Diagnosis of Venous Thromboembolism: 20 Years of Progress.

Many guidelines suggest incorporating clinical assessment, imaging, and D-dimer testing into diagnostic algorithms in patients with suspected deep venous thrombosis (DVT) and pulmonary embolism (PE). This special article reviews the evidence supporting the use of algorithms and their individual components for diagnosis of upper- and lower-extremity DVT and PE in adults, including pregnant women. The authors identified evidence through several electronic database searches to April 2017, evaluated the robustness of selected evidence, assessed whether diagnostic approaches that do not use algorithms are acceptable, and identified knowledge gaps that require further research.

Cheating in OSCEs: The Impact of Simulated Security Breaches on OSCE Performance.

Construct: Valid score interpretation is important for constructs in performance assessments such as objective structured clinical examinations (OSCEs). An OSCE is a type of performance assessment in which a series of standardized patients interact with the student or candidate who is scored by either the standardized patient or a physician examiner. BACKGROUND: In high-stakes examinations, test security is an important issue. Students accessing unauthorized test materials can create an unfair advantage and lead to examination scores that do not reflect students' true ability level. The purpose of this study was to assess the impact of various simulated security breaches on OSCE scores. APPROACH: Seventy-six 3rd-year medical students participated in an 8-station OSCE and were randomized to either a control group or to 1 of 2 experimental conditions simulating test security breaches: station topic (i.e., providing a list of station topics prior to the examination) or egregious security breach (i.e., providing detailed content information prior to the examination). Overall total scores were compared for the 3 groups using both a one-way between-subjects analysis of variance and a repeated measure analysis of variance to compare the checklist, rating scales, and oral question subscores across the three conditions. RESULTS: Overall total scores were highest for the egregious security breach condition (81.8%), followed by the station topic condition (73.6%), and they were lowest for the control group (67.4%). This trend was also found with checklist subscores only (79.1%, 64.9%, and 60.3%, respectively for the security breach, station topic, and control conditions). Rating scale subscores were higher for both the station topic and egregious security breach conditions compared to the control group (82.6%, 83.1%, and 77.6%, respectively). Oral question subscores were significantly higher for the egregious security breach condition (88.8%) followed by the station topic condition (64.3%), and they were the lowest for the control group (48.6%). CONCLUSIONS: This simulation of different OSCE security breaches demonstrated that student performance is greatly advantaged by having prior access to test materials. This has important implications for medical educators as they develop policies and procedures regarding the safeguarding and reuse of test content.

Validation and reliability of a disease-specific quality of life measure (the TranQol) in adults and children with thalassaemia major.

This study aimed to demonstrate the validity, reliability and responsiveness of a new disease-specific quality of life (QoL) questionnaire for children and adults with thalassaemia major, the Transfusion-dependent QoL questionnaire (TranQol). 106 participants (51 adults and 55 children) were recruited from six North American thalassaemia treatment centres with a mean age of 20·7 years (standard deviation [SD] 9, range 7-51 years). The mean total TranQol score was 71 (SD 17, 32-97) on a scale of 0-100. Patients with co-morbidities had significantly lower scores (63 vs. 75, P = 0·001). TranQol scores showed substantial agreement (P < 0·001) with the Health Utilities Index Mark 3 (all patients, r = 0·65), the Pediatric QoL (children, r = 0·77) and the Short Form (36) physical (adults, r = 0·69) and mental summary scores (r = 0·76). In the subgroup who rated their QoL as better, there was a 4·0 point (SD 9·0) improvement in TranQol scores, from baseline of 67·1-71·1 one week later (P = 0·008). Test-retest reliability was excellent (intra-class correlation coefficient, 0·93). The TranQol was valid, with acceptable correlation for all administered measures and was reliable and responsive to change. The TranQol can be incorporated into future studies of thalassaemia major.

Treatment of venous thromboembolism.

