Influence of Age on Outcome From Thrombolysis in Acute Stroke

Abstract

Background and Purpose— Thrombolysis for acute ischemic stroke in patients aged >80 years is not approved in some countries due to limited trial data in the very elderly. We compared outcomes between thrombolysed and nonthrombolysed (control) patients from neuroprotection trials to assess any influence of age on response. Method— Among patients with ischemic stroke of known age, pretreatment severity (baseline National Institutes of Health Scale Score), and 90-day outcome (modified Rankin Scale score; National Institutes of Health Scale score), we compared the distribution of modified Rankin score in thrombolysed patients with control subjects by Cochran-Mantel-Haenszel test and then logistic regression after adjustment for age and baseline National Institutes of Health Scale score. We examined patients ≤80 and ≥81 years separately and then each age decile. Results— Rankin data were available for 5817 patients, 1585 thrombolysed and 4232 control subjects; 20.5% were aged >80 years (mean±SD, 85.1±3.4 years). Baseline severity was higher among thrombolysed than control subjects (median National Institutes of Health Scale score 14 versus 13, P <0.05). The distribution of modified Rankin Scale scores was better among thrombolysed patients ( P <0.0001; OR, 1.39; 95% CI, 1.26 to 1.54). The association occurred independently with similar magnitude among young ( P <0.0001; OR, 1.42; 95% CI, 1.26 to 1.59) and elderly ( P =0.002; OR, 1.34; 95% CI, 1.05 to 1.70) patients. ORs were consistent across all age deciles >30 years; outcomes assessed by National Institutes of Health Scale score gave supporting significant findings, and dichotomized modified Rankin Scale score outcomes were also consistent. Conclusions— Outcome after thrombolysis for acute ischemic stroke was significantly better than in control subjects. Despite the expected poorer outcomes among elderly compared with young patients that is independent of any treatment effect, the association between thrombolysis treatment and improved outcome is maintained in the very elderly. Age alone should not be a barrier to treatment.