Management of left ventricular systolic dysfunction in heart failure

Management of Left Ventricular Heart Failure

Heart failure (HF) is described as a syndrome "representing the final common pathophysiological pathway of a wide spectrum of myocardial injuries. Those varied insults all produce ventricular systolic and/or diastolic dysfunction with resulting systemic circulatory impairment." (Young and Mills, 2004) Heart failure (HF) is stated in the work of Young and Mills entitled: "Clinical Management of Heart Failure" to have "become epidemic." (2004) Adding to the already large base of individuals with heart failure are the aging Baby Boomer generation. In fact, the American Heart Association states that approximately five million individuals have congestive heart failure (CHF) in the United States alone with another half-million individuals "developing symptomatic HF each year." (Young and Mills, 2004) Patients with heart failure are stated to comprise the "most expensive Medicare diagnosis-related group, with an average length of hospital stay ranging from 5 to 10 days and average costs calculated to be between $7,000 and $15,000." (Young and Mills, 2004)

The majority of these patients are treated in outpatient settings. Young and Mills state that heart failure was "first considered a dropsical condition with generalized edema from fluid retention. After the link to myocardial and circulatory failure was clarified, primate approaches focused primarily on herbal diuretics, lymphatic and thoracic or abdominal cavity drainage and 'foxglove tea'." (Young and Mills, 2004) More sophisticated cardiac glycoside preparations and alternative inotropic therapies resulted from a focus on pump inadequacy as a prime heart failure mechanism. (Young and Mills, 2004, paraphrased)

Young and Mills state that the contemporary definition of heart failure is complicated and best understood "as a milieu of cardiac pump dysfunction (systolic and/or diastolic), myocardial remodeling (ventricular hypertrophy and/or chamber dilationi) and hormonal, cytokine and neuroregulatory disturbances, with subsequent circulatory insufficiency. Structural cardiac remodeling is also a component of the syndrome, as are arrhythmias." (Young and Mills, 2004) According to Young and Mills there are many different diseases that can result in myocardial injury "with subsequent acute or chronic dysfunction" therefore, "prevention of injury is paramount."

I. Pathophysiology

Heart failure is a multifaceted syndrome. When there is injury to the heart along with the subsequent myocardial reparative processes produced are molecular responses, cellular activities and ultimately anatomic changes." (Young and Mills, 2004) Young and Mills state that contraction and relaxation abnormalities develop "with systemic flow decrements that trigger subsequent physiological responses. This process includes a variety of clinical manifestations ranging from asymptomatic ventricular dysfunction (both systolic and diastolic) to congestive states (volume overload from fluid retention), low cardiac output syndromes, or frank cardiogenic shock." (Young and Mills, 2004) According to Young and Mills (2004) critical to comprehension of the physiological responses to cardiac injury is comprehending the negative feedback cycles of heart failure. (2004, paraphrased)

II. Clinical Practice Guideline for Heart Failure Due to Left-Ventricular Systolic Dysfunction

In 2000 the Kaiser Foundation published an update on the Clinical Practice Guideline for Heart Failure Due to Left-Ventricular Systolic Dysfunction and stated that this clinical guideline updates previous clinical guidelines for treatment of heart failure due to left-ventricular systolic dysfunction. The Kaiser Foundation reported that ACE inhibitors (ACEI) "improve survival and symptoms..." And that they "remain the first line of therapy for patients with left-ventricular systolic dysfunction. They should be prescribed for all patients with left-ventricular systolic dysfunction unless specific contraindications exist. Recent evidence has shown that higher doses result in greater improvement in survival and fewer hosp8italization. Therefore, ACEI should be titrated toward the maximum dose until the highest tolerated dose is reached (maximum doses: lisinopril 40 mg po qd, captopril 100 mg pot id)." (Kaiser Foundation, 2000) Alternatives to ACE inhibitors are stated to include losartan which is stated to provide "similar but not superior benefit to ACE inhibitors in improve mortality and reduced hospitalization." (the Kaiser Foundation, 2000) Therefore, ACE inhibitors are stated to remain "the first line vasodilator" and that Losartan "should be prescribed instead of ACE inhibitors only in patients intolerant to ACE inhibitors because of intractable cough, rash or angioedema." (the Kaiser Foundation, 2000)