IMPORTANCE: Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common, potentially lethal condition with acute morbidity. OBJECTIVE: To review the etiology of VTE and the 3 phases of VTE treatment: acute (first 5-10 days), long-term (from end of acute treatment to 3-6 months), and extended (beyond 3-6 months). EVIDENCE REVIEW: Cochrane reviews, meta-analyses, and randomized controlled trials, as well as other clinical trials for topics not covered by the former, were reviewed. Literature searches using broad terms were used to find meta-analyses published in the last 15 years. The ninth edition of the American College of Chest Physicians Antithrombotic Therapy Guidelines was used to supplement the literature search. Guidelines from specialty organizations were consulted when relevant. The Canadian Agency for Drugs and Technologies in Health was searched for relevant cost-effectiveness studies. We also searched our own literature database of 8386 articles for relevant research. FINDINGS: Low-molecular-weight heparin (LMWH) along with with vitamin K antagonists and the benefits and proven safety of ambulation have allowed for outpatient management of most cases of DVT in the acute phase. Development of new oral anticoagulants further simplifies acute-phase treatment and 2 oral agents can be used as monotherapy, avoiding the need for LMWH. Patients with PE can also be treated in the acute phase as outpatients, a decision dependent on prognosis and severity of PE. Thrombolysis is best reserved for severe VTE; inferior vena cava filters, ideally the retrievable variety, should be used when anticoagulation is contraindicated. In general, DVT and PE patients require 3 months of treatment with anticoagulants, with options including LMWH, vitamin K antagonists, or direct factor Xa or direct factor IIa inhibitors. After this time, decisions for further treatment are based on balancing the risk of VTE recurrence, determined by etiology of the VTE (transient risk factors, unprovoked or malignancy associated), against the risk of major hemorrhage from treatment. Better prediction tools for major hemorrhage are needed. Experience with new oral anticoagulants as acute, long-term, and extended therapy options is limited as yet, but as a class they appear to be safe and effective for all phases of treatment. CONCLUSIONS AND RELEVANCE: The mainstay of VTE treatment is anticoagulation, while interventions such as thrombolysis and inferior vena cava filters are reserved for limited circumstances. Multiple therapeutic modes and options exist for VTE treatment with small but nonetheless important differential effects to consider. Anticoagulants will probably always increase bleeding risk, necessitating tailored treatment strategies that must incorporate etiology, risk, benefit, cost, and patient preference. Although great progress has been made, further study to understand individual patient risks is needed to make ideal treatment decisions.

Cerebral microembolization after bioprosthetic aortic valve replacement: comparison of warfarin plus aspirin versus aspirin only.

BACKGROUND: No human physiological data exists on whether aspirin only is as effective as warfarin plus aspirin in preventing cerebral microembolization in the early postoperative period after bioprosthetic aortic valve replacement (bAVR). METHODS AND RESULTS: We prospectively enrolled 56 patients who had no other indication for oral anticoagulation, who underwent bAVR and received, in an open-label fashion, either daily warfarin (for INR 2.0-3.0) plus 81 mg of aspirin (n=28) or 325 mg of aspirin only (n=28). Cerebral microembolization was quantified at 4 hours (baseline) and at 1 month postoperatively, by recording 1-hour bilateral middle cerebral artery (MCA) microembolic signals (MES). Platelet-function analysis (PFA) of closure times (CT) on collagen was also used as a marker of platelet-dependent activation. Follow-up to 1 year was complete. Preoperative demographics and baseline platelet function were equivalent in both groups. There was no mortality, stroke, or transient ischemic attack at 1 year in either group. No significant differences were found in the proportion of patients with MES among those receiving warfarin plus aspirin versus aspirin only, at baseline (68% versus 82%, respectively; P=0.4) and at 1 month (46% versus 43%; P=1.0) after bAVR. The total MES and PFA were also equivalent between groups, at baseline and follow-up. CONCLUSIONS: Early after bAVR, the effects of these 2 antithrombotic regimens on cerebral microembolization and platelet function are equivalent. These data bring new mechanistic support to the premise that aspirin only may safely be used early after bAVR in patients who have no other indication for oral anticoagulation.

Prospective evaluation of a pharmacogenetics-guided warfarin loading and maintenance dose regimen for initiation of therapy.

