Management of heart failure
Encyclopedia
Management of heart failure requires a muitimodal approach. It involves a combination of lifestyle modifications, medications, and possibly the use of devices or surgery.
Theoretically, patients with CHF have a diminished ability to excrete free water load. Hyponatremia frequently develops in decompensated heart failure due to the effects of excess circulating neuroendocrine hormones. While the activation of the renin-angiotensin-aldosterone axis due to decreased renal perfusion promotes both sodium and water retention, the activation of atrial natriuretic peptide due to atrial stretch favors sodium excretion, and the activation of antidiuretic hormone due to peripheral baroreceptors that sense hypotension as well as due to the activation of the sympathetic nervous system favors water retention alone, leading to disproportionately more water retention than sodium retention. The severity of the hyponatremia during an episode of decompensated heart failure can be predictive of mortality. Generally water intake should be limited to 1.5 L daily or less in patients with hyponatremia
, though fluid restriction may be beneficial regardless in symptomatic reduction.
by delaying progression of heart failure and reducing cardiovascular risk. Drugs used include: diuretic
agents, vasodilator agents, positive inotrope
s, ACE inhibitor
s, beta blocker
s, and aldosterone antagonist
s (e.g.spironolactone
). Some drugs which increase heart function, such as the positive inotrope Milrinone
, lead to increased mortality, and are contraindicated.
. Angiotensin II receptor antagonist
therapy (also referred to as AT1-antagonists or angiotensin receptor blockers), particularly using candesartan
, is an acceptable alternative if the patient is unable to tolerate ACEI therapy. ACEIs and ARBs decrease afterload by antagonizing the vasopressor effect of angiotensin, thereby decreasing the amount of work the heart must perform. It is also believed that angiotensin directly affects cardiac remodeling, and blocking its activity can thereby slow the deterioration of cardiac function.
therapy is indicated for relief of congestive symptoms. Several classes are used, with combinations reserved for severe heart failure:
If a heart failure patient exhibits a resistance to or poor response to diuretic therapy, ultrafiltration or aquapheresis
may be needed to achieve adequate control of fluid retention and congestion. The use of such mechanical methods of fluid removal can produce meaningful clinical benefits in patients with diuretic-resistant heart failure and may restore responsiveness to conventional doses of diuretics.9
– effects which worsen heart failure. However, current guidelines recommend β-blocker therapy for patients with systolic heart failure due to left ventricular systolic dysfunction after stabilization with diuretic and ACEI therapy, irrespective of symptomatic severity or blood pressure. As with ACEI therapy, the addition of a β-blocker can decrease mortality and improve left ventricular function. Several β-blockers are specifically indicated for CHF including: bisoprolol
, carvedilol
, nebivolol
and extended-release metoprolol
. The antagonism of β1 inotropic and chronotropic effects decreases the amount of work the heart must perform. It is also thought that catecholamines and other sympathomimetics have an effect on cardiac remodeling, and blocking their activity can slow the deterioration of cardiac function.
(a mildly positive inotrope and negative chronotrope), once used as first-line therapy, is now reserved for control of ventricular rhythm in patients with atrial fibrillation; or where adequate control is not achieved with an ACEI, a beta blocker and a loop diuretic. There is no evidence that digoxin reduces mortality in CHF, although some studies suggest a decreased rate in hospital admissions. It is contraindicated in cardiac tamponade and restrictive cardiomyopathy.
The inotropic agent dobutamine
is advised only in the short-term use of acutely decompensated heart failure, and has no other uses.
Phosphodiesterase inhibitors such as milrinone
are sometimes utilized in severe cardiomyopathy. The mechanism of action is through inhibiting the breakdown and thereby increasing the concentration of cAMP
similar to beta adrenoreceptor agonism, resulting in inotropic effects and modest diuretic effects.
is the only vasodilator regimen, other than ACE inhibitors or angiotensin II receptor antagonists, with proven survival benefits. This combination appears to be particularly beneficial in CHF patients with an African American background, who respond less effectively to ACEI therapy.
was shown in the EPHESUS trial to have a similar effect, and it is specifically labelled for use in decompensated heart failure complicating acute myocardial infarction. While the antagonism of aldosterone will decrease the effects of sodium and water retention, it is thought that the main mechanism of action is by antagonizing the deleterious effects of aldosterone on cardiac remodeling.
