High White Blood Cell Count Is a Risk Factor for Contrast-Induced Nephropathy following Mechanical Thrombectomy for Acute Ischemic Stroke

BACKGROUND: Although mechanical thrombectomy is a standard endovascular therapy for patients with acute ischemic stroke (AIS), the incidence of and risk factors for contrast-induced nephropathy (CIN) following mechanical thrombectomy are infrequently reported. OBJECTIVES: The aim of this study was to investigate the incidence and risk factors for CIN following mechanical thrombectomy for AIS, and whether the incidence of CIN is related to a poor prognosis. METHODS: We examined consecutive patients who underwent a mechanical thrombectomy in the period from January 2014 to March 2018. The patients' clinical backgrounds, treatments, and clinical prognoses were analyzed. CIN was defined as an increase in the serum creatinine level of ≥44.2 μmol/L (0.5 mg/dL) or 25% above baseline within 72 h after exposure to the contrast medium. RESULTS: In total, 80 patients (46 men and 34 women aged 74.5 ± 11.5 years) who met our inclusion criteria were analyzed. CIN occurred in 8.8% (7/80) of the patients following mechanical thrombectomy. Although no patients needed permanent dialysis, 1 required temporary dialysis. The median amount of contrast medium was 109 mL. A comparison between the groups with and without CIN showed a significant difference in white blood cell (WBC) count at the time of admission (11.6 ± 2.7 × 10(3)/μL and 8.1 ± 2.7 × 10(3)/μL; p < 0.01) and the cut-off value was 9.70 × 10(3)/μL. In multivariate analysis, contrast volume/estimated glomerular filtration rate by creatinine and WBC count were significantly associated with the incidence of CIN, with odds ratios of 1.64 (95% CI 1.02–2.65; p = 0.04) and 1.61 (95% CI 1.15–2.25; p < 0.01), respectively. CONCLUSIONS: This study found that CIN occurred in 8.8% of patients with AIS following mechanical thrombectomy. High WBC count was associated with an increased risk of CIN and may be helpful for predicting CIN.