Analysis of pooled data from the randomised controlled trials of endarterectomy for symptomatic XXXX .

@entity1 @entity850 @entity64 @entity543
BACKGROUND: Endarterectomy reduces risk of @entity64 in certain @entity1 with recently symptomatic internal @entity543 . However, investigators have made different recommendations about the degree of @entity850 above which surgery is effective, partly because of differences between trials in the methods of measurement of @entity850 . To accurately assess the overall effect of surgery, and to increase power for secondary analyses, we pooled trial data and reassessed carotid angiograms. METHODS: We pooled data from the European Carotid Surgery Trial (ECST), North American Symptomatic Carotid Endarterectomy Trial, and Veterans Affairs trial 309 from the original electronic data files. Outcome events were re-defined, if necessary, to achieve comparability. Pre-randomisation carotid angiograms from ECST were re-measured by the method used in the other two trials. RESULTS: Risks of main outcomes in both treatment groups and effects of surgery did not differ between trials. Data for 6092 @entity1 , with 35000 @entity1 -years of follow-up, were therefore pooled. Surgery increased the 5-year risk of ipsilateral @entity64 in @entity1 with less than 30% @entity850 (n=1746, absolute risk reduction -2.2%, p=0.05), had no effect in @entity1 with 30-49% @entity850 (1429, 3.2%, p=0.6), was of marginal benefit in those with 50-69% @entity850 (1549, 4.6%, p=0.04), and was highly beneficial in those with 70% @entity850 or greater without near-occlusion (1095, 16.0%, p<0.001). There was a trend towards benefit from surgery in @entity1 with near-occlusion at 2 years' follow-up (262, 5.6%, p=0.19), but no benefit at 5 years (-1.7%, p=0.9). INTERPRETATION: Re-analysis of the trials with the same measurements and definitions yielded highly consistent results. Surgery is of some benefit for @entity1 with 50-69% symptomatic @entity850 , and highly beneficial for those with 70% symptomatic @entity850 or greater but without near-occlusion. Benefit in @entity1 with carotid near-occlusion is marginal in the short-term and uncertain in the long-term.
