|1. Normal range in healthy subjects, N-BNP < 50 pmol/l.|
|2. N-BNP > 150 pmol/l strongly suggests HF in a newly symptomatic patient, but all clinical information should be taken into account.|
|3. In between these levels, HF is still possible, but all available clinical information must be taken into account. N-BNP may be elevated by renal impairment, atrial fibrillation, LVH, COPD, after myocardial infarction, in the elderly and by treatment with beta-blockers or digoxin. N-BNP may be decreased by hypothyroidism, treatment with diuretics, vasodilators, and ACE inhibitors.|
ACE = angiotensin-converting enzyme; COPD = chronic obstructive pulmonary disease; HF = heart failure; LVH = left ventricular hypertrophy; N-BNP = amino- terminal pro-brain natriuretic peptide.