, a recombinant form of B-natriuretic peptide, is indicated for use in patients with acute decompensated heart failure who have dyspnea at rest. Nesiritide promotes diuresis and natriuresis, thereby ameliorating volume overload. It is thought that, while BNP is elevated in heart failure, the peptide that is produced is actually dysfunctional or non-functional and thereby ineffective.
and conivaptan
antagonize the effects of antidiuretic hormone (vasopressin), thereby promoting the specific excretion of free water, directly ameliorating the volume overloaded state, and counteracting the hyponatremia that occurs due to the release of neuroendocrine hormones in an attempt to counteract the effects of heart failure. The EVEREST trial, which utilized tolvaptan, showed that when used in combination with conventional therapy, many symptoms of acute decompensated heart failure were significantly improved compared to conventional therapy alone although they found no difference in mortality and morbidity when compared to conventional therapy.
or more may benefit from cardiac resynchronization therapy (CRT; pacing both the left
and right ventricle
s), through implantation of a bi-ventricular pacemaker
, or surgical remodeling of the heart. These treatment modalities may make the patient symptomatically better, improving quality of life and in some trials have been proven to reduce mortality.
The COMPANION trial demonstrated that CRT improved survival in individuals with NYHA class III or IV heart failure with a widened QRS complex
on an electrocardiogram. The CARE-HF trial showed that patients receiving CRT and optimal medical therapy benefited from a 36% reduction in all cause mortality, and a reduction in cardiovascular-related hospitalization.
Patients with NYHA class II, III or IV, and LVEF of 35% (without a QRS requirement) may also benefit from an implantable cardioverter-defibrillator
(ICD), a device that is proven to reduce all cause mortality by 23% compared to placebo in patients who were already optimally managed on drug therapy. Patients with severe cardiomyopathy are at high risk for sudden cardiac death due to ventricular dysrhythmias. Although ICDs deliver electrical shocks to resynchronize heart rhythm which are potentially destressing to the patient, they have not been shown to affect quality of life
.
The number of (appropriate and inappropriate) shocks seems to be associated to a worse outcome. Although they are expensive, ICDs are potentially cost-effective in this setting.
Another current treatment involves the use of left ventricular assist device
s (LVADs). LVADs are battery-operated mechanical pump-type devices that are surgically implanted on the upper part of the abdomen. They take blood from the left ventricle and pump it through the aorta. LVADs are becoming more common and are often used by patients who have to wait for heart transplants.
or (temporary or prolonged) implantation of an artificial heart
. These remain the recommended surgical treatment options. However, the limited number of hearts available for transplantation in a growing group of candidates, has led to the development of alternative surgical approaches to heart failure. These commonly involve surgical left ventricular remodeling. The aim of the procedures is to reduce the ventricle diameter (targeting Laplace's law
and the disease mechanism of heart failure), improve its shape and/or remove non-viable tissue. These procedures can be performed together with coronary artery bypass surgery
or mitral valve repair
.
If heart failure ensues after a myocardial infarction due to scarring and aneurysm formation, reconstructive surgery may be an option. These aneurysms bulge with every contraction, making it inefficient. Cooley and coworkers reported the first surgical treatment of a left ventricular aneurysm in 1958. They used a linear closure after their excision. In the 1980s, Vincent Dor developed a method using a circular patch stitched to the inside of the ventricle (the endoventricular circular patch plasty or Dor procedure) to close the defect after excision. Dor's approach has been modified by others and is today the preferred method for surgical treatment of incorrectly contracting (dyskinetic) left ventricle tissue, although a linear closure technique combined with septoplasty might be equally effective. The multicenter RESTORE trial of 1198 participants demonstrated an increase in ejection fraction from about 30% to 40% with a concomitant shift in NYHA classes, with an early mortality of 5% and a 5-year survival of 70%. As of yet, it remains unknown if surgery is superior to optimal medical therapy. The STICH trial (Surgical Treatment for IschemiC Heart Failure) will examine the role of medical treatment, coronary artery bypass surgery and left ventricle remodeling surgery in heart failure patients. Results are expected to be published in 2009 and 2011.
