Is renal dysfunction associated with adverse stroke outcome after thrombolytic therapy?

Renal dysfunction is a prevalent comorbidity in acute stroke patients requiring thrombolytic therapy. Reports studying the relationship between renal dysfunction and risk of postthrombolytic symptomatic intracerebral hemorrhage (SICH) are contradictory. We aimed to compare the safety and effectiveness of thrombolytic therapy in acute stroke patients with and without renal dysfunction.

Based on the prospective stroke registries of 4 hospitals in Taiwan from 2007-2012, we identified acute stroke patients who received thrombolytic therapy. Clinically significant renal dysfunction was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2). Renal dysfunction was further defined as stage 3 (30 ≤ eGFR < 60 ml/min/ 1.73 m(2)), stage 4 (15 ≤ eGFR < 30 ml/min/1.73 m(2)) and stage 5 (<15 ml/min/1.73 m(2)). The rates of SICH and poor outcome (defined as modified Rankin scale score ≥4) at 3 months after thrombolytic therapy were compared in patients with and without renal dysfunction. SICH was determined according to the definition of the National Institute of Neurological Disorders and Stroke. Multivariable logistic regression was used to determine the effect of renal dysfunction on outcome. Patients with different stages of renal dysfunction were further analyzed to determine the effect of disease severity on outcome.

Of the 657 stroke patients with thrombolysis, 239 (36%) had renal dysfunction, including 212 patients in stage 3, 17 patients in stage 4 and 10 patients in stage 5 of renal dysfunction. Patients with renal dysfunction were older and more likely to have hypertension, ischemic heart disease, congestive heart failure and prior antiplatelet use than those without. There were no differences in SICH (8 vs. 7%, p = 0.580) and poor outcome (41 vs. 39%, p = 0.758) between patients with and without renal dysfunction. After multivariable analysis, renal dysfunction was not associated with SICH (odds ratio: 1.03, 95% confidence interval: 0.55-1.92) and poor outcome. Pretreatment stroke severity was the only factor significantly associated with both SICH and poor outcome at 3 months. When stratifying renal dysfunction into stage 3 and stage ≥4, there was no significant increase in SICH as the severity of renal dysfunction increased after multivariable adjustment.

Renal dysfunction did not increase the risk of SICH and poor outcome at 3 months after stroke thrombolysis. Further study comparing directly the risk and benefit of thrombolytic therapy versus no therapy in stroke patients with renal dysfunction is warranted.