Visit-To-Visit Variability in Systolic Blood Pressure Is a Novel Risk Factor for the Growth of Intracranial Aneurysms

Abstract

Background: Although rupture of unruptured intracranial aneurysms (UIAs) is closely associated with UIA growth during follow-up, few studies have investigated how UIAs grow during observation. Hypertension appears to affect the formation of intracranial aneurysms. However, few studies have investigated the association of blood pressure variability with UIA growth. Visit-to-visit variability (VVV) in systolic blood pressure (SBP) is a newly defined concept which appears to be a good predictor of stroke. With this factor in mind, here we conducted a prospective analysis of the results of 2 years of observation of UIAs by magnetic resonance angiography (MRA) and sought to identify risk factors for UIA growth and rupture. Methods: From December 2006 through June 2010, two hundred patients with 212 UIAs were followed for 2 years. Patient ages ranged from 31 to 91 years. Putative risk factors for the growth of UIAs were evaluated. Subjects were divided into two groups: a UIA growth group consisting of patients whose UIAs increased by 1 mm or more in size or who developed subarachnoid hemorrhage (SAH), and an unchanged group. Brachial blood pressure values were recorded at the time of diagnosis and during follow-up in the outpatient clinic. All blood pressure values were then averaged, and the VVV of SBP was defined as the standard deviation (SD) of a minimum of 5 blood pressure measurements at outpatient visits. Results: UIA growth occurred in 20 patients and SAH occurred in 1 patient. Current smoking tended to be more prevalent in the UIA growth group (p < 0.01). Five of the 12 patients with multiple UIAs showed UIA growth within 2 years and multiplicity was a significant risk factor for UIA growth (p < 0.01). The mean baseline size in the UIA growth group was larger than that in the unchanged group (p = 0.01) and 7 of the 18 patients with large UIAs, categorized as having an initial diameter of 7 mm or more, had an increase in UIA size over the 2 years (p < 0.01). On multivariable logistic regression analysis, current smoking, multiplicity, and UIA size ≥7 mm were significant risk factors for UIA growth. Although no significant difference was seen between the UIA growth and unchanged groups in office SBP during the observation period, VVV in SBP was significantly higher in the UIA growth group than in the unchanged group, and it was significantly and independently associated with UIA growth. Conclusions: VVV in SBP is a novel risk factor for the growth of UIAs and may be a key factor for the prevention of UIA rupture. Future research is needed to confirm that SBP stability prevents UIA rupture.

Patient- and Aneurysm-Specific Risk Factors for Intracranial Aneurysm Growth

“…6,[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] Table 1 gives an overview of the included patient populations. The mean duration of follow-up for all cohorts combined was 2.8 patient-years (range of mean follow-up per cohort, 1.0-18.9 years).…”

“…Eleven studies on 9 unique cohorts of patients were considered high quality according to the Newcastle Ottawa Scale ( Table I in the online-only Data Supplement). 6,9,11,12,14,16,19,20,22,23,25 Table 2 gives an overview of the definitions of aneurysm growth and the type of imaging modalities used to assess aneurysm growth. …”

Systolic Blood Pressure Variability is a Novel Risk Factor for Rebleeding in Acute Subarachnoid Hemorrhage

“… 27 Along with accompanying reports, 28 , 29 Rothwell et al 27 believed that these findings challenged the usual blood pressure hypothesis and had implications for diagnosis, treatment, and monitoring of patients with hypertension. Igase et al 30 also showed that the clinical significance of SBPV was higher than that of MSBP with regard to the growth of unruptured intracranial aneurysms. In addition, many reports have demonstrated that SBPV was significantly correlated with cardiac damage, renal dysfunction, and stroke.…”

Definition and Prioritization of Data Elements for Cohort Studies and Clinical Trials on Patients with Unruptured Intracranial Aneurysms: Proposal of a Multidisciplinary Research Group

“…• Hypertension (defined as systolic blood pressure greater than or equal to 140 mmHg or greater than or equal to 90 mmHg diastolic in adults or systolic or diastolic blood pressure above the 95 percentile in children) (preexisting CDE) [5,8,[11][12][13]. • Tobacco smoking status: (a) never, (b) former (including start and end date of smoking), (c) current (including starting date) and (d) unknown (modified CDE) [1,[9][10][11][12][13][14][15][16][17]. Radiological findings (Table 7).…”

“…• Anatomical aneurysm site based on angiography (modified CDE) [5,9,[18][19][20][21][22][23][24][25][26]. • Maximum aneurysm diameter (in mm) in any direction (new CDE) [5,8,9,[16][17][18][19][20][22][23][24][25][26][27][28][29]. • Maximum aneurysm height (in mm) perpendicular to aneurysm neck (new CDE) [30].…”