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
  • TSH – rule out hyper- or hypothyroidism
  • Fasting transferrin in patients of northern European descent – rule out hemochromatosis
  • Lipid studies
  • Glycosylated hemoglobin – rule out diabetes mellitus
• 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
  • Several recent studies suggest that higher levels are associated with mortality and morbidity at 1 year
  • 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

• Cardiac
  • Acute myocardial infarction
  • Cardiomyopathy
  • Valvular disease
  • Pericarditis
  • Arrhythmias (atrial fibrillation)
• Pulmonary
  • COPD
  • Asthma
  • Restrictive lung disease
  • Hereditary lung disease
  • Pneumothorax
  • Pulmonary embolism
• Other
  • Septic shock
  • Metabolic conditions
  • Thyrotoxicosis
  • Anxiety
  • Neuromuscular disorders
  • Obesity
  • Anemia

Screening

Monitoring

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)

• Cardiac
  • Myocardial infarction/ischemic heart disease
  • Arrhythmias (atrial fibrillation is most common)
  • Hypertension
  • Myocarditis
  • Congenital heart disease
  • Valvular disease (aortic stenosis)
• Infectious
  • Sepsis
  • Endocarditis
• Pulmonary
  • Embolism
  • Hypertension
  • Chronic obstructive pulmonary disease (COPD)
• High-output forms
  • Anemia
  • Thyrotoxicosis

Risk Factors

• Hypertension
• Diabetes mellitus (DM)
• Alcoholism
• Hyperlipidemia
• Coronary artery disease
• Thyroid disease

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
    • Rheumatic heart disease
    • Acute myocarditis
    • Anti-neoplastic drugs
    • Nutritional cardiomyopathy

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

Click the plus sign to expand the table of additional tests.

Test Name and Number	Comments
Digitoxin 0090085 Method: Quantitative CEDIA Immunoassay
Digoxin 0090080 Method: Immunoassay