The Batista procedure
was invented by Brazilian surgeon Randas Batista in 1994 for use in patients with non-ischemic dilated cardiomyopathy
. It involves removal of a portion of viable tissue from the left ventricle to reduce its size (partial left ventriculectomy), with or without repair or replacement of the mitral valve. Although several studies showed benefits from this surgery, studies at the Cleveland Clinic
concluded that this procedure was associated with a high early and late failure rate. At 3 years only 26 percent were event-free and survival rate was only 60 percent. Most hospitals have abandoned this operation and it is no longer included in heart failure guidelines.
Newer procedures under examination are based on the observation that the spherical configuration of the dilated heart reduces ejection fraction compared to the elliptical form. Mesh-like constraint devices such as the Acorn CorCap aim to improve contraction efficacy and prevent further remodeling. Clinical trials are underway. Another technique which aims to divide the spherical ventricle into two elliptical halves is used with the Myosplint device.
Diet and lifestyle measures
Patients with CHF are educated to undertake various non-pharmacological measures to improve symptoms and prognosis. Such measures include:- Moderate physical activity, when symptoms are mild or moderate; or bed restBed restBed rest is a medical treatment involving a period of consistent recumbence in bed. It is used as a treatment for an illness or medical condition, especially when prescribed or chosen rather than resulting from severe prostration or imminent death...
when symptoms are severe. - If sleep apneaSleep apneaSleep apnea is a sleep disorder characterized by abnormal pauses in breathing or instances of abnormally low breathing, during sleep. Each pause in breathing, called an apnea, can last from a few seconds to minutes, and may occur 5 to 30 times or more an hour. Similarly, each abnormally low...
is identified, treat with CPAP, BiPAP, dental appliances or surgery. Sleep apnea is an under recognized risk factor for heart failure - Weight reduction – through physical activity and dietary modification, as obesityObesityObesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
is a risk factor for heart failure and left ventricular hypertrophy. - Monitor weight - this is a parameter that can easily be measured at home. Rapid weight increase is generally due to fluid retention. Weight gain of more than 2 pounds is associated with admission to the hospital for heart failure
- Sodium restriction – excessive sodium intake may precipitate or exacerbate heart failure, thus a "no added salt" diet (60–100 mmol total daily intake) is recommended for patients with CHF. More severe restrictions may be required in severe CHF.
Fluid restriction
According to a review in 2009, there is apparently no evidence of benefit of fluid restriction in patients with clinically stable heart failure otherwise receiving optimal pharmacological treatment. The same review suggested that clinicians still choosing to restrict fluid intake for patients with HF should consider an individualized fluid prescription, potentially based on patient body weight, sodium intake, and likelihood of adherence.Theoretically, patients with CHF have a diminished ability to excrete free water load. Hyponatremia frequently develops in decompensated heart failure due to the effects of excess circulating neuroendocrine hormones. While the activation of the renin-angiotensin-aldosterone axis due to decreased renal perfusion promotes both sodium and water retention, the activation of atrial natriuretic peptide due to atrial stretch favors sodium excretion, and the activation of antidiuretic hormone due to peripheral baroreceptors that sense hypotension as well as due to the activation of the sympathetic nervous system favors water retention alone, leading to disproportionately more water retention than sodium retention. The severity of the hyponatremia during an episode of decompensated heart failure can be predictive of mortality. Generally water intake should be limited to 1.5 L daily or less in patients with hyponatremia
Hyponatremia
Hyponatremia is an electrolyte disturbance in which the sodium concentration in the serum is lower than normal. In the vast majority of cases, hyponatremia occurs as a result of excess body water diluting the serum sodium and is not due to sodium deficiency. Sodium is the dominant extracellular...
, though fluid restriction may be beneficial regardless in symptomatic reduction.
