommendations Should Clinicians Follow for a Cardiovascular Health Check?

OBJECTIVE To appraise guidelines on cardiovascular risk assessment to guide selection of screening interventions for a health check. DATA SOURCES Guidelines in the English language published between January 1, 2003, and May 2, 2009, were retrieved using MEDLINE and CINAHL. This was supplemented by searching the National Guideline Clearinghouse, National Library for Health, Canadian Medical Association Infobase, and G-I-N International Guideline Library. STUDY SELECTION We included guidelines developed on behalf of professional organizations from Western countries, containing recommendations on cardiovascular risk assessment for the apparently healthy population. Titles and abstracts were assessed by 2 independent reviewers. Of 1984 titles identified, 27 guidelines met our criteria. DATA EXTRACTION Rigor of guideline development was assessed by 2 independent reviewers. One reviewer extracted information on conflicts of interest and recommendations. RESULTS Sixteen of 27 guidelines reported conflicts of interest and 17 showed considerable rigor. These included recommendations on assessment of total cardiovascular risk (7 guidelines), dyslipidemia (2), hypertension (2), and dysglycemia (7). Recommendations on total cardiovascular risk and dyslipidemia included prediction models integrating multiple risk factors, whereas remaining recommendations were focused on single risk factors. No consensus was found on recommended target populations, treatment thresholds, and screening tests. CONCLUSIONS Differences among the guidelines imply important variation in allocation of preventive interventions. To make informed decisions, physicians should use only the recommendations from rigorously developed guidelines.

Safety of Treatment with Oral Anticoagulants in the Elderly A Systematic Review

Oral anticoagulants have documented efficacy for many indications and are widely used in elderly patients. However, there is concern about whether this treatment induces an excess of major bleeding in elderly patients. In this system atic review, the incidence of oral anticoagulant-related major bleeding among elderly patients was determined.A total of 58 reports were identified that evaluated an oral anticoagulant, included patients with a mean age of at least 60 years, and provided data on the occurrence of major bleeding or provided separate data on the occurrence of major bleeding in elderly versus younger patients.In 50 studies no age differentiation was given. Although the incidence of bleeding complications varied, a trend towards increased bleeding with increas ing age was shown in patients with major orthopaedic surgery and cardiac dis eases. In the 8 articles that provided separate data on the occurrence of bleeding in different age categories, there was a clear tendency towards a 2-fold increase in bleeding in elderly patients.These findings emphasise the need for caution in the use of oral anticoagulants in elderly patients. However, the decision to start oral anticoagulant treatment should be based on an evaluation of the risk/benefit balance on a careful patient-by-patient basis. In general, if oral anticoagulant treatment is started, the lowest possible effective International Normalised Ratios (INR) should be selected and regular monitoring should be done to avoid over-anticoagulation.

Combining risk factors with faecal immunochemical test outcome for selecting CRC screenees for colonoscopy

Objective Faecal immunochemical testing (FIT) is increasingly used in colorectal cancer (CRC) screening but has a less than perfect sensitivity. Combining risk stratification, based on established risk factors for advanced neoplasia, with the FIT result for allocating screenees to colonoscopy could increase the sensitivity and diagnostic yield of FIT-based screening. We explored the use of a risk prediction model in CRC screening. Design We collected data in the colonoscopy arm of the Colonoscopy or Colonography for Screening study, a multicentre screening trial. For this study 6600 randomly selected, asymptomatic men and women between 50 years and 75 years of age were invited to undergo colonoscopy. Screening participants were asked for one sample FIT (OC-sensor) and to complete a risk questionnaire prior to colonoscopy. Based on the questionnaire data and the FIT results, we developed a multivariable risk model with the following factors: total calcium intake, family history, age and FIT result. We evaluated goodness-of-fit, calibration and discrimination, and compared it with a model based on primary screening with FIT only. Results Of the 1426 screening participants, 1112 (78%) completed the questionnaire and FIT. Of these, 101 (9.1%) had advanced neoplasia. The risk based model significantly increased the goodness-of-fit compared with a model based on FIT only (p<0.001). Discrimination improved significantly with the risk-based model (area under the receiver operating characteristic (ROC) curve: from 0.69 to 0.76, (p=0.02)). Calibration was good (Hosmer-Lemeshow test; p=0.94). By offering colonoscopy to the 102 patients at highest risk, rather than to the 102 cases with a FIT result >50 ng/mL, 5 more cases of advanced neoplasia would be detected (net reclassification improvement 0.054, p=0.073). Conclusions Adding risk based stratification increases the accuracy FIT-based CRC screening and could be used in preselection for colonoscopy in CRC screening programmes.

Cardiac rehabilitation and survival in a large representative community cohort of Dutch patients.