Single-nucleotide polymorphisms in genes that affect warfarin metabolism (cytochrome P450 2C9 gene, CYP2C9) and response (vitamin K epoxide reductase complex 1 gene, VKORC1) have an important influence on warfarin therapy, particularly during initiation; however, there is a lack of consensus regarding the optimal pharmacogenetics-based initiation strategy. We conducted a prospective cohort study in which patients requiring warfarin therapy for atrial fibrillation or venous thromboembolism were initiated with a novel pharmacogenetics-initiation protocol (WRAPID, Warfarin Regimen using A Pharmacogenetics-guided Initiation Dosing) that incorporated loading and maintenance doses based on genetics, clinical variables, and response (n = 167, followed up for 90 days), to assess the influence of genetic variations on anticoagulation responses. Application of the WRAPID algorithm resulted in a negligible influence of genetic variation in VKORC1 or CYP2C9 on time to achievement of first therapeutic response (P = .52, P = .28) and risk of overanticoagulation (P = .64, P = .96). After adjustment for covariates, time to stable anticoagulation was not influenced by VKORC1 or CYP2C9 genotype. Importantly, time spent within or above the therapeutic range did not differ among VKORC1 and CYP2C9 genotype groups. Moreover, the overall time course of the anticoagulation response among the genotype groups was similar and predictable. We demonstrate the clinical utility of genetics-guided warfarin initiation with the WRAPID protocol to provide safe and optimal anticoagulation therapy for patients with atrial fibrillation or venous thromboembolism.

Experience of introducing an electronic health records station in an objective structured clinical examination to evaluate medical students' communication skills in Canada: a descriptive study.

PURPOSE: There is limited literature related to the assessment of electronic medical record (EMR)-related competencies. To address this gap, this study explored the feasibility of an EMR objective structured clinical examination (OSCE) station to evaluate medical students' communication skills by psychometric analyses and standardized patients' (SPs) perspectives on EMR use in an OSCE. METHODS: An OSCE station that incorporated the use of an EMR was developed and pilot-tested in March 2020. Students' communication skills were assessed by SPs and physician examiners. Students' scores were compared between the EMR station and 9 other stations. A psychometric analysis, including item total correlation, was done. SPs participated in a post-OSCE focus group to discuss their perception of EMRs' effect on communication. RESULTS: Ninety-nine 3rd-year medical students participated in a 10-station OSCE that included the use of the EMR station. The EMR station had an acceptable item total correlation (0.217). Students who leveraged graphical displays in counseling received higher OSCE station scores from the SPs (P=0.041). The thematic analysis of SPs' perceptions of students' EMR use from the focus group revealed the following domains of themes: technology, communication, case design, ownership of health information, and timing of EMR usage. CONCLUSION: This study demonstrated the feasibility of incorporating EMR in assessing learner communication skills in an OSCE. The EMR station had acceptable psychometric characteristics. Some medical students were able to efficiently use the EMRs as an aid in patient counseling. Teaching students how to be patient-centered even in the presence of technology may promote engagement.

Factors affecting residency rank-listing: a Maxdiff survey of graduating Canadian medical students.

BACKGROUND: In Canada, graduating medical students consider many factors, including geographic, social, and academic, when ranking residency programs through the Canadian Residency Matching Service (CaRMS). The relative significance of these factors is poorly studied in Canada. It is also unknown how students differentiate between their top program choices. This survey study addresses the influence of various factors on applicant decision making. METHODS: Graduating medical students from all six Ontario medical schools were invited to participate in an online survey available for three weeks prior to the CaRMS match day in 2010. Max-Diff discrete choice scaling, multiple choice, and drop-list style questions were employed. The Max-Diff data was analyzed using a scaled simple count method. Data for how students distinguish between top programs was analyzed as percentages. Comparisons were made between male and female applicants as well as between family medicine and specialist applicants; statistical significance was determined by the Mann-Whitney test. RESULTS: In total, 339 of 819 (41.4%) eligible students responded. The variety of clinical experiences and resident morale were weighed heavily in choosing a residency program; whereas financial incentives and parental leave attitudes had low influence. Major reasons that applicants selected their first choice program over their second choice included the distance to relatives and desirability of the city. Both genders had similar priorities when selecting programs. Family medicine applicants rated the variety of clinical experiences more importantly; whereas specialty applicants emphasized academic factors more. CONCLUSIONS: Graduating medical students consider program characteristics such as the variety of clinical experiences and resident morale heavily in terms of overall priority. However, differentiation between their top two choice programs is often dependent on social/geographic factors. The results of this survey will contribute to a better understanding of the CaRMS decision making process for both junior medical students and residency program directors.

