I was recently prescribed on a blood thinner. The thought of it makes me quite concerned. What is a blood thinner?

Blood thinners are a type of medicine that helps your blood flow smoothly through your blood vessels.

They are prescribed to those patients who have certain types of heart disease and heart defects, and also, a risk of stroke.

Millions of people take blood thinners every year.

The name “blood thinners” is a misnomer because these agents don’t really thin your blood.

Instead, they help prevent, or even break up, dangerous clots in your blood.

Don’t worry – your blood consistency is as normal as it was before you took the blood “thinners”.

If these clots are allowed to remain, they can travel into your heart to cause a heart attack, or to your brain to cause a stroke.

Oh. I was told that I have a condition called atrial fibrillation. What is that?

Atrial fibrillation (AF) is an abnormal heart rhythm. It is one of the different types of arrhythmias (abnormal heart rhythms and rates) that can exist.

In this case, the name “atrial fibrillation” suggests that the abnormal rhythm originates from our atrium, i.e. one of the two top chambers of our heart.

The word “fibrillation” means the atria of a patient is twitching very rapidly and quickly.

This means that the blood flow from the atria to the ventricles (lower chambers of our heart) is abnormal and impaired.

AF is one of the most common arrhythmias, especially when you reach the age of 65.

What is the cause of atrial fibrillation?

It is usually due to an electrical abnormality of the heart. In AF, the electrical activity within the atria is very disorganised.

But it may also be associated with an underlying heart disease, such as ischaemic heart disease (which is caused by coronary arteries being blocked), or problems with the heart muscle or valves.

It can also be caused by diseases originating from outside the heart, such as hyperthyroidism.

Whatever the cause, the most dangerous thing AF can lead to is a heightened risk of stroke.

It can also lead to heart failure because of the inefficient pumping mechanism of your heart.

Is AF the only condition that requires a blood thinner?

No, it isn’t. Here are some other conditions that may require you to have a blood thinner:

● Heart attack

Even though you have had a heart attack already, blood thinners can lower your risk of a second heart attack, which is higher than if you haven’t had a heart attack before.

● Stroke

Even after you’ve had a stroke, blood thinners can lower your risk of getting another one.

● Heart or coronary artery disease

● Irregular heart rhythm

● Systemic lupus erythematosus (SLE)

● Deep vein thrombosis (DVT)

● Artificial heart valve

You will also be at higher risk of blood clots if you are overweight, or recently had surgery (and are immobilised).

Are there different types of blood thinners?

Yes, there are antiplatelets and anticoagulants.

Antiplatelets prevent the blood cells we have in our bloodstream that are called platelets, from clumping together and forming clots.

Some examples of antiplatelets are aspirin, clopidogrel, dipyridamole and ticlopidine.

Anticoagulants are medicines that prevent blood clots from forming by increasing the time it takes for your blood to clot.

It works on a different pathway of clotting, compared to antiplatelets.

It reduces fibrin formation. Fibrin is the basis of a clot formation.

Examples of anticoagulants are warfarin, heparin, enoxaparin, rivaroxaban, apixaban and dabigatran.

What are the best blood thinner options?Aspirin is the oldest antiplatelet and is still considered the gold standard for all antiplatelets.

Studies are usually done comparing a new antiplatelet or anticoagulant against aspirin or warfarin respectively.

The newer anticoagulants (rivaroxaban, apixaban and dabigatran) have many studies comparing their efficacy and safety against warfarin and other older anticoagulants.

In general, the efficacy (how effective the drug is) and the safety of the new drugs are the same as the older ones.

The main difference is in the bleeding. There are less critical organ bleeds (brain bleeding etc) and less death from bleeding while using the newer anticoagulants, as compared to warfarin.

The newer anticoagulants also do not need as much blood monitoring as warfarin does.

There is, for example, no need to keep going to the doctor to take your blood and checking your INR (international normalised ratio), which measures how quickly your blood clots.

Aspirin has also been combined with the newer anticoagulants to give very good stroke and heart attack prevention results.

Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, email starhealth@thestar.com.my. The information contained in this column is for general educational purposes only. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.