AIMS To assess the effects of multi-disciplinary cardiac rehabilitation (CR) on survival in the full population of patients with an acute coronary syndrome (ACS) and patients that underwent coronary revascularization and/or heart valve surgery. METHODS AND RESULTS Population-based cohort study in the Netherlands using insurance claims database covering ∼22% of the Dutch population (3.3 million persons). All patients with an ACS with or without ST elevation, and patients who underwent coronary revascularization and/or valve surgery in the period 2007-10 were included. Patients were categorized as having received CR when an insurance claim for CR was made within the first 180 days after the cardiac event or revascularization. The primary outcome was survival time from the inclusion date, limited to a total follow-up period of 4 years, with a minimum of 180 days. Propensity score weighting was used to control for confounding by indication. Among 35 919 patients with an ACS and/or coronary revascularization or valve surgery, 11 014 (30.7%) received CR. After propensity score weighting, the adjusted hazard ratio (HR) associated with receiving CR was 0.65 (95% CI 0.56-0.77). The largest benefit was observed for patients who underwent coronary artery bypass grafting (CABG) and/or valve surgery (HR = 0.55, 95% CI 0.42-0.74). CONCLUSION In a large and representative community cohort of Dutch patients with an ACS and/or intervention, CR was associated with a substantial survival benefit up to 4 years. This survival benefit was present regardless of age, type of diagnosis, and type of intervention.

Diagnostic strategies for the management of patients with clinically suspected deep-vein thrombosis

Given the perceived inaccuracy of clinical diagnosis, patients with suspected deep vein thrombosis should have objective testing. Due to the inherent limitations of the reference method (contrast venography), several diagnostic strategies using noninvasive tests have been developed. These strategies share two components: anticoagulant therapy is initiated only in patients with an abnormal test, and serial testing is performed in patients with an initial normal test result. A thorough search of the literature was done to identify all studies that have evaluated the feasibility, accuracy, and safety of diagnostic strategies in patients with clinically suspected deep vein thrombosis. The safety of the individual diagnostic strategies was expressed as the total rate of venous thromboembolic complications. Feasibility was expressed as the mean number per patient of extra visits to the hospital and additional tests per patient. A total of 12 reports qualified for the analysis. The diagnostic strategies included venography, serial impedance plethysmography with and without 125I-fibrinogen leg scanning, serial ultrasound imaging with and without D-dimer determination, serial ultrasound imaging in combination with a clinical score, and a diagnostic work-up including ultrasound imaging, impedance plethysmography, D-dimer determination, and a clinical score. The observed venous thromboembolic complication rates varied between 0.4% and 2.6%. Feasibility was lowest for the initial serial impedance plethysmography strategy (mean number of extra hospital visits and mean number of additional tests, 4.1 per patient). Strategies that used the D-dimer test complimentary to ultrasound imaging or the combination of impedance plethysmography and a clinical score performed best (mean number of extra hospital visits and mean number of additional tests, approximately 0.3 per patient). All available noninvasive diagnostic strategies are as accurate and safe as contrast venography for the treatment of patients with clinically suspected deep vein thrombosis. The recently introduced simplified diagnostic strategies allow treatment decisions to be made on the day of presentation in most patients.

Cardiac rehabilitation uptake and its determinants in the Netherlands.

Aims: Despite its documented efficacy, cardiac rehabilitation (CR) is still not well implemented in current clinical practice. The aims of the present study were to assess CR uptake rates in the Netherlands, and to identify factors that determine uptake. Methods: The cohort consisted of persons insured with Achmea Zorg en Gezondheid. Based on insurance claims, we assessed CR uptake rates in 2007 among patients with an acute coronary syndrome (ACS), patients who underwent coronary artery bypass graft surgery, percutaneous coronary intervention (PCI), or valvular surgery, and patients with stable angina pectoris (AP) or chronic heart failure (CHF). In addition, we evaluated the relation between CR uptake and demographic, disease-related, and geographic factors for patients with an ACS and/or intervention. Results: The CR uptake rate in the entire cohort (n = 35,752) was 11.7%. The uptake rate among patients with an ACS and/or intervention (n = 12,201) was 28.5%, as opposed to 3.0% among patients with CHF or stable AP (n = 23,551). The highest CR uptake rate was observed in patients who underwent cardiac surgery (58.7%). Factors associated with lower CR uptake were female gender, older age, elective PCI (as compared to acute PCI), unstable AP (as compared to myocardial infarction), larger distance to the nearest provider of CR, and comorbidity. Conclusion: A minority of Dutch patients eligible for CR received CR. Future implementation strategies should focus on females, elderly patients, patients with unstable AP and/or after elective PCI, patients with long travelling distances to the nearest CR provider, and patients with comorbidities.

