Challenging question because of a few variables. By my experience most of these people will have elevated numbers prior to "acute" event. In the US heart failure is treated by most physicians as a "disease/diagnosis" - but it should represent a symptom/sign of the underlying disease. When explaining to patients it is similar to finding that there is an elevation in temperature/fever - treatment will often be with meds/antibiotics - yet the medical diagnosis will be after an investigation to confirm etiology. For CHF the medical evaluation is complex and due to value based modifiers in the US even good doctors are unable to complete the accurate evaluation - so the patient is given meds for treatment of a symptom. Over time the patient will go from episodes of acute CHF to mild to a baseline. As you look at study of the subject it would be nice to have consideration of the accurate facts of the patient at baseline. (example: those who simply present and the medical team guesses at the cause v. patients who have had a complete evaluation of their: a) rhythm by 30 day monitor or implanted loop, b) accurate valvular description of all 4 valves - aortic in mid systole is best, c) size of chambers, d) description of coronary anatomy and disease state, e) metabolic profile, f) blood evaluation for anemia and protein/serum perturbations, g) nocturnal hypoxia h) other history and active disease issues along with other more rare issues case by case. Generally cases that we get of "CHF" are only dealing with the issue until we can grasp/understand and then treat the underlying condition. Most of these patients will have elevation of BNP before the massive event that causes decompensation. If your question is about the trend, that will also be complex because of the variables associated with treatment (IV diuretics, meds) could affect the target range of how high the BNP would have gone. Sorry for the long answer - We treat a lot of patients who are not well cared for and this entire subject is very predictable - but as it is the best money maker for the hospitals (average 7 admits per year) there is just not much interest in the strategy of fixing the reason rather than treating the symptom.

Main cinical use of BNP is in an acute setting. It is difficult to answer the question as to how early increase in BNP occur after the pathophysiological abnormality has set in. Both clinical presentation and elevated BNP detection in blood has a time lag after the pathophysiological abnormality has been initiated. Which occur first is the debate. I think by the time patient becomes symptomatic (usually dyspnoea), BNP will be elevated. There can be further increase in the numbers as heart failure progresses. I am not aware of any study which has specifically addressed this question.

Dear Jalue Hua,

BNP, with a half-life of 20min, can rise in appr. 120min, reflecting PWP changes, while NT-proBNP, having a half-life of 60-120min, rises in appr. 12h.

Hi Dr Hua , Dr koshy ,Dr Allen and Eliana.. Thanks everybody. Very interesting question. Exact time is very difficult to find. BNP level may be elevated in asymptomatic LV dysfunction before the development of clinical overt heart failure. I totally agree with Dr koshy that most of the patients with heart failure with LV dysfunction probably will have increased BNP level during presentation because BNP level trend to rise in these patients before the development of symptoms.. Following article might help.. Thanks

A very interesting question, a little philosophic one : what is older, an egg or a chicken. But, as I suppose, should be easy to answer: chronic heart failure of any cause is a disease with a long period of insidious and asymptomatic/ subclinical progression of many intrinsic adaptive mechanisms. So, without any data about the question, it is logical to suppose that the slow and steady augment of BNP as one of those mechanisms must precede an overt expression of heart insufficiency, brutal ( pulmonary oedema) or a slow one, leading to a classical dropsy. Maybe since the very beginnings of the first hypoxic signs , paroxysmal nocturnal dyspnoe or sleep apnoe syndrome. For how long time, I do not know, but probable very early

There is a different range of BNP which is produced by the cardiac ventricle in different condition and that amount in pg will show the severity of the cardiac disease.