- To diagnose LCOS after CABG, the cut-off value was determined based on the level of NT-proBNP with the highest sensitivity and specificity, the highest J index, on N1 with 951, 5 pg / ml: sensitivity of 92.3%, the specificity of 78.7%; J index (Youden Index) of 0.71; AUC (CI95%) of 0.865 (0.72 - 1) with p <0.05.