Pharmacological management
There is a significant evidence–practice gap in the treatment of CHF; particularly the underuse of ACE inhibitors and β-blockers and aldosterone antagonists which have been shown to provide mortality benefit. Treatment of CHF aims to relieve symptoms, to maintain a euvolemic state (normal fluid level in the circulatory system), and to improve prognosisPrognosis
Prognosis is a medical term to describe the likely outcome of an illness.When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because...
by delaying progression of heart failure and reducing cardiovascular risk. Drugs used include: diuretic
Diuretic
A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...
agents, vasodilator agents, positive inotrope
Inotrope
An inotrope is an agent that alters the force or energy of muscular contractions. Negatively inotropic agents weaken the force of muscular contractions...
s, ACE inhibitor
ACE inhibitor
ACE inhibitors or angiotensin-converting enzyme inhibitors are a group of drugs used primarily for the treatment of hypertension and congestive heart failure...
s, beta blocker
Beta blocker
Beta blockers or beta-adrenergic blocking agents, beta-adrenergic antagonists, beta-adrenoreceptor antagonists or beta antagonists, are a class of drugs used for various indications. They are particularly for the management of cardiac arrhythmias, cardioprotection after myocardial infarction ,...
s, and aldosterone antagonist
Aldosterone antagonist
Aldosterone antagonist refers to diuretic drugs which antagonize the action of aldosterone at mineralocorticoid receptors. This group of drugs is often used as adjunctive therapy, in combination with other drugs, for the management of chronic heart failure...
s (e.g.spironolactone
Spironolactone
Spironolactone , commonly referred to as simply spiro, is a diuretic and is used as an antiandrogen.It is a synthetic 17-lactone drug that is a renal competitive aldosterone antagonist in a class of pharmaceuticals called...
). Some drugs which increase heart function, such as the positive inotrope Milrinone
Milrinone
Milrinone is a phosphodiesterase 3 inhibitor. It potentiates the effect of cyclic adenosine monophosphate .Milrinone also enhances contraction of the left ventricle by increasing Ca2+-ATPase activity on the cardiac sarcoplasmic reticulum...
, lead to increased mortality, and are contraindicated.
Angiotensin-modulating agents
ACE inhibitor (ACE) therapy is recommended for all patients with systolic heart failure, irrespective of symptomatic severity or blood pressure. ACE inhibitors improve symptoms, decrease mortality and reduce ventricular hypertrophyVentricular hypertrophy
Ventricular hypertrophy is the enlargement of ventricles in the heart. Although left ventricular hypertrophy is more common, enlargement can also occur in the right ventricle, or both ventricles.- Physiology :...
. Angiotensin II receptor antagonist
Angiotensin II receptor antagonist
Angiotensin II receptor antagonists, also known as angiotensin receptor blockers , AT1-receptor antagonists or sartans, are a group of pharmaceuticals which modulate the renin-angiotensin-aldosterone system...
therapy (also referred to as AT1-antagonists or angiotensin receptor blockers), particularly using candesartan
Candesartan
Candesartan is an angiotensin II receptor antagonist used mainly for the treatment of hypertension. The prodrug candesartan cilexetil is marketed by AstraZeneca and Takeda Pharmaceuticals, commonly under the trade names Blopress, Atacand, Amias, and Ratacand.-Clinical use:As all angiotensin II...
, is an acceptable alternative if the patient is unable to tolerate ACEI therapy. ACEIs and ARBs decrease afterload by antagonizing the vasopressor effect of angiotensin, thereby decreasing the amount of work the heart must perform. It is also believed that angiotensin directly affects cardiac remodeling, and blocking its activity can thereby slow the deterioration of cardiac function.
Diuretics
DiureticDiuretic
A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...
therapy is indicated for relief of congestive symptoms. Several classes are used, with combinations reserved for severe heart failure:
- Loop diureticLoop diureticLoop diuretics are diuretics that act on the ascending loop of Henle in the kidney. They are primarily used in medicine to treat hypertension and edema often due to congestive heart failure or renal insufficiency...
s (e.g. furosemideFurosemideFurosemide or frusemide is a loop diuretic used in the treatment of congestive heart failure and edema. It is most commonly marketed by Sanofi-Aventis under the brand name Lasix...
, bumetanideBumetanideBumetanide is a loop diuretic of the sulfamyl category to treat heart failure. It is often used in people in whom high doses of furosemide are ineffective. It is marketed by Hoffmann-La Roche. The main difference between the two substances is in bioavailability and pharmacodynamic potency...
