Heart Failure

Diagnosis

Indications for Testing

  • Clinical diagnosis compatible with congestive heart failure (CHF); Framingham criteria may be helpful

Criteria for Diagnosis

  • Framingham criteria to establish clinical diagnosis of congestive heart failure
    • At least 1 major and 2 minor criteria must be met
      • Major criteria
        • Paroxysmal nocturnal dyspnea
        • Neck vein distention
        • Rales
        • Cardiomegaly
        • Acute pulmonary edema
        • S3 gallop
        • Increased venous pressure (>16 cm H20)
      • Minor criteria
        • Extremity edema
        • Nocturnal cough
        • Dyspnea on exertion
        • Hepatomegaly/splenomegaly
        • Pleural effusion
        • Cardiac output reduced by one-third from normal
        • Tachycardia (≥120 bpm)
      • Major or minor criteria
        • Weight loss ≥4.5 kg over 5 days of treatment

Laboratory Testing

  • Initial testing – CBC, urinalysis, electrolytes, BUN, creatinine, transaminases
  • Natriuretic peptides – B-type (BNP) and N-terminal proBNP (NT proBNP)
    • High sensitivity and specificity for differentiating between cardiac and noncardiac causes
      • Useful to rule out CHF due to high negative predictive value (>98%)
    • Concentrations expected to exceed diagnostic cutoff in 90% of patients with CHF
    • Best documented use is emergency testing in patients presenting with acute dyspnea and a clinical scenario suggesting CHF
      • BNP <100 pg/mL or NT proBNP <300 pg/mL – heart failure unlikely
        • Cutoff of 100 pg/mL provides maximal combination of sensitivity, specificity and negative predictive value for contributing to diagnosis of CHF
      • BNP 100-400 pg/mL or NT proBNP 300-450 pg/mL (<50 years) or 300-900 pg/mL (50-75 years) – heart failure possible
      • BNP >400 pg/mL or NT proBNP >450 pg/mL (<50 years); >900 pg/mL (50-75 years); >1,800 pg/mL (>75 years) – heart failure likely
    • Single cutpoint strategy BNP <100 pg/mL or NT proBNP <900 pg/mL – some suggest heart failure unlikely
    • Performs slightly better in men than in women and in younger (<70 years) rather than older patients; may not be as useful in the very aged (>75 years)
    • Clinical sensitivity and specificity of NT proBNP

       Clinical Sensitivity and Specificity of NT proBNP

      Age (years)

      <45

      45-54

      55-64

      65-74

      ≥75

      Diagnostic cutoff (pg/mL)

      <125

      <125

      <125

      <125

      <450

      Males, clinical sensitivity

      82

      88

      90

      92

      87

      Males, clinical specificity

      96

      93

      88

      87

      89

      Females, clinical sensitivity

      87

      91

      89

      94

      82

      Females, clinical specificity

      85

      86

      80

      58

      88

    • BNP not useful in patients with shock – elevated in both septic and cardiac shock
    • In renal failure (GFR <60 mL/min/1.73 m2) – BNP 200 pg/mL or NT proBNP 1,200 pg/mL; heart failure likely
    • In obesity – BNP 170 pg/mL for BMI <25kg/m2; 110 pg/mL for BMI 25-35 kg/m2; 54 pg/mL for BMI ≥35 kg/m2
  • Other possible testing
  • Suggested referral to specialist within 6 weeks for raised levels of BNP (see NICE 2010 chronic heart failure guideline)

Imaging Studies

  • Chest x-ray – bilateral interstitial infiltrates, cephalization of vessels, cardiomegaly, Kerley B lines, effusions
  • Ventilation/perfusion (V/Q) scan, pulmonary angiography – rule out pulmonary embolism

Other Testing

  • EKG – Q waves, ventricular hypertrophy, heart block, atrial fibrillation
  • Echocardiogram – frequently reduced ejection fraction
    • Role in excluding valvular disease
    • Test of choice (NICE 2010 revised) before natriuretic peptides, if patient has recent urinary infection (within 2 weeks)
  • Sleep study

Prognosis

  • BNP
    • Several recent studies suggest BNP value at discharge may be a reliable indicator of recurrent admission and morbidity
      • <300 pg/mL associated with benign course
    • Reduction of NPs during therapy associated with improved clinical outcome
    • BNP >125 pg/mL or NT proBNP >1,000 pg/mL with rising values – predictive of adverse outcome
  • Soluble ST2
    • Marker of fibrosis – assesses a different biochemical pathway from BNP
    • Several recent studies suggest that higher levels are associated with mortality and morbidity at 1 year
      • Increased risk with rising levels
    • Complements prognostic value of NT proBNP
    • Useful in risk stratification and assessment in patients with known CVD
  • Galectin-3
    • Emerging prognostic biomarker
    • Marker of cardiac fibrosis
    • May be useful in stratification, particularly combined with NT proBNP

Differential Diagnosis

Screening

  • National Academy of Clinical Biochemistry Laboratory Medicine Practice guidelines state that screening is reasonable in high-risk patients (eg, diabetic patient with history of myocardial infarction)
    • BNP or NT proBNP

Monitoring

  • Serial use of NP measurements to guide titration of therapy
    • No randomized studies prove risk vs. benefit ratio is acceptable

Clinical Background

Heart failure is a clinical syndrome in which the heart muscle is unable to pump enough blood to meet tissue demands. It is often referred to as congestive heart failure.

