NPPB and acute kidney injury: In addition to the statistically significant incremental value added by NT-proBNP to these two scores, the addition of the low vascular density evaluated by OCT-A further improved the performance of the AKI model for model 1 (chi-square = 35.66; P = 0.013) as well as for model 2 (chi-square = 45.96; P = 0.002) (Figs 3 and 4).