Thrombolysis for acute ischemic stroke in the unwitnessed or extended therapeutic time window.

Abstract

OBJECTIVE: To assess the utility of IV thrombolysis (IVT) treatment in patients with acute ischemic stroke (AIS) with unclear symptom onset time or outside the 4.5-hour time window selected by advanced neuroimaging.

METHODS: We performed random-effects meta-analyses on the unadjusted and adjusted for potential confounders associations of IVT (alteplase 0.9 mg/kg) with the following outcomes: 3-month favorable functional outcome (FFO; modified Rankin Scale [mRS] scores 0-1), 3-month functional independence (FI; mRS scores 0-2), 3-month mortality, 3-month functional improvement (assessed with ordinal analysis on the mRS scores), symptomatic intracranial hemorrhage (sICH), and complete recanalization (CR).

RESULTS: We identified 4 eligible randomized clinical trials (859 total patients). In unadjusted analyses, IVT was associated with a higher likelihood of 3-month FFO (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.12-1.96), FI (OR 1.42, 95% CI 1.07-1.90), sICH (OR 5.28, 95% CI 1.35-20.68), and CR (OR 3.29, 95% CI 1.90-5.69), with no significant difference in the odds of all-cause mortality risk at 3 months (OR 1.75, 95% CI 0.93-3.29). In the adjusted analyses, IVT was also associated with higher odds of 3-month FFO (adjusted OR [ORadj] 1.62, 95% CI 1.20-2.20), functional improvement (ORadj 1.42, 95% CI 1.11-1.81), and sICH (ORadj 6.22, 95% CI 1.37-28.26). There was no association between IVT and FI (ORadj 1.61, 95% CI 0.94-2.75) or all-cause mortality (ORadj 1.75, 95% CI 0.93-3.29) at 3 months. No evidence of heterogeneity was evident in any of the analyses (I2 = 0).

CONCLUSION: IVT in patients with AIS with unknown symptom onset time or elapsed time from symptom onset >4.5 hours selected with advanced neuroimaging results in a higher likelihood of CR and functional improvement at 3 months despite the increased risk of sICH.