NPPB and depressive disorder: At multiple regression analysis, among the set of variables considered potential predictors of functional status as assessed by the 6MWT (age, gender, ACE-R-Memory, ACE-R-Fluency, FAB, TMT-A, depression, anxiety, Log-BNP and LVEF), Log-BNP and TMT-A were identified as significant and independent predictors of functional status (Table 3).