Contrast-Associated Acute Kidney Injury in Endovascular Thrombectomy Patients With and Without Baseline Renal Impairment

Background and Purpose— In ischemic stroke, baseline renal impairment is present in 20 to 35% of patients and may increase the risk of contrast-associated acute kidney injury (CA-AKI). We aimed to determine whether endovascular thrombectomy (EVT) patients with baseline renal impairment are at increased risk of CA-AKI. Methods— Consecutive EVT patients were identified from a prospective database. Patients were stratified by estimated glomerular filtration rate. The primary outcome was CA-AKI assessed at 24 to 72 hours following EVT, defined as an increase in serum creatinine of ≥26.5 µmol/L or 1.5× baseline serum creatinine. Secondary outcomes included requirement for renal replacement therapy and 3-month mortality. Results— Three hundred thirty-three EVT patients (201 men; mean±SD age 63.9±15.8 years) were included. The mean±SD iohexol contrast volume used in diagnostic and EVT imaging was 236±77 mL per patient. CA-AKI occurred in 11 (3.3%) patients; none required renal replacement therapy, but 4 of 11 (36.4%) had died by 3 months. Propensity score–adjusted logistic regression showed that estimated glomerular filtration rate <30 mL/(min·1.73 m2 ) was a significant predictor of CA-AKI (odds ratio, 19.93; 95% CI, 2.33–170.74;P =0.006). The dose of contrast was not associated with an increased risk of CA-AKI (P >0.05). Multiple logistic regression adjusted for potential confounders demonstrated that CA-AKI was independently associated with increased mortality (odds ratio, 4.68; 95% CI, 1.05–20.97;P =0.04).Conclusions— There is utility in obtaining baseline creatinine levels to identify patients at risk of CA-AKI and to establish a diagnosis of CA-AKI in patients with subsequent creatinine rises. However, contrast-requiring diagnostic imaging and EVT should not be delayed by waiting for the results of baseline renal function.