Intravenous Thrombolysis for Acute Ischemic Stroke Across Kidney Function

The effectiveness and safety of recombinant tissue-plasminogen activator (rt-PA; alteplase) for acute ischemic stroke in patients with low estimated glomerular filtration rate (eGFR) are uncertain. We evaluated whether the risks and benefits of rt-PA versus no rt-PA vary by eGFR category.

We conducted a population-based cohort study of 4 632 rt-PA-eligible adults with acute ischemic stroke and a recorded eGFR in Ontario, Canada (2002-2013). Propensity score overlap weighting was used to balance treated and untreated patients. Primary outcomes were transformation to intracranial hemorrhage (ICH) and functional independence at hospital discharge. Secondary outcomes were in-hospital and one-year mortality. Analyses were stratified by eGFR category (mL/min per 1.73 m2): ≥60, 30-59, and < 30 or receiving maintenance dialysis.

After weighting, 1 354 patients were included. For eGFR ≥ 60, ICH occurred in 58/402 (14.4%) with rt-PA and 23/402 (5.7%) without rt-PA; weighted relative risk (RRw) 2.56 (99% CI, 1.77-3.69). For eGFR 30-59, ICH was 36/246 (14.6%) vs. 10/246 (4.0%); RRw 3.67 (99% CI, 2.17-6.20). For eGFR < 30 or maintenance dialysis, event counts were small, preventing reliable estimation. rt-PA was associated with greater discharge independence across all eGFR categories. In-hospital mortality did not differ by treatment within eGFR categories. One-year mortality was lower with rt-PA for eGFR ≥ 60, with comparable point estimates for eGFR 30-59 and < 30 or maintenance dialysis.

In patients with low kidney function, rt-PA increases ICH risk but improves functional outcomes. The balance of risks and benefits appears broadly consistent across eGFR categories.