A prospective observational study of a cohort of outpatients with an acute medical event and reduced mobility: incidence of symptomatic thromboembolism and description of thromboprophylaxis practices

Family history of venous thromboembolism as a risk factor and genetic research tool

Familial clustering of venous thromboembolism (VTE) was described as far back as 1905 by Briggs. Although Egeberg discovered inherited deficiency of antithrombin in 1965, it was not until Dahlback discovered resistance to activated protein C in 1993 that it became clear that genetic factors are common risk factors of VTE. Several genes have been linked to familial aggregation of VTE and genome-wide association studies have found several novel gene loci. Still, it has been estimated that much of the heritability for VTE remains to be discovered. Family history (FH) of VTE is therefore still important to determine whether a patient has an increased genetic risk of VTE. FH has the potential to represent the sum of effects and interactions between environmental and genetic factors. In this article the design, methodology, results, clinical and genetic implications of FH studies of VTE are reviewed. FH in first-degree relatives (siblings and/or parents) is associated with a 2–3 times increased familial relative risk (FRR). However, the FRR is dependent on age, number of affected relatives, and presentation of VTE (provoked/unprovoked). Especially high familial risks are observed in individuals with two or more affected siblings (FFR> 50). However, the familial risk for recurrent VTE is much lower or non-significant. Moreover, FH of VTE appears mainly to be important for venous diseases (i. e. VTE and varicose veins). The familial associations with other diseases are weaker. In conclusion, FH of VTE is an important research tool and a clinically potential useful risk factor for VTE.

Time trends and case fatality rate of in-hospital treated pulmonary embolism during 11 years of observation in Northwestern Italy

Pulmonary embolism (PE) is a common disorder with high mortality and morbidity rates. However, population-based information on its incidence and prognosis remains limited. We conducted a large epidemiology study collecting data on hospitalisation for PE (from 2002 to 2012) in a population of about 13 million people in Northwestern Italy. Patients were identified using the ICD-9-CM codes: 415.11, 415.19; gender and age specific incidence rate of PE during the study period were estimated using the resident population for each year of the study. Furthermore, time trends in the in-hospital PE-related mortality and case fatality rate were calculated. Results were adjusted for possible confounders. A total of 60,853 patients (mean age 72.8 years, ± 14.1, 59.6 % females) with PE were included; the overall crude incidence rate for the entire study period was 55.4 and 40.6 events per year per 100,000 inhabitants for women and men, respectively (p < 0.001). However, this difference was completely lost after standardisation for age. The incidence of PE significantly increased in both genders during the study period. In-hospital case fatality rate significantly decreased throughout the study period (p < 0.001) in women (from 15.6 % to 10.2 %) and in men (from 17.6 % to 10.1 %). The observed decrease of the in-hospital case-fatality throughout the study period remained significant also after adjustment for possible confounders. In conclusion, time trends over an 11-year period show an increasing incidence of PE, but a significant reduction in mortality during hospitalisation. Reduction in the case fatality rate remained significant after adjustment for these possible confounders.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Familial Clustering of Venous Thromboembolism - A Danish Nationwide Cohort Study

BACKGROUND

Identification of risk factors for venous thromboembolism (VTE) is of utmost importance to improve current prophylactic regimes and treatment guidelines. The extent to which a family history contributes to the risk of VTE needs further exploration.

OBJECTIVES

To examine the relative rate of VTE in first-degree relatives compared with the general population.

METHODS

By crosslinking Danish nationwide registries we identified patients with VTE between 1978 and 2012, and their familial relations. The first member in a family to acquire VTE was defined as the proband. All first-degree relatives to probands were followed from the VTE date of the proband and until an event (VTE), death, emigration, 100 year birthday or end of study: 31st of December 2012, whichever came first. The relative rate of VTE was estimated by standardized incidence ratios (SIR) using time-dependent Poisson regression models, with the general population as a fixed reference.

RESULTS

We identified 70,767 children of maternal probands, 66,065 children of paternal probands, and 29,183 siblings to sibling probands. Having a maternal proband or a paternal proband were associated with a significantly increased VTE rate of 2.15 (CI: 2.00-2.30) and 2.06 (CI: 1.92-2.21), respectively. The highest estimate of VTE was observed among siblings (adjusted SIR of 2.60 [CI: 2.38-2.83]). Noteworthy, the rate of VTE increased for all first-degree relatives when the proband was diagnosed with VTE in a young age (≤ 50 years).

