GSTM1 and chronic kidney disease: For VV ECMO, the univariable analysis found that female sex (OR, 2.99; 95% CI, 1.01–8.86; P = 0.048), a history of chronic kidney disease (CKD) (OR, 0.00; 95% CI, 0.00–0.00; P < 0.01), ECMO running time (OR, 1.02; 95% CI, 1.01–1.04; P < 0.01), and initial Hb level < 8.0 g/dL (OR, 4.93; 95% CI, 1.21–20.07; P = 0.03) were associated with an increased risk of ECMO-related vascular complications (S5 Table).