Population-based study of carotid endarterectomy in Western Australia

BACKGROUND: Previous studies reported an increase in the rates of operation following the publication of major trials that demonstrated the benefit of carotid endarterectomy in reducing stroke. The aim of this study was to determine whether carotid endarterectomy rates have continued to rise despite the reducing trend in most manifestations of atherosclerotic cardiovascular disease. METHODS: Record linkage was used to select patients who had a carotid endarterectomy during the interval from 1988 to 2001. Incidence rates were age-standardized and trends were examined with Poisson regression. RESULTS: The rate increased by 13.8 per cent per year between 1988 and 1998; however, from 1999 onwards the rate of carotid surgery fell by 15.8 per cent per year. In octogenarians, the rate increased steadily from 0.9 to 5.1 per 100,000 person-years between 1992 and 2000. The proportion of octogenarians also increased significantly from 0.9 per cent in 1988-1990 to 19.5 per cent in 2000-2001 (chi2=60.11, 4 d.f., P<0.001). CONCLUSION: For the first time a recent decline has been observed in the rate of carotid endarterectomy, most likely owing to a combination of the deceasing incidence of atherosclerosis and more widespread use of effective drugs in the treatment of cardiovascular disease. The rate and proportion of operations in patients aged 80 years or older has increased steadily.