The document provides guidelines for NT pro BNP and BNP levels based on a patient's age and clinical setting. For patients in an emergency department setting, NT pro BNP should be over 400 pg/ml if under 50, over 900 pg/ml if between 50-70, and over 1800 pg/ml if over 75. BNP should be over 400 pg/ml regardless of age in emergency. For an outpatient setting, NT pro BNP should be under 125 pg/ml and BNP under 35 pg/ml. The document outlines appropriate biomarker levels for evaluating heart failure in different clinical scenarios.