) – most commonly used class in CHF, usually for moderate CHF. - Thiazide diuretics (e.g. hydrochlorothiazideHydrochlorothiazideHydrochlorothiazide, abbreviated HCTZ, HCT, or HZT, is a first-line diuretic drug of the thiazide class that acts by inhibiting the kidneys' ability to retain water. This reduces the volume of the blood, decreasing blood return to the heart and thus cardiac output and, by other mechanisms, is...
, chlorthalidone, chlorthiazide) – may be useful for mild CHF, but typically used in severe CHF in combination with loop diuretics, resulting in a synergistic effect. - Potassium-sparing diureticPotassium-sparing diureticPotassium-sparing diuretics are diuretic drugs that do not promote the secretion of potassium into the urine.They are used as adjunctive therapy, together with other drugs, in the treatment of hypertension and management of congestive heart failure....
s (e.g. amilorideAmilorideAmiloride is a potassium-sparing diuretic, first approved for use in 1967 , used in the management of hypertension and congestive heart failure. Amiloride was also tested as treatment of cystic fibrosis, but it was revealed inefficient in vivo due to it's short time of action, therefore...
) – used first-line use to correct hypokalaemia.- SpironolactoneSpironolactoneSpironolactone , commonly referred to as simply spiro, is a diuretic and is used as an antiandrogen.It is a synthetic 17-lactone drug that is a renal competitive aldosterone antagonist in a class of pharmaceuticals called...
is used as add-on therapy to ACEI plus loop diuretic in severe CHF. - EplerenoneEplerenoneEplerenone is an aldosterone antagonist used as an adjunct in the management of chronic heart failure. It is similar to the diuretic spironolactone, though it may be more specific for the mineralocorticoid receptor and is specifically marketed for reducing cardiovascular risk in patients...
is specifically indicated for post-MI reduction of cardiovascular risk.
- Spironolactone
If a heart failure patient exhibits a resistance to or poor response to diuretic therapy, ultrafiltration or aquapheresis
Aquapheresis
Aquapheresis is a medical technology designed to remove excess salt and water from the body safely, predictably, and effectively from patients suffering from a condition called fluid overload. It removes the excess salt and water and helps to restore a patient’s fluid balance or...
may be needed to achieve adequate control of fluid retention and congestion. The use of such mechanical methods of fluid removal can produce meaningful clinical benefits in patients with diuretic-resistant heart failure and may restore responsiveness to conventional doses of diuretics.9
Beta blockers
Until recently (within the last 20 years), β-blockers were contraindicated in CHF, owing to their negative inotropic effect and ability to produce bradycardiaBradycardia
Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...
– effects which worsen heart failure. However, current guidelines recommend β-blocker therapy for patients with systolic heart failure due to left ventricular systolic dysfunction after stabilization with diuretic and ACEI therapy, irrespective of symptomatic severity or blood pressure. As with ACEI therapy, the addition of a β-blocker can decrease mortality and improve left ventricular function. Several β-blockers are specifically indicated for CHF including: bisoprolol
Bisoprolol
Bisoprolol is a drug belonging to the group of beta blockers, a class of drugs used primarily in cardiovascular diseases. More specifically, it is a selective type β1 adrenergic receptor blocker. The FDA approved Duramed Pharmaceutical's application for Zebeta Oral Tablets as a new molecular...
, carvedilol
Carvedilol
Carvedilol is a non-selective beta blocker/alpha-1 blocker indicated in the treatment of mild to moderate congestive heart failure . It is marketed under various trade names including Carvil , Coreg , Dilatrend , Eucardic , and Carloc as a generic drug ., and as a...
, nebivolol
Nebivolol
Nebivolol is a β1 receptor blocker with nitric oxide-potentiating vasodilatory effect used in treatment of hypertension and, in Europe, also for left ventricular failure...
and extended-release metoprolol
Metoprolol
Metoprolol is a selective β1 receptor blocker used in treatment of several diseases of the cardiovascular system, especially hypertension. The active substance metoprolol is employed either as metoprolol succinate or metoprolol tartrate...
