UNILATERAL ASYMPTOMATIC CAROTID DISEASE DOES NOT REQUIRE SURGERY

Background and purpose: The efficacy of carotid endarterectomy (CEA) i n symptomatic patients with >70% stenosis is accepted. The stroke risk of asymptomatic patients may not justify surgical intervention. The a im of this study is to use natural history data from a single unit to identify asymptomatic patients who would benefit from CEA. Methods: Fi ve hundred and sixty-four patients attending for duplex ultrasound ass essment of the internal carotid artery between 1986 and 1993 were retr ospectively identified as focally asymptomatic with >40% ipsilateral s tenosis. Patients were traced using hospital records, family practitio ner databases and the Office of Population of Census and Surveys. The number of strokes, transient ischaemic attacks and cause of death were determined. Exclusions were 15 (2.7%) asymptomatic occlusions and 49 patients (8.7%) who underwent surgery for asymptomatic disease. Result s: Thirteen patients (2.6%) were not traced, leaving 487 study patient s. The average follow-up was 41 months (range, 1-120 months). Mean pre sentation age was 69 years (S.D. 8.9), and the male to female ratio wa s 3:2. One hundred and fifty-six (32%) patients died. Forty-three pati ents suffered strokes, of whom two had bilateral strokes. In total the re were 16 (i/p) strokes, 25 (c/l) strokes and four strokes undetermin ed. The average yearly stroke rate was 2.74 per 100 person years and t he (i/p) rate 1.02 per hundred person years. There was no effect of ag e, sex or degree of stenosis on stroke. The presence of bilateral dise ase did increase the risk of stroke (rel risk 2.35, p=0.029) but not i psilateral stroke (rel risk 1.6, p = 0.39). Patients with unilateral a symptomatic carotid disease had an all stroke rate of less than 5% in the first year after presentation and this was unaffected by degree of stenosis. In patients with bilateral disease the stroke rate in the f irst year after presentation increased with degree of stenosis to a st roke rate of 9.6 per 100 person years in patients with >90% contralate ral stenosis. Conclusions: This data suggests that CEA will riot benef it patients with unilateral asymptomatic disease. Patients with bilate ral disease warrant inclusion in clinical trials.