Background Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence.Methods ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362.

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Among the considerations affecting the therapeutic approach to patients with atherosclerosis of the lower extremities is their associated risk of death, myocardial infarction, stroke, and limb loss. To investigate the relationship of these events to the severity of peripheral vascular disease we undertook a 6-year review of 247 consecutive patients undergoing lower extremity noninvasive vascular assessment. There were 130 men and 117 women with a mean age of 65 +/- 15 years. Patients were categorized into four groups according to their ankle-brachial pressure indexes at their first visit. Ninety-seven patients had normal indexes (greater than or equal to 0.92), 86 had indexes of 0.50 to 0.91, 39 had indexes of 0.31 to 0.49, and 25 had indexes within the ischemic range, less than or equal to 0.30. At 6 years 64% of the patients with ischemic indexes were dead. This incidence was significantly higher than that of any other patient category (p less than 0.01). Diabetes also had a significantly adverse effect on survival. The incidence of stroke and myocardial infarction was similar for all disease groups. Thirteen percent and 32% of patients with indexes of 0.31 to 0.49 and less than or equal to 0.30, respectively, underwent limb amputation. We conclude that patients with evidence of mild to moderate peripheral vascular disease have a survival rate and risk of vascular-related disorders similar to those of patients of similar age with little evidence of disease, whereas an ankle-brachial pressure index less than or equal to 0.30 is associated with a malignant prognosis.

Pseudomonas aeruginosa is a pathogen in both humans and animals. This bacterium, most often associated with respiratory infections in cystic fibrosis patients, was found to be the causative agent in bovine mastitis outbreaks among 11 Irish dairy herds. Epidemiological findings suggested that the infection was spread to all herds by teat wipes that had been contaminated with this organism. Two molecular-typing strategies were used in an attempt to determine the genomic relationship(s), if any, of the P. aeruginosastrains isolated from the various herds and to verify whether the same strain was responsible for each outbreak. Thirty-six isolates from the mastitis outbreaks were tested and compared to fourteen clinical isolates from Cork University Hospital. With one exception, all outbreak-linked strains produced identical patterns when ribotyped withClaI and PvuII enzymes. Eight of the clinical isolates gave the same ClaI ribotype pattern as the mastitis-causing strains. However, PvuII proved more discriminatory, with only the outbreak isolates producing identical patterns. Similar results were obtained with RW3A-primed DNA amplification fingerprinting, with all outbreak isolates except one displaying the same fingerprint array. The clinical strains produced several fingerprint patterns, all of which were different from those of the mastitis-causing isolates. Fine-resolution DNA fingerprinting with a fluorescence-labelled RW3A primer also identified a number of low-molecular-weight polymorphisms that would have remained undetected by conventional methods. These data support the view that the sameP. aeruginosa strain was responsible for the mastitis outbreaks in all 11 herds.

The risk of stroke in patients with asymptomatic carotid disease appears to be related to the presence of a high-grade stenosis. To determine the prevalence of such lesions, duplex scanning was performed on 348 unselected volunteers without symptoms who attended hospital-sponsored health fairs. There were 209 women and 139 men whose ages ranged from 24 to 91 years. Risk factors included hypertension (37%), diabetes (8%), and smoking (23%). One hundred seven subjects (31%) had evidence of extracranial carotid artery disease, 13 (4%) with greater than 50% stenosis, and three (1%) with greater than 80% stenosis of the internal carotid artery. Bilateral disease was present in 50 patients. Disease prevalence and severity were significantly correlated with age (p less than 0.001) and hypertension (p less than 0.01) but not with diabetes or smoking. The incidence of disease was similar in men and women. Although carotid plaques are common in people older than 50 years of age who do not have symptoms, the prevalence of high-grade stenosis--even in the elderly hypertension population--is low, casting doubt on the cost-effectiveness of generalized screening.