Heart Failure

Latest updates: January 26, 2014

The American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) recently published their 2013 guidelines for the management of heart failure, updated from 2009. A summary by the AHA of the major changes and additions to its class I recommendations can be found here and are as follows:

• A new focus on guideline-directed medical therapy (GDMT), which represents the optimal medical therapy and includes angiotensin-converting enzyme (ACE) inhibitors; angiotensin II receptor blockers (ARBs) when the patient is intolerant to ACE inhibitors; β-blockers; and, in select patients, aldosterone antagonists, hydralazine nitrates, and diuretics as the main pharmacologic therapy for heart failure–reduced ejection fraction (HFrEF)
• A discussion on how heart failure therapy guided by natriuretic peptides can be useful to achieve optimal dosing in GDMT for select clinically euvolemic heart failure patients in a well-structured outpatient disease management program. As before, the guidelines acknowledge that the usefulness of serial measurement of cardiac biomarkers to reduce hospitalization or mortality in patients with heart failure, or the usefulness of therapy guided by such biomarkers for acutely decompensated heart failure are not well-established
• A broadening of indications for aldosterone antagonists in symptomatic HFrEF patients to now include mild to moderate heart failure (New York Heart Association [NYHA] class II) patients with a history of a prior cardiovascular hospitalization or elevated plasma natriuretic peptide levels, in addition to formerly existing indications for patients with severe heart failure
• An expansion of cardiac resynchronization therapy to patients with milder symptoms (NYHA class II) but with left bundle branch block and a QRS duration of 150 ms or greater

Other changes cited by the AHA:

• An emphasis on education and transitions of care
• An intent to harmonize with other guidelines, consensus documents, and position papers, which are cross-referenced, and the introduction of detailed evidence tables containing quick tabulations and summary data of landmark papers
• A comparison of the ACCF/AHA stages of heart failure with NYHA Functional Classification, and emphasis on multivariable risk scores to estimate subsequent risk in heart failure patients

Key points

• Heart failure is a condition in which the heart cannot pump sufficient oxygenated blood to meet the metabolic needs of the body tissues or can do so only from an elevated filling pressure; maximal oxygen utilization is reduced in proportion to the degree of heart failure
• Worsening heart failure necessitates a search for factors that can alter ventricular function
• All patients with left ventricular systolic dysfunction benefit from combination therapy with angiotensin-converting enzyme (ACE) inhibitors/angiotensin II receptor antagonists, β-blockers, diuretics, aldosterone antagonists, and digoxin (in more symptomatic patients)
• Treatment with ACE inhibitors and β-blockers should not be discontinued abruptly, as this may precipitate worsening heart failure
• Non-drug therapy, including placement of an implantable cardioverter-defibrillator (ICD) or biventricular pacing, should be considered in patients who meet specific electrocardiographic and reduced ejection fraction criteria
• Respiratory distress in a patient with acute pulmonary edema is a medical emergency and requires immediate treatment to decrease the pulmonary capillary pressure, reverse alveolar fluid accumulation, and restore normal arterial oxygenation
  • Allowing the legs to be dependent helps reduce pulmonary capillary pressure. Prompt decreases in pulmonary capillary pressure can be achieved with the following:
    • Sublingual nitrates administered every few minutes, with close attention to arterial blood pressure and the patient's respiratory status
    • Intravenous nitrates, although the intravenous route requires more time for uptitration than the sublingual route
    • Intravenous morphine, which also decreases systemic vascular resistance
    • Intravenous nesiritide
    • Intravenous furosemide or bumetanide, although the onset of action may take at least 15 minutes
  • Oxygen is administered to achieve an arterial oxygen saturation greater than 90%. Ventilation is improved with the patient sitting up rather than recumbent. Early use of bilevel positive airway pressure may improve oxygenation but has not been shown to reduce the need for intubation or 30-day mortality
• Severe heart failure or heart failure that has developed suddenly or worsened suddenly is a potential emergency that requires hospital admission and aggressive medical therapy
• Survival of patients with heart failure is improved with treatment, but the annual mortality rate remains high

Background

Description

• Heart failure may be left sided, with pulmonary edema as a predominant symptom, or right sided, often with hepatomegaly and systemic edema
• Left-sided heart failure is characterized by reduced exercise tolerance, fatigue, dyspnea, weakness, cough, cardiac enlargement, pulmonary rales, elevated jugular venous pressure, a positive hepatojugular reflux sign, peripheral edema, and S₃ gallop rhythm
• Right-sided heart failure is associated with edema, elevated jugular venous pressure, S₃ gallop over the right ventricle, hepatomegaly, and often ascites or anasarca
• Both sides of the heart often are involved, with a combination of the signs and symptoms characteristic of left-sided and right-sided heart failure
• Exercise intolerance and fatigue are common in all patients with heart failure
• Heart failure also may be characterized as systolic and/or diastolic. In patients with systolic heart failure, the left ventricular ejection fraction is reduced, whereas in patients with diastolic heart failure, left ventricular systolic function typically is preserved, but the altered ventricular compliance results in a high filling pressure. This distinction should be made during the diagnostic evaluation because the two conditions have different prognoses and may respond differently to treatment