CONCLUSION

A family history of VTE was associated with a significantly increased rate of VTE among first-degree relatives compared with the general population.

Prior thromboprophylaxis and outcome in patients experiencing acute venous thromboembolism after an acute medical illness

BACKGROUND

Even despite the use of thromboprophylaxis, some patients with an acute medical illness develop symptomatic venous thromboembolism (VTE). It is unclear whether the outcome in these patients is different in those in whom prophylaxis was not prescribed.

PATIENTS AND METHODS

We used the RIETE (Registro Informatizado Enfermedad TromboEmbolica) database to compare the 3-month outcome (death, fatal pulmonary embolism, VTE recurrences, major bleeding) of patients with acute VTE after immobilization for an acute medical disease, according to the use of prophylaxis.

RESULTS

Thromboprophylaxis was prescribed in 1313 (37%) of the 3527 patients included in August 2014. Acute infection was the most frequent cause of immobilization. Patients who received prophylaxis were more frequently immobilized in hospital than at home (70% vs. 22%), and fewer patients were immobilized for cancer (13% vs. 22%). During the first 3months of treatment, the rates of all-cause death (23 vs. 21%), fatal PE (2.6 vs. 3.1%), VTE recurrences (2.4% vs. 2.8%), and major bleeding (4.2% for both) did not differ between the two groups. Thromboprophylaxis was not associated with each outcome in multivariate analysis.

CONCLUSIONS

The outcome in patients with VTE provoked by medical immobilization was not influenced by the use of thromboprophylaxis during the period of immobility.

[Prevention of venous thromboembolic events by fondaparinux 2.5 mg in general practice. ArchiMed Ville]

OBJECTIVE

To evaluate the mean duration of treatment course with fondaparinux 2.5 mg (ARIXTRA(®)) in the setting of ambulatory general medicine, with respect to its indication in thromboprophylaxis for medically ill patients and to describe the population treated.

METHODS

Observational, prospective, national, multicenter, pharmaco-epidemiological study, performed in France, at the request of the Transparency Commission (a division of the French Health Regulatory Authority). The general practitioners had to include the first three adult patients, considered as patients at high risk of venous thromboembolic events and immobilized for acute medical illness, treated with initiation of thromboprophylaxis by fondaparinux 2.5 mg.

RESULTS

Two hundred and seventeen general practitioners included 840 patients. The mean age of patients was 63.6±18.1 years, and 63% of patients (n=520/831) were females. The real total administration duration of the treatment by fondaparinux 2.5 mg was known for 797 patients and was 15.8±12.4 days on average (range: 1-90 days, median: 10 days). In 40% of patients, the duration ranged from 6 to 14 days [duration consistent with the summary of product characteristics (SmPC)]. Among the 834 patients analyzed, 569 (68%) suffered from at least one acute illness and had at least one risk factor for venous thromboembolism (VTE). The indication did fully comply with the summary of product characteristics of fondaparinux 2.5 mg in 52% of the patients (n=434/834 patients).

CONCLUSION

The results of the ArchiMed study support that the thromboprophylaxis treatment with fondaparinux 2.5 mg in ambulatory general medicine, and the associated medical conditions were usually consistent with the SmPC or guidelines. However, a difference was found for the duration and the initial indication, in situations that may be regarded as presenting a risk by the prescriber.

Bleeding and venous thromboembolism arising in acutely ill hospitalized medical patients. Findings from the Spanish national discharge database

BACKGROUND

There is scarce evidence to identify which acutely ill medical patients might benefit from prophylaxis against venous thromboembolism (VTE).

METHODS

The Spanish National Discharge Database was used to identify predictors of bleeding and VTE during hospitalization for an acute medical illness.

RESULTS

Of 1,148,301 patients, 3.10% bled, 1.21% were diagnosed with VTE, and 8.64% died. The case-fatality rate was: 20.8% for bleeding and 19.7% for VTE. Eight clinical variables were independently associated with an increased risk for VTE and bleeding, one with a decreased risk for both events, 4 with an increased risk for VTE and a decreased risk for bleeding, 2 with an increased risk for bleeding but a decreased risk for VTE, and 1 with a decreased risk for bleeding. When all these variables were considered, we composed a risk scoring system, in which we assigned points to each variable according to the ratio between the odds ratio for bleeding and for VTE. Overall, 21% of patients scored less than 0 points and had a bleeding vs. VTE ratio of 1.19; 55% scored 0 to 1.0 points and had a ratio of 2.13; and 24% scored over 1.0 points and had a ratio of 6.10.

