Intravenous thrombolysis for acute ischemic stroke across kidney function

Background — 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.

Methods — 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.

Results — 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.

Conclusions — 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.