Thrombin-anti-thrombin levels and patency of arterio-venous fistula in patients undergoing haemodialysis compared to healthy volunteers : a prospective analysis

Peer reviewedPublisher PD

Utility of B-type natriuretic peptide in predicting medium-term mortality in patients undergoing major non-cardiac surgery

We assessed the ability of pre-operative B-type natriuretic peptide (BNP) levels to predict medium-term mortality in patients undergoing major noncardiac surgery. During a median 654 days follow-up 33 patients from a total cohort of 204 patients (16%) died. The optimal cut-off in this cohort, determined using a receiver operating characteristic curve, was >35pg.mL-1. This was associated with a 3.47-fold increase in the hazard of death (p=0.001) and had a sensitivity of 70% and a specificity of 68% for this outcome. These findings extend recent work demonstrating that BNP levels obtained before major noncardiac surgery can be used to predict peri-operative morbidity, and indicate that they also forecast medium-term mortality.This work was supported by a grant from TENOVUS Scotland. The Health Services Research Unit is core-funded by the Chief Scientists Office of the Scottish Executive Health Department.Peer reviewedAuthor versio

Barriers and enablers to walking in individuals with intermittent claudication: a systematic review to conceptualize a relevant and patient-centered program

Background: Walking limitation in patients with peripheral arterial disease (PAD) and intermittent claudication (IC) contributes to poorer disease outcomes. Identifying and examining barriers to walking may be an important step in developing a comprehensive patient-centered self-management intervention to promote walking in this population. Aim: To systematically review the literature regarding barriers and enablers to walking exercise in individuals with IC. Methods: A systematic review was conducted utilizing integrative review methodology. Five electronic databases and the reference lists of relevant studies were searched. Findings were categorized into personal, walking activity related, and environmental barriers and enablers using a social cognitive framework. Results: Eighteen studies including quantitative (n = 12), qualitative (n = 5), and mixed method (n = 1) designs, and reporting data from a total of 4376 patients with IC, were included in the review. The most frequently reported barriers to engaging in walking were comorbid health concerns, walking induced pain, lack of knowledge (e.g. about the disease pathology and walking recommendations), and poor walking capacity. The most frequently reported enablers were cognitive coping strategies, good support systems, and receiving specific instructions to walk. Findings suggest additionally that wider behavioral and environmental obstacles should be addressed in a patient-centered self-management intervention. Conclusions: This review has identified multidimensional factors influencing walking in patients with IC. Within the social cognitive framework, these factors fall within patient level factors (e.g. comorbid health concerns), walking related factors (e.g. claudication pain), and environmental factors (e.g. support systems). These factors are worth considering when developing self-management interventions to increase walking in patients with IC. Systematic review registration CRD42018070418

Effects of wheat and oat-based whole grain foods on serum lipoprotein size and distribution in overweight middle aged people : a randomised controlled trial

Peer reviewedPublisher PD

A pragmatic multi-centre randomised controlled trial of fluid loading and level of dependency in high-risk surgical patients undergoing major elective surgery : trial protocol

Peer reviewedPublisher PD

Introducing endovenous laser therapy ablation to a national health service vascular surgical unit e the aberdeen experience

Objectives: To report early clinical outcomes and learning experience following the introduction of endovenous laser ablation (EVLA) to an NHS vascular unit. Design: Prospective observational study. Results: Between February 2006 and January 2008, 631 consecutive patients underwent EVLA to 704 refluxing truncal veins e 579 GSV, 119 SSV and 6 straight segments of anterior accessory GSV. 275/631 (44%) patients had local anaesthesia (LA) plus sedation, 237 (38%) had LA only and 119 (18%) had general anaesthesia. All were treated using the 810 nm diode laser. Adjuvant procedures on-table included foam sclerotherapy 129/704 (18%), multiple stab avulsions 53/ 704 (8%) and 3 limbs had both. Three-month follow-up with duplex examination is complete in 635/704 limbs (90%). Complete occlusion was noted in 610 veins (96%), 14 (2.2%) were partially occluded and 11 (1.7%) showed no occlusion. 193 (30%) of the 635 limbs seen at follow-up required further treatment for residual varicosities using foam sclerotherapy. There has been one non-fatal pulmonary embolus associated with EVLA and no other complications. Conclusions: EVLA is safe and technically effective. It has a defined learning curve requiring new operator skills which can be readily acquired.peer-reviewe

Double-blind randomized placebo-controlled trial of the antiplatelet effects of aspirin-clopidogrel combination versus aspirin alone at endovascular intervention for intermittent claudication of the lower limb

