Association of ultrasonic texture and echodensity features between sides in patients with bilateral carotid atherosclerosis.

OBJECTIVES: Our objective was to estimate the correlation of echodensity and textural features, using ultrasound and digital image analysis, between plaques in patients with bilateral carotid stenosis. DESIGN: Cross-sectional observational study. METHODS: Patients undergoing carotid endarterectomy were recruited from Vascular Surgery at the Royal Victoria and Jewish General hospitals in Montreal, Canada. Bilateral pre-operative carotid ultrasound and digital image analysis was performed to extract echodensity and textural features using a commercially available Plaque Texture Analysis software (LifeQMedical Ltd). Principal component analysis (PCA) was performed. Partial correlation coefficients for PCA and individual imaging variables between surgical and contralateral plaques were calculated with adjustment for age, sex, contralateral stenosis, and statin use. RESULTS: In the whole group (n = 104), the six identified PCA variables and 42/50 individual imaging variables were moderately correlated (r = .211-.641). Correlations between sides were increased in patients with ≥50% contralateral stenosis and symptomatic patients. CONCLUSION: Textural and echodensity features of carotid plaques were similar between two sides in patients with bilateral stenosis, supporting the notion that plaque instability is determined by systemic factors. Patients with unstable features of one plaque should perhaps be monitored more closely or treated more aggressively for their contralateral stenosis, particularly if this is hemodynamically significant.

The critical role of the external carotid artery in cerebral perfusion of patients with total occlusion of the internal carotid artery.

AIM: The ipsilateral external carotid artery (ECA) can potentially provide an important collateral pathway for cerebral blood flow in the presence of occlusion or severe stenosis of the internal carotid artery (ICA), recovering up to 15% of the middle cerebral arterial flow. The aim of the study is to elucidate the role of ECA in cerebral flow of patients with total ICA occlusion. METHODS: Retrospective study of prospectively collected data of 139 patients with total ICA occlusions. The patients were divided to symptomatic and asymptomatic and were categorized in four subgroups according to the stenosis rates: A) ipsilateral ECA<70% and contralateral internal carotid artery stenosis <70%; B) ipsilateral ECA stenosis <70% and contralateral internal carotid artery stenosis ≥70%; C) ipsilateral ECA stenosis ≥70% and contralateral ICA stenosis <70%; D) ipsilateral ECA stenosis ≥70% and contralateral ICA stenosis ≥75%. RESULTS: Fifty eight (41.7%) patients were asymptomatic. The highest rate (48.2%) of asymptomatic patients was in Group A. Among patients with strokes, the highest rate belonged in groups C and D (44.4% and 50% respectively) where ipsilateral ECA stenosis was ≥70% irrespectively of the contralateral ICA patency. Ipsilateral external carotid artery stenosis ≥70% proved to be and independent risk factor for symptom presentation (P=0.013). CONCLUSION: The study reveals the significant role of ECA patency in cerebral flow in patients with ICA occlusion.

Lipid management and peripheral arterial disease.

Peripheral arterial disease (PAD) is a common disorder usually associated with silent or symptomatic arterial disease elsewhere in the circulation and a "cluster" of cardiovascular risk factors (e.g. smoking, dyslipidemia, hypertension, and insulin resistance/diabetes mellitus). The medical management of PAD should focus on both the relief of symptoms and prevention of secondary cardiovascular complications. This approach must include smoking cessation, optimal cholesterol levels, blood pressure and glycemic control as well as prescribing antiplatelet therapy. This review focuses on the evidence supporting the use of lipid-lowering drugs in PAD. Several trials indicate that getting low density lipoprotein-cholesterol levels to target (<2.6 mmol/l; 100 mg/dl), or even lower, is associated with improvement of symptoms and a reduction in vascular events in patients with PAD.

Long-term treatment of deep venous thrombosis with a low molecular weight heparin (tinzaparin): a prospective randomized trial.

OBJECTIVES: Evaluation of the effectiveness and safety of the low molecular weight heparin (LMWH) tinzaparin versus unfractionated heparin (UFH) followed by acenocoumarol in proximal deep venous thrombosis (DVT). DESIGN: Prospective, randomized clinical trial. MATERIAL AND METHODS: Consecutive patients (n=108) with acute leg DVT, confirmed by duplex, were randomized to either tinzaparin alone or UFH and acenocoumarol for 6 months. Patients were evaluated ultrasonographically at entry, 1, 3, 6 and 12 months. Thrombus regression, reflux distribution and the incidence of complications were studied. A cost-analysis, comparing the two treatments, was performed. RESULTS: The overall incidence of major events (mortality, DVT recurrence, pulmonary embolism, major bleeding, heparin-induced thrombocytopenia) was significantly different (p=0.035) in favor of tinzaparin (7 versus 17 events). The ultrasonographic clot volume score (an index of recanalization) decreased significantly in both treatment groups. However, tinzaparin produced significantly more extended overall recanalization from 3 months onwards (p<0.02). Thrombus regression was equivalent or in favor of tinzaparin in the different DVT subgroups and venous segments, but the statistical significance varied. Reflux showed non-significant differences overall or in subgroups. A cost-analysis resulted in favor of LMWH. CONCLUSIONS: A fixed daily dose of tinzaparin for 6 months was at least as effective and safe as UFH and acenocoumarol. Regarding major events and recanalization, there was a significant benefit in favor of tinzaparin. Long-term DVT treatment with tinzaparin could represent an alternative to conventional treatment.

Low molecular weight heparins in the long-term treatment of venous thromboembolism.

Low molecular weight heparins (LMWHs) have extensively replaced unfractionated heparin (UFH) in both thromboprophylaxis and initial treatment of venous thromboembolism (VTE) and their use for such indications is now well established. This paper reviews the role of LMWHs in the long-term treatment of VTE. Venous thrombosis, although a very frequent occurrence in everyday practice, still remains controversial in its treatment. Available literature comparing different LMWHs with UFH and oral anticoagulants (OAs) is presented. Comparison and evaluation of the effectiveness, safety and costs of alternative treatments are also made. The differences of various LMWHs are discussed and the need for separate clinical trials for every single LMWH is highlighted.