Topic Editor: Robert Giles, MBBS, BPharm
Review Date: 10/19/2012
Definition
Congestive heart failure (CHF) is a complex clinical syndrome in which the heart has insufficient output to meet the body's physiological needs. It results from a functional or structural cardiac disorder(s) that impairs ventricular filling or ejection. CHF may involve the left ventricle, right ventricle or both.
Description
- CHF most commonly arises from ventricular dysfunction, less commonly due to structural cardiac anomalies, arrhythmias or conduction disorders
- Ventricular dysfunction usually results from ischemic heart disease (systolic dysfunction), hypertension (diastolic and systolic dysfunction) or both. Other major causes are degenerative valvular disease, idiopathic cardiomyopathy, and alcoholic cardiomyopathy
- Signs and symptoms of CHF include manifestations of venous congestion (e.g., Dyspnea on exertion, peripheral edema) and low cardiac output (e.g., Fatigue)
- The New York Heart Association (NYHA) classification for CHF
- Class I (mild) patients have no limitation of physical activity
- Class II (mild) patients have slight limitation of physical activity
- Class III (moderate) patients have marked limitation of physical activity
- Class IV (severe) patients have symptoms at rest with inability to carry out physical activity
- Diagnosis of CHF is based upon careful history, physical examination, characteristic chest radiographic findings, laboratory studies and echocardiography
- Treatment involves pharmacotherapy and correction of any underlying disorders
- Patients with chronic CHF may rapidly deteriorate into acute decompensated heart failure (See Cardiogenic pulmonary edema). This document focuses predominantly on the management of chronic CHF
Epidemiology
Incidence/prevalence
- Acute CHF is a leading cause of hospitalization among people aged =65 years in the United States, Europe, Australia, and New Zealand
- Affects approximately 5.7 million people in the U.S.
- CHF is mentioned on 34% of cardiovascular related death certificates and was the underlying cause in 7% of cardiovascular related deaths in the U.S.
- More than 670,000 new patients are diagnosed with CHF annually in the U.S.
- Prevalence of CHF in the western world is estimated at 1–2%, with incidence of approximately 5–10/1,000 people per year
Age
- CHF occurs predominately in the elderly, with ~80% of cases occurring in patients aged =65 years
- At age 40 the lifetime risk of developing new CHF is 20%. At age 80 the lifetime risk of developing new CHF is still 20% despite decreased life expectancy
Gender
- The prevalence of CHF is higher in males (3%) then females (2%)
Race
- Both incidence and prevalence of CHF is higher among African-Americans, Hispanics, Native Americans, and immigrants from developing nations
Genetics
- Familial cardiomyopathy is a predisposing factor to developing CHF (rare)
Risk factors
- Alcohol abuse
- Arrhythmias
- Cardiomyopathy
- Cigarette smoking
- Cocaine abuse
- Congenital heart disease
- Coronary heart disease
- Diabetes
- Dyslipidemia
- Emphysema
- Exposure to cardiotoxic agents
- Hypertension
- Left ventricular hypertrophy
- Low physical activity
- Male gender
- Myocardial infarction
- Obstructive sleep apnea
- Older age
- Overweight or obesity
- Peripheral vascular disease
- Renal insufficiency
- Severe anemia
- Thyroid dysfunction (both hyper and hypothyroidism)
- Valvular heart disease
Etiology
- Cardiomyopathy (including alcoholic and pregnancy-related cardiomyopathy)
- Congenital heart disease
- Dietary indiscretion (sodium overload)
- Drugs leading to sodium retention (glucocorticoids, NSAIDs, vasodilators)
- Dysrhythmias
- Hypermetabolism
- Hypertension
- Metabolic/Endocrine (hypo or hyperthyroidism, hypoadrenalism)
- Myocardial infiltrative disease
- Myocardial ischemia/infarction
- Myocarditis
- Negative inotropic drugs (beta blockers, calcium channel blockers)
- Pulmonary embolism (Right sided failure)
- Severe anemia
- Structural heart disease with left to right shunt
- Valvular abnormalities (ventricular obstructive or atrial regurgitate)
History