Intermittent claudication is a common problem which causes significant impairment of quality of life and increased mortality. Endovascular recanalization, widely used for symptomatic relief, carries a high risk of reocclusion. Platelets play a central role in this process. Aspirin currently used in claudicants reduces the risk, and more potent antiplatelet strategies may reduce this further. The aim of this study was to investigate the antiplatelet effect of aspirin–clopidogrel versus aspirin alone in patients with claudication undergoing endovascular intervention. Methods: This was a double-blind randomized placebo-controlled trial; 132 patients were randomized to clopidogrel and aspirin or to placebo and aspirin with a loading dose 12 h before endovascular intervention. Flow cytometric measurement of platelet fibrinogen binding and P-selectin expression as measures of platelet activation status and of platelet responsiveness to stimulation at baseline, 12 h post-loading dose, 1 h, 24 h and 30 days postintervention. Results: Platelet activation was significantly diminished in the clopidogrel group at 12 h post-loading dose compared to baseline (P-selectin: 27·3 per cent reduction, P = 0·017; bound fibrinogen: 34·7 per cent reduction, P = 0·024; stimulated bound fibrinogen: 49 per cent, P < 0·001). No significant change was observed in the control group. Platelet function was significantly suppressed in the clopidogrel group at 1 h, 24 h and 30 days after endovascular intervention compared to the placebo group (P < 0·001). Conclusion: Clopidogrel–aspirin combination dramatically inhibits platelet function in claudicants before and after intervention. The combination treatment may help reduce reocclusion after endovascular recanalization.peer-reviewe

Randomized clinical trial of the antiplatelet effects of aspirin–clopidogrel combination versus aspirin alone after lower limb angioplasty

There is a high risk of reocclusion after successful lower limb angioplasty. Platelets play a central role in this process. The aim of this study was to investigate the antiplatelet effect of a combination of aspirin and clopidogrel compared with aspirin alone in patients with claudication undergoing endovascular revascularization. Methods This was a double-blind randomized placebo-controlled trial. Some 132 patients were randomized to clopidogrel and aspirin or placebo and aspirin, with a loading dose 12 h before endovascular intervention. Flow cytometric measurements of platelet fibrinogen binding and P-selectin expression were taken as measures of platelet function at baseline, 12 h after the loading dose, and 1 h, 24 h and 30 days after intervention. Results Within 12 h of the loading dose, platelet activation in the clopidogrel group had decreased (P-selectin by 27·3 per cent, P = 0·017; fibrinogen binding by 34·7 per cent, P = 0·024; stimulated fibrinogen binding by 49·2 per cent, P < 0·001). No change was observed in the placebo group. Platelet function in the clopidogrel group was significantly suppressed compared with baseline at 1 h, 24 h and 30 days after endovascular intervention (stimulated fibrinogen binding by 53·9, 51·7 and 57·2 per cent respectively; all P < 0·001). Conclusion A combination of clopidogrel and aspirin inhibited platelet function more than aspirin alone in patients with claudication before and after angioplasty.peer-reviewe

Clopidogrel has no effect on D-dimer and thrombin-antithrombin III levels in patients with peripheral arterial disease undergoing peripheral percutaneous transluminal angioplasty

Objective: Coagulation activation markers are significantly elevated in patients with peripheral arterial disease compared with healthy controls. The more severe the disease, the higher the markers. Increased coagulation activation may contribute to the disease process and the risk of complications in patients with peripheral arterial disease, particularly after endovascular intervention. Animal studies have shown that clopidogrel significantly inhibits coagulation activation. The aim of this study was to determine whether combination of aspirin and clopidogrel affects thrombin-antithrombin III and D-dimer in patients with intermittent claudication undergoing angioplasty, compared with aspirin alone. Methods: This was a double blind, randomized placebo-controlled trial conducted in a vascular unit in a tertiary referral center. One hundred thirty-two patients with intermittent claudication were randomized to clopidogrel and aspirin or placebo and aspirin, with a loading dose 12 hours before endovascular intervention. D-dimer and thrombin-antithrom- bin III (TAT) levels were measured using enzyme-linked immunosorbent assay at baseline, 1 hour before, and 1 hour, 24 hours, and 30 days after intervention in 103 patients who underwent endovascular intervention. Results: There was a significant rise in D-dimer levels at 1 hour and 24 hours after angioplasty in both groups (placebo group: 63.69, 141.45, 122.18 ng/mL; clopidogrel group: 103.79, 159.95, 134.69 ng/mL), but no difference between the two groups (P .514). Similarly there was a significant rise in TAT levels at 1 hour after angioplasty in both groups (placebo group: 2.93, 6.16 g/L; clopidogrel group: 3.39, 5.27 g/L), with no significant difference between the two groups (P .746). Conclusion: Endovascular intervention results in a significant increase in TAT and D-dimer. The addition of clopidogrel to aspirin has no effect on TAT and D-dimer before or after endovascular intervention.peer-reviewe