Background: RCTs have demonstrated better outcomes for coiling compared to clipping in patients with aneurysmal subarachnoid haemorrhage (aSAH). After these trials, the proportion of patients with coiled aneurysms has steadily increased, as have the numbers of physicians and hospitals providing the treatment. We studied whether coiling is also associated with a better outcome than clipping after aSAH in daily clinical practice.
Methods: In Dr Foster Global Comparators, an administrative dataset from 22 tertiary care hospitals from Europe, the USA, and Australia, we retrieved data from 7658 aSAH patients discharged in 2007-2013 in whom the aneurysm had been occluded by clipping (n=3510) or coiling (n=4148). We calculated crude case-fatality rates with 95% confidence intervals (CI) at 14 days, and used multiple logistic regression to adjust for age, sex and differences in comorbidity/disease severity. Because the results from the administrative dataset contradicted those of the RCTs, we further explored our findings in a large clinical dataset (n=1501) consisting of prospectively collected consecutive aSAH patients treated 2006-2015 with clipping or coiling in two large European centres allowing additional adjustment for clinical condition on admission, aneurysm size and location.
Results: In the administrative dataset the overall crude case-fatality rate at 14 days was 6·4% (95%CI 5·6-7·2%) after clipping and 8·2% (95%CI 7·4-9·1%) after coiling. After adjustment for age, sex and comorbidity/severity, the odds ratio (OR) for case-fatality within 14 days after coiling compared to clipping was 1·32 (95%CI 1·10-1·58). In the clinical dataset crude 14-day fatality rate was 5·7% (95%CI 4·2-7·8%) for clipping and 9·0% (95%CI 7·3-11·2%) for coiling. In multivariable logistic regression analysis the OR for case-fatality within 14 days for coiling compared to clipping was 1·7 (95%CI 1·1-2·7), for case-fatality within 90 days 1·28 (95%CI 0·91-1·82) and for poor functional outcome at 90 days 0·78 (95%CI 0·6-1·01).
Conclusion: In current clinical practice, outside the setting of a clinical trial, coiling after aSAH is associated with higher 14-day case-fatality and not with the substantial benefit on functional outcome as observed within the trials.