By Matthew E. Fink, MDLouis and Gertrude Feil Professor and Chair, Department of Neurology, Associate Dean for Clinical Affairs, New York Presbyterian/Weill Cornell Medical College
SOURCE: Zuurbier CCM, Molenberg R, Mensing LA, et al. Sex difference and rupture rate of intracranial aneurysms: An individual patient data meta-analysis. Stroke 2022;53:362-369.
Over many years of observation, it has been noted by clinicians that women have a higher risk of rupture of intracranial aneurysms than men, but in epidemiological studies this was not found to be an independent risk factor. These investigators undertook a review of several large, prospective studies and performed a meta-analysis to assess the characteristics that might be different between men and women to explain these observations. They compared rupture rates using a regression model that was adjusted for well-validated risk factors for aneurysm rupture, which included specific populations, presence of hypertension, age, size of the aneurysm, previous subarachnoid hemorrhage, site of the aneurysm, history of smoking, and a positive family history of aneurysmal hemorrhage.
Patient data came from nine cohort studies totaling 9,940 patients, with 66% women and 12,193 unruptured intracranial aneurysms. There were 24,357 person-years of follow-up. Aneurysm rupture occurred in 133 women, for a rate of 1.04%, and in 63 men, for a rate of 0.74%. Women with ruptured aneurysms were older than men, were less often smokers, and more often had internal carotid artery aneurysms. They also tended to have larger-sized aneurysms than men. The adjusted women/men hazard ratio was 1.39. This study confirmed the finding that aneurysm rupture risk is higher in women than men, but it still does not explain the differences based on patient or aneurysm-related risk factors. Further study of the causes for these differences should be investigated.