CONCLUSIONS

A risk score based on variables documented at admission can identify patients with different ratios (near 1.0; about 2.0; and >6.0) between the rate of bleeding and of VTE.

Preventing venous thromboembolism in elective upper limb surgery

BACKGROUND

Deep venous thrombosis (DVT) and pulmonary embolism (PE) have considerable clinical and economic consequences. The prevention of venous thrombosis and PE are increasingly seen as quality markers for surgery. Guidance is available from a number of sources to stratify risk for different patients and procedures and to define an appropriate standard of care. Despite this, best practice is unclear.

METHODS

We reviewed the available guidance for orthopedic surgeons undertaking elective upper limb surgery with respect to prescribing DVT prophylaxis. Material was identified from publications produced by professional and regulatory bodies, including United States Surgeon General, United Kingdom Department of Health, the American Academy of Orthopaedic Surgeons, the Scottish Intercollegiate Guideline Network, the National Institute for Clinical Excellence, and the American College of Chest Physicians, as well as a structured MEDLINE database search.

RESULTS

The picture is particularly confused in the case of elective upper limb surgery. Much of the evidence for prescribing DVT prophylaxis is related to lower limb surgery or trauma surgery.

CONCLUSIONS

Failing to prescribe prophylaxis against venous thromboembolism (VTE) may be presented as a failure of care. We present a review of current guidance and the supporting evidence in order to establish evidence-based best practice and a standard of care for elective upper limb surgery.

LEVEL OF EVIDENCE

Review Article.

Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

This guideline addressed VTE prevention in hospitalized medical patients, outpatients with cancer, the chronically immobilized, long-distance travelers, and those with asymptomatic thrombophilia.

METHODS

This guideline follows methods described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

For acutely ill hospitalized medical patients at increased risk of thrombosis, we recommend anticoagulant thromboprophylaxis with low-molecular-weight heparin (LMWH), low-dose unfractionated heparin (LDUH) bid, LDUH tid, or fondaparinux (Grade 1B) and suggest against extending the duration of thromboprophylaxis beyond the period of patient immobilization or acute hospital stay (Grade 2B). For acutely ill hospitalized medical patients at low risk of thrombosis, we recommend against the use of pharmacologic prophylaxis or mechanical prophylaxis (Grade 1B). For acutely ill hospitalized medical patients at increased risk of thrombosis who are bleeding or are at high risk for major bleeding, we suggest mechanical thromboprophylaxis with graduated compression stockings (GCS) (Grade 2C) or intermittent pneumatic compression (IPC) (Grade 2C). For critically ill patients, we suggest using LMWH or LDUH thromboprophylaxis (Grade 2C). For critically ill patients who are bleeding or are at high risk for major bleeding, we suggest mechanical thromboprophylaxis with GCS and/or IPC at least until the bleeding risk decreases (Grade 2C). In outpatients with cancer who have no additional risk factors for VTE we suggest against routine prophylaxis with LMWH or LDUH (Grade 2B) and recommend against the prophylactic use of vitamin K antagonists (Grade 1B).

CONCLUSIONS

Decisions regarding prophylaxis in nonsurgical patients should be made after consideration of risk factors for both thrombosis and bleeding, clinical context, and patients' values and preferences.

[Comparison of platelet monitoring in patients receiving thromboprophylaxis with fondaparinux or a low molecular weight heparin. The Ariane study]

OBJECTIVE

To describe and compare the conditions of use of fondaparinux and low molecular weight heparin (LMWH) in the prevention of venous thromboembolism in routine general practice with a focus on platelet monitoring.

METHOD

This was an observational and pharmaco-epidemiological survey, performed in France in general practice in adult patients receiving thromboprophylaxis with fondaparinux or a LMWH. The study collected data on medical conditions justifying thromboprophylaxis, reasons for platelet monitoring and type of prescription.