III. Beta-Blockers

In more than 20 trials involving approximately 10,000 heart failure patients, the Kaiser Foundation states that "beta-blockers carvedilol, metoprolol, and bisoprolol [non-formulary]) lengthened survival, improved symptoms, and prevented hospitalizations. All patients with systolic dysfunction and NYHA class II - III symptoms should receive a beta-blocker unless they have an absolute contraindication or are unable to tolerate the drug." (the Kaiser Foundation, 2000)

A. ACE Inhibitors

Recommended medications are inclusive of those that "...have evidence that they improve life expectancy and symptoms when used. The following medications are stated to be those accepted for use and it is related that the dosages of these medications should be "titrated to the doses used in clinical trials" (NHS Institute for Innovation and Improvement, 2008) however, in the situation where they cannot be reached it is suggested that the dosage be titrated to the "maximum tolerated dose on the assumption that nay of the drug is better than none" (NHS Institute for Innovation and Improvement, 2008):

(1) Angiotensin-converting enzyme (ACE) inhibitors;

(2) Beta-blockers;

(3) Angiotensin-II receptor antagonists;

(4) Aldosterone antagonists;

(5) the following drugs improve symptoms but are not known to reduce mortality:

(6) Diuretics (thiazide or loop);

(7) Digoxin. (NHS Institute for Innovation and Improvement, 2008)

The Angiotensin-converting enzyme inhibitors are stated to be "recommended as first-line treatment in all people with left ventricular systolic dysfunction (LVSD) "with or without symptoms of heart failure." (NHS Institute for Innovation and Improvement, 2008) Additionally it is stated that strong evidence exists that ACE inhibitors "...increase life expectancy in people with LVSD and reduce the risk of hospitalization -- the effect is greatest in those with more severe LVSD or more severe symptoms, but benefit occurs for all degrees of severity." (NHS Institute for Innovation and Improvement, 2008)

Prescribed for individuals who are intolerant of ACE inhibitors due to cough are

Angiotensin-II receptor antagonists which provide an alternative to angiotensin converting enzyme (ACE) inhibitors." (NHS Institute for Innovation and Improvement, 2008) There is stated to be evidence that AIIRAs supports life expectancy improvement and symptoms for those with heart failure due to left ventricular systolic dysfunction (LVSD)

B. Beta-Blockers

Beta-blockers are recommended for all individuals with left ventricular systolic dysfunction heart failure combined with treatment of diuretics and ACE inhibitors. There is stated to be strong evidence that beta-blockers "...when added to standard treatment, improve life expectancy and reduce the risk of hospitalization in people with heart failure" and that beta-blockers bring about an improvement in symptoms. However, it is stated that all beta-blockers may not have the same efficacy.

The evidence supports the use of bisoprolol, carvedilol, modified-release metoprolol, and nebivolol as these appear to be superior in treatment however, little if any evidence exists for the use of other beta-blockers. In the situation of the individual who is not presently taking a beta-blocker it is recommended that they be started on a beta-blocker from the group stated just previously, all of which are licensed for treatment of heart failure.

There is stated to be growing evidence that "the beneficial effect of beta-blockers in heart failure is not a class effect, so switching to a beta-blocker licensed for heart failure" is likely the better choice. (NHS Institute for Innovation and Improvement, 2008) There is a warning that beta-blockers may at times result in symptoms becoming worse therefore the doses should begin low and then titrate to the target dose gradually.