- History is critical in providing clues to the cause (e.g., MI or uncontrolled hypertension; or the precipitating event, such as noncompliance with diet or medications) and for assessment of disease severity
- Symptoms of CHF can relate to either reduction in cardiac output or excessive fluid retention
- Symptoms:
- Shortness of breath, initially only on exertion but as severity increases, eventually at rest. This is due to pulmonary congestion and edema
- Orthopnea - Difficulty breathing with being supine position. Patients may require propping up in order to sleep
- Paroxysmal nocturnal dyspnea - waking up breathless at night while supine
- Fatigue and weakness; due to poor cardiac output
- Peripheral edema of feet, ankles, legs, sacrum, scrotum, and occasionally, increased abdominal girth. This is caused by decreased venous return and high central venous pressure which leads to tissue edema and ascites
- Cough may be dry, irritative, or productive of clear, pink , frothy, or blood tinged sputum
- Decreased appetite and nausea due to poor blood flow to the gastrointestinal (GI) tract
- Diaphoresis
- Non specific findings may occur in the elderly – confusion, falls, functional decline
Physical findings on examination
- Ascites
- Cough which may be productive of clear or pink sputum
- Cyanosis (due to poor systemic perfusion)
- Displaced (laterally) apical beat
- Jugular venous distension
- Hepatojugular reflex
- Hepatomegaly
- Lung examination with wheeze or bibasilar crackles
- Lung percussion with decreased resonance at bases (consistent with effusion)
- Mitral/ tricuspid regurgitation
- Pitting peripheral edema
- S3, S4 or summation gallop
- Scrotal edema/effusion
- Tachycardia
- Tachypnea
The Framingham criteria are one of several useful tools to aid the diagnosis of chronic heart failure. This criteria has a high sensitivity but low specificity. The diagnosis of CHF requires a minimum of 2 major criteria, or 1 major criteria plus 2 minor criteria.
- Major criteria:
- Acute pulmonary edema
- Cardiomegaly on chest radiograph
- Central venous pressure >12 mmHg
- Crackles (>10 cm above the lung base)
- Jugular venous distension
- Left ventricular dysfunction on echocardiogram
- Orthopnea or paroxysmal nocturnal dyspnea
- S3 gallop
- Weight loss >4.5 kg in response to CHF treatment
- Minor criteria:
- Bilateral ankle/pedal edema
- Dyspnea on exertion
- Hepatomegaly
- Nocturnal cough
- Pleural effusion
- Tachycardia (>120 beats/min)
- KILLIP classification for staging CHF:
- I) Minimal signs
- II) Bilateral crepitations in chest (present in less than one-third of lung fields)
- III) Bilateral crepitations in the chest (all over lung fields) + S3 (ventricular gallop rhythm)
- IV) Cardiogenic shock + end organ hypoperfusion (e.g., renal failure)
Blood test findings
Initial evaluation of patients with suspected CHF
- Brain natriuretic peptide (BNP)
- BNP is a cardiac peptide neurohormone secreted primarily by the myocytes in the cardiac ventricles
- When the cardiac ventricles become stressed and as blood volume expansion or pressure overload occurs, the left ventricular myocytes secrete the precursor pro-BNP, which in turn releases the active hormone BNP
- BNP acts as a vasodilator and has diuretic and natriuretic properties
- This test can be helpful in evaluating CHF, as the majority of patients with symptomatic CHF have BNP levels of >500 pg/mL
- CHF is not likely if the BNP level is 100 pg/mL
- BNP levels between 100 and 500 pg show no clear discrimination, and although being consistent with CHF, is not diagnostic. Values in this range require clinical judgment
- The predictive value of BNP is unclear in critically ill patients as other etiologies (renal failure, sepsis, and many other causes) may result in abnormal BNP levels
- Complete blood count (CBC): To evaluate for anemia or infection as the cause of CHF
- Fasting blood glucose levels: Diabetes is a risk factor for development of CHF
- Fasting lipid profile: Abnormal lipid profile, especially elevated LDL, is a risk factor for ischemic heart disease
- Liver function tests (LFTs): Venous congestion may cause hepatic dysfunction and elevated liver enzymes
- Serum electrolytes (including calcium and magnesium):
