Epidemiology and risk factors for cancer-associated thrombosis

Cancer associated thrombosis (CAT) has been demonstrated a long time ago and is a frequent comorbid condition. Some risk factors are well established and related to the treatment of cancer: surgery, chemotherapy, radiation therapy, indwelling catheters. Other risk factors depend on tumour type and patient presentation, in particular pancreatic and brain cancer, bed resting and previous venous thrombosis. With the advances in cancer treatment and care, patients with cancer live longer and experience various therapies, sometimes during a long time. There is a need to better define the incidence and prevalence of CAT in the light of new therapeutic strategies and patient survival. This article focuses on the description of incidence and prevalence of CAT in the literature and on the description of risk factors, traditional but also emerging ones.

[College of the French Vascular Medicine Teachers (CEMV) statement: Arterial Doppler waveforms analysis (simplified Saint-Bonnet classification)]

Lower extremity peripheral artery disease is a frequent disease. Arterial Doppler waveforms analysis is a key element in vascular medicine, especially to diagnose lower peripheral artery disease. Although Doppler waveforms are often used, descriptions are highly heterogeneous. This review presents the simplified Saint-Bonnet classification that is tought to vascular medicine residents in order to homogenize arterial flow description.

Low-molecular-weight heparins for cancer-associated thrombosis: Adherence to clinical practice guidelines and patient perception in TROPIQUE, a 409-patient prospective observational study

PURPOSE

Data on long-term treatment with low-molecular-weight heparins (LMWH) in cancer patients treated for venous thromboembolism are scarce. Study objectives were to document the long-term clinical use of LMWH and patient perception in this setting.

METHODS

Adult cancer patients receiving antineoplastic treatment or palliative care and LMWH for cancer associated venous thromboembolism (CAT) were eligible to participate in this prospective observational study. Main outcome was adherence to clinical practice guidelines based on recommended LMWH treatment doses for at least 3months in the absence of severe renal insufficiency. Patients' perception of the treatment was assessed in an ancillary study using the Perception Anticoagulant Treatment Questionnaire (PACT-Q).

RESULTS

Among 409 included cancer patients aged 65±12.1years, overall adherence to practice guidelines as defined in the protocol was 55.3% (226 patients). However, 98.0% of patients received a prescription for 3months or more and mean LMWH treatment duration for VTE was 6.27±0.15months which meets guidelines recommendations. Main patients' expectations scored on a 1-5 scale were blood clots prevention (mean 3.94±0.75), symptom relief (mean 3.98±1.04) and ease of use (mean 4.22±0.9). LMWH treatment appeared convenient (global score 79.7±17.1 on a 0 to 100 scale) and 69.1% of patients were satisfied or very satisfied.

CONCLUSION

Despite incomplete strict adherence to guidelines, treatment duration with LMWH was adequate showing substantial progress in the management of CAT patients. Patients expectations were high while treatment was perceived convenient with a high degree of satisfaction.

Superficial vein thrombosis and recurrent venous thromboembolism: a pooled analysis of two observational studies

BACKGROUND

The management strategies for symptomatic isolated superficial vein thrombosis (SVT) (without concomitant deep vein thrombosis [DVT] or pulmonary embolism [PE]) have yet to achieve widespread consensus. Concerns have been raised regarding the usefulness of prescribing anticoagulant treatments to all patients with isolated SVT. Determining the isolated SVT subgroups who have the highest risks of venous thromboembolism (VTE) recurrence (composite of DVT, PE, and new SVT) may facilitate the identification of patients who are likely to benefit from anticoagulant treatment.

DESIGN AND METHODS

We performed a pooled analysis on individual data from two observational, multicenter, prospective studies, to determine predictors for VTE recurrence and their impact in an unselected population of symptomatic isolated SVT patients.

RESULTS

One thousand and seventy-four cases of symptomatic isolated SVT were followed up at 3 months. VTE recurrence was observed in 3.9% of the patients; 16.2% of the patients did not receive anticoagulants, and 0.6% experienced a VTE recurrence. Cancer, personal history of VTE and saphenofemoral/popliteal involvement significantly increased the risk of subsequent VTE or DVT/PE in univariate analyses. Only male sex significantly increased the risk of VTE or DVT/PE recurrence in multivariate analyses. Twelve percent of the patients had cancer or saphenofemoral junction involvement, and were at higher risk of DVT/PE recurrence than patients without those characteristics (4.7% vs. 1.9%, P= 0.06).

CONCLUSIONS

In patients with symptomatic SVT, only male sex significantly and independently increased the risk of VTE recurrence. Cancer or saphenofemoral junction involvement defined a population at high risk for deep VTE recurrence. Some SVTs might be safely managed without anticoagulants.

