Chapter 2 - Heart Failure

Question 1

What is chronic heart failure?

Answer 1

Heart failure occurs when the heart in unable to sufficiently pump blood around the body to meet the body’s needs.

Question 2

What are the symptoms of heart failure?

Answer 2

• SOB
• Swelling (commonly feet, ankles, stomach, lower back)
• Fatigue

Question 3

What measurement is commonly used to describe heart

Answer 3

Ejection fraction

EF = stroke volume* / end diastolic volume

*stroke volume = end diastolic volume - end systolic volume

Question 4

What is the ejection fraction?

Answer 4

EF - is the % of blood volume leaving the heart with each beat, and is a measure of left ventricular pumping function.

Question 5

The smaller the ejection fraction…..

Answer 5

…. the more severe the heart failure.

Question 6

What is the normal EF %?

Answer 6

60%

Question 7

People with an EF

Answer 7

<40%

Question 8

What are the ‘typical’ signs and symptoms of someone with heart failure?

Answer 8

SOB, nocturnal paroxysmal dyspnoea (severe SOB and coughing waking someone up at night), orthopnoea (SOB when lying down), ankle swelling,

Question 9

What are the common risk factors for developing HF?

Answer 9

Myocardial infarction, HTN, diabetes, thyroid disease, left ventricular hypertrophy (muscle wall of heart’s left ventricle becomes thickened).

Question 10

How may thyroid disease contribute to the development of HF?

Answer 10

Thyroid hormones have an impact on cardiac myocytes: http://circ.ahajournals.org/content/116/15/1725

Question 11

What is cardiac output?

Answer 11

The amount of blood pumped by the heart in one minute.

Question 12

What happens to cardiac output in a patient with HF?

Answer 12

Cardiac output decreases, consequently leads to a fall in blood pressure.

Question 13

How does the heart attempt to maintain normal cardiac output in HF?

Answer 13

By increasing the heart rate (beats per minute). This may allow less time for filling.

Question 14

Decreased BP due to decreased cardiac output activates which two systems in the body?

Answer 14

RAAS system and sympathetic nervous system - in order to raise blood pressure. (Increasing myocardial contractility, tachycardia and vasoconstriction).

Although this mechanism is trying to increase cardiac output, chronic activation may exhaust the failing heart further.

Question 15

How does the RAAS system work to raise BP?

Answer 15

Renin secreted by kidneys works to convert angiotensinogen (produced in the liver) to angiotensin 1. ACE then works to convert ang 1 to ang 2.

Ang 2 causes vasoconstriction (increase BP) and causes aldosterone to be released (increased water retention).

Question 16

Which drug/ classes of drugs may precipitate HF?

Answer 16

B-blockers
rate-limiting CCBs (diltiazem and verapamil)
Corticosteroids
Antiarrythmics (class 1) 
NSAIDs
Lithium

Question 17

The severity of heart failure is classified by the New York Heart Association (NYHA) as what?

Answer 17

Class I: No limitations. Ordinary physical activity does not cause fatigue, breathlessness or palpitation (asymptomatic LVD included in this category).

Class II: Slight limitation of physical activity. Comfortable at rest. Ordinary physical activity results in fatigue, palpitation, breathlessness or angina (symptomatically ‘mild’ heart failure)

Class III: Marked limitation of physical activity. Although comfortable at rest, less than ordinary physical activity will lead to symptoms (symptomatically ‘moderate’ heart failure).

Class IV: Inability to carry out any physical activity without discomfort. Symptoms of congestive cardiac failure are present even at rest. With any physical activity, increased discomfort is experienced (symptomatically ‘severe’ heart failure).

Question 18

What is B-type natriuretic peptide (BNP) and what is its significance in HF?

Answer 18

BNP is secreted from by the ventricles of the heart in response to excess stretching of myocytes. Plasma concentrations of BNP are elevated in HF.

Question 19

What is the first line treatment for HF?

Answer 19

ACE Inhibitor - shown to prolong life and delay progression of the disease. Beneficial use for patients with both symptomatic and asymptomatic HF.

Question 20

When should B-blockers be considered in treatment of HF in addition to an ACE Inhibitor?

Answer 20

When patient has symptomatic heart failure and has a LVEF of <40%.

Question 21

Which B-blockers have been studied and therefore licensed to be used for the treatment of HF?

Answer 21

Birsoprolol
Carvedilol
Nebivolol

Question 22

If patients are still symptomatic after initial treatment with an ACEI and B-blocker, what is the next step in pharmacological treatment?

Answer 22

Adding in an aldosterone antagonist –> Spironolactone or eplerenone. These have been shown to reduce symptoms and hospitilisation in HF, whilst increasing patient survival.

Question 23

What is the role of diuretics in HF?

Answer 23

Symptom control of oedema and dyspnoea (shortness of breath)

Question 24

If treatment with an ACEI, B-blocker and aldosterone antagonist is still failing in the treatment of HF, what is the next step in therapy?

Answer 24

Consider adding angiotensin receptor neprilysin inhibitor (ARNI) –> sacubitril/valsartan.

Inhibits neprilysin which is an enzyme that breaks down natriuretic peptides which regulate fluid homeostasis, therefore protecting the cardiovascular system from fluid overload.

IMPORTANT: if treatment with an ARNI is being started ACEI or ARB must be stopped.

Question 25

What other drug(s) may be used in the treatment of HF?

Answer 25

Ivabridine - purely heart rate regulator. Considered in patients who are in sinus rhythm, have a resting HR of >/= 70bpm and persisting symptoms.

Hydralazine-isosorbide dinitrate - reserved for use in those who can’t tolerate ACEI or ARBs. Should be used in conjunction with B-blocker and aldosterone antagonist. Can also be used in conjunction with digoxin and diuretic therapy.

Digoxin - used in patients in sinus rhythm and with an EF of = 45% who are unable to tolerate B-blocker. Should be used in conjunction with ACEI (or ARB) and aldosterone antagonist.

Question 26

What kind of diuretics are first line in HF with reduced ejection fraction?

Answer 26

Loop diuretics e.g furosemide, bumetanide or torasemide

Also effective if patients have a low GFR of 30ml/min or less.

Question 27

Which statin and at what dose does NICE recommend for the primary prevention of cardiovascular disease?

Answer 27

Atorvastatin 20mg

Question 28

Which statin and at what dose does NICE recommend for the secondary prevention of cardiovascular disease?

Answer 28

Atorvastatin 80mg

Question 29

When should statin therapy be intiated for primary prevention of CVD?

Answer 29

Patients with a 10-year risk of CVD of 10% or more

Question 30

Which calculator does NICE recommend to assess cadivascular risk?

Answer 30

QRISK2

Question 31

What factors do CVD risk calculators underestimate in patients which may give an inaccurate result?

Answer 31

• serious mental disorder
• antiretroviral therapy
• autoimmune disorders such as systemic inflammatory disorders
• medication causing dislipidaemia e.g antipsychotics, corticosteroids or immunosupressants
• triglyceride concentration >4.5mmol/l

Question 32

What is the MHRA advice regarding high dose simvastatin (80mg)

Answer 32

Increased risk of myopathy

Question 33

What is the max dose of simvastatin if giving with concomitent bezafibrate or ciprofibrate?

Answer 33

10mg daily

Question 34

What is the max dose of simvastatin if giving concomitently with amiodarone, amlodipine, verapamik, diltiazem or ranolazine?

Answer 34

20mg