- Useful in the assessment of electrolyte abnormalities, such as hypokalemia, hyponatremia, or hypomagnesemia in CHF patients
- Hyperkalemia may be found in renal failure patients
- CHF medications may cause hyperkalemia or hypokalemia
- Hyponatremia is a marker for severe CHF
- Serum creatinine: Elevated serum creatinine is a predictor of all-cause mortality in chronic CHF and also provides evidence of end-organ hypoperfusion
- Thyroid function tests: To identify thyroid disease which might cause or exacerbate CHF
Other laboratory test findings
- Urinalysis: May reveal proteinuria associated with cardiovascular disease (CVD)
Radiographic findings
- Chest radiograph (posteroanterior and lateral if possible – otherwise, portable – anteroposterior): To evaluate cardiac size, chamber enlargement, pulmonary congestion, pleural effusions or other pulmonary disease
- Cardiac CT or MRI can be utilized in the evaluation of multiple parameters such as chamber size, chamber disease, ventricular mass, pericardial disease, wall motion, cardiac function and coronary artery disease
- 2-D echocardiography with Doppler is the gold standard in CHF diagnosis. It provides information on cardiac anatomy, wall motion, pericardial pathology and valvular function. A diminished left ventricular ejection fraction (LVEF) is diagnostic of LV systolic dysfunction
- In the event echocardiography is not available, radionuclide ventriculography may be performed to assess LVEF and volume
Other diagnostic test findings
- 12-lead ECG: May show arrhythmia, acute or prior infarction, and changes consistent with cardiac ischemia as the cause of CHF. ECG can provide some information on diastolic versus systolic LV function and valvular disease; however, echocardiography is more sensitive and specific
- Maximal exercise testing in patients with CHF can be useful in assessing whether CHF is the cause of their exercise limitation
- Other tests may be indicated based on clinical suspicion:
- Evaluation for hemochromatosis, rheumatologic diseases, amyloidosis, or pheochromocytoma
- Holter monitoring in patients who might have arrhythromogenic causes of CHF. Patients with a history of prior MI are more likely to have cardiac arrhythmias
- Human Immunodeficiency Virus (HIV) testing
- Serum and urine electrophoresis for light-chain disease
- Sleep studies for sleep apnea
- Cardiac catheterization and coronary angiography may be considered in the following situations:
- If symptoms of CHF worsen (without a clear cause) in patients without angina or known CAD
- CHF which is caused by systolic dysfunction and associated with suspected unstable angina or regional wall-motion abnormalities (where revascularization would be considered)
- When cardiomyopathy is highly suspected, and catheterization results might support cardiac surgical interventions
- In situations where cardiac transplantation or left ventricular assist devices are being considered
- In cases of CHF secondary to post infarction ventricular aneurysm or other mechanical complications of MI
- Endomyocardial biopsy may be of value in a minority of patients with suspicious causes of CHF
General treatment items
- Treatment consists of a combination of pharmacologic and nonpharmacologic therapies
- Dietary and activity restrictions
- A low-sodium diet (2 g/day) is recommended for CHF patients
- Fluid restriction may be beneficial in some patients (e.g. 1500-2000 mL/day)
- Daily weight monitoring is often valuable in detecting fluid accumulation and the need for medical attention and modification of pharmacotherapy - diet
- Hypertension is responsible for increased afterload on a failing left ventricle and should be treated with one or more of the agents listed below
- Diuretics and salt restriction reduce preload and are indicated in patients with CHF, a reduced LVEF and evidence of fluid retention
- Angiotensin-converting enzyme inhibitors (ACEIs) help in reducing both preload and afterload and are recommended for all patients with CHF and reduced LVEF, unless contraindicated. Patients should be commenced on a low dose and the dose titrated upwards. ACEIs may also be used in patients with signs of CHF post myocardial infarction.
