CONTEXT A low ankle brachial index (ABI) indicates atherosclerosis and an increased risk of cardiovascular and cerebrovascular events. Screening for a low ABI can identify an asymptomatic higher risk ...group potentially amenable to preventive treatments. OBJECTIVE To determine the effectiveness of aspirin in preventing events in people with a low ABI identified on screening the general population. DESIGN, SETTING, AND PARTICIPANTS The Aspirin for Asymptomatic Atherosclerosis trial was an intention-to-treat double-blind randomized controlled trial conducted from April 1998 to October 2008, involving 28 980 men and women aged 50 to 75 years living in central Scotland, free of clinical cardiovascular disease, recruited from a community health registry, and had an ABI screening test. Of those, 3350 with a low ABI (≤0.95) were entered into the trial, which was powered to detect a 25% proportional risk reduction in events. INTERVENTIONS Once daily 100 mg aspirin (enteric coated) or placebo. MAIN OUTCOME MEASURES The primary end point was a composite of initial fatal or nonfatal coronary event or stroke or revascularization. Two secondary end points were (1) all initial vascular events defined as a composite of a primary end point event or angina, intermittent claudication, or transient ischemic attack; and (2) all-cause mortality. RESULTS After a mean (SD) follow-up of 8.2 (1.6) years, 357 participants had a primary end point event (13.5 per 1000 person-years, 95% confidence interval CI, 12.2-15.0). No statistically significant difference was found between groups (13.7 events per 1000 person-years in the aspirin group vs 13.3 in the placebo group; hazard ratio HR, 1.03; 95% CI, 0.84-1.27). A vascular event comprising the secondary end point occurred in 578 participants (22.8 per 1000 person-years; 95% CI, 21.0-24.8) and no statistically significant difference between groups (22.8 events per 1000 person-years in the aspirin group vs 22.9 in the placebo group; HR, 1.00; 95% CI, 0.85-1.17). There was no significant difference in all-cause mortality between groups (176 vs 186 deaths, respectively; HR, 0.95; 95% CI, 0.77-1.16). An initial event of major hemorrhage requiring admission to hospital occurred in 34 participants (2.5 per 1000 person-years) in the aspirin group and 20 (1.5 per 1000 person-years) in the placebo group (HR, 1.71; 95% CI, 0.99-2.97). CONCLUSION Among participants without clinical cardiovascular disease, identified with a low ABI based on screening a general population, the administration of aspirin compared with placebo did not result in a significant reduction in vascular events. TRIAL REGISTRATION isrctn.org Identifier: ISRCTN66587262
Objective To determine whether drug-eluting stent (DES) use varies among Scottish hospitals, and the extent to which any variations are explained by differences between operators, patients and ...lesions. Methods Multi-level analysis of consecutive patients treated with percutaneous coronary intervention (PCI) between April 2005 and March 2006 in Scotland, using the Scottish Coronary Revascularization Registry. Results A total of 38 operators performed 5967 PCI procedures on 8489 lesions. Crude level of DES use was 47.6%, and the results varied among hospitals (range 30.6–61.8%, χ2 = 341.6, P < 0.0001). There was significant between-operator variation in the null model. This was attenuated by the addition of hospital as a fixed effect. Nonetheless, the final model demonstrated significant between-operator variability σ2 = 0.486 (0.249–0.971) and between-hospital variation, after case-mix adjustment. Conclusions Within Scotland, marked variation existed among hospitals in the use of DES. Operator was the most important factor at patient level, and hospital of treatment, rather than case-mix, was the most important modifier of between-operator variation. Patient selection for DES is complex and may contribute to much of the variations demonstrated. Consensus criteria would provide more detail than is included in current guidance, may aid decision-making for individual patients, reduce opportunity costs and ensure equity of access.
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BFBNIB, NMLJ, NUK, OILJ, PNG, UL, UM, UPUK, VSZLJ
1. The effects of venous occlusion on the coagulation and fibrinolytic systems were investigated in six patients with type 1 (insulin-dependent) diabetes and 11 age- and sex-matched non-diabetic ...control subjects. The coagulation parameters (fibrinogen, prothrombin time, partial thromboplastin time with kaolin, von Willebrand factor antigen) did not differ between patients and control subjects either before or after 20 min of venous occlusion. No rise was observed in von Willebrand factor antigen after venous occlusion in either group. 2. In the diabetic patients, chronic activation of the fibrinolytic system was found at baseline, which was indicated by a shortened euglobulin lysis time (P < 0.01), increased tissue plasminogen activator activity (P < 0.05) and decreased plasminogen activator inhibitor type 1 antigen level (P < 0.05), when compared with control subjects. In both groups venous occlusion resulted in significant increments in all measurements, except plasminogen activator inhibitor type 1 antigen level. The post-occlusion values did not differ between the two groups, except the plasminogen activator inhibitor type 1 antigen level, which remained significantly lower in the diabetic patients. The mean increments in each parameter did not differ between the two groups. 3. Coagulation and fibrinolysis were assessed in response to acute insulin-induced hypoglycaemia. Von Willebrand factor antigen levels increased significantly in both groups, with no difference in maximal increments. Significant activation of the fibrinolytic system occurred in response to hypoglycaemia, demonstrated by shortened euglobulin lysis time and increased fibrin plate lysis, tissue plasminogen activator antigen level and tissue plasminogen activator activity.
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