Title: Btype Natriuretic Peptide BNP in the Diagnosis of Acute Congestive Heart Failure CHF
1B-type Natriuretic Peptide(BNP) in the Diagnosis
of Acute Congestive Heart Failure (CHF)
- Scott M Silvers, MD
- 1st Annual Pan American Conference
- Emergency Medicine Clinical Policies
- November 6 7, 2003
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6Lecture Outline
- Introduction to BNP
- Case
- Critical Question
- Literature Search
- Critical Literature Evaluation
- Evidence-based Recommendations
7Introduction to BNP
- 32-aa polypeptide
- Found in heart ventricles
- Produced with ? ventricular stretch and volume
- Results in vasodilation, natriuresis, diuresis,
and reduced preload - Increases with worsening heart failure
8Introduction to BNP
Maisel AS, et al. N Engl J Med.
2002347(3)161-167.
9Introduction to BNP
Morrison LK, et al. J American Coll of Card.
200239(2)202-209.
10Case
- Current History
- Ms. GM is a 76 yo woman with a history only of
obstructive lung disease who presents to the
emergency department with 2 days of progressively
worsening shortness of breath. - Physical Examination
- T 37C HR 110 BP 170/90 RR 40 SO2
(air) 87 - She is unable to speak long sentences.
- Neck veins difficult to assess
- Heart difficult to hear over her lung sounds
- Lungs diffuse wheezing with decreased breath
sounds and rales at the bases - Abdomen normal
- Extremities warm with moderate pitting edema
11Chest X-ray
12Critical Question
- What is the utility of a B-type natriuretic
peptide (BNP) measurement in the diagnosis of
congestive heart failure among patients
presenting to an emergency department
with shortness of breath?
13Curiosity Poll
- How many people have a BNP assay available to
them where they practice?
14Literature Search
- Medline January 1995 Present
- Keywords
- Brain natriuretic peptide, B-type natriuretic
peptide, B natriuretic peptide, or BNP - 1, 745 papers
- Limits
- Human subjects, clinical trials, meta-analyses
- 164 papers
15Literature Search
- Abstracts of clinical studies reviewed
- Patients presenting with shortness of breath to
acute care centers - 5 papers
- Reviews and clinical policies 2000 - present
(references crosschecked)
16Typical Study Methodology
- Adult patients presenting to an acute care
facility - Primary complaint shortness of breath
Exclusion Criteria
- Obvious non-CHF cause of shortness of breath
- Renal Failure
- Acute myocardial infarction
17Typical Study Methodology
- Evaluation by an emergency physician
- Assessment of clinical probability of CHF
- BNP assay sent
- Results not revealed to emergency physician
- Patient treated and dispositioned
- Physician team blinded to BNP measurement assign
final diagnosis after evaluation of case
18Typical Study Methodology
- Clinical findings
- Chest x-ray
- Echocardiography
- Nuclear cardiology
- Cardiac Catheterization
- Framingham and NHANES scores
- Clinical response to therapies
19Critical Literature EvaluationBNP in Diagnosing
CHF
- 5 published studies to date
- 2 report data from the same sample
20Critical Literature EvaluationBNP in Diagnosing
CHF
21Critical Literature EvaluationBNP in Diagnosing
CHF
- Maisel et al, (NEJM 2002)
- Prospective, multinational N 1,586
- All clinical risk patients evaluated as one
sample - BNP
- Sensitivity 90 Specificity 76
- NPV 89 PPV 79
- BNP
- Sensitivity 97 Specificity 62
- NPV 96 PPV 71
- Study Grade 1
22Critical Literature EvaluationBNP in Diagnosing
CHF
- McCullough et al, (Circulation 2002)
- Prospective, multinational N 1,538
- Excluded 48 patients without clinical risk
assessement - BNP
- Low and Intermediate clinical probability (0
79) - Sensitivity 94 Specificity 70
- NPV 93 PPV 74
- High clinical probability (80 100)
- Sensitivity 49 Specificity 96
- NPV 68 PPV 91
- Study Grade 2 (Post-study Analysis)
23Critical Literature Evaluation
24Critical Literature Evaluation
25Critical Literature Evaluation
26Critical Literature Evaluation
Maisel AS, et al. N Engl J Med.
2002347(3)161-167.
27Critical Literature Evaluation
- Possible Limitation of BNP
- Among rats given acute CHF, BNP may take over 1
hour to rise.
Nakagawa O, et al. J Clin Invest.
1995961280-1287.
28Evidenced-based Recommendations
- Patients presenting to an emergency department
- Primary complaint shortness of breath
Excludes
- Obvious non-CHF cause of shortness of breath
- Renal Failure
- Acute myocardial infarction
29Evidenced-based Recommendations
- A BNP rule-out the diagnosis of congestive heart
failure when the diagnosis is uncertain.
(Probability
30Evidenced-based Recommendations
- Among low and intermediate clinical probability
patients, a BNP used to help rule-out the diagnosis of congestive
heart failure. (Probability - Among patients without a history of CHF, a BNP
88 pmol/L (400 pg/ml) may be used to rule-in the
diagnosis of CHF when the diagnosis is uncertain.
(Probability 95) - A BNP 220 pmol/L (1,000 pg/ml) may be used to
rule-in the diagnosis of acute CHF among patients
presenting with a history of CHF. (Probability
95)
31Evidenced-based Recommendations
- When evaluating a patient who presents with
possible CHF within 1 hour from symptom onset,
use caution in the interpretation of a low BNP
level as BNP may take over 1 hour to rise.
32Key References
- Davis M, et al. Plasma brain natriuretic peptide
in assessment of acute dyspnea. Lancet.
1994343440-444. - Dao Q, et al. Utility of B-type natriuretic
peptide in the diagnosis of congestive heart
failure in an urgent-care setting. J Amer Coll
Card. 200137(2)379-385. - Morrison LK, et al. Utility of a rapid
B-natriuretic peptide assay in differentiating
congestive heart failure from lung disease in
patients presenting with dyspnea. J Amer Coll
Card. 200239(2)202-209. - Maisel AS, et al. Rapid measurement of B-type
natriuretic peptide in the emergency diagnosis of
heart failure. New Eng J Med.
2002347(3)161-167. - McCullough PA, et al. B-typenatriuretic peptide
and clinical judgement in emergency diagnosis of
heart failure Analysis from breathing not
properly (BNP) multinational study. Circulation.
2002106416-422. - Nakagawa O, et al. Rapid transcriptional
activation and early mRNA turnover of brain
natriuretic peptide in cardiocyte hypertrophy. J
Clin Invest. 1995961280-1287.
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34The End