- Angiotensin II receptor blockers (ARBs) recommended in ACEI-intolerant patients with CHF and reduced LVEF
- The combination of hydralazine plus nitrates is recommended to improve ventricular function and improve exercise tolerance. This combination improves survival in patients who are unable to tolerate ACEIs or ARBs. These agents may also improve survival as an add-on therapy to ACEI/ARB and beta-blockers amongst African-Americans
- Beta-adrenergic receptor antagonists (B-blockers) blunt the effects of adrenergic input. They should be started at a low dose and gradually be titrated upward. Carvedilol, bisoprolol and metoprolol are currently recommended for use in CHF
- Aldosterone antagonists may be used adjunctively in moderate to severe CHF to improve diuresis, CHF symptoms, decrease tachycardia and ventricular arrhythmias, decrease cardiac workload, and improve LVEF. Serum potassium concentration needs to be monitored if these agents are prescribed
- Antithrombotic therapy (e.g. Warfarin, aspirin, clopidogrel) may be indicated in some patients to decrease the risk of thromboembolism
- Positive inotropic agents such as digitalis glycosides or inhibitors of heart-specific phosphodiesterases may result in improved contractility of the failing heart. Digoxin may slightly increase cardiac output and result in improvement in CHF symptoms. It decreases CHF hospitalizations but provides no mortality benefit. It is especially useful in patients with underlying atrial fibrillation
- A new class of drugs called human B-type natriuretic peptides (hBNPs) have been used to cause loss of salt and fluids. The example of this class is nesiritide. Despite theoretically reducing afterload and being indicated for decompensated heart failure – the evidence fails to support use of this agent for CHF. Additionally, nesiritide is not without side effects (O'connor 2011)
- Avoid the use of diltiazem and verapamil in patients with systolic dysfunction.
- Avoid non steroidal anti-inflammatory drugs which can worsen CHF
- Surgeries and other procedures:
- Heart valve surgery may be indicated if valvular disease is contributing to CHF; mitral valve repair or replacement is beneficial if mitral regurgitation is the causative condition
- Cardiac transplantation is considered in patients who develop CHF unresponsive to other therapeutic maneuvers. Preference is given to patients who are 55 years old, have no contraindications, and otherwise have a life expectancy of >1 year
- Biventricular pacing for ventricular dyssynchrony may improve symptoms and survival
- Implantable cardiac defibrillators (ICDs) are useful to prevent sudden cardiac death
- Revascularization procedures such as CABG and percutaneous coronary intervention (PCI) should be considered in selected patients with CHF and CAD
Medications indicated with specific doses
Beta-Blockers:
- Bisoprolol
- Carvedilol
- Metoprolol
Angiotensin-converting enzyme inhibitors:
- Benazapril
- Captopril
- Enalapril
- Fosinopril
- Lisinopril
- Moexipril
- Perindopril
- Quinapril
- Ramipril
- Trandolapril
Angiotensin II receptor blockers:
- Azilsartan
- Candesartan
- Eprosartan
- Irbesartan
- Losartan
- Olmesartan
- Telmisartan
- Valsartan
Cardiac glycosides:
- Digoxin [Oral]
- Digoxin [IV]
Vasodilators:
- Hydralazine [Oral]
- Hydralazine [IV]
Nitrates
- Isosorbide dinitrate
- Isosorbide mononitrate
Loop diuretics:
- Bumetanide [Oral]
- Bumetanide [IV]
- Furosemide [Oral]
- Furosemide [IM/IV]
- Torsemide [Oral]
- Torsemide [IV]
Thiazide-type diuretics
- Chlorthalidone
- Hydrochlorothiazide
- Indapamide
- Metolazone
Aldosterone antagonists
- Eplerenone
- Spironolactone
Dietary or Activity restrictions
- Losing weight, if overweight
- Cholesterol lowering by lifestyle modification or statin therapy
- Mild exercise to stay active
- Reducing alcohol intake
- Quitting smoking
- Restricting salt and fluids
Disposition
Admission criteria
- Patients with decompensated heart failure and acute pulmonary edema
- Admission criteria includes:
- Arrhythmias
- Acute coronary syndrome or acute myocardial infarction
- Confusion
- Cardiogenic pulmonary edema that is of new onset or sufficient in severity to require inpatient treatment
- Dyspnea at rest or with minimal exertion
- Hypercapnia
- Hypotension
- Hypoxia (O2 sat 90%)
- Renal dysfunction – acute change in renal function
Discharge criteria
- Resolution of issue that met criteria for admission
- Adequate investigation of the underlying cause
- Stabilization of the condition on oral medications
- Stable daily weight
- Adequate family and patient education
- Outpatient follow-up arranged
