Heart failure, what is ARNI (angiotensin receptor/neprilysin inhibitor)?

By Cristiano Antonino On May 4, 2023

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Angiotensin receptor/neprilysin inhibitor (ARNI) drug is a new treatment for heart failure

The combination of sacubitril and valsartan has helped people live longer and have a better quality of life.

However, like all medicines, ARNI drugs have side effects.

What is an ARNI drug?

ARNI, or an angiotensin receptor/neprilysin blocker, is two drugs combined to treat heart failure.

Contains an ARB (angiotensin II receptor blocker) and a neprilysin inhibitor.

Sacubitril/valsartan is the only ARNI drug currently available.

How ARNI works

Valsartan is the ARB part of an ARNI drug.

It lowers blood pressure by preventing blood vessels from narrowing.

Sacubitril is the neprilysin inhibitor.

Inhibiting or limiting neprilysin allows the body to:

Get rid of more sodium (salt).
Open the blood vessels more.
Pee more.

When your body gets more sodium (salt) from your blood, your blood pressure drops.

This makes it easier for your heart to push blood to your cells.

Who can take an ARNI drug?

You can take an ARNI drug if you’ve just received a heart failure diagnosis with a reduced ejection fraction (a measure of your heart’s pumping function) of 40 percent or less.

A normal ejection fraction is between 55% and 65%.

Also, you can switch to an ARNI drug if you were taking an ACE inhibitor or ARB for heart failure.

However, if you are switching from an ACE inhibitor to an ARNI drug, you will need to wait 36 hours between stopping one and starting the other.

This prevents swelling that may occur under the skin (angioedema).

What dose of ARNI do I take?

Most people start with a dose of 49/51 mg (milligrams) of sacubitril/valsartan twice a day.

After the first two to four weeks, they gradually increase their dose to 97/103 mg sacubitril/valsartan twice a day.

Your provider will give you a guide to figure out your doses.

If your kidneys are not working well or you have low blood pressure, you can take a dose of 24/26 mg sacubitril/valsartan.

Also, people who have already taken a small dose of an ACE inhibitor or ARB can take this smaller dose of an ARNI drug instead.

Why is ARNI used?

Many people start taking an ARNI drug because they want to stop taking an ACE inhibitor that is making them cough.

Also, an ARNI drug helps the left ventricle work better.

This is important because your left ventricle pumps oxygen-rich blood throughout your body.

One study showed that after taking ARNI drugs for one year, people increased their left ventricular ejection fraction from 28.2% to 37.8%.

Who shouldn’t take ARNI drugs?

You should not take ARNI drugs if:

You have angioedema (facial swelling) when you have taken an ACE inhibitor or ARB drug.
You are pregnant or breastfeeding.
You are already taking an ACE inhibitor or ARB drug.
You have a serious liver problem.
You are taking aliskiren.
You are overly sensitive to ARBs or ARNIs.

What does ARNI treat?

ARNI drugs treat heart failure with reduced ejection fraction (Phase C).

During stage C heart failure, you have structural heart disease and symptoms of heart failure.

Also, ARNI drugs can help people with heart failure with preserved ejection fraction (normal pumping function but your heart is stiff and can’t hold as much blood).

This is an ejection fraction of 50% or higher.

How common are ARNI drugs?

Only about 10% of the more than 2 million people who could benefit from an ARNI drug are using it.

What are the benefits of ARNI drugs?

Compared to ACE inhibitors or ARBs, ARNI drugs can:

Help you live longer.
Improve the quality of your life.
Slow down the progression of heart failure.
Reduce the amount of time you spend in the hospital.

One large study found that participants who took an ARNI drug had a 20 percent decrease in the risk of cardiovascular death or heart failure hospitalization.

What are the side effects of ARNI drugs?

ARNI side effects include:

Renal dysfunction.
Low blood pressure (hypotension).
High potassium (hyperkalemia).
Angioedema (very rare, but more common in black people).

Your doctor will need to do a blood test to check your potassium level during the first few weeks that you are taking an ARNI drug.

He will also want to check your blood pressure and make sure your kidneys are working properly.

If you have kidney problems, you may need to take a smaller dose of ARNI medications or stop taking them.

You can prevent your blood pressure from getting too low by taking blood pressure medications at different times than your ARNI dose.

Side effects usually disappear in 14 days.

If they don’t go away, your doctor may give you a smaller dose of ARNI medication.

Then he can increase the dose one to two weeks after the side effects end.

What’s next for someone taking an ARNI drug?

Estimates based on studies predict that these drugs can give a person 55 years of age and older another 2.1 years without a heart-related hospital stay or fatal event.

Someone 65 and older can get another 1.6 years without such occurrences.