[The best of vascular medicine in 2006]

Peripheral arterial disease (PAD) remains an under-diagnosed affection, and the ankle-brachial index (ABI), a simple diagnostic method, is poorly known and seldom used, and the vascular patient's prescription list is frequently insufficient regarding results obtained in large trials with good methodology. The French ATTEST study underlines the fact that ABI is measured in less than 1 out of 3 patients with PAD. In ATTEST study, less than 10% have the triple therapy validated in PAD : antiplatelet drugs, statins and ACE-inhibitors. The international REACH registry included more than 60 000 patients suffering from atherosclerosis, including 8 000 cases with PAD. This survey evidences that in PAD patients, the annual cardiovascular complication rate is significantly higher than in patients with coronary artery disease (18 vs 13%); again PAD appears systematically under-treated when compared to CAD. These epidemiological surveys highlight the importance of screening of atherosclerotic lesions with the aim of setting an active prevention of CV complications. The new guidelines insist on the screening of PAD in patients at risk, as well as on the importance of the global management after initiating the triple therapy, independent of the CV risk factors. In a 5-year longitudinal study from an initial cohort of 2265 subjects, Aboyans et al. studied the progression of PAD by repeated measurements of ABI at the level of ankles and toes. Factors of progression for large-vessels PAD were active smoking, the total/HDL-cholesterol ratio, Lp(a) and CRP. Importantly, diabetes was not associated to the PAD progression in large vessels, but in contrast, it was the sole factor associated to the progression of PAD in small vessels. In an Austrian study published this year in the NEJM, Schillinger et al. compared balloon angioplasty versus the use of Nitinol stent for the treatment of long stenoses of the superficial femoral artery. In case of claudication, these lesions are usually treated medically, whereas surgery is required for more severe cases. The fact that stenting these long lesions of the superficial femoral artery provides benefits in terms of restenosis opens a approach for the endovascular therapy, to be confirmed by larger trials.

[The best of vascular medicine in 2005]

It is illusory to think that one year is long enough to establish all the truths that will guide our clinical practice in vascular medicine. On the contrary, one year was long enough to contradict what the preceding twelve months had set out to demonstrate. Consequently, promising trials in the treatment of abdominal aortic aneurysms by endoprostheses have been the object of contradictory debate with regards to the long-term benefits. In fundamental research, circulating progenitors of endothelial cells have been shown to be a marker of atherosclerosis, but is it a better marker than LDL-cholesterol values? The demonstration that these progenitors are of value in the treatment of essential ischaemia of the lower limbs is awaited. Finally, ximelagatran, a direct thrombin antagonist, seemed to have all the qualities of an ideal anticoagulant: easy to use, safe... until the report of raised hepatic enzymes, the clinical relevance of which remains to be determined. In the good news section: the Systolic Pressure Index, an unquestioned marker of arterial disease. Its reduction was known to be correlated with the prevalence of cardiovascular complications. However, it has now been shown that an increase in the index is also associated with cardiovascular complications, a real U-shaped curve. Renal arterial stenosis should be considered in patients with left ventricular failure presenting with flash pulmonary oedema. In the absence of cardiac pathology, BNP would seem to be a good biological marker of haemodynamically significant renal arterial stenosis. Finally, should superficial femoral artery stenosis be treated by an active stent. To date, there is no formal proof.

Optimisation de l’interrogatoire dans l’évaluation du risque de maladie thromboembolique veineuse : l’étude OPTIMEV

Venous thromboembolism (VTE) is a frequent disease and remains a major cause of mortality and morbidity among our patients. During the 20 past years, clinical description, diagnostic tools, and treatment have changed dramatically. Most published data describing risk factors for VTE no longer apply to the patients seen in daily practice. We present here the rationale, aims, and methodology of the OPTIMEV Study (OPTimisation de l'Interrogatoire pour la Maladie thromboEmbolique Veineuse).

RATIONALE

Risk factors for VTE are numerous, complex and interactions between them and their clinical importance is difficult to measure (table I). For example, odds ratios for VTE recurrence vary greatly across longitudinal studies. We searched the National Library of Medecine (PubMed) and the Amedeo website using the following keywords: "venous thromboembolism", "pulmonary embolism", "deep vein thrombosis", "risk factors". We selected 84 relevant articles published between 1972 and 2005. Based on this literature analysis, we identified the following major risk factors: VTE recurrence, surgery, cancer, immobilization, age, biological factors. For these factors, data are lacking and some questions are proposed.

OBJECTIVES

The broad objective of the study is to better evaluate clinical risk factors that fit today's practice against VTE. Specific aims are: 1) to determine whether risk factors are different between proximal and distal deep vein thrombosis (DVT); 2) to develop and prospectively validate a new prediction rule for outpatients. The primary hypothesis is that careful assessment of VTE recurrence, adequate surgical thromboprophylaxis, cancer staging, and varicose vein stratification according to the CEAP classification, is mandatory for accurate evaluation of thromboembolic disease risk.