RESULTS

Four hundred and seventy general practioners included 837 analysable patients (450 treated with fondaparinux and 387 with LMWH). In the fondaparinux group, the mean age was 61.5±17.3 and 259 (57.6 %) patients were women. In the LMWH group, the mean age was 61.7±17.8 and 205 (53.0 %) patients were women. The reasons of prescribing were: bedridden related to a severe acute medical illness in 255 (56.7 %) patients with fondaparinux and 244 (63.1 %) with LMWH, and reduction of mobility associated with trauma without fracture respectively in 121 (26.9 %) and 85 (22.0 %) of patients. Associated risk factors were varicose veins, obesity and a history of thrombosis. Platelet monitoring was prescribed in 168 (37.6 %) patients treated with fondaparinux. In this group, these prescription were considered "appropriate" in 94 (20.9 %) patients, of whom 76 (16.9 %) were monitored for screening purposes, and "not appropriate" in 67 (14.9 %) patients, because prescribed to monitor thrombo-prophylaxis. In the LMWH group, a platelet count was prescribed in 370 (96.1 %) patients, of whom 312 (81.0 %) receiving a prescription only in order to monitor thromboprophylaxis.

DISCUSSION

The results provided in the Ariane study were coherent with literature data (Etape and Depart studies). In comparison with the CNAM study, which evaluated prescription practices for LMWH in thromboprophylaxis in France in 1999, and which reported a global rate of platelet monitoring of 70.0 %, the rate reported in the Ariane study (81.0 %) seems to represent an improvement in the practice standards. Since 2009, Afssaps does not recommend a systematic monitoring with LMWH at acute or prophylactic dose, outside a post surgical context or in case of pre-treatment with unfractionated heparin.

CONCLUSION

The Ariane study provides important information on platelet monitoring in patients treated with fondaparinux or LMWH, and also on thromboprohylaxis in general practice.

Predictive and associative models to identify hospitalized medical patients at risk for VTE

BACKGROUND

Acutely ill hospitalized medical patients are at risk for VTE. We assessed the incidence of VTE in the observational International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) study and derived VTE risk assessment scores at admission and associative VTE scores during hospitalization.

METHODS

Data from 15,156 medical patients were analyzed to determine the cumulative incidence of clinically observed VTE over 3 months after admission. Multiple regression analysis identified factors associated with VTE risk.

RESULTS

Of the 184 patients who developed symptomatic VTE, 76 had pulmonary embolism, and 67 had lower-extremity DVT. Cumulative VTE incidence was 1.0%; 45% of events occurred after discharge. Factors independently associated with VTE were previous VTE, known thrombophilia, cancer, age > 60 years, lower-limb paralysis, immobilization ≥ 7 days, and admission to an ICU or coronary care unit (first four were available at admission). Points were assigned to each factor identified to give a total risk score for each patient. At admission, 67% of patients had a score ≥ 1. During hospitalization, 31% had a score ≥ 2; for a score of 2 or 3, observed VTE risk was 1.5% vs 5.7% for a score ≥ 4. Observed and predicted rates were similar for both models (C statistic, 0.65 and 0.69, respectively). During hospitalization, a score ≥ 2 was associated with higher overall and VTE-related mortality.

CONCLUSIONS

Weighted VTE risk scores derived from four clinical risk factors at hospital admission can predict VTE risk in acutely ill hospitalized medical patients. Scores derived from seven clinical factors during hospitalization may help us to further understand symptomatic VTE risk. These scores require external validation.

Venous thromboembolism risk stratification in medically-ill hospitalized cancer patients. A comprehensive cancer center experience

Cancer and its treatment are recognized risk factors for VTE. Compliance rate with published VTE prophylaxis guidelines is low. Decision on when to offer prophylaxis for hospitalized cancer patients is difficult to make. This paper describes current clinical practice in offering VTE prophylaxis to hospitalized cancer patients. Prophylaxis rate and rate of VTE will be correlated with the risk level. We prospectively followed all consecutive adult cancer patients admitted to medical units over a 5-month period. Caprini risk assessment model, with some modifications, was utilized to determine risk of VTE. Six hundred and six patients (51% males, median age 52 years, range 18-91) were included. Reasons for admission included infections (25%), chemotherapy (22%) and palliative care (10%). In addition to cancer, the most frequently encountered risk factors for VTE were: Immobilization (35%), age > 60 years (31%) and body mass index > 30 in (20%). Patients were grouped according to their total risk score: low (9%), moderate (44%) and high risk (47%). VTE prophylaxis rate was 55.1% for the whole study group. Following discharge, patients were followed for 60 days. The incidence of VTE was 3.4% in the moderate and 4.2% in the high risk groups, while none in the low risk group developed VTE. Many additional risk factors for VTE are usually encountered in hospitalized cancer patients. Cancer alone may not be an enough reason for VTE prophylaxis. Risk assessment model able to stratify patients into different risk categories will simplify decision making and enhance VTE prophylaxis rate.