Effects on cardiovascular disease risk of a web-based health risk assessment with tailored health advice: A follow-up study

Introduction: A large proportion of the cardiovascular disease (CVD) burden can potentially be prevented by primary prevention programs addressing major causal risk factors. A Web-based health risk assessment (HRA) with tailored feedback for individual health promotion is a promising strategy. We evaluated the effect on CVD risk of such a program among employees of a Dutch worksite. Methods: We conducted a prospective follow-up study among 368 employees who voluntarily participated in a Web-based HRA program at a single Dutch worksite in 2008. The program included a multicomponent HRA through a Web-based electronic questionnaire, biometrics, and laboratory evaluation. The results were combined with health behavior change theory to generate tailored motivational and educational health advice. On request, a health counseling session with the program physician was available. Follow-up data on CVD risk were collected 1 year after initial participation. The primary outcome was a change in Framingham CVD risk at 6 months relative to baseline. We checked for a possible background effect of an increased health consciousness as a consequence of program introduction at the worksite by comparing baseline measurements of early program participants with baseline measurements of participants who completed the program 6 months later. Results: A total of 176 employees completed follow-up measurements after a mean of 7 months. There was a graded relation between CVD risk changes and baseline risk, with a relative reduction of 17.9% (P = 0.001) in the high-risk category (baseline CVD risk ≥20%). Changes were not explained by additional health counseling, medication, or an increase in health consciousness within the company. Conclusions: Voluntary participation in a Web-based HRA with tailored feedback at the worksite reduced CVD risk by nearly 18% among participants at high CVD risk and by nearly 5% among all participants. Web-based HRA could improve CVD risk in similar populations. Future research should focus on the persistence of the effects underlying the CVD risk reduction.

Individualized duration of oral anticoagulant therapy for deep vein thrombosis based on a decision model

Summary.  Background: The optimal duration of oral anticoagulant therapy for patients with a first episode of deep vein thrombosis (DVT) is still a matter of debate. However, according to the ACCP consensus strategy a limited stratification in treatment duration is advocated, i.e. 3 months for patients with a transient risk factor and 1 year or longer for patients with recurrent disease or a consistent risk factor such as thrombophilia or cancer. This consensus strategy is founded on the mean optimal duration of therapy obtained in large cohorts of patients and is mainly based on the risk of recurrent venous thromboembolism (VTE), with only minimal consideration for the patients bleeding risk. Objective: The aim of this study is to optimize the anticoagulant treatment strategy with vitamin K antagonists for the individual patient with DVT. Methods: Based on an extensive literature study, a mathematical model was constructed to balance the risk of recurrent VTE against the risk of major hemorrhagic complications. The following parameters are incorporated in the model: baseline estimates and risk factors for recurrent VTE and bleeding, clinical course of DVT, and efficacy of treatment with vitamin K antagonists. With the use of these parameters, the risk for a recurrent VTE and a bleeding episode can be calculated for the individual patient. The optimal duration of anticoagulant therapy can be defined as the timepoint at which the benefit of treatment (prevention of VTE) is counterbalanced by its risk (bleeding). Results/conclusions: How long a patient should receive anticoagulant treatment is a matter of balancing the benefits and risks of treatment. The model shows that the optimal treatment duration varies greatly from patient to patient according to the patients unique bleeding and recurrence risk.

Colorectal cancer risk factors in the detection of advanced adenoma and colorectal cancer

Several risk factors for colorectal cancer (CRC) have been identified. If individuals with risk factors are more likely to harbor cancer or it precursors screening programs should be targeted toward this population. We evaluated the predictive value of colorectal cancer risk factors for the detection of advanced colorectal adenoma in a population based CRC colonoscopy screening program. Data were collected in a multicenter trial conducted in the Netherlands, in which 6600 asymptomatic men and women between 50 and 75 years were randomly selected from a population registry. They were invited to undergo a screening colonoscopy. Based on a review of the literature CRC risk factors were selected. Information on risk factors was obtained from screening attendees through a questionnaire. For each CRC risk factor, we estimated its odds ratio (OR) relative to the presence of advanced neoplasia as detected at colonoscopy. Of the 1426 screening participants who underwent a colonoscopy, 1236 (86%) completed the risk questionnaire. 110 participants (8.9%) had advanced neoplasia. The following risk factors were significantly associated with advanced neoplasia detected by colonoscopy: age (OR: 1.06 per year; 95% CI: 1.03-1.10), calcium intake (OR: 0.99 per mg; 95% CI: 0.99-1.00), positive CRC family history (OR: 1.55 per first degree family member; 95%CI: 1.11-2.16) and smoking (OR: 1.75; 95%CI: 1.09-2.82). Elderly screening participants, participants with lower calcium intake, a CRC family history, and smokers are at increased risk of harboring detectable advanced colorectal neoplasia at screening colonoscopy.