METHODS

We conducted a multicenter, prospective, cohort study of 10000 patients. Enrollees are inpatients and outpatients presenting with a clinical suspicion of VTE in Emergency Departments and outpatient clinics in France. 4173 patients have been enrolled at this time (Figure 2). All eligible patients are enrolled during a selected period of time through different seasons. Data are collected by physicians in charge of the patients using an electronic case recording form. Collected data include baseline characteristics, risk factors, results of diagnostic investigations. Outcome measures obtained through telephone interview at 3 and 12 months include cancer diagnosis, VTE recurrence, haemorrhagic events, treatments, death. Univariate and multivariate analysis will be performed using multilevel logistic regression. The study organization is performed by the Centre d'Investigation Clinique de Grenoble and is sponsored by the French Society of Vascular Medicine. First results, to be published in 2006, will allow development of new prediction rules for VTE diagnosis.

[The best of vascular medicine in 2004]

The wealth of information in vascular pathology merits close examination. The French Cardiology Society vascular group turned its attention to arteries, veins, hypertension and a more fundamental investigation to analyse the results from some illuminating studies which appeared in 2004, despite some pertinent therapeutic doubts. Examination of the trials discussed here shows the importance, as much in vascular pathology as elsewhere, of founding our practice on evidence based medicine.

Aortic thrombosis and ulcerative colitis

Arterial thrombotic accidents in the course of inflammatory bowel disease are rare. They generally affect young adults whose disease is active. We observed a case of aortic and renal arterial thrombosis in a 40-year-old woman who was suffering from ulcerative colitis. Surgical thrombectomy ensured good postoperative results, without any ischemic or renal sequelae. Six days later the patient presented with distal thrombosis of the splenic artery, which receded under anticoagulant treatment. The physiopathology of thromboembolic events in the course of inflammatory bowel disease is uncertain. Such events result from a state of hypercoagulability of various mechanisms, which can be observed in active inflammatory bowel disease. This possibility of serious arterial thrombosis argues in favor of long-term anticoagulant treatment when inflammatory bowel disease is active.

[Quantitative assessment of carotid stenosis: comparison between Doppler ultrasound, spiral computed tomography angiography, magnetic resonance angiography and digital angiography]

BACKGROUND

The North American Symptomatic Carotid Endarterectomy Trial has confirmed the benefit of carotid endarterectomy in comparison to medical treatment in stroke prevention in symptomatic patients having a carotid stenosis of 70% or more. The Asymptomatic Carotid Atherosclerosis Study has concluded that the benefit of surgical treatment remains significant in asymptomatic patients with 60% (or more) stenosis of the ipsilateral internal carotid artery, when mortality rate remains inferior to 3%. In these two trials, angiography has been used to quantify the stenosis. Though this test is carrying some neurological and renal risks, replacing the angiography stenosis grading for a non or less invasive test, seems to be permissible.

METHODS

In our retroprospective study, the assessments of the carotid stenosis by several non-invasive tests findings were compared to the angiography results. Nineteen carotid arteries of fifteen patients, both symptomatic and asymptomatic, having a carotid stenosis at least 60% or more and being detected by the Doppler ultrasound were explored either by magnetic resonance angiography (MRA), spiral computed tomography angiography (SCTA) and angiography.

RESULTS

The ultrasonography and angiography findings were well correlated (r=0,88; p<0.002) according to the Spearman test. The assessments of the MRA were better correlated to the angiography than to the SCTA (respectively r=0.91, p<0.0001 and r=0,68, p<0.001). Using both ultrasonography and MRA as a confirmatory test, the rate of injustified carotid endarterectomy was 25%. And this rate rose up to 33% when the ultrasonography was used with the SCTA. It is noteworthy that negative predictive value of ARM was 100%. To reduce the mortality rate, several surgical teams managed the carotid stenosis without angiography.

CONCLUSION

MRA could replace angiography, on condition that the rate of unjustified carotid endarterectomy lowers and becomes acceptable. Far reaching complementary studies are necessary to confirm the fiability of those non-invasive tests. In order to raise the benefit to carotid endarterectomy, the research studies should turn to the predictive score determination of a surgical international risk and towards the "High benefit" patients groups after endarterectomy.

Arterioportal fistulas: twelve cases

During the last 20 years, we encountered 14 arterioportal fistulas in 12 patients. Gastrointestinal hemorrhage or mesenteric artery insufficiency were the most frequent conditions found after the diagnosis. Arterioportal arterial fistulas were congenital in two cases and acquired in 10; seven of these 10 were iatrogenic. One patient had three successive and different sites of arterioportal fistula. The fistula originated from a branch of the celiac axis in nine cases, the superior mesenteric artery in three, and the inferior mesenteric artery in two. One patient died of massive anal bleeding before any treatment was possible. Eight fistulas were treated surgically and five by arterial embolization. After treatment there was no early mortality, while hemorrhagic and ischemic complications regressed in all cases. Three hemorrhagic recurrences were observed in patients with preexisting cirrhosis (two cases) or by recurrence of a congenital arteriovenous fistula (one case). Closure of symptomatic arterioportal fistula is justified. The choice of the most appropriate method for each patient should be discussed between the surgeon and interventional radiologist on a case by case basis.