B-type natriuretic peptide assessment in ambulatory heart failure patients: insights from IMPROVE HF

Background B-type natriuretic peptide (BNP) levels provide diagnostic and prognostic information in heart failure. This study determined the frequency of BNP assessment and analyzed demographic characteristics, clinical variables and the utilization of guideline-recommended heart failure therapies by BNP level in outpatients with reduced left ventricular ejection fraction (LVEF). Methods and results The IMPROVE HF registry (The Registry to Improve the Use of Evidence-Based Heart Failure Therapies in the Outpatient Setting) is a prospective cohort study of patients at least 18 years of age with a LVEF 35% or less and chronic heart failure or previous myocardial infarction (MI) presenting to cardiology and multispecialty practices. The medical records of 15 381 patients were reviewed. BNP was measured in 4213 (27.4%) patients and the median plasma BNP level was 384 pg/ml (interquartile range 158–877 pg/ml). Patients were stratified by plasma BNP measurements into the following tertiles: 219 pg/ml or less, more than 219 to 649 pg/ml, and more than 649 pg/ml. Jugular venous distension, pedal edema, rales and systolic murmur on physical examination and elevated renal function parameters were associated with higher BNP levels. BNP assessment and elevated BNP levels were not associated with greater use of any of the quality of care measures. However, patients with a BNP in the top tertile were less likely to be treated with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers or aldosterone antagonists compared with patients with a BNP in the bottom tertile. Conclusion Among practices participating in IMPROVE HF, BNP was not measured in most outpatients with reduced LVEF and chronic heart failure or previous MI. BNP assessment or the BNP level in patients with recorded measurements, with few exceptions, did not impact the utilization of guideline-recommended therapies.