Epidemiology

Incidence and prevalence:

• One hundred to 400 new cases of heart failure are diagnosed per 100,000 persons per year
• One thousand or more new cases are diagnosed per 100,000 persons over age 65 per year
• There are approximately 1,000 to 2,000 cases of heart failure per 100,000 persons
• Five thousand or more cases are diagnosed per 100,000 persons over age 65; heart failure is the most common inpatient diagnosis in the U.S. in patients over age 65
• Heart failure occurs at some stage in patients with most forms of severe heart disease, regardless of the underlying cause
• Heart failure leads to a total of 12 to 15 million office visits per year

Demographics:

• Incidence increases with age
• Heart failure is more common in men than in women between 40 and 75 years of age, but among persons over age 70, both sexes are affected equally
• The prevalence of heart failure is estimated to be 25% greater in black persons than in white persons
• Dilated and hypertrophic forms of cardiomyopathy may run in families, and specific genetic defects are known. Susceptibility to myocardial infarction, which is a frequent cause of heart failure, may have a genetic component. Hypertension is frequently familial. Hemochromatosis can lead to both cardiomyopathy and accelerated coronary artery disease

Causes and risk factors

Causes:

• ST-segment elevation myocardial infarction is the most common cause of heart failure in the U.S.
• Untreated or inadequately treated hypertension is the second most common cause of heart failure in the U.S.
• Common causes of left-sided heart failure include ischemic heart disease, hypertension, arrhythmias (especially atrial fibrillation), valvular disease (aortic stenosis, aortic regurgitation, mitral regurgitation), cardiomyopathy, high-output states (anemia, hyperthyroidism), congenital heart disease, volume overload (eg, in patients with renal failure who miss dialysis), and alcoholism
• The most common cause of right-sided heart failure is left-sided heart failure; other causes include chronic pulmonary disease, pulmonary embolism, primary pulmonary hypertension, and valvular disease (mitral stenosis)
• Rare causes of heart failure include uncommon high-output states (osteitis deformans, beriberi), valvular disease (tricuspid incompetence, pulmonary stenosis), infective endocarditis, isolated right ventricular cardiomyopathy, hyperthyroidism, vitamin deficiency, myocarditis, toxic substances, illicit drugs (eg, cocaine and amphetamines), endomyocardial fibrosis, hemochromatosis, and amyloidosis
• Serious causes requiring very prompt recognition and treatment include acute myocardial infarction, rupture of the intraventricular septum, acute valvular incompetence, pulmonary embolism, cardiac tamponade masquerading as heart failure, and acute fulminant myocarditis

Risk factors:

• Obesity
• Obstructive sleep apnea
• Cigarette smoking
• Pregnancy
• Infection, especially pulmonary infection
• Diabetes
• Physical inactivity
• Renal insufficiency

Screening

Summary approach

• Although some patients with left ventricular dysfunction are asymptomatic and means of documenting such dysfunction, as well as agents with the potential to prevent progression to more advanced stages of heart failure, are available, there are currently no widely accepted data-driven or guideline-driven recommendations for screening asymptomatic patients for heart failure
• Monitoring patients with underlying disorders, such as coronary artery disease and hypertension, may identify patients in whom early treatment for heart failure may be beneficial
• The role of B-type natriuretic peptide (BNP) measurement in screening for asymptomatic left ventricular dysfunction remains uncertain

Population at risk

• Elderly patients
• Patients with previous myocardial infarction
• Patients with poorly controlled hypertension
• Patients with other disorders outlined in Causes and risk factors

Screening modalities

Echocardiography and BNP measurement are used primarily in diagnosis, and their role in screening of asymptomatic patients has not been established. However, first-degree relatives of patients with familial cardiomyopathy may be candidates for echocardiography.

Primary prevention

Summary approach

• Although some patients with left ventricular dysfunction are asymptomatic and means of documenting such dysfunction, as well as agents with the potential to prevent progression to more advanced stages of heart failure, are available, there are currently no widely accepted data-driven or guideline-driven recommendations for prevention of heart failure in asymptomatic patients
• It is logical to attempt to prevent and to recognize and treat the underlying causes of heart failure as early as possible. Hypertension and coronary artery disease are two major risk factors for the development of heart failure
• In patients who already have heart failure, pharmacologic therapy and device placement are helpful in preventing disease progression and complications such as sudden cardiac death

Population at risk

• Elderly patients
• Patients with previous myocardial infarction
• Patients with poorly controlled hypertension
• Patients with other disorders outlined in Causes and risk factors

Preventive measures

• Smoking cessation is important, as cigarette smoking is a risk factor for coronary artery disease, which, in turn, can result in heart failure
• Excessive alcohol intake and use of cocaine should be avoided, as they are associated with an increased risk of heart failure
• A low-fat diet is important for the prevention of coronary artery disease
• Regular exercise reduces the incidence of hypertension, type 2 diabetes, and coronary artery disease