Pulmonary embolism: update on management and controversies.

Pulmonary embolism is a common and potentially fatal cardiovascular disorder that must be promptly diagnosed and treated. The diagnosis, risk assessment, and management of pulmonary embolism have evolved with a better understanding of efficient use of diagnostic and therapeutic options. The use of either clinical probability adjusted or age adjusted D-dimer interpretation has led to a reduction in diagnostic imaging to exclude pulmonary embolism. Direct oral anticoagulation therapies are safe, effective, and convenient treatments for most patients with acute venous thromboembolism, with a lower risk of bleeding than vitamin K antagonists. These oral therapeutic options have opened up opportunities for safe outpatient management of pulmonary embolism in selected patients. Recent clinical trials exploring the use of systemic thrombolysis in intermediate to high risk pulmonary embolism suggest that this therapy should be reserved for patients with evidence of hemodynamic compromise. The role of low dose systemic or catheter directed thrombolysis in other patient subgroups is uncertain. After a diagnosis of pulmonary embolism, all patients should be assessed for risk of recurrent venous thromboembolism to guide duration of anticoagulation. Patients with a venous thromboembolism associated with a strong, transient, provoking risk factor can safely discontinue anticoagulation after three months of treatment. Patients with an ongoing strong risk factor, such as cancer, or unprovoked events are at increased risk of recurrent events and should be considered for extended treatment. The use of a risk prediction score can help to identify patients with unprovoked venous thromboembolism who can benefit from extended duration therapy. Despite major advances in the management of pulmonary embolism, up to half of patients report chronic functional limitations. Such patients should be screened for chronic thromboembolic pulmonary hypertension, but only a small proportion will have this as the explanation of their symptoms. In the remaining patients, future studies are needed to understand the pathophysiology and explore interventions to improve quality of life.

Association of Splanchnic Vein Thrombosis on Survival: 15-Year Institutional Experience With 1561 Cases.

Background Previous studies regarding survival in patients with splanchnic vein thrombosis (SVT) are limited. This study measured overall survival in a large cohort of SVTs through linkage to population-based data. Methods and Results Using a previously derived text-search algorithm, we screened the reports of all abdominal ultrasound and contrast-enhanced computed tomography studies at The Ottawa Hospital over 14 years. Screen-positive reports were manually reviewed by at least 2 authors to identify definite SVT cases by consensus. Images of uncertain studies were independently reviewed by 2 radiologists. One thousand five hundred sixty-one adults with SVT (annual incidence ranging from 2.8 to 5.9 cases/10 000 patients) were linked with population-based data sets to measure the presence of concomitant cancer and survival status. Thrombosis involved multiple veins in 314 patients (20.1%), most commonly the portal vein (n=1410, 90.3%). Compared with an age-sex-year matched population, patients with SVT had significantly reduced survival in particular with local cancer (adjusted relative excess risk for recent cases 12.0 [95% CI, 9.8-14.6] and for remote cases 9.7 [7.7-12.2]), distant cancer (relative excess risk for recent cases 5.7 [4.5-7.3] and for remote cases 5.4 [4.4-6.6]), cirrhosis (relative excess risk 8.2 [5.3-12.7]), and previous venous thromboembolism (relative excess risk 3.8 [2.4-6.0]). One hundred fifty (23.9%) of patients >65 years of age were anticoagulated within 1 month of diagnosis. Conclusions SVT is more common than expected. Most patients have cancer and the portal vein is by far the most common vein involved. Compared with the general population, patients with SVT had significantly reduced survival, particularly in patients with concomitant cancer, cirrhosis, and previous venous thromboembolic disease. Most elderly patients did not receive anticoagulant therapy.

Does Emotional Intelligence at medical school admission predict future licensing examination performance?

