IV thrombolysis and renal function

Objective: To investigate the association of renal impairment on functional outcome and complications in stroke patients treated with IV thrombolysis (IVT).

Methods: In this observational study, we compared the estimated glomerular filtration rate (GFR) with poor 3-month outcome (modified Rankin Scale scores 3–6), death, and symptomatic intracranial hemorrhage (sICH) based on the criteria of the European Cooperative Acute Stroke Study II trial. Unadjusted and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Patients without IVT treatment served as a comparison group.

Results: Among 4,780 IVT-treated patients, 1,217 (25.5%) had a low GFR (<60 mL/min/1.73 m²). A GFR decrease by 10 mL/min/1.73 m² increased the risk of poor outcome (OR [95% CI]): (OR_unadjusted 1.20 [1.17–1.24]; OR_adjusted 1.05 [1.01–1.09]), death (OR_unadjusted 1.33 [1.28–1.38]; OR_adjusted 1.18 [1.11–1.249]), and sICH (OR_unadjusted 1.15 [1.01–1.22]; OR_adjusted 1.11 [1.04–1.20]). Low GFR was independently associated with poor 3-month outcome (OR_adjusted 1.32 [1.10–1.58]), death (OR_adjusted 1.73 [1.39–2.14]), and sICH (OR_adjusted 1.64 [1.21–2.23]) compared with normal GFR (60–120 mL/min/1.73 m²). Low GFR (OR_adjusted 1.64 [1.21–2.23]) and stroke severity (OR_adjusted 1.05 [1.03–1.07]) independently determined sICH. Compared with patients who did not receive IVT, treatment with IVT in patients with low GFR was associated with poor outcome (OR_adjusted 1.79 [1.41–2.25]), and with favorable outcome in those with normal GFR (OR_adjusted 0.77 [0.63–0.94]).

Conclusion: Renal function significantly modified outcome and complication rates in IVT-treated stroke patients. Lower GFR might be a better risk indicator for sICH than age. A decrease of GFR by 10 mL/min/1.73 m² seems to have a similar impact on the risk of death or sICH as a 1-point-higher NIH Stroke Scale score measuring stroke severity.