Systolic blood pressure factors in subarachnoid haemorrhage but not in intracranial aneurysm
Systolic blood pressure appears to have a strong association with aneurysmal subarachnoid haemorrhage (aSAH) but not with unruptured intracranial aneurysm (UIA), whereas current smoking and female sex are risk factors for both conditions, a study has found.
The study included 89,951 individuals who had standardized measurements of blood pressure and completed self-administered questionnaires. UIA occurred in 97 individuals and aSAH in 117. The corresponding detection rates were 8.2 and 9.9 per 100,000 person-years.
On Cox regression analysis, UIA risk was significantly high in individuals who currently smoked (hazard ratio [HR], 4.1, 95 percent CI, 2.4–7.1) and in women (HR, 2.8, 1.7–4.5). There was no association found for systolic blood pressure (p-trend=0.62).
On the other hand, the most important risk factors for aSAH were current smoking (HR, 3.4, 2.2–5.4), female sex (HR, 1.8, 1.2–2.7) and increasing systolic blood pressure (p-trend=0.006).
Contrary to previous studies reporting an association between hypertension and UIA, the current study collected potential risk factors before and not at the time of UIA detection, making reverse causation unlikely, researchers pointed out. [Stroke 2015;46:3093-3098; Stroke 2013;44:984-987; Int J Stroke 2016;11:917-927]
The current data thus indicate that systolic blood pressure may be associated with rupture but not formation of intracranial aneurysms, they added.