Management of left ventricular 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)

IV. Contraindications

Contraindications to beta-blockers are stated to include "bronchospastic disease, symptomatic bradycardia or advanced heart block (unless treated with a pacemaker). Bronchospastic disease should be distinguished from wheezing due to heart failure and from COPD without bronchospasm, neither of which should exclude the use of beta-blockers. A relative contraindication is asymptomatic bradycardia (heart rate < 60 beats/minute)." (the Kaiser Foundation, 2000) it is reported that treatment should not be initiated in patients "in the midst of an acute decompensation. The benefits and safety of beta-blockers in patients with class IV heart failure remain uncertain and use in these patients should be considered experimental." (the Kaiser Foundation, 2000) the following chart lists the medications that are used for treating heart failure.

Figure

Medications for Treating Heart Failure

DRUG

INITIAL DOSE

MAXIMAL DOSE

ACE INHIBITORS

Lisinopril

Captopril

5 mg po qd

6.25-12.5 mg po rid

40 mg po qd

100 mg po tid

LOOP DIURETICS

Furosemide

Burmetanide

10- 40 mg po qd

0.5 mg IV

400 rug po qd

10 mg IV qd

THIAZIDE-RELATED

DIURETICS

Hydrochlorothiazide

Metolazone

25 mg po qd

2.5 mg po (as a SINGLE

TEST DOSE INITIALLY).

MAXIMALLY EFFECTIVE

WHEN GIVEN 30 MINUTES

PRIOR to FUROSEMIDE

50 mq po qd

10 mg po qd

Digoxin

0.125 mg po qd

0.5 mg po qd

Hydralazine

10-25 mg po tid - qid

100 mg po tid

75 mg po qid

Isosobide Dinitrate

10 mg po tid

80 mg po tid

60 mg po qid

Losartan

(non-formulary)

12.5 mg po qd

50 mg po qd

Spironolactone

12.5-25 mg po qd

50 mg po qd

BETA BLOCKERS

Carvedilol

Hetoprolol

3.125 mg po ql2h

6.25 mg po (susp)

12.5 mg po ql2h

25-50 mg po ql2h

100 mg po ql2h

V. NHS Guidelines for Treating LVHF

Stated as 'management issues' for left ventricular heart failure in the NHS 'Clinical Knowledge Summary' published by the NHS are the following components:

(1) if left ventricular systolic dysfunction has not been confirmed by echocardiography, consider referring for this;

(2) Offer life-style advice on issues such as diet, smoking, alcohol and exercise;

(3) Be alert to the presence of psychological problems, such as anxiety and depression;

(4) Manage other conditions such as hypertension, hyperlipidaemia, diabetes, and coronary heart disease;

(5) Start treatments (unless contraindicated) as outlined in the section in what sequence should I start the drugs?: (a) All people with heart failure should initially take an ACE inhibitor (usually with a diuretic); (b) if the person cannot tolerate an ACE inhibitor because of cough, an angiotensin-II receptor antagonist is a suitable alternative;

(6) Once the person is stabilized on optimum doses of ACE inhibitor and diuretic, start a beta-blocker;

(7) if the person remains symptomatic despite optimum doses of diuretic, ACE inhibitor, and beta-blocker, consider adding spironolactone or digoxin;

(8) Digoxin is recommended for anyone with heart failure who is also in atrial fibrillation (see the CKS topic on Atrial fibrillation);

(9) Consider palliative care measures for people with end-stage heart failure. (NHS Institute for Innovation and Improvement, 2008)

VI. NHS Management of LVHF

Management of left ventricular systolic dysfunction confirmed by echocardiography involves the following:

(1) Offer advice on smoking cessation, exercising regularly, avoiding excessive alcohol intake, and controlling weight;

(2) Ensure that comorbidities, such as hypertension, hyperlipidaemia, diabetes, and coronary heart disease are being managed appropriately. (NHS Institute for Innovation and Improvement, 2008)

The role of the multidisciplinary team is one that includes an integrated and multi-disciplinary approach which is critical in the proper management of heart failure. Care delivered by a multi-disciplinary team is stated to result in a reduction in hospitalization, an improvement in symptoms and an increase in life expectancy for the individual. (NHS Institute for Innovation and Improvement, 2008) it is additionally related that the heart failure nursing specialist makes the provision of support that is valuable and that there is evidence "of improved outcomes in people followed up by specialist nurses after hospital discharge." (NHS Institute for Innovation and Improvement, 2008) it is additionally related that access to this type of care is varied between different locations.

VII. Medications

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)