heart_failure

Heart Failure

Definition

A complex clinical syndrome with symptoms and signs that result from any structural or functional impairment of ventricular filling or ejection of blood

Causes

IHD, MI, valvular heart disease (VHD)
hypertension
Others
- familial,genetic, RV pacing, peripartum or stress-induced cardiomyopathies
- amyloidosis
- cardiotoxicity with cancer or other treatments
- substance abuse - alcohol, cocaine, or methamphetamine
- tachycardia, myocarditis, autoimmune causes, sarcoidosis,
- iron overload, including haemochromatosis
- thyroid disease and other endocrine metabolic and nutritional causes

Symptoms

breathlessness - many other causes of SOB though
leg swelling
orthopnoea
bendopnoea

New York Heart Failure Classification

I - cardiac disease but no symptoms or limitation of daily activities
II - mild symptoms and slight limitation to ordinary activity
III - significant limitation due to symptoms. Comfortable only at rest
IV - severe limitation and symptoms at rest

Signs

raised JVP
a square-wave response to the Valsalva manoeuvre
pitting oedema of legs
fine crep's on chest auscultation - beware other causes

Investigations

FBC, U&E's (Ca++, Mg++), LFTs, Glu, TSH
fasting lipid profile
Fe studies (serum iron, ferritin, transferrin saturation)
urinalysis
ECG and ECHO

Management

Treatment of HF is dependent on classification:

HFrEF

Goal of Heart Failure Mx. The 4 pillar approach:

ACEi or ARB or ARNi
a β-blocker
an MRA
SLGT2i

To prescribe a combination of all at low initial doses and titrate to target/max tolerated doses (with doubling of doses), one at a time.

Euvolaemic

ACEi or, if not tolerated, ARB and
heart failure β blocker then add
MRA |

Hypervolaemic

diuretics should be commenced to achieve euvolaemia where possible

ACEi or, if not tolerated, ARB and
MRA then when euvolaemic, add
heart failure β blocker

STRATEGY

double the dose of each, one at a time, every 2–4/52(except MRAs; up-titrated in 4–8/52), or as tolerated.
add the next drug before reaching target or maximum tolerated dose, eg, if the patient is euvolaemic, a heart failure beta blocker may be started before achieving target or maximum tolerated dose of an ACE inhibitor.
clinical and lab review every 1–2/52 after each medicine initiation and dose increase.

Medications

ACE inhibitors (ACEi)

Medications

ACEi	initial	target
enalapril	2.5mg OD	20mg OD
lisinopril	2.5mg OD	50mg OD
perindopril	2.5mg OD	10mg OD
ramipril	2.5mg bd	5mg bd

Angiotensin Receptor Blockers (ARB)

ARB	initial	target
candesartan	4mg OD	32mg OD
irbesartan	75mg OD	300mg OD
losartan	25mg OD	100mg OD
valsartan	40mg bd	160mg bd
olmesartan	10mg OD	40mg OD

Heart β-blockers

β blockers	initial	target
bisoprolol	1.25mg OD	10mg OD
carvedilol	3.125mg bd	50mg bd
nebivolol	1.25mg OD	10mg OD

Aldosterone Receptor Antagonists (MRA)

MRA	initial	target
spironolactone	25mg OD	50mg OD
eplerenone	25mg OD	50mg OD

Angiotensin Receptor/Neprilysin Inhibitors (ARNi)

ARNI	initial	target
sacubitril/valsartan	49/51mg bd	97/103mg bd

SGLT-2 inhibitors

Dapagliflozin	10mg OD
Canagliflozin	100-300mg OD
Empagliflozin	10mg OD
Ertuglifozin	5-15mg OD

Other

other	initial	target
ivabradine	5mg bd	7.5mg bd

If symptoms persist, consider:

add hydralazine and nitrate (esp if Afro-Caribbean)
digoxin for those in sinus
for LVEF ≤ 35%, change ACE inhibitor (or ARB) to an angiotensin receptor-neprilysin inhibitor (ARNI).
for LVEF ≤ 35%, add ivabradine(hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blocker) for sinus HR>75

Diuretics

beware of stopping diuretics in HF when renal function worsens. Diuretics are NOT the cause of reduced renal function in HF and NOT associated with increased mortality in this setting.
diuretics are NOT intrinsically nephrotoxic
caution needs to be exercised in monitoring electrolyte changes - patients with HF commonly have a degree of renal failure and, combined with other cardiac medications, are at risk of BRASH syndrome.

Diuretic type	example	electrolyte side effect
Loop diuretics	furosemide bumetanide	low K, low Ca high Na
Thiazides & thiazide like	bendroflumathiazide indapamide metolazone	low Na/K/Mg high Urate/Glu hypochloraemic metabolic alkalosis
Potassium sparing: aldosterone antagonist	spironolactone eplerenone	low Na High K
Potassium sparing: aldosterone independent	amiloride triamterene	low Na high K metab acidosis
SGLT2 inhibitors	dapagliflozin	not directly

Subcutaneous furosemide infusion is effective when oral agents are not appropriate or suitable. The use of an elastomeric pump can simplify this. Setup guide using Braun elastomeric pumps

Author: Dr Dylan Jenkins, Oct 2023
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