. The antagonism of β1 inotropic and chronotropic effects decreases the amount of work the heart must perform. It is also thought that catecholamines and other sympathomimetics have an effect on cardiac remodeling, and blocking their activity can slow the deterioration of cardiac function.
Positive inotropes
DigoxinDigoxin
Digoxin INN , also known as digitalis, is a purified cardiac glycoside and extracted from the foxglove plant, Digitalis lanata. Its corresponding aglycone is digoxigenin, and its acetyl derivative is acetyldigoxin...
(a mildly positive inotrope and negative chronotrope), once used as first-line therapy, is now reserved for control of ventricular rhythm in patients with atrial fibrillation; or where adequate control is not achieved with an ACEI, a beta blocker and a loop diuretic. There is no evidence that digoxin reduces mortality in CHF, although some studies suggest a decreased rate in hospital admissions. It is contraindicated in cardiac tamponade and restrictive cardiomyopathy.
The inotropic agent dobutamine
Dobutamine
Dobutamine is a sympathomimetic drug used in the treatment of heart failure and cardiogenic shock. Its primary mechanism is direct stimulation of β1 receptors of the sympathetic nervous system. Dobutamine was developed by a laboratory led by Drs...
is advised only in the short-term use of acutely decompensated heart failure, and has no other uses.
Phosphodiesterase inhibitors such as milrinone
Milrinone
Milrinone is a phosphodiesterase 3 inhibitor. It potentiates the effect of cyclic adenosine monophosphate .Milrinone also enhances contraction of the left ventricle by increasing Ca2+-ATPase activity on the cardiac sarcoplasmic reticulum...
are sometimes utilized in severe cardiomyopathy. The mechanism of action is through inhibiting the breakdown and thereby increasing the concentration of cAMP
Cyclic adenosine monophosphate
Cyclic adenosine monophosphate is a second messenger important in many biological processes...
similar to beta adrenoreceptor agonism, resulting in inotropic effects and modest diuretic effects.
Alternative vasodilators
The combination of isosorbide dinitrate/hydralazineIsosorbide dinitrate/hydralazine
Isosorbide dinitrate/hydralazine is a fixed dose combination drug treatment specifically indicated for African Americans with congestive heart failure. It is a combination of hydralazine and isosorbide dinitrate . It is the first race-based prescription drug in the United States...
is the only vasodilator regimen, other than ACE inhibitors or angiotensin II receptor antagonists, with proven survival benefits. This combination appears to be particularly beneficial in CHF patients with an African American background, who respond less effectively to ACEI therapy.
Aldosterone receptor antagonists
The RALES trial showed that the addition of spironolactone can improve mortality, particularly in severe cardiomyopathy (ejection fraction less than 25%.) The related drug eplerenoneEplerenone
Eplerenone is an aldosterone antagonist used as an adjunct in the management of chronic heart failure. It is similar to the diuretic spironolactone, though it may be more specific for the mineralocorticoid receptor and is specifically marketed for reducing cardiovascular risk in patients...
was shown in the EPHESUS trial to have a similar effect, and it is specifically labelled for use in decompensated heart failure complicating acute myocardial infarction. While the antagonism of aldosterone will decrease the effects of sodium and water retention, it is thought that the main mechanism of action is by antagonizing the deleterious effects of aldosterone on cardiac remodeling.
Recombinant neuroendocrine hormones
NesiritideNesiritide
Nesiritide is the recombinant form of the 32 amino acid human B-type natriuretic peptide, which is normally produced by the ventricular myocardium...
, a recombinant form of B-natriuretic peptide, is indicated for use in patients with acute decompensated heart failure who have dyspnea at rest. Nesiritide promotes diuresis and natriuresis, thereby ameliorating volume overload. It is thought that, while BNP is elevated in heart failure, the peptide that is produced is actually dysfunctional or non-functional and thereby ineffective.