C. Diuretics

Diuretics should be used on a routine basis for treating the symptoms of congestion and fluid retention in individuals with heart failure and the diuretics should be titrated on a 'as needed' basis following the beginning of treatments for heart failure. It is stated to be unknown whether diuretics "improve life expectancy and other endpoints." (NHS Institute for Innovation and Improvement, 2008) it is further related that loop diuretics are preferred over thiazide diuretics, as loop diuretics are stated to be "more effective at relieving congestive symptoms." (NHS Institute for Innovation and Improvement, 2008)

In the event the individual is taking thiazide, it is stated that the thiazide "...must be stopped before a loop diuretic is started (otherwise severe electrolyte disturbances may occur)." (NHS Institute for Innovation and Improvement, 2008) the combination of thiazide with a loop diuretic is stated to give a "...synergistic diuretic effect and may be useful in some people with persistent fluid overload -- usually this would only be initiated by a specialist or on specialist advice." (NHS Institute for Innovation and Improvement, 2008) Thiazide is added by some specialists when "large doses of loop diuretic are required (e.g. frusemide 80 -- 160 mg daily)." (NHS Institute for Innovation and Improvement, 2008)

Individuals with resistant fluid retention "...despite optimum medical management" may require that metalazone be combined with a loop diuretic and this generally requires that it be carried out in a hospital since "...severe electrolyte disturbances can occur." (NHS Institute for Innovation and Improvement, 2008) Stated to be equally effective are "...Bendroflumethiazide (Bendrofluazide) 10 mg daily and metolazone 10 mg daily for 3 days." (NHS Institute for Innovation and Improvement, 2008)

It is stated that individuals with heart failure of the left ventricular systolic dysfunction type and whose symptoms remain "moderately to severely symptomatic despite optimal treatment with angiotensin-converting enzyme (ACE) inhibitor, beta-blocker, and loop diuretic should be prescribed spironolactone at a dose of 12.5 -- 50 mg once a day." (NHS Institute for Innovation and Improvement, 2008) There is stated to be plenty of evidence that adding spironolactone to a loop diuretic and ACE inhibitor "...increases life expectancy, improves symptoms, and reduces the risk of hospitalization." (NHS Institute for Innovation and Improvement, 2008)

D. Aspirin

Aspirin should be prescribed for individuals with heart failure who have "known atherosclerotic vascular disease (including coronary heart disease)." (NHS Institute for Innovation and Improvement, 2008) There is no specific trial evidence that supports the use of aspirin for individuals with heart failure however, good evidence is in existence that aspirin brings about a reduction in the "risk of vascular events in people with atherosclerotic vascular disease." (NHS Institute for Innovation and Improvement, 2008) in some cases it has been found that aspirin worsens heart failure through bringing about a reduction in the benefits of angiotensin-converting enzyme (ACE) inhibitors.

VIII. Other Instructions on Management of LVHF

A. Salt and Fluid Intake

It recommended that individuals with heart failure minimize their intake of salt as well as to limit fluids in those with advanced heart failure in order to "reduce exacerbations of fluid overload." (NHS Institute for Innovation and Improvement, 2008) While the precise amount is not clearly known, it is stated that "in practice a fluid restriction of 1.5 -- 2 liters per day is advised." (NHS Institute for Innovation and Improvement, 2008)

B. Anticoagulants

Anticoagulants should be considered in individuals with heart failure who are "...in sinus rhythm, anticoagulation should be considered if there is a history of thromboembolism, left ventricular aneurysm, or intracardiac thrombus." (NHS Institute for Innovation and Improvement, 2008)

C. Oxygen Therapy

Oxygen therapy is stated to be worth considering only after a specialist assessment as there is stated to be "...limited evidence for the role of oxygen therapy in heart failure due to left ventricular systolic dysfunction." (NHS Institute for Innovation and Improvement, 2008) While both the National Institute for Health and Clinical Excellence and the American guidelines do not make a specific recommendations in regards to oxygen therapy it is stated that European guidelines stated that "...although oxygen is used for the treatment of acute heart failure, it generally has no place in the management of chronic heart failure." (NHS Institute for Innovation and Improvement, 2008) if daytime hypoxemia exists or nocturnal hypoxemia exists, PaO@ on air of less than 73 kPa or oxygen saturation below 90% for at least 30% of the night, respectively, that long-term oxygen therapy is recommended.