BACKGROUND: Medical school admissions committees are seeking alternatives to traditional academic measures when selecting students; one potential measure being emotional intelligence (EI). If EI is to be used as an admissions criterion, it should predict future performance. The purpose of this study is to determine if EI scores at admissions predicts performance on a medical licensure examination. METHODS: All medical school applicants to the University of Ottawa in 2006 and 2007 were invited to complete the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT v2.0) after their interview. Students were tracked through medical school into licensure and EI scores were correlated to their scores on the Medical Council of Canada Qualifying Examination (MCCQE) attempted between 2010 and 2014. RESULTS: The correlation between the MSCEIT and the MCCQE Part I was r (200) = .01 p =. 90 The covariates of age and gender accounted for a significant amount of variance in MCCQE Part I scores (R 2 = .10, p<.001, n=202) but the addition of the MSCEIT scores was not statistically significant (R 2 change = .002, p=.56). The correlation between the MSCEIT and the MCCQE Part II was r(197) = .06, p = .41. The covariates of age and gender accounted for some variance in MCCQE Part II scores (R 2 = .05, p = .007, n=199) but the addition of the MSCEIT did not (R 2 change = .002 p =.55). CONCLUSION: The low correlations between EI and licensure scores replicates other studies that have found weak correlations between EI scores and tests administered at admissions and during medical school. These results suggest caution if one were to use EI as part of their admissions process.

CONTEXTE: Les comités d'admission des facultés de médecine sont à la recherche d'alternatives aux mesures académiques traditionnelles lors de la sélection des étudiants; une mesure potentielle étant l'intelligence émotionnelle (IÉ). Si l'IÉ doit être utilisée comme critère d'admission, elle devrait pouvoir prédire la performance future. L'objectif de cette étude est de déterminer si les résultats de l'IÉ lors des admissions prédisent la performancelors d'un examen de certification. MÉTHODES: Tous les candidats à la faculté de médecine de l'Université d'Ottawa en 2006 et en 2007 ont été invités à remplir le test d'intelligence émotionnelle Mayer-Salovey-Caruso (MSCEIT v2.0) après leur entrevue. Les étudiants ont été suivis tout au long de leurs études en médecine jusqu'à leur début de pratique et les résultats de l'IÉ ont été corrélés à leurs résultats lors de l'examen d'aptitude du Conseil médical du Canada (EACMC) tentéentre 2010 et 2014. RÉSULTATS: La corrélation entre le MSCEIT et la partie I de l'EACMC était de r (200) = 0,01 p = 0,90. Les covariables de l'âge et du genre comptaient pour une partie importante de la variance dans les résultats de la partie I de l'EACMC (R 2 = 0,10, p < 0,001, n = 202), mais l'ajout des résultats du MSCEIT n'était pas statistiquement significatif (changement de R 2 = 0,002, p = 0,56). La corrélation entre le MSCEIT et la partie II de l'EACMC était de r (197) = 0,06 p = 0,41. Les covariables de l'âge et du genre comptaient pour une certaine variance dans les résultats de la partie II de l'EACMC (R 2 = 0,05, p = 0,007, n = 199), mais l'ajout des résultats du MSCEIT ne comptait pas (changement de R 2 = 0,002, p = 0,55). CONCLUSION: Les faibles corrélations relevées entre les résultats de l'IÉ et la certificationconfirment les conclusionsd'autres études qui ont obtenu de faibles corrélations entre les résultats de l'IÉ et les tests donnés aux admissions et à la faculté de médecine. Ces résultats appellent à la prudence si quelqu'un devait utiliser l'IÉ dans son processus d'admission.

Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis.

BACKGROUND: Several diagnostic strategies using ultrasound imaging, measurement of D-dimer, and assessment of clinical probability of disease have proved safe in patients with suspected deep-vein thrombosis, but they have not been compared in randomized trials. METHODS: Outpatients presenting with suspected lower-extremity deep-vein thrombosis were potentially eligible. Using a clinical model, physicians evaluated the patients and categorized them as likely or unlikely to have deep-vein thrombosis. The patients were then randomly assigned to undergo ultrasound imaging alone (control group) or to undergo D-dimer testing (D-dimer group) followed by ultrasound imaging unless the D-dimer test was negative and the patient was considered clinically unlikely to have deep-vein thrombosis, in which case ultrasound imaging was not performed. RESULTS: Five hundred thirty patients were randomly assigned to the control group, and 566 to the D-dimer group. The overall prevalence of deep-vein thrombosis or pulmonary embolism was 15.7 percent. Among patients for whom deep-vein thrombosis had been ruled out by the initial diagnostic strategy, there were two confirmed venous thromboembolic events in the D-dimer group (0.4 percent; 95 percent confidence interval, 0.05 to 1.5 percent) and six events in the control group (1.4 percent; 95 percent confidence interval, 0.5 to 2.9 percent; P=0.16) during three months of follow-up. The use of D-dimer testing resulted in a significant reduction in the use of ultrasonography, from a mean of 1.34 tests per patient in the control group to 0.78 in the D-dimer group (P=0.008). Two hundred eighteen patients (39 percent) in the D-dimer group did not require ultrasound imaging. CONCLUSIONS: Deep-vein thrombosis can be ruled out in a patient who is judged clinically unlikely to have deep-vein thrombosis and who has a negative D-dimer test. Ultrasound testing can be safely omitted in such patients.

