External Validation of the ELAPSS Score for Prediction of Unruptured Intracranial Aneurysm Growth Risk

Mayte Sánchez van Kammen, Jacoba P Greving, Satoshi Kuroda, Daina Kashiwazaki, Akio Morita, Yoshiaki Shiokawa, Toshikazu Kimura, Christophe Cognard, Anne C Januel, Antti Lindgren, Timo Koivisto, Juha E Jääskeläinen, Antti Ronkainen, Liisa Pyysalo, Juha Öhman, Melissa Rahi, Johanna Kuhmonen, Jaakko Rinne, Eva L Leemans, Charles B MajoieW Peter Vandertop, Dagmar Verbaan, Yvo B W E M Roos, René van den Berg, Hieronymus D Boogaarts, Walid Moudrous, Ido R van den Wijngaard, Laura Ten Hove, Mario Teo, Edward J St George, Katharina A M Hackenberg, Amr Abdulazim, Nima Etminan, Gabriël J E Rinkel, Mervyn D I Vergouwen

Research output: Contribution to journalArticleAcademicpeer-review


Background and PURPOSE: Prediction of intracranial aneurysm growth risk can assist physicians in planning of follow-up imaging of conservatively managed unruptured intracranial aneurysms. We therefore aimed to externally validate the ELAPSS (Earlier subarachnoid hemorrhage, aneurysm Location, Age, Population, aneurysm Size and Shape) score for prediction of the risk of unruptured intracranial aneurysm growth.

METHODS: From 11 international cohorts of patients ≥18 years with ≥1 unruptured intracranial aneurysm and ≥6 months of radiological follow-up, we collected data on the predictors of the ELAPSS score, and calculated 3- and 5-year absolute growth risks according to the score. Model performance was assessed in terms of calibration (predicted versus observed risk) and discrimination (c-statistic).

RESULTS: We included 1,072 patients with a total of 1,452 aneurysms. During 4,268 aneurysm-years of follow-up, 199 (14%) aneurysms enlarged. Calibration was comparable to that of the development cohort with the overall observed risks within the range of the expected risks. The c-statistic was 0.69 (95% confidence interval [CI], 0.64 to 0.73) at 3 years, compared to 0.72 (95% CI, 0.68 to 0.76) in the development cohort. At 5 years, the c-statistic was 0.68 (95% CI, 0.64 to 0.72), compared to 0.72 (95% CI, 0.68 to 0.75) in the development cohort.

CONCLUSION: s The ELAPSS score showed accurate calibration for 3- and 5-year risks of aneurysm growth and modest discrimination in our external validation cohort. This indicates that the score is externally valid and could assist patients and physicians in predicting growth of unruptured intracranial aneurysms and plan follow-up imaging accordingly.

Original languageEnglish
Pages (from-to)340-346
Number of pages7
Issue number3
Publication statusPublished - 1 Sep 2019

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