Lower rate of aneurysm repair in England versus the USA
medwireNews: A comparison of country-specific data suggests that the rate of abdominal aortic aneurysm repair is lower, and that of aneurysm-related mortality higher, in England compared with the USA.
The researchers found that among patients with intact abdominal aortic aneurysms, the overall rate of repair was half as high in England as the USA (odds ratio [OR]=0.49) between 2005 and 2012. Over this time period, the rate of repair increased from 27.11 to 31.85 procedures per 100,000 persons in England, and from 57.85 to 64.17 procedures per 100,000 persons in the USA.
Although the incidence of aneurysm-related mortality decreased over the 8-year period in both countries – from 53.55 to 34.43 per 100,000 persons in England and from 16.24 to 9.03 per 100,000 persons in the USA – the overall mortality rate was around 3.5 times higher in England (adjusted OR=3.54).
“[These findings] raise the question of whether outcomes in England would be improved if the repair thresholds used in the USA were adopted,” say study authors Alan Karthikesalingam (St. George’s University of London, UK) and colleagues.
The researchers analyzed data from 29,300 patients who underwent repair of intact abdominal aortic aneurysms in England, and an estimated 278,921 who underwent repair in the USA.
Intact aneurysms were a mean of 5.3 mm larger at the time of repair in patients treated in England compared with the USA, a significant difference. When the researchers applied population weighting for age and gender, the mean aneurysm diameter at the time of repair was 63.7 mm in England, compared with 58.3 mm in the USA.
The authors caution that “[t]he rates of aneurysm repair and of aneurysm-related death were derived from separate data sets in both countries,” and therefore a causal association between country and outcome was not shown. However, the observations were based on a similar time period, and “suggest the possibility of a causal relationship,” they write in The New England Journal of Medicine.
Karthikesalingam and colleagues also showed that hospitalization due to aneurysm rupture was significantly more common in England versus the USA (OR=2.23), and the proportion of repairs that were carried out using an endovascular procedure was significantly lower in England (45.5 vs 67.0%).
Although rates of aneurysm rupture and mortality were higher in England than in the USA, the incidence of in-hospital mortality among patients who underwent aneurysm repair was not significantly different between the countries, with rates of 2.6% in England and 1.8% in the USA (0.9 vs 0.8% among patients undergoing endovascular repair and 4.1 vs 4.0% among those undergoing open repair).
Similarly, 78.5% of patients survived for 3 years or more following aneurysm repair in England, compared with 79.5% of patients in the USA, a nonsignificant difference.
These similar rates of in-hospital and 3-year mortality suggest that “the increased rate of aneurysm repair in the USA did not come at the expense of greater perioperative or postoperative risk,” write the authors.
Moreover, they add that their observations indicate “that the lower rate of aneurysm repair in England may have adverse consequences.”
By Claire Barnard
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