Vasopressin receptor antagonists
TolvaptanTolvaptan
Tolvaptan , also known as OPC-41061, is a selective, competitive vasopressin receptor 2 antagonist used to treat hyponatremia associated with congestive heart failure, cirrhosis, and the syndrome of inappropriate antidiuretic hormone . Tolvaptan was approved by the U.S...
and conivaptan
Conivaptan
Conivaptan is a non-peptide inhibitor of antidiuretic hormone . It was approved in 2004 for hyponatremia caused by syndrome of inappropriate antidiuretic hormone , and there is some evidence it may be effective in heart failure...
antagonize the effects of antidiuretic hormone (vasopressin), thereby promoting the specific excretion of free water, directly ameliorating the volume overloaded state, and counteracting the hyponatremia that occurs due to the release of neuroendocrine hormones in an attempt to counteract the effects of heart failure. The EVEREST trial, which utilized tolvaptan, showed that when used in combination with conventional therapy, many symptoms of acute decompensated heart failure were significantly improved compared to conventional therapy alone although they found no difference in mortality and morbidity when compared to conventional therapy.
Devices
Patients with NYHA class III or IV, left ventricular ejection fraction (LVEF) of 35% or less and a QRS interval of 120 msMillisecond
A millisecond is a thousandth of a second.10 milliseconds are called a centisecond....
or more may benefit from cardiac resynchronization therapy (CRT; pacing both the left
Left ventricle
The left ventricle is one of four chambers in the human heart. It receives oxygenated blood from the left atrium via the mitral valve, and pumps it into the aorta via the aortic valve.-Shape:...
and right ventricle
Right ventricle
The right ventricle is one of four chambers in the human heart. It receives deoxygenated blood from the right atrium via the tricuspid valve, and pumps it into the pulmonary artery via the pulmonary valve and pulmonary trunk....
s), through implantation of a bi-ventricular pacemaker
Artificial pacemaker
A pacemaker is a medical device that uses electrical impulses, delivered by electrodes contacting the heart muscles, to regulate the beating of the heart...
, or surgical remodeling of the heart. These treatment modalities may make the patient symptomatically better, improving quality of life and in some trials have been proven to reduce mortality.
The COMPANION trial demonstrated that CRT improved survival in individuals with NYHA class III or IV heart failure with a widened QRS complex
QRS complex
The QRS complex is a name for the combination of three of the graphical deflections seen on a typical electrocardiogram . It is usually the central and most visually obvious part of the tracing. It corresponds to the depolarization of the right and left ventricles of the human heart...
on an electrocardiogram. The CARE-HF trial showed that patients receiving CRT and optimal medical therapy benefited from a 36% reduction in all cause mortality, and a reduction in cardiovascular-related hospitalization.
Patients with NYHA class II, III or IV, and LVEF of 35% (without a QRS requirement) may also benefit from an implantable cardioverter-defibrillator
Implantable cardioverter-defibrillator
An implantable cardioverter-defibrillator is a small battery-powered electrical impulse generator which is implanted in patients who are at risk of sudden cardiac death due to ventricular fibrillation and ventricular tachycardia. The device is programmed to detect cardiac arrhythmia and correct it...
(ICD), a device that is proven to reduce all cause mortality by 23% compared to placebo in patients who were already optimally managed on drug therapy. Patients with severe cardiomyopathy are at high risk for sudden cardiac death due to ventricular dysrhythmias. Although ICDs deliver electrical shocks to resynchronize heart rhythm which are potentially destressing to the patient, they have not been shown to affect quality of life
Quality of life
The term quality of life is used to evaluate the general well-being of individuals and societies. The term is used in a wide range of contexts, including the fields of international development, healthcare, and politics. Quality of life should not be confused with the concept of standard of...
.
The number of (appropriate and inappropriate) shocks seems to be associated to a worse outcome. Although they are expensive, ICDs are potentially cost-effective in this setting.
Another current treatment involves the use of left ventricular assist device
Ventricular assist device
A Ventricular assist device, or VAD, is a mechanical circulatory device that is used to partially or completely replace the function of a failing heart...
s (LVADs). LVADs are battery-operated mechanical pump-type devices that are surgically implanted on the upper part of the abdomen. They take blood from the left ventricle and pump it through the aorta. LVADs are becoming more common and are often used by patients who have to wait for heart transplants.