A comparison of two intensities of warfarin for the prevention of recurrent thrombosis in patients with the antiphospholipid antibody syndrome.

BACKGROUND: Many patients with the antiphospholipid antibody syndrome and recurrent thrombosis receive doses of warfarin adjusted to achieve an international normalized ratio (INR) of more than 3.0. However, there are no prospective data to support this approach to thromboprophylaxis. METHODS: We performed a randomized, double-blind trial in which patients with antiphospholipid antibodies and previous thrombosis were assigned to receive enough warfarin to achieve an INR of 2.0 to 3.0 (moderate intensity) or 3.1 to 4.0 (high intensity). Our objective was to show that high-intensity warfarin was more effective in preventing thrombosis than moderate-intensity warfarin. RESULTS: A total of 114 patients were enrolled in the study and followed for a mean of 2.7 years. Recurrent thrombosis occurred in 6 of 56 patients (10.7 percent) assigned to receive high-intensity warfarin and in 2 of 58 patients (3.4 percent) assigned to receive moderate-intensity warfarin (hazard ratio for the high-intensity group, 3.1; 95 percent confidence interval, 0.6 to 15.0). Major bleeding occurred in three patients assigned to receive high-intensity warfarin and four patients assigned to receive moderate-intensity warfarin (hazard ratio, 1.0; 95 percent confidence interval, 0.2 to 4.8). CONCLUSIONS: High-intensity warfarin was not superior to moderate-intensity warfarin for thromboprophylaxis in patients with antiphospholipid antibodies and previous thrombosis. The low rate of recurrent thrombosis among patients in whom the target INR was 2.0 to 3.0 suggests that moderate-intensity warfarin is appropriate for patients with the antiphospholipid antibody syndrome.

A randomized trial comparing 2 low-molecular-weight heparins for the outpatient treatment of deep vein thrombosis and pulmonary embolism.

BACKGROUND: Low-molecular-weight heparins (LMWHs) are now standard therapy for the treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE). No published trials have compared LMWHs, and few studies have examined outpatient therapy for PE. Only tinzaparin sodium has demonstrated superiority to unfractionated heparin in a clinical trial. METHODS: We compared 2 LMWH products, tinzaparin and dalteparin sodium, for the treatment of acute DVT and PE in a randomized, controlled clinical trial of consecutive outpatients presenting to a venous thromboembolism service at 4 tertiary-care hospitals. Patients were treated with subcutaneous tinzaparin sodium, 175 IU/kg every 24 hours, or subcutaneous dalteparin sodium, 200 IU/kg every 24 hours, for at least 5 days. Warfarin sodium therapy was started simultaneously and continued for 90 days. The primary end point was efficacy (recurrence of venous thromboembolism); safety (bleeding) was a composite end point. RESULTS: Two hundred fifty-four patients received tinzaparin (39 with PE and 215 with DVT) and 251 received dalteparin (51 with PE and 200 with DVT). Most patients had an active malignancy or idiopathic DVT/PE. The outcome events occurred in 11 (4.4%; 95% confidence interval [CI], 2.2%-7.7%) and 15 patients (5.9%; 95% CI, 3.3%-9.5%) in the dalteparin and tinzaparin groups, respectively, including 9 and 10 recurrences, respectively, and 2 and 5 major hemorrhages, respectively (P = .44). The 95% CI on the difference of -1.5% was -5.3% to 2.4%. CONCLUSIONS: Tinzaparin and dalteparin are safe and effective for the outpatient treatment of DVT or PE. Our finding of no differences between the LMWHs based on major clinical end points means that practical issues can be the deciding factor on which drug to use.

