Age and outcome after aneurysmal subarachnoid hemorrhage: why do older patients fare worse?

Abstract

Advanced age is a recognized prognostic indicator of poor outcome after subarachnoid hemorrhage (SAH). The relationship of age to other prognostic factors and outcome was evaluated using data from the multicenter randomized trial of nicardipine in SAH conducted in 21 neurosurgical centers in North America. Among the 906 patients who were studied, five different age groups were considered: 40 years or less, 41 to 50, 51 to 60, 61 to 70, and more than 71 years. Twenty-three percent of the individuals enrolled were older than 60 years of age. Women outnumbered men in all age groups. Level of consciousness (p = 0.0002) and World Federation of Neurological Surgeons grade (p = 0.0001) at admission worsened with advancing age. Age was also related to the presence of a thick subarachnoid clot (p = 0.0001), intraventricular hemorrhage (p = 0.0003), and hydrocephalus (p = 0.0001) on an admission computerized tomography scan. The rebleeding rate increased from 4.5% in the youngest age group to 16.4% in patients more than 70 years of age (p = 0.002). As expected, preexisting medical conditions, such as diabetes (p = 0.028), hypertension (p = 0.0001), and pulmonary (p = 0.0084), myocardial (p = 0.0001), and cerebrovascular diseases (p = 0.0001), were positively associated with age. There were no age-related differences in the day of admission following SAH, timing of the surgery and/or location, and size (small vs. large) of the ruptured aneurysm. During the treatment period, the incidence of severe complications (that is, those complications considered life threatening by the reporting investigator) increased with advancing age, occurring in 28%, 33%, 36%, 40%, and 46% of the patients in each advancing age group, respectively (p = 0.0002). No differences were observed in the reported frequency of surgical complications. No age-related differences were found in the overall incidence of angiographic vasospasm; however, symptomatic vasospasm was more frequently reported in the older age groups (p = 0.01). Overall outcome, assessed using the Glasgow Outcome Scale at 3 months post-SAH, was poorer with advancing age (p < 0.001). Multivariate analysis of overall outcome, adjusting for the different prognostic factors, did not remove the age effect, which suggests that the aging brain has a less optimal response to the initial bleeding. Age as a risk factor is a continuum; however, there seems to be a significant increased risk of poor outcome after the age of 60 years.

Prediction of Outcomes in Young Adults With Aneurysmal Subarachnoid Hemorrhage

“…19) The male dominance among patients with SAH has been observed in childhood and adolescence, whereas the female preponderance with male to female ratio of 2:1 is frequently observed in adult group of patients. 6,9,20) The reports on the sex dominance in young adults are variable. 5,7,11,14,21) A slight male dominance was noted (58.3%) in the present study.…”

“…16) Old age and female sex are strong predictors of poor outcome in the general population. 9) Studies discussing outcomes of aneurysmal SAH in young adults have demonstrated favorable outcomes in this subgroup of patients. 5,7,11,14,21) As these patients continue to improve after discharge, vigilant supportive and rehabilitation care should be emphasized to ensure the optimal recovery.…”

Natural course of subarachnoid hemorrhage is worse in elderly patients

“…Aging probably is one of the most significant independent factors. It impairs several physiologic patterns related to cerebrovascular hemodynamics and homeostasis 6,7,8,9,10,11,12 . There is a decline in cerebral blood flow velocity with age, which may be associated with certain changes as: decreased cerebral blood flow (CBF) or metabolic demands; vessel changes like progressive kinking, calcifications (Figure 4), elongation, stenosis and lower cardiac output 1,2,3,11,13,14,15 .…”

“…All those statements justify that elderly usually present with more severe SAH than younger patients, characterized by higher Fisher and Hunt Hess grades. After treatment, elderly are also prone to face severe neurological and systemic complications, like vasospasm, hydrocephalus, brain and heart ischemic insults and others 6,7,8,9,10 . Cerebral vasospasm (VSP) is the major complication associated with aneurysmal SAH that results in delayed ischemic deficits in up to 25% of all cases.…”

Time course of recovery following poor-grade SAH: the incidence of delayed improvement and implications for SAH outcome study design

“…This is consistent with prior studies demonstrating an association between younger age and more favorable outcomes following SAH. 10,11,14,20,24,31 Although patients 65 years of age or younger had more than 5 times the odds of improvement beyond 6 months, when improvement specific to the time intervals beyond 1 year was analyzed, age was no longer a significant predictor. This finding suggests that while younger age has its benefits in recovery, the most delayed improvement is driven primarily by other factors.…”