COW Week 19

Your 82yo M patient with ischemic CM (EF 40%) presents to clinic with DOE, 3 pillow orthopnea, and elevated JVP. His BNP is 550. He returns one week later after aggressive diuresis with 1 pillow orthopnea, reduced JVP, and less dyspnea. His BNP is 520. What do you do?

a. increase diuresis
b. admit the patient to CCU
c. decrease diuresis
d. refer for AICD



The purpose of this question is to emphasize that BNP is not a reliable indicator for clinical response to diuresis and CHF management in patient's over the age of 80. However, BNP can be useful in younger patients. This was demonstrated in the TIME-CHF trial. 499 patients with NYHA class II or greater, LVEF less then 45%, prior CHF hospitalization in the last year, and bnp greater the 2x the upper limit of normal were randomized to therapy aimed at improving clinical symptoms vs. improving clinical symptoms and reducing BNP. The study showed that “heart failure therapy guided by N-terminal BNP did not improve overall clinical outcomes or quality of life compared with symptom-guided treatment.”

In TIME-CHF, there was no significance in the primary outcomes of 18-month survival free from any hospitalization of quality of life for the total cohort for BNP-guided management vs. symptom-guided management. Given the lack of significance in the primary outcome, subgroup analyses need to be interpreted with caution. However, for patients less then 75 years, there was significant benefit for hospital free survival and overall survival. For patients greater then 75 years, there was no significant difference in hospital free survival or overall survival. 

There are other situations in which BNP is not as reliable besides age and these include obesity and renal failure. BNP levels are inversely related to BMI.


References for BNP and obesity:

Wang  T.J., Larson  M.G., Levy  D., Benjamin  E.J., Leip  E.P., Wilson  P.W., Vasan  R.S.;  Impact of obesity on plasma natriuretic peptide levels, Circulation 109 2004 594-600

Mehra  M.R., Uber  P.A., Park  M.H., Scott  R.L., Ventura  H.O., Harris  B.C., Frohlich  E.D.;  Obesity and suppressed B-type natriuretic peptide levels in heart failure, J Am Coll Cardiol 43 2004 1590-1595

McCord  J., Mundy  B.J., Hudson  M.P.;  et al.  Relationship between obesity and B-type natriuretic peptide levels, Arch Intern Med 164 2004 2247-2252