The outpatient bleeding risk index: validation of a tool for predicting bleeding rates in patients treated for deep venous thrombosis and pulmonary embolism.

BACKGROUND: Long-term anticoagulation prevents recurrent thrombosis in patients with idiopathic deep venous thrombosis or pulmonary embolism, but with a risk of clinically important so-called major bleeding. Physician- and patient-based decisions on the optimal duration of therapy are sensitive to the bleeding risk. The Outpatient Bleeding Risk Index potentially provides a means of calculating the potential risk of bleeding using easily elicited clinical findings, but, to our knowledge, the authors of the index have provided the only published validation of it. We sought to determine the accuracy of the index in our population of patients. METHODS: We prospectively applied the Outpatient Bleeding Risk Index to consecutive patients in our clinic who had been objectively diagnosed as having pulmonary embolism or deep venous thrombosis and who were about to undergo standard therapy. Standard therapy consisted of a minimum of 5 days of low-molecular-weight heparin therapy overlapped with warfarin sodium therapy, and continuation of warfarin therapy for at least 3 months, with a target international normalized ratio of 2.5. Patients were placed in 3 risk groups (low, moderate, or high), as defined by the index. The survival curves of the groups, using major hemorrhages as the events, were then compared by the log-rank test. RESULTS: Bleeding rates were lower than expected, but the index did discriminate between low- and moderate-risk groups (P =.03, log-rank test). The rate of major hemorrhage per 100 person-years was 0% (95% confidence interval, 0%-2.8%) in the low-risk group and 4.3% (95% confidence interval, 1.1%-11.1%) in the moderate-risk group. The rate in the high-risk group could not be defined because only 2 patients were at high risk. CONCLUSION: The Outpatient Bleeding Risk Index discriminates between low- and moderate-risk patients, and could be used to guide decisions on the optimal duration of anticoagulant therapy.

The ACE D/D genotype is protective against the development of idiopathic deep vein thrombosis and pulmonary embolism.

The deletion/deletion (D/D) genotype of the angiotensin converting enzyme (ACE) has been purported to be a risk for post-operative thrombosis.This D/D genotype has not been evaluated as a risk factor for idiopathic venous thromboembolism (VTE). The primary objective of the present study was to determine whether the D/D genotype of ACE is independently associated with the occurrence of idiopathic venous thromboembolic disease. We prospectively enrolled consecutive patients with at least one objectively confirmed idiopathic VTE. Friends of cases were recruited as controls and matched to cases by sex, ethnicity, and age. Patients were tested for the ACE I/D polymorphism in addition to factor V Leiden, prothrombin G20210A, and factor VIII levels. Three hundred cases and 300 controls were enrolled; 97% were Caucasian. There were 148 females and 152 males in each group with a mean age of 56.21 years (SD = 15.33). The ACE D/D genotype was present in 25.3% of cases and 32.4% of controls for an adjusted odds ratio of 0.66 (95% CI = 0.433 to 0.997). We can conclude that the ACE D/D genotype is protective against idiopathic venous thromboembolism.

Estimating quality of life in acute venous thrombosis.

IMPORTANCE: Future funding for new treatments in venous thromboembolism will be guided by cost-utility analyses. There is little available information on the utility of acute venous thromboembolism, limiting the validity of economic analyses. OBJECTIVE: To measure the quality of life in the health states relating to thromboembolism cost-utility analyses. DESIGN: A prospective cohort study. SETTING: A single-center, university-affiliated thrombosis clinic. PARTICIPANTS: Two hundred sixteen thrombosis clinic patients with a history of lower limb deep vein thrombosis (DVT) or pulmonary embolism (PE). EXPOSURES: Participants consented to take a standard gamble interview. Each participant rated the quality of life in acute DVT, acute PE, and bleeding complication health states. MAIN OUTCOMES AND MEASURES: The standard gamble measured quality of life (utility value) for acute DVT, acute PE, major intracranial bleeding event, minor intracranial bleeding event, and gastrointestinal bleeding event. RESULTS: Two hundred fifteen responses were included in the analysis. Twenty-six percent had experienced both PE and DVT; 54%, DVT alone; and 20%, PE alone. Forty-two percent had experienced more than 1 episode of thrombosis, and 23% had had cancer-associated thrombosis. We found the median utility for acute DVT was 0.81 (interquartile range [IQR], 0.55-0.94); acute PE, 0.75 (IQR, 0.45-0.91); major intracranial bleeding event, 0.15 (IQR, 0.00-0.65); minor intracranial bleeding event, 0.75 (IQR, 0.55-0.92); and gastrointestinal bleeding event, 0.65 (IQR, 0.15-0.86). The median length of symptoms for DVT or PE was 1 week (IQR, <1-3 weeks). CONCLUSIONS AND RELEVANCE: To our knowledge, this is the largest published study on utilities in which the participants had personal experience of venous thromboembolism. We present unique information for economic analyses but have also identified future challenges for research in this area. Our summary results differ from those previously published, and we found wide variation in individual responses.