Surgery
The final option, if other measures have failed, is heart transplantationHeart transplantation
A heart transplant, or a cardiac transplantation, is a surgical transplant procedure performed on patients with end-stage heart failure or severe coronary artery disease. As of 2007 the most common procedure was to take a working heart from a recently deceased organ donor and implant it into the...
or (temporary or prolonged) implantation of an artificial heart
Artificial heart
An artificial heart is a mechanical device that replaces the heart. Artificial hearts are typically used in order to bridge the time to heart transplantation, or to permanently replace the heart in case transplantation is impossible...
. These remain the recommended surgical treatment options. However, the limited number of hearts available for transplantation in a growing group of candidates, has led to the development of alternative surgical approaches to heart failure. These commonly involve surgical left ventricular remodeling. The aim of the procedures is to reduce the ventricle diameter (targeting Laplace's law
Laplace's law
Laplace's law or The law of Laplace may refer to several concepts,* Biot-Savart law, in electromagnetics, it describes the magnetic field set up by a steady current density....
and the disease mechanism of heart failure), improve its shape and/or remove non-viable tissue. These procedures can be performed together with coronary artery bypass surgery
Coronary artery bypass surgery
Coronary artery bypass surgery, also coronary artery bypass graft surgery, and colloquially heart bypass or bypass surgery is a surgical procedure performed to relieve angina and reduce the risk of death from coronary artery disease...
or mitral valve repair
Mitral valve repair
Mitral valve repair is a cardiac surgery procedure performed by cardiac surgeons to treat stenosis or regurgitation of the mitral valve. The mitral valve is the "inflow valve" for the left side of the heart. Blood flows from the lungs, where it picks up oxygen, through the pulmonary veins, to the...
.
If heart failure ensues after a myocardial infarction due to scarring and aneurysm formation, reconstructive surgery may be an option. These aneurysms bulge with every contraction, making it inefficient. Cooley and coworkers reported the first surgical treatment of a left ventricular aneurysm in 1958. They used a linear closure after their excision. In the 1980s, Vincent Dor developed a method using a circular patch stitched to the inside of the ventricle (the endoventricular circular patch plasty or Dor procedure) to close the defect after excision. Dor's approach has been modified by others and is today the preferred method for surgical treatment of incorrectly contracting (dyskinetic) left ventricle tissue, although a linear closure technique combined with septoplasty might be equally effective. The multicenter RESTORE trial of 1198 participants demonstrated an increase in ejection fraction from about 30% to 40% with a concomitant shift in NYHA classes, with an early mortality of 5% and a 5-year survival of 70%. As of yet, it remains unknown if surgery is superior to optimal medical therapy. The STICH trial (Surgical Treatment for IschemiC Heart Failure) will examine the role of medical treatment, coronary artery bypass surgery and left ventricle remodeling surgery in heart failure patients. Results are expected to be published in 2009 and 2011.
The Batista procedure
Batista Procedure
The Batista procedure was an experimental cardiac surgical procedure that aimed to reverse the effects of remodeling in cases of end-stage dilated cardiomyopathy refractory to conventional medical therapy...
was invented by Brazilian surgeon Randas Batista in 1994 for use in patients with non-ischemic dilated cardiomyopathy
Dilated cardiomyopathy
Dilated cardiomyopathy or DCM is a condition in which the heart becomes weakened and enlarged and cannot pump blood efficiently. The decreased heart function can affect the lungs, liver, and other body systems....
. It involves removal of a portion of viable tissue from the left ventricle to reduce its size (partial left ventriculectomy), with or without repair or replacement of the mitral valve. Although several studies showed benefits from this surgery, studies at the Cleveland Clinic
Cleveland Clinic
The Cleveland Clinic is a multispecialty academic medical center located in Cleveland, Ohio, United States. The Cleveland Clinic is currently regarded as one of the top 4 hospitals in the United States as rated by U.S. News & World Report...
concluded that this procedure was associated with a high early and late failure rate. At 3 years only 26 percent were event-free and survival rate was only 60 percent. Most hospitals have abandoned this operation and it is no longer included in heart failure guidelines.
Newer procedures under examination are based on the observation that the spherical configuration of the dilated heart reduces ejection fraction compared to the elliptical form. Mesh-like constraint devices such as the Acorn CorCap aim to improve contraction efficacy and prevent further remodeling. Clinical trials are underway. Another technique which aims to divide the spherical ventricle into two elliptical halves is used with the Myosplint device.