Heart Failure

Question 1

NYHA classification

Answer 1

Class 1 - Asymptomatic, even during exertion
Class 2 - Comfortable at rest but ordinary physical activity results in symptoms e.g. getting up stairs
Class 3 - Comfortable at rest but less than ordinary physical activity results in symptoms i.e. minimal exertion
Class 4 - Symptomatic at rest

Question 2

Which medications are for symptomatic benefit only?

Answer 2

Diuretics (except mineralocorticoid receptor antagonist)

Digoxin - reduces risk of HF hospitalisation

Question 3

Which medication has the greatest/largest reduction in mortality?

Answer 3

Beta blockers

Question 4

What is the mechanism of loop diuretics?

Answer 4

Act on THICK ascending loop of Henle - reduce reabsorption of NaCl, inhibit Na-K-Cl cotransporter. This leads to more NaCl excreted and water follows
In acute HF continuous infusion has same outcomes as 12hr bolus dose

Question 5

What is the mechanism of thiazide diuretics?

Answer 5

Inhibit Na-Cl transporter in distal tubule
Longer acting, more hypotensive effect, best to be used as adjuncts to loop diuretics
Not effective if CrCl <40ml/min

Question 6

What effects does angiotensin II have?

Answer 6

Vascular smooth muscle constriction
Sympathetic activation
Growth factor stimulation

ACE inhibitor inhibits conversion of angiotensin I to angiotensin II
Either start ACEi or ARB NOT both together

Question 7

Which beta blockers have proven to reduce mortality in HF patients?

Answer 7

Carvedilol (one study showed that it had lower mortality vs Metoprolol)
Metoprolol
Bisoprolol
Nebivolol

Question 8

What is the mechanism of Ivabradine?

Answer 8

Inhibits I(f) channel at sinus node and slows HR 
Only effective if in SR (doesn’t work in AF) 

To qualify for this need to have - NYHA class 2 or 3, SR, EF ≤35%, resting HR ≥77bpm, on guideline directed standard therapy with max tolerated dose b-blocker

Question 9

What is ARNI (angiotensin receptor neprilysin inhibition)?

Answer 9

Combination of ARB and Neprilysin inhibitor
Sacubitril/Valsartan (also known as Entresto) superior to ACEi or ARB alone
Recommended in HFrEF patient who remain symptomatic despite optimal medical therapy with ACEi, b-blocker, MRA - must be NYHA class 2-4, EF ≤40%

DO NOT coadminister with ACEi (need to wait 36hrs after last dose)

Question 10

What is the mechanism of digoxin?

Answer 10

Inhibits Na-K ATPase
Also its benefit thought to be due to enzyme inhibition of vagal afferent fibres, decrease sympathetic outflow from CNS
Used to reduce risk of HF hospitalisation in patient with LVEF <45% intolerant of b-blocker or for those who have persistent symptoms despite ACEi + b-blocker + MRA

Question 11

When is cardiac resynchronisation therapy (CRT) recommended?

Answer 11

EF ≤35%, sinus rhythm, NYHA class 3 or ambulatory 4, despite optimal therapy have cardiac dysynchrony QRS ≥150 in LBBB

Question 12

What is the main cause of early mortality following cardiac transplant?

Answer 12

Rejection - diagnosed by biopsy

Late mortality due to graft failure, infection (non-CMV), malignancy

Question 13

What are the features of transplant coronary disease?

Answer 13

Diffuse intimal thickening of coronaries
Distal —> proximal
Non-calcified