Influence of renal impairment on outcome for thrombolysis-treated acute ischemic stroke ENCHANTED (Enhanced Control of Hypertension and Thrombolysis Stroke Study) post hoc analysis

Abstract

Background and Purpose-Renal dysfunction (RD) is associated with poor prognosis after stroke. We assessed the effects of RD on outcomes and interaction with low- versus standard-dose alteplase in a post hoc subgroup analysis of the ENCHANTED (Enhanced Control of Hypertension and Thrombolysis Stroke Study). Methods-A total of 3220 thrombolysis-eligible patients with acute ischemic stroke (mean age, 66.5 years; 37.8% women) were randomly assigned to low-dose (0.6 mg/kg) or standard-dose (0.9 mg/kg) intravenous alteplase within 4.5 hours of symptom onset. Six hundred and fifty-nine (19.8%) patients had moderate-to-severe RD (estimated glomerular filtration rate, <60 mL/min per 1.73 m(2)) at baseline. The impact of RD on death or disability (modified Rankin Scale scores, 2-6) at 90 days, and symptomatic intracerebral hemorrhage, was assessed in logistic regression models. Results-Compared with patients with normal renal function (>90 mL/min per 1.73 m(2)), those with severe RD (<30 mL/min per 1.73 m(2)) had increased mortality (adjusted odds ratio, 2.07; 95% confidence interval, 0.89-4.82; P=0.04 for trend); every 10 mL/min per 1.73 m(2) lower estimated glomerular filtration rate was associated with an adjusted 9% increased odds of death from thrombolysis-treated acute ischemic stroke. There was no significant association with modified Rankin Scale scores 2 to 6 (adjusted odds ratio, 1.03; 95% confidence interval, 0.62-1.70; P=0.81 for trend), modified Rankin Scale 3 to 6 (adjusted odds ratio, 1.20; 95% confidence interval, 0.72-2.01; P=0.44 for trend), or symptomatic intracerebral hemorrhage, or any heterogeneity in comparative treatment effects between low-dose and standard-dose alteplase by RD grades. Conclusions-RD is associated with increased mortality but not disability or symptomatic intracerebral hemorrhage in thrombolysis-eligible and treated acute ischemic stroke patients. Uncertainty persists as to whether low-dose alteplase confers benefits over standard-dose alteplase in acute ischemic stroke patients with RD.