Effect of 200µG/day of vitamin K1 on the variability of anticoagulation control in patients on warfarin: a randomized controlled trial.

BACKGROUND: Controversy exists whether low-dose vitamin K supplementation can improve anticoagulation control in patients with unstable anticoagulation under warfarin. In a single- centre randomized, double-blind, placebo-controlled study, we evaluated the effectiveness of 200 µg/day of vitamin K1 in patients with unstable control under warfarin. METHODS: Effectiveness of Vitamin K1 supplementation was primarily assessed by the percentage (%) of Time-in-Therapeutic-Range (TTR) and secondarily by the standard deviation (SD) of the patient's INR values; the proportion of out-of-range INRs; and the number of dose changes on warfarin. Their change scores were obtained by subtracting the mean value in the 6 months pre-randomization from the mean value in the 6 months post-randomization. Multivariable linear-regressions identified factors associated with anticoagulation instability. RESULTS: Fifty out of 54 patients were analyzed (intervention: n=26; placebo: n=24). Most indications (87%) for anticoagulation were venous thromboembolism (VTE). The intervention was associated with a greater reduction in the change scores for the SD of INRs between the pre and post-randomization periods compared with placebo. The mean change score was -0.259±0.307 with the intervention and -0.046±0.345 with placebo (p=0.026). There was no effect on the change scores of the (%) TTR (p=0.98), the number of INRs out-of-range (p=0.58) and the number of dose changes (p=0.604). Factors independently associated with increased variability in the SD of INRs were increased alcoholic drinks/week (p=0.017), dosing errors (p=0.0009) and missed INR appointments (p=0.035). CONCLUSION: Vitamin K1 supplementation reduces the SD of INRs as an indicator of the variability in anticoagulation control in patients treated with warfarin for VTE.

Hospital mortality due to pulmonary embolism and an evaluation of the usefulness of preventative interventions.

BACKGROUND: Mortality rates due to pulmonary embolism (PE) are difficult to estimate often due to the presence of comorbid disease. OBJECTIVES: To determine the accuracy of hospital records in identifying PE cases, PE-related mortality, and the number of PE-related deaths which are potentially preventable. METHODS: Retrospective chart review of PE cases hospitalized at The Ottawa Hospital over an 8 year period. Cases were reviewed to determine accuracy of coding, as well as the certainty with which PE was the cause of death. In PE-related deaths, a determination was made as to whether any interventions may have been life-saving. RESULTS: 498 cases of 612 (81%) cases coded as PE were correctly coded. 111 (22%) died during hospitalization, 63% of deaths were attributed to PE. The presence of a cardiorespiratory comorbidity or cancer was independently associated with an increased rate of death due to PE. 54% of PE-related deaths were determined to be potentially preventable, most commonly by appropriate DVT prophylaxis. A significantly higher number of cancer patients as compared to non-cancer patients may have potentially had their death due to PE prevented by an inferior vena cava filter (IVCF). Systemic thrombolysis was deemed to be potentially life-saving in 1/38 PE-related deaths. CONCLUSION: Hospital mortality due to clinically recognized PE can be determined by chart review of PE cases identified using the ICD coding system. Death due to PE is often potentially preventable; in the subgroup with cancer and DVT/PE, an IVCF may be a potentially useful intervention to prevent death due to PE. Prospective studies are needed to confirm these results.