Influence of age on thrombolysis outcome in wake-up stroke.

Background And Purpose: Thrombolysis in patients >80 years remains controversial; we hypothesized that >80-year-old patients with wake-up ischemic stroke (WUIS) will benefit from thrombolysis despite risks because of poor outcomes with no treatment.

Methods: The study included 68 thrombolysed patients with WUIS (33 [48%] >80 years), 54 nonthrombolysed patients with WUIS (21 [39%] >80 years), and 117 patients (>80 years old) thrombolysed within 4.5 hours of symptom onset (reference group). Mortality and modified Rankin Scale (mRS) were assessed at 90 days.

Results: Baseline characteristics of thrombolysed and nonthrombolysed >80 and ≤80-year-old patients with WUIS were comparable. Thrombolysis outcomes in >80-year-old patients with WUIS were better than in nonthrombolysed >80-year-old patients with WUIS (90-day mortality: 24% versus 47%, P=0.034; mRS 0-2: 30% versus 5%, P=0.023; mRS 0-1: 15% versus 5%, P=0.24) and comparable with thrombolysed ≤80-year-old patients with WUIS. Thrombolysis was associated with odds ratio 0.27 (95% confidence interval, 0.05-0.97) for mortality and odds ratio 28.6 (95% confidence interval, 1.8-448) for mRS 0 to 2 at 90 days in >80-year-old patients with WUIS after adjusting for stroke severity and risk factors.

Conclusions: Thrombolysis may be associated with greater benefit in >80-year-old patients with WUIS but a selection bias favoring thrombolysis in those most likely to benefit may significantly reduce interpretability of these findings.