D. Exercise

Exercise is stated to be recommended for individuals with heart failure as what is termed to be part of "lifestyle advice." (NHS Institute for Innovation and Improvement, 2008) it is additionally reported that cardiac rehabilitation programs may provide benefits for some people with heart failure as these programs "...have been shown to be effective in people with coronary heart disease, reducing hospitalization rates, improving quality of life, and improving exercise performance. It is likely that people with heart failure will gain similar benefits." (NHS Institute for Innovation and Improvement, 2008)

It is additionally reported that findings stated by a Cochrane review were that there is evidence of "...significant improvements in morbidity and mortality with exercise intervention in heart failure." (NHS Institute for Innovation and Improvement, 2008)

IX. Herbal Treatments

A. Hawthorne Extract - Hawthorne extract has been found to have "...positive inotropic effects and to improve coronary blood flow, with improvement in the symptoms of heart failure. A Cochrane review is underway to assess the efficacy of Hawthorn extract in the management of chronic heart failure. At present, there is insufficient evidence to make any recommendations regarding its use in heart failure. (NHS Institute for Innovation and Improvement, 2008)

B. Terminalia arguna - Terminalia arguna was found to improve both "...symptoms and signs of heart failure in a crossover randomized controlled trial (RCT) of 12 people with severe heart failure (New York Health Authority class IV) [Ernst, 2001]. This improvement was maintained over the 28 months that the herb was taken. These promising results require confirmation.

C. Sunitag (a Chinese remedy) - Sunitag in research is shown to have "...limited evidence of any benefit in heart failure. (NHS Institute for Innovation and Improvement, 2008)

X. Supplements

A. Co-enzyme Q10 -- reported to be present in lower concentrations in the myocardium of people with heart failure. However, placebo-controlled trials have not found any mortality or morbidity benefits from use of co-enzyme Q10 supplements in people with heart failure, and the long-term safety profile is not yet known." (NICE, 2003 in: NHS Institute for Innovation and Improvement, 2008)

B. L-arginine - found to improve exercise tolerance in a small crossover RCT in which people with heart failure were treated with either L-arginine supplements or placebo." (NHS Institute for Innovation and Improvement, 2008)

XII. Diet

Because there is stated to be little evidence in relation to diet and nutrition for individuals with heart failure the National Institute for Health and Clinical Excellence (NICE) makes no specific recommendation regarding diet in people with heart failure, but makes specific points stated to include those as follows:

(1) reduction of weight may be appropriate in some individuals with heart failure;

(2) nutritional assessment can be difficult as many individuals with heart failure may be malnourished however, this may be masked by retention of fluid;

(3) a diet that is low in salt is advised often for controlling retention of fluid;

(4) Individuals with heart failure that is related to alcohol should not drink alcohol as "...chronic excessive alcohol consumption can damage cardiac muscle and lead to heart failure" and as well "cardiac function may improve, or completely recover, if alcohol is avoided." (NHS Institute for Innovation and Improvement, 2008) Smokers with LVHF should be advised to quit smoking and they should be referred to smoking cessation services as smoking "...can have adverse effects on hemodynamic and oxygen delivery." (NHS Institute for Innovation and Improvement, 2008)

XII. Exercise

It is stated that inactivity leads to "...physical deconditioning, which leads to a worsening of symptoms and exercise performance. Training can improve exercise performance without adversely affecting cardiac function." (NHS Institute for Innovation and Improvement, 2008) Individuals with heart failure should be provided encouragement to "...adopt regular aerobic exercise (such as brisk walking) and/or resistive exercise (e.g. weight training). This may be more effective when part of an exercise or rehabilitation program." (NHS Institute for Innovation and Improvement, 2008)

Summary and Conclusion

Each individual case of LVHF varies in some way or another and it is critically important that each case be assessed instead of on a 'class' basis on an individual basis as the proper combinations of medications may differ between individuals with LVHF.