Epidemiology

  • Prevalence
    • >10% in patients >80 years (National Health and Nutrition Examination Survey, 2005-2006)
    • 1% in patients <60 years
  • Age – ≥65 years
  • Sex – M>F (difference narrows as women age)

Etiology (numerous)

Risk Factors

Categorization

  • Diastolic vs. systolic dysfunction
  • Low-output vs. high-output
  • Acute vs. chronic
  • Left-sided vs. right-sided

Clinical Presentation

  • Dyspnea, orthopnea, paroxysmal nocturnal dyspnea
  • Fatigue and weakness
  • Nausea and anorexia
  • Physical examination includes tachycardia, S3/S4, pulsus alternans, pulmonary rales, ascites, hepatomegaly, jaundice, pedal edema, cachexia

Pediatrics

Clinical Background

Epidemiology

  • Incidence – cardiomyopathy occurs in 8/100,000 infants

Etiology

  • Most chronic heart failure in children is related to congenital heart disease
    • Increased systolic output with pulmonary over-circulation
      • Ventricular septal defect 
      • Large patent ductus arteriosus
      • Persistent aorta pulmonary connections
    • Low cardiac output
      • Hyperplastic left heart
      • Critical aortic stenosis
      • Severe coarctation of the aorta
    • Acquired disorders

Clinical Presentation

  • Neonates
    • Poor feeding
    • Irritability
    • Respiratory difficulty
  • Children
    • Fatigue
    • Anorexia
    • Dyspnea, cough
    • Abdominal pain

Diagnosis

Indications for Testing

  • Clinical diagnosis compatible with congestive heart failure; Framingham criteria may be helpful (refer to Diagnosis tab)

Laboratory Testing

  • Initial testing – CBC, urinalysis, electrolytes, BUN, creatinine, transaminases
  • Natriuretic peptides (BNP and NT proBNP)
    • Different optimal diagnostic cutoff values necessary
      • Higher concentrations of natriuretic peptides that decrease rapidly
    • Natriuretic cutpoints must be age- and gender-related in children
      • Cutoffs also vary by type of test

Imaging Studies

  • Refer to Diagnosis tab

Other Testing

  • Refer to Diagnosis tab

Prognosis

  • Natriuretic peptides – unlike adults, not enough literature available to suggest use is helpful
    • Single study indicated BNP ≥300 pg/mL was prognostic for poorer outcome (Price, et al, Circulation, 2006)

Indications for Laboratory Testing

  • Tests generally appear in the order most useful for common clinical situations
  • Click on number for test-specific information in the ARUP Laboratory Test Directory
Test Name and Number Recommended Use Limitations Follow Up
proBrain Natriuretic Peptide, NT 0050083
Method: Quantitative Electrochemiluminescent Immunoassay

Aid in assessing severity of CHF and prognosis in symptomatic and asymptomatic patients

ProBNP is generally more sensitive but less specific than BNP

In patients with renal insufficiency, NT proBNP may accumulate to concentrations that no longer correlate with New York Heart Association functional classifications

Do not use as a stand-alone test; assess clinical presentation and other evaluation (eg, chest x-ray, echocardiogram)

 
B-Type Natriuretic Peptide 0030191
Method: Quantitative Chemiluminescent Immunoassay
Aid in assessing severity of CHF and prognosis in symptomatic and asymptomatic patients

Blood concentrations of natriuretic peptides may be elevated in patients with myocardial infarction and in patients who are candidates for or are undergoing renal dialysis

False-positive results more common in females >75 years

Do not use as a stand-alone test; assess clinical presentation and other evaluation (eg, chest x-ray, echocardiogram)

 
ST2, Soluble 2002270
Method: Quantitative Enzyme Immunoassay

Use for prognostication and risk assessment in heart failure

Test complements prognostic value of NT proBNP

Possibility of interference with anti-reagent antibodies and patient sample

Biological variability – 30% for healthy adults

 
Galectin-3, Serum 2007138
Method: Quantitative Enzyme Immunoassay

Use for prognostication in heart failure

   
Additional Tests Available
 
Click the plus sign to expand the table of additional tests.
Test Name and NumberComments
CBC with Platelet Count and Automated Differential 0040003
Method: Automated Cell Count/Differential

Rule out sepsis

Urinalysis, Complete 0020350
Method: Reflectance Spectrophotometry/Microscopy

Rule out infection and hematuria

Electrolyte Panel 0020410
Method: Quantitative Ion-Selective Electrode/Enzymatic

Rule out electrolyte abnormalities

Hepatic Function Panel 0020416
Method: Quantitative Enzymatic/Quantitative Spectrophotometry

Rule out hepatic involvement

Creatinine, Serum or Plasma 0020025
Method: Quantitative Enzymatic

Rule out renal failure

Digitoxin 0090085
Method: Quantitative CEDIA Immunoassay
Digoxin 0090080
Method: Immunoassay